FULL POWER PERFORMANCE consumers ETEC 800 turbo system Kevin Freeman, owner of the Sled Shop SkiDoo in Presque Isle, ME came here to dyno test his first FPP Etec 800 sytem that his tech guys had installed on a 2012 sled that had come in on trade. Kevin (who reminded me that hes been coming down here to tune open mod drag sleds since the 1980s) was here several years ago validating his first FPP 4Tec turbo system set up to run on ME pump gas. After his good experience with the small fleet of FPP turbo 4tecs his guys installed for customers, he decided to try a boosted Etec 800. Like the FPP 4tec turbo, the intercooled FPP Etec turbo system utilizes a Garrett turbo with ball bearings (low friction ball bearings = instant boost and throttle response). The additional fuel needed for high HP is delivered by two extra injectors fired by a Dobeck boost/ rpm configured control box. So here it is, on ME pump gas. Heres the baseline pump gas setting, with timing set as delivered by Bombardier. Zero knock, safe A/F but a bit lower power than FPP made with their Etec preproduction turbo system. Note that as we did on the first FPP Etec turbo, boost was measured after the throttle blades. FPP turbo Etec 800, standard ignition timing. EngSpd STPPwr STPTrq BSFA_B AFRA_B FulA_B BoostP Air_1s RPM CHp Clb-ft lb/hph Ratio lbs/hr psig SCFM

6600 125.4 99.8 0.722 11.82 88.7 2.7 229.1 6700 128.7 100.9 0.711 11.89 89.7 2.9 233.0 6800 132.9 102.6 0.703 11.85 91.5 2.9 236.8 6900 139.0 105.8 0.692 11.76 94.4 3.1 242.4 7000 145.1 108.8 0.683 11.68 97.2 3.2 248.0 7100 150.2 111.1 0.654 12.07 96.3 3.3 253.8 7200 155.9 113.7 0.640 12.07 97.8 3.3 257.7 7300 159.3 114.6 0.643 11.90 100.3 3.2 260.8 7400 161.6 114.7 0.638 12.02 101.1 3.2 265.3 7500 165.1 115.6 0.630 12.15 101.9 3.3 270.4 7600 169.4 117.1 0.631 12.03 104.8 3.4 275.4 7700 174.4 119.0 0.626 12.00 107.0 3.4 280.6 7800 180.0 121.2 0.615 12.04 108.5 3.3 285.4 7900 186.6 124.0 0.593 12.19 108.5 3.4 288.9 8000 188.9 124.0 0.599 12.11 110.8 3.4 293.3 8100 188.4 122.2 0.603 12.24 111.4 3.6 297.8 8200 184.8 118.3 0.613 12.51 110.9 3.9 303.1 8300 177.1 112.1 0.648 12.65 112.4 4.3 310.5

Next, local SkiDoo dealer Jim Cooper used his BUDS system (Kevin didnt bring his own BUDS computer with him) to crank the timing all the way to the stops. Since that has worked so well on the stock Etec 800 (many Etec 800 DTR members have done this,

and all have been pleased), we wanted to see what an extra few degrees (the BUDS timing adjustments are vague) of timing would do to the boosted engine: FPP turbo Etec 800, advanced ignition timing EngSpd STPPwr STPTrq LamAF1 BoostP Air_1s AirInT ElpsTm RPM CHp Clb-ft Ratio psig SCFM degF Secnds

6600 126.0 100.3 13.65 2.7 227.2 28.8 0.72 6700 128.6 100.8 13.44 2.7 232.5 28.8 1.18 6800 132.7 102.5 13.22 2.8 236.3 28.8 1.50 6900 138.2 105.2 12.79 2.8 241.9 28.8 1.84 7000 146.0 109.5 12.52 2.9 248.6 28.9 2.26 7100 152.3 112.6 12.54 3.1 254.3 28.9 2.58 7200 158.8 115.8 12.54 3.1 260.7 28.9 2.98 7300 164.2 118.1 12.40 3.1 264.1 28.9 3.30 7400 168.5 119.6 12.27 3.0 268.5 28.9 3.67 7500 172.4 120.7 12.17 3.1 272.4 28.9 3.97 7600 176.1 121.7 12.13 3.1 277.1 28.9 4.27 7700 181.7 123.9 12.15 3.1 281.8 28.9 4.66 7800 187.2 126.1 12.09 3.1 285.3 29.0 5.07 7900 190.4 126.5 12.11 3.0 288.0 29.0 5.40 8000 192.4 126.3 12.29 3.0 290.7 29.0 5.77 8100 193.7 125.6 12.42 3.0 293.9 29.1 6.15 8200 193.5 123.9 12.40 3.2 298.4 29.1 6.48 8300 191.9 121.4 12.61 3.4 303.5 29.1 6.80 8400 189.5 118.5 12.92 3.6 308.8 29.1 7.11 8500 188.0 116.2 12.90 3.8 313.8 29.1 7.40

It was interesting to note that in advanced timing increased torque, horsepower and airflow the boost pressure actually dropped by about .4 PSI! This might be the result of less exhaust heat energy spinning the exhaust turbine less, and more of it used to expand gases in the combustion chambers, creating additional torque. But, as we often see in NA engines, making the engines happier with more optimal timing creates added airflow CFM. So, adding that .4 PSI back with controller adjustment, the advanced timing would surely have boosted power even more. Kevin was pleased to make 190+ HP with zero clicks of deto on his pump gas. But he wanted to see what the limit of his pump gas was, and how the detonation protection of the Etec system would function. So Justin Fuller tweaked the boost pressure to what should have been 5 psi boost, and the engine began to detonate at 7500 RPM and the detonation protection system sensed that, and then began pulling massive amounts of timing from the Etec 800 causing airflow, horsepower and boost pressure to drop! Power tailed off, and by 7800 began to drop. This reaction to detonation was reasonably quickresulting in lower boost and airflow CFM beyond 7800, which resulted in drastically reduced torque and HP at higher revs, preventing damage to the engine.

