Welcome to Car Tuning Tips

8/3/2019 Welcome to Car Tuning Tips

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Welcome to Car Tuning Tips

Car Tuning Tips represents the cutting edge of car tuning techniques. We cover the latest

methods and tips to get the most performance from your engine. Get an overview of thebest methods and learn what each part does and if it is worth fitting.

If you are after parts or details about a specific model of car can we recommend that you

also visit TorqueCars our main sponsor and one of the largest online tuning sites around.

We quickly yearn for more power in our cars. As we start to investigate the options wequickly learn that cars are far from fully tuned. The aim of most manufacturers is to

achieve an average power figure as defined in their sales brochure, optimum fuel

economy to fit into the tax bands and finally to produce a car that is reliable.

There is much that can be done to improve a car but we need to accept the car tuning

mantra there is always a hidden cost. It is also true that your power gain is proportionalto your base power so you need to work from the most powerful engine you can affordfor the best return on your tuning investment.

:

Generally speaking we will be pushing the engine harder so it will require more frequent

servicing intervals to maintain reliability. With the extra power released you will almostcertainly (unless the engine is very inefficient) lose some fuel economy. You will also

induce stress on weaker components and these will need to be uprated to cope with the

extra power.

Engine tuningFirstly owners look to increase the power of their engine. Breathing mods ieintake and

exhaust are usually the first to be considered. Next up we move on to internalengine

modifications ranging from reboring and engine, engine swapsandrebuilding the engine.
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The head of the engine is easier to work on with many owners changing their cams forfast road camshafts and porting and polishing the head for bettergas flow. It is worth

looking into getting uprated valvesand springswhile you have the head off if you are

serious about your engine tuning.

With forced induction engines (turbos and superchargers) you have a lot more optionsopen to you and these give very good power gains for a minimal outlay. With a remap

you can increase power by as much as 50%. Aperformance intercoolerwill greatly

benefit most engines as the OEM intercoolers are either ineficient or non existant.

Handling modifications

If you are making the car go faster your top priority should be stopping the car. Uprated

brakes include performance pads and disks. Suspension modifications will help to

improve the handling and safety of the car. You shouldnt overlook the importance ofyourtires and the right tire can dramatically improve your cars grip and handling. Alloy

wheelsalso have a number of performance benefits and should not be considered a purely

asthetic modification.

Drivetrain tuning
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The power comes out of the engine and needs to pass thedrivetrainto the wheels. An

efficient drivetrain will include a low ratio gearbox and a limited slip differential.

It is our aim to cover the sensible modifications and outline the benefits and drawbacks ofeach. We will also advice of the hidden cost of each part in our well written guides.

Method 1

Method 1

Nitrous injection kits

Nitrous has many names, the most popular is NoS which is actually a brand. Dinitrous

Monoxide is the chemical name but for the purpose of this article we shall refer to it asnitrous. We will explore how it works and the various setup options available and see

what this does for performance.

Read the rest of this page

Fast road cams (Sports camshafts)

What is the camshaft, what does it do and how can it be modified. The camshaft is

located at the top of an engine. Is is a long shaft with a series of lobes along it and it
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rotates relative to engine speed. The lobes push close the valves in the head and allow the

engines cylinders to suck in air/fuel and expel exhaust gases.

Read the rest of this page

Intake Valve tips

The job of the intake valves is to control the flow of air and fuel into the engine, and then

Read More...

Uprated Fuelling

One thing a performance tuner needs to take into account is the importance of the air tofuel mixture. IfRead More...

Blow off valves or dump valves
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In a turbo engine the pressures build up as air is compressed and forced into the engine.

The turbo is Read More...

Aftermarket Superchargers

A supercharger compresses the intake air effectively forcing more air into the engine.

More air means you have more oxygen Read More...

Port matching an engine

The ports on the engine allow the air into the engine and the exhaust gases out. There aretypically 2 Read More...

Fast road cams for everyday use.

The camshaft is located at the top of the engine and looks like a metal bar with egg

shaped lobes Read More...

Cold air vents and CAI kits

You may have noticed that your car feels much more powerful on cold mornings than it

does in the middle Read More...

Remote turbo kits
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It can be quite time consuming to add a turbo charger to a NASP engine. The biggestproblems include avoiding Read More...

Ceramic exhaust coatings

Ceramic exhaust coatings are gaining popularity with performance car tuners. We willtake a look at why so many people Read More...

Induction kits & cone filters

Like all of us, car engines need to breathe. They use an air fuel mixture which has to be

precisely Read More...

Gas flowing a head

Gas flowing a head Many things go on in the head of an engine. Primarily the air cominginto the Read More...

Performance Intercoolers

We all know that cold Air carries more oxygen that warmer air. You may have noticedthat when air is Read More...
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Performance valve springs

The valve springs pull the valves up when they are closed thereby sealing the valve. Thecamshaft pushes the valve open Read More...

1. Nitrous has many names, the most popular is NoS which is actually a brand.Dinitrous Monoxide is the chemical name but for the purpose of this article we shall refer

to it as nitrous. We will explore how it works and the various setup options available andsee what this does for performance.

We understand that an engine needs oxygen in order to burn fuel. We also know that

colder air carries more oxygen than warmer air. Nitrous is ideal for enhancing the

combustion process because it releases oxygen as it burns. This property make it ideal forthe explosive power requirements of drag racing.

An added benefit is that nitrous cools the air charge allowing even more oxygen into the

engine. Obviously when you have more oxygen you will need to balance this up by usingmore fuel. The aim then is to match the fuelling with the extra oxygen released whennitrous is introduced into an engine.

Installation is relatively simple and you can choose from various configurations. One

adds the nitrous into the intake manifold along side the fuel injectors, alternatively it can

be introduced between the air filter and intake manifold. The latter is sprayed into air so
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is referred to as a dry system, the former is mixed with fuel and is referred to as a wet

system.

nder current UK legislation you are not able to run a car with 2 forms of fuel and nitrousis classified as a fuel (although it isnt). Most insurers will also only cover cars if the

nitrous is disabled for road use. So nitrous injection is the preserve of the track and dragstrip.

Nitrous refills are a hidden cost. Although medical nitrous seems similar it is worthnoting that automotive nitrous has some very nasty additives and must not be inhaled.

You can however use medical grade nitrous in car engine. Medical nitrous is called

laughing gas and this where we get the drag term funny cars from.

Nitrous should only be used in short bursts at full throttle. The amount of power you getdepends on the jet size you select. Most cars will handle a 25bhp shot easily. Some turbo

and larger engined cars can run with 50 bhp and 75bhp shots.

It is a good idea to have a purge vent which vents nitrous to the outside of a car. This is a

good way of clearing the nitrous lines. Starting an engine filled with nitrous is asking fortrouble so if you have triggered your nitrous whilst the car is stationary with the engine

off YOU MUST ENSURE that the engine is free of Nitrous BEFORE starting it.

2.

Fast road cams (Sports camshafts)

What is the camshaft, what does it do and how can it be modified. The camshaft islocated at the top of an engine. Is is a long shaft with a series of lobes along it and it

rotates relative to engine speed. The lobes push close the valves in the head and allow theengines cylinders to suck in air/fuel and expel exhaust gases.

Ultimately you want the intake valve opened as long as possible and want to delay the

exhaust valve opening until the piston has started to enter the blow phase. Timing iscritical. If the intake is not open for sufficiently long a time or the exhaust valves open

early much of the power from the engine will be gone.

We describe the cam as a duration. A 720* degree duration would not open the valves

and a 1 degree duration would keep the valves closed all of the time. Manufacturersoptimise their cams for best fuel economy at around 3000 rpm and require a smooth

tickover. This caution gives the tuner a good oportunity to improve things. (A camshaft

duration is based on 2 revolutions of the crank or 720 degrees.)

The 3 power bands of cam durations.


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An average family car will typically have a cam duration of 250 degrees or lower. By

grinding down each side of the lobe on the cam you can decrease the duration. As a

general rule of thumb upto 265 degrees gives a good balance of extra power andmaintains smooth running and is most suited to a standard engine.

Moving up to 290 degrees we have what is called a fast road cam. This will give anoticable increase in top end power but you will start to experience a slightly lumpy idle.

Economy will also be impaired but in most cases you will be within your cars emissionstandards. This is what most readers of cartuningtips.com will be aiming at.

For ultimate performance you can increase the duration to 320 degrees. Tickover will be

very irratic, the car is unlikely to pass any kind of emission check and your fuel economy

will not exist!

When cams are marked for competition use only it will indicate that the cam is prone to

excessive wear. This wear effectively reduces the lift and sucks your power. A

competition cam is replaced at frequent intervals and is not something the average carowner wants to be doing.

Honda have a dual cam lobe which allows a profile for high rpm use and another for low

engine speeds giving a much wider power band and good fuel economy.

3.

Fast road cams for everyday use.

The camshaft is located at the top of the engine and looks like a metal bar with eggshaped lobes on it. The shape and size of the lobe determines the amount of time thatthe heads valves are open, and the amount they are open. The valves allow the mixture of

fuel and air into the engine and, after combustion, the exhaust gases to flow out of the

cylinder.
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Most modern engines have a double overhead cam and configuration with one cannot

controlling the intake side of the engine and another controlling the exhaust side. A

single a overhead cam has the lobes arranged in a double pattern to allow them toperform the same function.

Double overhead cams are more tunable and allow a greater degree of control andaccuracy. The downsides to fitting a fast road cam includes lumpy idling and loss of

power lowdown. Some high performance cams are constructed of a softer material thanstandard cans and therefore suffer from premature wear. Motorsport cams will need

replacing every few races so for road use we would recommend a fast road cam.

For maximum flexibility selected can with between the 257and 285. These are

typically referred to as a stage 1 or fastroad cam. (If you have a high revving engine stickto the upper end of these guidelines). A camshaft will be one of the biggest car tuning

mods for a NASP engine. We do not recommend a different cam profile if you polish and

port the engine.

When fitting cams always get new followers lifters and springs or at least check these

components for wear.

4.

Performance valve springs

The valve springs pull the valves up when they are closed thereby sealing the

valve. The camshaft pushes the valve open against the spring. As you can imagine this is

a high wear high stress component of the engine. They need to be fitted using a valvespring compressor any other attempt at installing them will usually result in your

chasing a spring around the garage.

If the valve spring is too strong it cause excessive wear on the cam. If it is too weak then

the valve will not fully close, or at least will not close quickly enough. In a highly tuned
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engine you cannot afford to skimp on the selection of valve springs. If one of these

breaks then the valve will stick open and this will cause catastrophic engine damage,

depending on which part of the suck,bang, blow cycle the engine is at.

The springs also prevent bounce. When the valve is pulled back into its closed position

the last thing you want is for it to bounce open again as it closes.

If a spring is compressed and each coil is in contact with the coils above and below you

have what is known as coil bind. The spring is extremely stressed at this bind point andyou should ensure that you do not approach this bind point otherwise the cam lobes,

lifters and follows will be damaged.

When you buy a valve spring it will come with 2 numbers, a height and a tension. The

two should be read together and the installed height noted on the spring will exert thetension at that height. Should the installed height be different then the tension will also be

different.

We recommend that you err on the site of a higher spring tension if you are unsure of the

exact requirements of your rebuilt engine. When the valve springs are installed you cancheck for correct opening by rotating the engine through TDC and beyond for each

cylinder and measuring the clearance to the piston. The overlap period is critical and you

need to take careful measurements at this point. There should be a minimum clearance tothe piston of 0.1 and a little more on the exhaust valves .

Incorrect oil selection, and indeed to high an oil pressure, can alter the dynamics of the

valve train and therefore engine life so stick to your manufacturers recommendations.

Always investigate clatter or chatter in the head of an engine as this is usually the sign of

a looming problem.

5.

Intake Valve tips
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The job of the intake valves is to control the flow of air and fuel into the engine,

and then released exhaust gases after combustion. The intake valves have quite a hardlife due to the rapid opening and closing, and have a big impact on the performance of the

engine.

The intake valve is shaped much like a trumpet and is pulled shut when its job is finished.

If it does not close fully you will lose power from your engine, and risk damaging theintake side of your engine as the flame front seeps through the gap.

Larger valves allow you to have a larger intake aperture and will allow more air fuel into

the engine, and more effectively expel the exhaust gases. As an alternative to largervalves, manufacturers have opted for a greater number of valves. There is no reason why

you cannot have larger valves on the a 16 valve engine where there is sufficient clearance

space within the cylinder.

We initially had eight valve engines, where each cylinder had two valves an intake andthen exhaust valve. The next innovation was increasingly is to 16 valves which doubled

the number of valves to each cylinder. We now have Audi engines with four cylindersand 20 valves of varying sizes.
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In some engines the valves are selected according to engine speed, and innovations such

as the Honda VTEC mechanism effectively allows two cam profiles to control the rate of

opening and closing of valves for any given engine speed. While you have the head offthe engine you may as well get it fully ported and gas flowed.

Although engines will benefit from having the valves re-seated especially if acompression test reveals a loss of compression on one or more of the cylinders. A

problem with the valves could be due to a worn lifter or cam

6.

Gas flowing a head

Gas flowing a head

Many things go on in the head of an engine. Primarily the air coming into the engine

flows through the head and into the cylinder via an open inlet valve. The air moving intoan engine is travelling at high speed and any turbulence caused can substantially alter theflow of the air.

Think of air like water. If you dive into a pool of water and land flat, the soft gentle water

becomes hard and you really feel it. The difference is the speed you are travelling at. Thefaster you smash into the surface the harder it seems. Also moving quickly in water takes

proportionally more effort the faster you go due to the increased drag.

Air travelling at speed also becomes solid. I know that the physicists out there will pick

me up on this but it is really the simplest analogy I can use to describe the way air movesand flows. A small ridge or dimple in the surface that the air is flowing over will create a

turbulent stream and effectively slow up the flow of air.

When you gas flow a head the aim is to get the air moving as freely through the head as

possible. Bends are either eliminated or made more shallow. Where possible the physicalarea inside the head is increased to allow for greater flow of air.
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Larger valves will also enable the air to flow into the engine more freely. The larger the

engine capacity the bigger the benefit of gas flowing the head as more air is moving

around. Gas flow is measured on a flow bench and as the head is worked it is remeasured.A professional will get a feel for the type of channels that need to be made inside the

head.

Inside the head near the valves there are often steps where a mass produced head isknocked out of the factory for speed. Removing these steps will further enhance the air

flow and many car owners report a noticeable power increase solely from this machining

away of the steps and grooves around the valve.

Particular attention should be paid to the ports. These are the holes into which theinduction manifold connects to the engine and the exhaust headers connect to holes on

the other side of the head. Aim to get the holes matched up avoiding steps or ridges for

smooth inlet and exhaust from the engine. Porting can be carried out with a drill with agrinding wheel and should be performed with long sweeping strokes to avoid cutting new

grooves and steps into the ports.