FPP turbo Etec 800, boost increased too high for pump gas EngSpd STPPwr STPTrq BoostP FulPrA LamAF1 Air_1s RPM CHp Clb-ft psig psig Ratio SCFM

6600 126.3 100.5 2.7 46.8 13.86 228.1 6700 128.7 100.9 2.8 46.9 13.50 233.6 6800 133.3 103.0 2.8 46.8 13.36 238.8 6900 139.5 106.2 2.9 46.7 13.04 245.1 7000 146.4 109.8 3.2 46.5 12.86 252.2 7100 155.3 114.9 3.4 46.2 12.61 260.8 7200 161.7 117.9 3.6 46.2 12.42 267.7 7300 168.4 121.2 3.8 46.1 12.29 276.7 7400 176.3 125.1 4.1 45.9 12.28 284.5 7500 185.2 129.7 4.4 45.5 12.21 292.7 7600 192.2 132.8 4.6 45.5 12.15 299.1 7700 199.0 135.7 4.3 45.9 12.05 299.0 7800 201.5 135.7 3.5 46.5 11.91 294.3 7900 199.3 132.5 3.1 47.0 11.93 292.1 8000 196.1 128.7 2.9 47.2 12.10 291.5 8100 194.1 125.8 2.8 47.0 12.24 293.4 8200 193.0 123.6 3.0 46.7 12.30 297.1 8300 191.3 121.1 3.3 46.4 12.48 303.0 8400 190.0 118.8 3.7 45.9 12.67 309.0 8500 189.1 116.8 3.9 45.6 12.85 315.0

BOOST, TIMING, & FUEL On the dyno, we often jockey ignition timing and boost pressure levels, to enable us achieve maximum reliable power on a given octane. Do we go with more timing and lower boost, or less timing and more boost? Less timing advance and higher boost mean higher exhaust temperature (and hotter pipes) helping drive the turbos exhaust turbine harder and more quickly and higher intake charge temperature (less dense and more prone to deto) especially on two-strokes that have some of the intake charge spend time inside the hotter exhaust header pipe on the bottom half of each piston stroke, before the returning sound wave shoves it back into the exhaust port. More timing and less boost can have the opposite effect along with the increase in transfer of combustion heat into the heads while the expanding burning mixture drives the pistons down instead of heating the pipe(s). But what about fuel flow? We can make max HP at about 13/1 A/F, but we get the greatest combustion chamber cooling effect (and least power output) at 10/1. What shall we do? Jockeying all three about, and watching for/ listening to detonation is what we must do while we observe torque and horsepower on the dyno (or observe clutch RPM during field testingwas that 50 more RPM, or 50 less RPM?). Some years ago DynoTech was contracted to create an optimal pump gas tune (ignition timing curve, fuel flow, and boost level) for a turbocharged Buell motorcycle that was being considered for production (details of the turbo Buell Diablo were made public in

Cycle World, May 2010, page 44). We built five Buell X1 engines/ bikes for H-D to test with custom dished low compression pistons with tight squish band clearance to obtain the combustion chamber turbulence necessary for rapid flame speed. We also designed and fitted each bike with efficient side-mounted intercoolers with plastic pro-stock style air scoops (theres a photo of one of the turbo Buell X1 test bikes on our motorcycle dyno on this website when you click on About DynoTech). H-D had loaned us engineering software to enable us to tune the front and rear (hotter running) cylinders individually. Their target was 125+ rear wheel HP (about 50% increase over naturally aspirated X1s). After trying 100s of combinations of boost/ ignition timing/ A/F ratio we wound up with front/ rear ignition timing nearly identical to the stock factory curves with boost pressure and fuel flow that made over 130 RWHP! Part of the H-D endurance testing that these bikes ultimately passed included filling the bikes fuel tanks with pump gas and [underpaid] test riders would run in high gear, WOT (at a high speed test track in Alabama) non stop until the tanks were emptywith no electronic deto protection! According to the CW article, the turbocharged Buell X1 test bikes exhibited greater reliability than the normally aspirated high compression X1s. The point is, people too often assume that we MUST retard ignition timing when we pressurecharge any engine. But if our goal is to achieve max safe HP on a given octane fuel, we should not be afraid to experiment with ignition timing. In retrospect, we should have tried the added boost with standard timing on this turbo Etec 800, or perhaps timing in the middle positionwe may have made over 200HP with that setup. We were short on time. But Kevins target was 190HP on pump gas, and maybe standard boost with just one degree of added timing to standard will do the trick. Kevin can field test his first FPP turbo Etec 800 and let his clutches indicate relative horsepower, and his sleds excellent deto protection will tell him if hes got the proper boost and timing. The final analysis and tune will depend on actual field conditions with engine and intercooler temperatures normalized.