Areas to be checked are the valve seams. If these do not properly close there will be a

loss of air flow and potentially substantial decrease of power. Valves should always beproperly seated and a grinding paste can help improve the closure of the valve to the

head.

7

Port matching an engine

The ports on the engine allow the air into the engine and the exhaust gases out.

There are typically 2 per cylinder, an inlet and an exhaust. The inlets or ports are joinedto the manifold or headers via a gasket. Whenever you get a join between two surfaces

there is typically a step or at the very least a ridge or seam.
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These ridges or seams cause turbulence and break up the flow of the air into the engine.

This turbulence slows up the air and reduces the efficiency of the engine.

When port matching is applied to an engine the intake and exhaust manifold or headersare matched up to the engine block ports to avoid this step.

In its simplest diy form a grinding wheel is used to cut away excess metal and widen the

receiving port. This reduces turbulence and allows a better flow into the engine.

We need to point out that this is a very exact science and should only be attempted at

home on basic engines. Anything remotely advanced and you risk ruining the airflow intothe engine.

For best results you will need a proper flow bench and a computerised CNC milling

machine where optimum results can be achieved.

While many believe that bigger ports and manifolds are better for performance this is notalways the case. In some applications reducing the port or changing the angle of the inlet

port are what give a power gain.

In a race environment an inlet on an engine is completely re machined with the old port

blocked up with metal effectively moving the entire port. The aim is to straighten the

flow of air into the engine. Most standard engines have ports at right angles to the

cylinder and the air has to bend through 90 degrees as it flows into the engine. On a highperformance engine you will get a better flow rate the nearer to the cylinder angle you

can get.

The induction length plays a part and there is an optimum size, the trick is balancing thelag at the beginning of the intake stroke with the additional push of air near the end of the

intake. This will need to take into account the configuration of the engine and the desired

power band.


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Inlet valves and engine head design will usually prevent the ideal 180 degree (straight)

inlet but you should be able to get much better than the standard 90 degree bend.

See also the article on Gas Flowing a head as this is very closely related to port matchingand the terms are often used interchangeably. Gas flowing a head will usually include

work on the valve seat and valves.

8.

Reboring an engine

To increase the power of an engine you can increase the cylinder capacity. The

best way to increase the cylinder capacity of an engine is by physically making eachcylinder a larger diameter.

Firstly sit down and do your research. You need to check that you can get a gasket,

piston with rings and other components to match your chosen bore capacity. You cannot

undo the reborn and certainly do not want to have to redo it again.

There are two main types of engine firstly the cast iron block and secondly the aluminiumblock. The cast iron blocks are good candidates for RE boring. It is recommended that

you get the block stress tested before proceeding especially if you are making substantial

changes to the diameter. Aluminium blocks may not be RE bored easily, but you may beable to get different size steel cylinder liners to achieve a similar effect.

We boring and engine is a specialist job and not something that can be performed at

home unless you have a very accurate drilling machine. You cannot afford to drill off

centre or you risk a piston going awol during some enthusiastic driving.
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Youll also need to check that the head will fit on to your new cylinder capacity. You

need to check that the gasket still provides an airtight seal. It is also a good idea that you

get the head re machined to match the capacity you have selected, and this will help airflow into the engine.

Another option to increase the cylinder capacity of an engine is by using a stroker kit.This changes the length of the crank and when combined with a lower profile piston you

are able to increase the amount of capacity within the cylinder.

Running in the engine after a rebore involves lots of low speed but high load driving. By

this we mean plenty of hill work, towing and stop start driving. You must keep the revs

of the engine and down during this time. It is also vital that you avoid oil additives which

prevents the bedding in process from taking place effectively. If you have scored acrosshatch pattern into the cylinder wall this will help the piston and ring to bed in

properly whilst the engine is under load.

9.

Blow off valves or dump valves

In a turbo engine the pressures build up as air is compressed and forced into the

engine. The turbo is driven by the exhaust gases so the faster the engine goes the more airyou get forced into the engine. This is fine until you lift off the accelerator. You engine

speed does not instantly change and you are not asking for fuel to go into the engine

where does the compressed intake air go?

This is the job of the recirculating valve also known as a dump or blow off valve.
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Well you certainly dont want it to go bang, which it would if the air was not released.

Enter the Blow off valve. This effectively vents the air out of the intake area and most

OEM recirculating valves put this air in to the air intake upstream from the filter where itdoes no harm and is actually ready for the next press of the accelerator.

If this process takes a while you have a situation where the turbo compressor is trying to

compress air beyond its design. This caused the turbine to spin more slowly and createsdrag on the exhaust. In a high performance engine this could easily damage the turbo.

Aftermarket valves can handle much more pressure and respond more quickly than the

OEM ones. If you remap a turbo engine you should also replace the recirculating valve.

The dump valve or blow off valve vents this pressurised air into the atmosphere ratherthan discretely back into the intake beyond the turbo and filter. This gives the option of a

noise as it does this and there are plenty to choose from. Some variations include a

whistle, a clatter, a pop, a pfffst noise like a bus brake and variations on these themes.

Do not confuse a blow off valve with a screamer pipe or a waste gate control these workin different ways and have more to do with the cars exhaust flow through the turbo than

the intake flow.

Performance Intercoolers

We all know that cold Air carries more oxygen that warmer air. You may have

noticed that when air is compressed it gets warmer. If you feel the connecting hose on the

footpump as you put air into the tire you would notice that a substantial amount of heat

can be generated. In a forced air induction engine which uses either a turbo or asupercharger the air charge is much hotter than in an engine without forced induction.

The intercooler works much like a radiator and the cold air from outside is forced through

a matrix where the warm charge air is contained. This has the effect of reducing thetemperature of the warm air intake. All intercooler is will create drag or slow the flow of
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intake air coming into the engine, but the benefits of having a colder air charge far

outweighs this.

When designing an intercooler much work goes in to preventing this drag effect. The sizeof the intercooler, along with the dimensions of the internal piping needs to be matched to

the requirements of your engine. Bigger is not always better.

The intercooler, usually, is sited in front of the radiator so it can benefit from the cold air

as it passes into the engine bay. Some manufacturers have mounted the intercooler on thetop of the engine, fitting a Vent to the bonnet allowing the cold air to flow through the

intercooler. Perfect siting of the intercooler will often require an excessive amounts of

ducting which negates the benefit, so a compromise are usually has to be made in mostapplications.

The same rules of exhaust design applied to intake design, sudden changes in pipediameter should be avoided and funnels used instead. Bends should be subtle and gradual

and there should be no internal seems particularly on joins which will hinder the air flow.

Standard intercoolers look relatively inefficient when compared with high performanceaftermarket ones, and nearly every forced induction car will benefit with higher power

figures when an intercooler is fitted.

So will an intercooler make a difference on a NASP engine? Unfortunately the reductionin air temperature is not sufficient to justify the extra drag on the intake air so you would

lose power. Intercoolers work well on turbo and supercharged engine. The more boost

you are running the better the power gains will be.

10.

Cold air vents and CAI kits

You may have noticed that your car feels much more powerful on cold morningsthan it does in the middle of summer. This is due to the effects of air temperature. It is a

simple fact that cold air carriers are more oxygen and warmer air. An intake vent will

help to address this problem, and can be a stylish addition to your car.


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Therefore for performance applications you really want to be sucking cold air into the

engine. The problem we will encounter though is that an engine produces a lot of heat.

The more power you are producing the more heat will be released by the engine.

The job of the radiator is to take heat from the engine exposing is to the cold outside airand therefore reducing the temperature of the engine. The problem with this arrangementis that the temperatures under the bonnet of the car rise to very high levels in a relatively

short period of time.

One way of reducing the under bonnet temperature is to put lagging around the exhaust,

particularly the headers. This will also help the catalyst to reach operating temperaturemore quickly. Motor sport teams make good use of vents in the bonnet and wing of the

car. These allow additional air flow through the engine bay and help to dissipate the high

temperatures.

Ideally you want your air intake to be sucking in the fresh air from outside of the engine

bay, and one way of achieving this is quite simply to have a vent cut in the bonnet just

above the intake area. You will need to be careful that you do not suck water into the airintake as this will really not help the engine.

The best applications we have seen include a cold air induction kit fed from a vent on the

bonnet with the induction kit housed in a box to separate it from the hot air in the engine.

An intercooler may also be used to help reduce the temperature of the intake charge intypical high pressure turbo and supercharged applications. Citing the intercooler behind

a vent will be substantially better than mounting it near the radiator, where the hot airaround the radiator will reduce the effectiveness of the intercooler.

You cannot just cut holes in the bonnet if you look underneath the bonnet and remove thesound deadening material you will notice that there are sets of reinforcement bars usually

in the pattern of triangles. You should not cut through any of these bars, unless you want

to reduce the rigidity of the bonnet or risk it bending and flexing as you drive along.When creating vents you also have to be conscious that you are not exposing any
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electrical components to the possibility of water ingress. A shield or scoop may help to

minimize this risk.

The addition of a carbon fibre bonnet with integral vents will help also as this will bemore effective at dissipating the heat much better than steel unvented bonnet.

11.

Induction kits & cone filters

Like all of us, car engines need to breathe. They use an air fuel mixture which has

to be precisely balanced into what is referred to as an air to fuel ratio or AFR. For petrol

engines 14.5:1 is the petrol cruising AFR but under load the engine needs more fuel, withtypically around a 13:1 AFR. In a turbo engine the AFR might be 11 11.6:1. A lambda

sensor sniffs the exhaust and determines the amount of unburnt oxygen and will adjust

the fuelling to maintain a clean efficient burn avoiding running rich or lean.

The prime motivation for fitting an induction kit is generally to get the lovely inductionroar sound that is muffled by the air box. In larger engines, high performance engines and

turbo engines you may also see slight top end power gains.

Adding an induction kit allows a car to suck in air more freely. Induction kits typically

comprises a cone or hemispherical filter with no air box. The idea is that more air canenter the engine. The standard paper filters that car have in their air boxes are somewhat

restrictive to airflow.

A performance air filter needs to compromise between filtration and drag. They are

generally made from foam, gauze, cotton or a mixture of the three. We have found thatcotton filters give the best filtration to reduced drag.

Oil is generally used to aid the filtration as it traps the small particles of dirt instead of

allowing them to flow into the engine. We read much online of problems caused toAFM/MAF (intake sensors) caused by oil fouling. In reality this will only generally

happen if you have primed the filter with too much oil so there is little to worry about as

long as the filter is properly maintained.

Induction kits should not be confused with performance air filters. The latter fit in theOEM intake box and are swap in replacements. An induction kit replaces the air box and

is generally a cone, cylinder or hemisphere shape. Good induction kits include a cold air

feed, some type of partial air box to shield it from engine temperatures and full fitting

instructions.


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One advantage of inductions kits is the fact that most are washable and will last for many

years, saving you from buying a new paper filter each year. (Although considering the

low cost of paper filters it doesnt make economic sense to buy an induction kit if youjust want to save money in the long term.)

You certainly get what you pay for and cheap one size fits all induction kits do little forperformance or sound.

If the engine can suck in more air then it is able to burn more fuel so you are effectivelyincreasing the efficiency and power output of the engine.

Not all engines will benefit from an induction kit!

It is worth noting that not all engines will experience power gains from an induction kit.

Smaller engined cars (those under 1.4 especially) will actually feel less powerful with an

induction kit. In this case you should use a panel air filter which replaces the standard

paper one inside the OEM air box.

Bear in mind that a standard air filter has a much greater surface area than the intake pipe

and this generally makes up for the drag caused by the filter.

In these smaller engines a certain amount of excess oxygen will not be matched with fuelas the injectors are not big enough and cannot keep up. This causes the engine to run

lean. An air filter should also be matched to a good exhaust system to allow a balanced

flow through the engine. More air in means more exhaust gases.

In all cars induction kits will suffer from a higher intake temp due to the hot under

bonnet temperatures. We all know that hot air carries less oxygen. Removing the air boxmakes the intake temperature rise as air is taken from this hot region rather than from a

vent taken from a cooler place.

You can negate this issue by adding a cold air feed pipe which pulls in air from outsidethe engine bay. Some manufactures take air from the front wing or just behind the

headlights but there is nothing stopping you from cutting a new vent in the hood to allow

in fresh cold air.

Most dyno runs are taken with the bonnet open so will not reflect real world power gains.To combat this problem add a cold air feed to pipe in fresh cold air from outside the

engine bay.

12.

Ceramic exhaust coatings


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Ceramic exhaust coatings are gaining popularity with performance car tuners. We

will take a look at why so many people are getting ceramic coatings applied to theirexhausts.

In very general terms cooler air means greater potential engine power. We can assert this

because it follows that the cooler the under bonnet temperature is the cooler the air intakecharge will be. Cool air carries more oxygen so allows more fuel to burned. Even in carswhere cold air is fed directly from the outside of the car into the intake you will still

experience a minor power loss as heat is conducted through the intake system to the

intake charge.

It is also true that hot exhaust gases flow more quickly than cooler gases. Indeed a

cooling of the exhaust can cause dramatic alterations to the flow characteristics of the

engine.

The aim then is to trap all this heat in the exhaust at least until the pipes clear the enginebay. This has the added benefit that the catalyst gets up to temperature more quickly and

start working efficiently.

Why choose ceramic then? Well ceramic is a very poor conductor of heat and is therefore

a great insulator. It can be bonded to the exhaust permenantly, looks much better than abare metal pipe and will help the exhaust to resist corrosion.

Due to the cost involved we generally see the main exhaust headers upto the catalysttreated with a ceramic coating. While there is nothing stopping you from getting the fullexhaust stystem coated we have to state that the effect diminishes the further back you go

and the main point of this exercise is to lower the engine bay temperatures.

How is the ceramic coating applied? It is generally sprayed onto the exhaust in a very

high temperature spray at temperatures around 11,000 celcius! This high temperatureliquifies the ceramic source material and allows it to bond with the target metal surface.

There are a number of patented process out there and ceramic coating certainly remains

the preserve of the professional with the right equipment.

If the target surface is dirty or rusty the ceramic coating may not always bond as well as itshould so we have to stress that surface preparation is key.

Drawbacks include the minor point that the engine will take slightly longer to reach

operating tempeature. The extra heat within the exhaust will also reveal any weaknesses

and stress points in the exhaust. Cast iron manifolds are more prone to this but we have toask what a cast iron manifold is doing on a performance engine as stainless steel headers

flow much more freely.


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There is now an alternative to ceramic coatings with the arrival of ceramic wraps on the

market which can be cut and wrapped around the exhaust. We would also add that heat

proof paint and various other grades ofexhaust wrap are also available but ceramiccoating remains the most effective insulator

13.

The Benefits of exhaust wraps

As all regular Car Tuning Tips readers know, hot air carries less oxygen than cold

air. This can have a big impact on your engines performance. As most cars have an air

intake in the engine bay it becomes essential to ensure that you keep these temperaturesas low as possible.

One of the largest contributors to heat in the engine bay is the exhaust, and the manifold

headers in particular. An exhaust wrap is a simple thermal bandage that wraps around theexhaust and acts as an insulator and helps to keep the heat transfer to a minimum.

For those that argue an exhaust wrap will cause more rapid deterioration of the exhaust

we would have to concur that this is a possibility. The actual deterioration acceleration is

minimal and will reduce the life of your headers from say 15 years to 13 years. In realitymany people have an exhaust header with pre-existing weaknesses or extensive rust. The

extra temperatures with an exhaust wrap in place will certainly highlight these weak spots

and soft areas and are the cause for the rumors that exhaust wraps ruin the exhaust.

We should also stress that you cannot just use any material as an exhaust wrap. Due tothe extremely high temperatures encountered, particularly on turbo charged petrol

engines you will risk an engine fire if you use the wrong product. Proper performance

exhaust wraps are inflammable and are rated to well above and beyond the operatingtemperatures of your engine.
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Apply the exhaust wrap after ensuring the surface area is clean and free from rust, oil and

dirt. Some choose to apply a heat proof paint such as that used on BBQ and grills before

applying the wrap. The wrap needs to be tightly wound and typically every part of theexhaust will have a double thickness over it as you cover half the previous wind with the

successive one.

A metal clip or similar heavy duty clip should be applied to the end to ensure that the

wrap stays firmly in place. As a precaution we would recommend another clip part wayalong each branch to give some extra security. The last thing you want to happen is

for the wrap to unwind and become entangled in your belts and pulleys.

14.

Sports exhausts

Engines need to get rid of the exhaust fumes created by the combustion process inthe same way that we need to breath out when our bodies have consumed the oxygen inour lungs. If our nostrils were blocked up we would and we had a narrow straw to breathe

through we would survive unless we started to exert ourselves. We would quickly need to

ease off because we couldnt breathe.

Engines are the same, if the exhaust is too narrow the engine will struggle to breatheproperly and performance will be impaired.

Headers, these connect the engine to the exhaust pipe. A typical engine has 4 ports (6 if itis a 6 cylinder etc) and these are channeled down into a single tail pipe. If there are roughparts in this header or the shape inhibits the flow of the engine then it will take longer to

expel the exhaust gasses and also be much harder to do so fully.

Most standard headers are cast in iron and this leaves a pitted surface and often thick cast

seams are left in the metal. Stainless steel headers make for a better flow, the bends canbe more precisely made and the internals are seam free. A standard cast header can be

improved with a grinding wheel and polishing wheel. Smooth out the rough internals and

remove any cast seams. Aim also to reduce the internal angles by grinding away theexcess metal.

Down pipe flexi coupling. This prevents vibration from the engine affecting the exhaust

mountings and also protects the engines from car body movement. Again this should be

internally as smooth as possible and any welded seams should be smoothed down.


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Catalysts. A subject in their own right. This forces the exhaust gases to react with the

catalytic material to reduce the emissions of the engine. A free flowing sports cat can do

a little to increase the power output of the engine. Removing the cat altogether can causeproblems in a closed loop system and will not yield much of a noticeable power gain over

a sports catalyst. Overall gains for a sport cat or decat installation are 2-6 bhp.

Main exhaust. This will need to bend around the contours underneath the car so it would

be best to minimise the bends as much as possible. Generally though the exhaust has togo around the rear axle so bends cannot be avoided. When joining pipes of different

diameters you should always make the join a cone shape otherwise you will suffer from a

turbulent flow of exhaust gases. Stainless steel is a good long life material provided it isbent to shape rather than cut and welded.

Silencer. Sometimes cars have an expansion box before the final silencer. The job of the

silencer is to control and muffle the noise of the engine. In most setups the exhaust gasses

are channeled through a series of baffles which contain a sound deadening material. The

more freely the exhaust gases can flow through this the better. The larger the bore of thesilencer the deeper the tone of the exhaust. Twin pipes and slashes do little to alter the

flow of gasses and are primarily there for aesthetic purposes but the larger the volume ofthese pipes the greater the air flow.

So the bigger the exhaust the more power you can make, right? WRONG! Back pressure,

a small amount of resistance in the exhaust keeps the low down power of the engine. A

large exhaust will reduce the torque of the engine and leave it with no low down pullingpower. The diameter of the exhaust is a precise calculation and takes into account the

engines volumetric efficiency. The exhaust is too large if local cats can sleep inside it at

night! Ideally you want less back pressure as the engine revs increases and to this end

some manufacturers have fitted a valve to the exhaust which opens to increase the flowrate of an engine at high rpm.

15.

Sports exhaust silencers

The basic job of a silencer in an exhaust is to dissipate the sound waves coming

from the engine. In the UK and America where early cars had poor silencers we have aculture that associates noise with power. In Japan where engines were introduced with

silencers the accepted exhaust note is very quiet and more of a buzz.

Are silencers really necessary? The noise an engine generates is phenomenally loud and

most of this exits the engine via the exhaust. The noise is to great to be comfortable whendriving and is a nuisance to everyone else around. For this reason then most countries

have legislation requiring a silencer to be fitted to the exhaust.


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Most silencers around contain some kind of sound deadening material to absorb the

sound waves but exhausts work in different ways.

There are 2 primary exhaust types one contains a series of baffles and this reduces theexhaust flow as well as reducing the noise emitted.

The second type is a straight through pipe with perforations in it. The perforations take

the sound energy and as this bounces back of the outside of the silencer it distorts and

reduces the sound waves in the main exhaust charge.

Some manufactures have a primary and secondary resonating chamber to break up the

sound and these can be of one or both types outlined above.

In a performance engine you really want the exhaust gases to be emitted as quickly as

possible. The baffle type of exhaust is too restrictive in this instance so we would need tolook to a straight through exhaust back box.

The benefits of the perforated pipe are obvious. The main exhaust stream is allowed to

continue virtually unimpeded and the holes primarily allow the sound waves to penetrate

and be absorbed.

The overall bore size of the entire exhaust system has an optimum setting. To small and itis restrictive, too large and the exhausts will flow more slowly. A larger bore silencer will

not affect the airflow by a noticeable amount, and the larger the silencer the deeper the

sound.

If you are performance tuning your engine, you need to choose a silencer that does notrestrict the engine. A silencer alone will not add power to an engine but a restrictive

silencer will rob you of power.

16.

Sports Cats vs de-cat pipe

The catalyst (also referred to as a pollution or smog control) resides inside the

exhaust. Its job is to create cleaner emissions by causing a reaction which reduces theCO2 and NO2 in the exhaust. Because they are constructed of a matrix they impede the

flow of exhaust gases and have been blamed by many as power stealers. What options are

out there that regain this robbed power?


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Primarily there are 2 options to get faster flowing gases through the exhaust:-

The first and easiest is referred to as a de-cat. It is quite simply a pipe that sits where the

catalyst should go and effectively the entire catalyst is removed.

What are the drawbacks of a de-cat? It is illegal in most states and countries unless your

car can still meet its stringent emissions requirements without one. Many people swap

back the catalyst at the time of the annual test to obtain a roadworthyness certificate butthe Police are increasingly using spot checks at the road side to catch people out.

Some engines will also have a probe further up the exhaust from the catalyst and if this

reports dirty exhaust fumes it will adjust the ignition timing typically running the

engine lean. This will result in a loss of power and could even cause the ecu to go into a

limp home mode.

The second and most professional option is a sports catalyst. These are manufactured to

higher tolerances than the OEM ones and have much better flow characteristics. The

drawbacks of the sports cats are usually the cost but in real terms they cost little morethan a standard original brand catalyst.

When you put a car on a rolling road what sort of results can you expect to see? Car

Tuning Tips took a Mitsubishi Evo IV onto a rolling road and the baseline power with theoriginal catalyst was 295bhp.

With the decat pipe this increased to 305 bhp and then when the sports catalyst wasintroduced power reached 304 bhp. So we have to conclude that there is very little

perfromance difference between a sports cat and a decat. The standard EVO catalyst isactually very good which is why we see little gain between them but on more humble

engines power gains reach around 5-10% higher.
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If your catalyst needs replacing we would strongly recommend that you source a suitable

sports catalyst rather than going for an illegal decat option. If you are using the car off

road then the decat would be the sensible and most cost effective option open to you.

Method 2

Uprated Fuelling

One thing a performance tuner needs to take into account is the importance of the

air to fuel mixture. If this is too lean or too rich the engine power will be reduced and thisalso impacts upon the reliability of the engine. The more power you are extracting from

an engine the greater is requirement for the air/fuel mixture.

The main fuel pumps are usually sufficient to cope with most off the shelf tuning

modifications. However when turbos, superchargers or extensive engine work has beencarried out there is a need to increase the output of the fuel pump. It is not unusual in the

motorsport world to see multiple fuel pumps installed. Having a couple of fuel pumps can

also help with starvation in low tank conditions as each will typically have its own fuel

pickup.

The injectors will also need uprating as these deliver a measured amount of fuel and are

sold in sizes. Often times adding a set of injectors from a larger engined model of yourcar will have the desired result. This fuel mixes with the air in the intake manifold beforeit enters the chamber so see the articles on air intake to fine tune this part of your engine.

Another critical component in fuelling is the fuel pressure regulator. This maintains a set

pressure in the fuel lines. The engine also has to return excess fuel to the tank via a return

feed if the pressure is too great. Factory fit fuel pressure regulators can be unreliable andalmost any aftermarket fuel pressure regulator valve with react faster to changes in the
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throttle position. So although your power will not increase with an uprated fuel pressure

regulator the power will arrive more quickly and the car will be a much snappier drive.

Remember though that increasing the fuel line pressure will increase the stress the fuelline is under and will show up any weaknesses there may be.

Blocked fuel filters are a major cause of lost power and should always be one of the firstthings you look at if you are suffering from fuel starvation or bad starting conditions.

1.

Petrol, octane and additive tips

There is an ever increasing array of fuel on offer. With the addition of a wholeplethora of additives the motorist can be left wondering what is the best for his car.

Which octane is best and should you use additives? Are all brands of fuel the same?

The quick answer is that all fuels and additives are not the same. We typically buy petrol

by its octane rating. The octane rating or RON is solely an indicator of how resistant thefuel is to knock. (Knock is premature ignition caused by pressure within the engine)

In general most Japanese performance cars require a high RON fuel as the Japanese

domestic market use a high octane fuel as standard. If you increase the compression in an

engine or add a turbo for example you will certainly benefit from the extra RON.

An engine contains a knock sensor and if it detects that knock is occurring it retards the

ignition timing of the offending cylinder. If you put a higher octane fuel in your car it is

unlikely to cause any damage. Unless the engine is experiencing knock on a lower octane

fuel you are unlikely to get any performance benefit either.

Running an engine which requires high octane fuel on a lower octane will typically cause

damage. So avoid going lower than your makers specification. High octane fuel does not

mean it is more powerful or that you will get better economy.
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IT JUST MEANS THAT IT IS MORE RESISTANT TO ENGINE KNOCK!

High octane fuels in the UK typically range from 97-99 RON. Check with your local

forecourt. Try a higher Octane and see if you benefit from it, if you do then this showsthat the engine was not operating at peak efficiency under the lower octane.

Race fuels are also available that exceed 99 RON but should only be used in highly

modified engines or engines which run high compressions such as Japanese cars and

turbo cars.

All petroleum producers put additives in their fuel. These are a carefully controlled blend

to enhance both the storage and use of the fuel and maintain the octane levels. Detergents

added will help to keep the injectors and engine clean. This in turn means the engine is

more efficient and you will get better economy.

Other additives may include bio elements such as esthers or alcohol. We are firmly

opposed to the compulsory addition of bio-fuel into our regular petrol. There needs to be

more research carried out as early indicators show this to be detrimental to most petrol

engines.

Of all the fuel additives we have encountered the only one we can say has made a

difference is REDEX. After a long run every car I have used it in shows an improvement

of around 2mpg. The older the car the better the improvement.

The octane boosters usually work out more expensive than buying the higher octane fuel

in the first place.

2.

Engine Balancing and Blueprinting tips.

Think of an engine as a series of metal components moving at great speed changing

direction frequently. The faster the speed of the engine the greater the vibration and

forces encountered. There is a limit to how fast and engine can goes safely, andmanufacturers set this red line and include a Rev limiter.


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Disruptions, or vibrations, within the engine will sap power, and substantially reduce the

life of the engine. To get more power from an engine each of the main dynamically

moving components need to be balanced and precisely machined. This will allow the

upper Rev limit of the engine to be substantially increased. In the Formula one world thelarge engines are capable of revving to speeds of over 20,000 RPM. This is an indicator

of how under tuned are stock engines are.

There are two parts to balancing an engine. The first is where the components arephysically weighed and material added or taken away to ensure that they balance.

Typically this is performed on the pistons connecting rods and bolts. When these fast

moving components have the same weight they will exert the same amount of forces ateach parts of the engine cycle. This phase of engine balancing is often referred to as a

blueprint stying where each component of the engine is exactly matched to the requiredspecification.

Where possible mass is also removed from the engine as lighter components aregenerally able to move at faster speeds and change direction more easily.

When an engine is in motion you need to take into account the dynamic forces

generated. So the second phase of engine balance requires specialist equipment where

the engine components are assembled and monitored for dynamic imbalance.

By balancing your engine you will benefit from more power, better economy, longer

engine life and a higher red line. The higher the revs the greater the power produced, onthe basis that the engine is using more air and more fuel per minute. Peak power alsotends to arrive on most engines part way through the rev band and many engines are just

getting into their potential stride as the rev limit approaches.

3.
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Cryogenic engine treatments

When building a new engine you really want it to be as strong as possible.Cryogenic treatments were discovered by accident. It was noticed that metal exposed to

the cold temperatures of space and high temperatures of re-entry were substantially

stronger.

The effect of slow cooling and slow heating up was even better than the sudden

temperature changes and the process of cryogenic engine treatments arrived.

An engine is stripped and sprayed with liquid nitrogen in a controlled manner droppingits temperature to near absolute zero for a long period. Then the temperature is slowly

raised to 150C and held for around 12 hours. This process can be repeated a few times

for better results. Cryogenic engine treatments result in a much harder and smootherfinish to the metal with obvious benefits to the car tuner.

Whole engines cannot be effectively treated in this way so they must be stripped down

and the individual components treated.

The resulting metal is substantially harder so is capable of with standing much higher

stress than a standard block. The molecular level smoothing also reduces friction which isanother source of power loss and internal engine stress.

There are a growing number of companies offering a full cryogenic service for engine

builders. The initial costs are relatively high and this renders cryogenic treatments theexclusive preserve of the motorsport team or serious tuner.

Eventually the cost will come down and this will be a viable option for all car tuning

enthusiasts. Rarely do we see a tuning process that doesnt introduce negative points. All

power gains tend to come with a hidden price but cryogenics seems to have onlypositives and upsides. Expect a net power gain of around 3% and much better reliability

from a cryogenically treated engine.

4.

Electric water pumps

The coolant needs to run round the engine taking the heat from the block and

dissipating it in the radiator. Most cars come with mechanical water pumps which have a


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number of drawbacks, www.CarTuningTips.com will take a look at the benefits of

upgrading to an electric water pump.

Mechanical pumps take a lot of power from the engine. They also rotate and thereforepump in proportion to the engine RPM. This does an adequate job but causes the

following 2 issues.

1. After a hard run with lots of heat in the engine the pump will slow down as you

slow down. This can mean the engine temperature raises to dangerously highlevels.

2. When the engine is cold the coolant is being pumped round at the same rate as a

warm engine causing the engine to take longer to warm up.

This is tolerable on a standard car which rarely is driven hard. But when you have ahighly tuned car and frequently take it for a spirited drive you can start to experience

problems associated with overheating.

The solution then is to go with an electric water pump. This has a separate controller and

allows much more control over the flow of coolant around the engine.

1. You can preset the engine temperature for high (better economy) or cooler (better

performance).

2. The average temperature is much closer to the preset temperature.3. The electric pump is only working when the engine is up to temperature allowing

the engine to warm up more quickly.

4. The pump can run after the car is stopped to cool any residual hot spots.5. Water speed can be faster than with a mechanical pump when required.

So there are many benefits from an electric water pump. When you fit this you remove

the engine thermostat which controls the flow around the engine as the new EWP

controller does this. For simple installation many owners remove the mechanical water

pumps impeller to reduce drag but retain the belt tension and pulley.

What are the drawbacks? Reliability has been sited as a possible issue. Electric motors

wear whereas the mechanical water pumps pretty much keep on going. Although certain

VAG engine water pumps have plastic impellers which brake requiring complete

replacement of the whole water pump. As long as you keep an eye the condition of yourengine you should have little trouble with an electric water pump.

5.

Water injection
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In a forced induction engine (turbos, superchargers and twin chargers) and to some

extent a NASP engine with a high compression ratio you have the ever present risk ofdetonation. This is where the fuel prematurely ignites typically causing major engine

damage.

When adding or increasing the amount of air going into the engine you have an icreasedrisk of detonation. One solution is to use a higher octane fuel because it will be moreresistant to knock.

More professional engine buildings are looking to the benefits of water injection. Simplyput the water dampens the fuel air mix allowing it to resist detonation for a longer

duration.

Ehtanol/water mixes are sometimes used but for the purpose of this article we shall focus

on water injection.

Water can be injected at any stage along the intake. Some proponents of water injectioninsist that it is better to spray this before the compressor and allow the water to better

vapourise, some insist that it is sprayed just after the turbo and there are also fans of

direct injection at the point of fuel delivery.

Each system has is merits and drawbacks and depends to a large extent on the engine.

A crude setup can deliver a set amount of water each time but ideally you will need some

form of engine management to match the fuel and water delivery to allow for the

optimum settings and benefits to be obtained.

A water injection kit can be purchased now from many motorsport retailers and these

typically come with everything you need.


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Some water injection systems use your screen wash reservoir but ideally you should

have a separate water reservoir with a level warning device fitted as some screen washes

contain undesirable elements to be spraying into your engine.

Problems.

Water can cause corrosion so it becomes essential to properly maintain your engine andthe intake will ideally need to be periodically removed for inspection.

If the water reservoir dries up then you will risk engine damage unless the fuel and airmixture is reduced.

Benefits.

In addition to the extra detonation resistance water injection will provide a cleaning

action and help to remove carbon deposits from the engines valves and cylinders keepingthe egnine in peak condition.

I have yet to be fully conviced that the merits of water injection outweight the potentialproblems. Considering a properly designed and built engine with lower compression

pistons will suffice it does seem a bit of a bodge. However in high stress ultra highperformance settings it gives an opportunity to release a little extra power from the

engine.

6.

Remote turbo kits

It can be quite time consuming to add a turbo charger to a NASP engine. Thebiggest problems include avoiding detonation, making space to join the turbo to theexhaust and sorting out the fuelling and mapping.

Although still a big job the remote turbo is being hailed as the simple bolt on solution for

NASP engines.

A remote turbo, so called because of its remote location is generally fitted at the back ofthe car near or instead of the rear silencer. It can also be mounted part way along the

exhaust but this can be prone to damage and reduces the cars ground clearance.

The remote location ensures that the exhaust gases are substantially cooler than they

would be in the exhaust headers. Due to the catalyst and expansion box the exhaust gasesare also flowing a little slower. These two factors make it a lot easier to add a remote

turbo.


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The lower boost they produce and cooler temperatures they run at help the simplify the

installation. The long pipe run back to the air intake will act as an intercooler negating the

need for an additional intercooler.

Your remote turbo will need a very good supply of oil and we would recommend fitting

an oil pump and taking an oil feed from the engine sump. An inline oil cooler can help iftemperature issues ensue.

Although remote turbo kits are available you can actually source suitable turbos frombreakers yards and salvage agents. Go with a small turbo set to low boost with a

wastegate and diverter valve for best results, unless you are prepared to lower the

compression of the engine.

You will need to adjust the fuelling and the engine mapping to cope with the additionalsupply of air and this is best done on a rolling road.

Avoid detonation by running a low boost, using high octane fuel and adding a waterinjection system if you do not want the expense and inconvenience of a full engine

rebuild.

7.

Aftermarket Superchargers

A supercharger compresses the intake air effectively forcing more air into theengine. More air means you have more oxygen and when this is matched to more fuel

you will benefit from more power. There are a number of benefits to superchargerscompared to turbos, but there are also some drawbacks. We aim to provide sufficientinformation here to allow you to ascertain if a supercharger will provide a solution to

you.

The supercharger is powered by a belt from the engine. Superchargers force air in at a

constant rate in line with the engine speed. As engine speed decreases the intake flow
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matches this precisely. Because it is driven by a belt from the engine some power is lost

as this needs to drive the compressors. This is more than made up for by the extra power

on offer.

Superchargers work better than turbos in aftermarket bolt on application because the

power increase is so well matched to the engine speed. With a turbo the power levels

fluctuate with the exhaust gases and there tends to be lag low down and a big power hikein the top end. Superchargers deliver power throughout the rev range so although it will

not typically peak as high as a turbo you will benefit from a no lag boost low down in

the rev range.

The biggest problem with superchargers is where to site them. A simple solution presentsitself on cars with air-conditioning. As the air con is heavy, and saps power a

performance car is better off without it. Removing the air con leaves a nice space for the

supercharger compressor to fit. The belt will usually be the right length and you will beable to utilise the air conditioning compressor mountings to fit on the supercharger.

When fitting a supercharger you will need to get the engine timing remapped. Depending

on your boost level you will need to look at the fuelling. It is surprising how much more

fuel you need to run to match the extra air coming into the engine.

There are a number of supercharge and turbo applications around. The VW twin chargeris a case in point. These are designed to give the benefits of each system and a relatively

small engine, like a 1.4 is able to produce the power of an engine 2 times its size. The

engine, being smaller is lighter and there are performance benefits all round.

8.

Adding a turbo

We all know that one of the best ways to improve a cars performance is to upradeto forced induction. More air going into the engine means that you can burn more fuel

and produce more power.

In games we often see that turbo upgrades are easy to do and give phenomenal power

gains to a car but is it like that in the real world?

If you have too much pressure in an engine then it will cause the fuel to prematurely

ignite. This can lead to serious engine problems so when you add a turbo you need to

actually reduce the pressure in the engine.


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We do this by lowering the compression ratio. This can be achieved only with some

major engine work. Adding a thicker gasket or even worse using 2 gaskets, will do very

little to the compression ratio and will be prone to premature failure.

Ways to lower the engines compression ratio.

Replacing the pistons with low compression pistons and using a stroker kit to alter the

throw of the pistons will potentially reduce the engines compression ratio. Reboring the

engine will increase the cylinder capacity but this should be mated to lower compressionpistons. It is also possible on some engines to enlarge the head area around the valves but

this would not be very practical or effective.

If you are unable or unwilling to reduce the engines compression ratio then your options

are restricted to a low pressure forced induction system. You could also use a higheroctane fuel, which is by its very nature more resistant to knock. It is worth noting that

many Japanese cars engines have high compression ratios and already prefer higher

octane fuels giving little scope for adding a turbo without substantial internal work.

Alternatively a water injection system can dampen the air fuel charge down and delay the

effect of premature ignition. There are a number of considerations and drawbacks to

water injection so this should only be used in certain situations.

Fitting the turbo

Now that the engine is able to cope with the extra air and fuel without prematurely

igniting we have to get the turbo plumbed in. The plumbing requires a custom exhaust

header and you will need to route the air intake piping through the turbo.

A turbo will need the following components to work properly. A wastegate to control theflow of exhaust gases through the turbo, a diverter or blow off valve to vent overboost on

closed throttle and a good supply of oil. Additionally Car Tuning Tips suggest you fit an

intercooler to lower the intake air charge as the turbo compressiong will significantly

warm it up.

Because the engine is undergoing a dramatic transformation you will certainly need to

alter the timing map. If you get the timing wrong you risk destroying your engine so it is

best left in the hands of an expert who can set this up on a rolling road.

Keep a close eye on engine oil temperature, you may need to add an oil cooler if your carstarts to overheat. We also suggest you user a higher grade of oil, the engine will be

working much harder after all and the heat in a turbo unit can really degrade mineral oils

very quickly.


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It is certainly a good idea to overhaul an engine thoroughly before adding a turbo charger.

Fitting forged parts is a good idea as this will help to maintain the reliability of your

engine.

A good source of cheap turbos is your local wreckers, breakage or salvage yard. A new

turbo can set you back substantial amounts of money. With turbos being commonlyinstalled on VAG group cars and many Japanese performance cars there should be a good

selection to choose from. It is also worth checking the classified adverts for old turbos asmany owners uprate their turbos and seek to sell on the old one.

Remember that bigger turbos spool up more slowly and are suited to high revving or

large capacity engines. When adding a turbo to a NASP engine the Car tuning tips

recommend you stick with a smaller turbo unit and as a bonus you will benefit from afaster spool up and lower lag.

A turbo can dramatically increase the power of your engine. Typically power gains range

from 40% to 200% of your base power although a sensible figure to aim for is around 75-100% of a power increase but this does depend on how strong your base engine is and

how much work you have had done on it.

If you have not lowered the compression ratio of your engine or strengthened it then we

suggest you stick with a very low boost setting and settle for a 25% power hike.Superchargers are easier to add than a turbo so you should consider this as a low cost,

lower hassle alternative to turbo charging.

9.

Turbo engine tuning

When deciding on a power train which should you go for? I will admit to being a little

biased towards turbos. Here is my take on Turbo Engines.

The sheer exhileration and excitement you get as the turbo kicks in is something that

sticks with you for a long time.

I will concede that due to lag the turbo does not produce much power low down. Even the

mighty Mitusbishi EVO suffers from terrible lag low down in the power range. Instead ofthis getting you down view it as a car with a split personality. In heavy traffic it is civiland economical but if you are overtaking or enjoying a thrash there is a monster waiting

to be unleashed.

Nearly all turbo engines are built to withstand more pressure in the combustion process.Most cars with turbos (yes even diesels) can be remapped to release loads more power. A

remap is a simple reprogram of the cars computer which controls the wastegate, fuelling


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and thereby the amount of fuel/air that can be burnt. A remap will cost a few hundred

pounds but will typically give another 30% of reliable power to your car.

After this modification there are loads more, if you strip down the engine and get it gasflowed and ported, strengthen the rods,pistons and crank and get it balanced you can look

at doubling the power output of the engine. (Some cars can cope with 100% more power

without an extensive rebuild although reliability may suffer.

A turbo upgrade will also yield substantial power gains, so look out for an OEM(standard case with uprated internals) or after market (bigger housing requiring minor

modifications to the cars exhaust, wastegate and air intake housing diameters.) A ball

bearing turbo will spool up quicker. Smaller turbos reduce the problem with lag. A twinturbo setup with a boost controller will control the sheer power and manage the delivery

to a more progressive level again minimising lag. Large turbo conversions will make

bigger power figures but tend to suffer more from lag at the lower end of the rev range

10.

Big turbo conversions

A turbo charger has a finite capacity to force air into the engine. The basic principle that

more air equals more power holds true (as long as there is a sufficient supply of fuel tomatch this).

Hybrid turbos are one way to increase the capacity of your turbo, with different impellersthe characteristics can be changed. But for larger power gains you really need to add a

larger turbo.

A larger turbo is obviously physically bigger than an OEM one, and it will therefore

require a custom exhaust header and different oil feed lines.

The benefits of a big turbo conversion is a massive increase in power. The increase

typically focuses on the top end of the rev range where you get a massive power

increase.

There is a a downside, a large turbo takes a while to get up to speed and it can seem quite

hesitant (a condition known as turbo lag) where the engine struggles for power below

3000 rpm. Big capacity engines (2.5 litres upwards) are best suited to large turbos as theycan sustain the exhaust flow rates that the turbo needs to spool up.
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Some tuners use a twin turbo setup fitting a smaller initial turbo (or even a supercharger)

and then bringing the big turbo online when the exhaust flow rates can support it.

A ball bearing turbo will spool up more quickly than a thrust bearing one and the ballbearing turbos are more tolerant of larger power figures. (Thrust bearings tend to prove

unreliable when pushed beyond 350bhp).

So can you just bolt on a big turbo and everything will work? Unfortunately things are

not this easy and the car will need to beremapped. A standard ECU will usually have afailsafe that cuts in where boost exceeds a certain limit so this will need to be removed.

Also when increasing the power of an engine you will need to strengthen the bottom end

of the engine and ensure the head is capable of flowing the supply of air and fuel

correctly. This also means increasing the injector capacity and supplying fuel at a greaterrate will usually need a higher capacity fuel pump.

You will also need to uprate the intercooleras a standard intercooler can becomerestrictive when you have a larger turbo.

11.

Hybrid turbos

One great way to easily uprate and improve a turbocharged engine is with the aid of a

hybrid turbo. Sometimes it is quite hard to fit a larger turbo to an engine, the most notable

reason being the lack of space available. Add to this the complexity of fitting a larger unit

into the exhaust manifold and relocating the oil feed and air intake piping. So you can seethat there is a lot to recommend getting different turbo internals in a standard turbo

housing as this becomes a bolt in upgrade.

Turbos are simple double ended propellers or impellers. The size, angle and shape of

these will greatly affect the performance characteristics of the engine. By adjusting the

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