April 2008

Sunday, April 06, 2008

DynoTech : April dyno schedule, tailing off now

monday 4/7  CJ motorsports or powersports (sorry can't remember which) from Booneville NY coming with new 09 SkiDoo 1200 four stroke. Arrival 2pm, run by 3pm. Live on dynocams. had it running by  3pm, but have an issue with max revs limited by ecu to 4500, runs perfect from idle to 4500 then two-steps there, must be issue with tether etc, CJ will come back tomorrow with BUDS computer, get it running then. Got it fixed, made 20 part throttle/ ful throttle dyno runs, similar hp to nytro but you have to see the comparison graphs to appreciate how different two identical HP engines can be.

4/10 Thursday AM  Brian Neuman, Yamaha 650 flat track bike for maxing our carb/ timing on Cycledyne eddy current roller owner of bike and driver Brian were there to max out HP, engine builder was 300 miles away, maxed out fuel flow but timing was fixed, a phone call to engine builder revealed he wanted timing left at x degrees leave it alone, he's never been to a dyno but I have dyno tuned 1000's of engines all make max HP at different timing even identical engines by identical builders, we just retard/ advance timing make max HP and drive it there. Bike owner will be back with adjustable stator plate will dyno test again. PM Rob Randal F7 mod asphalt racer for Boondocker tuning Rob had Cat 800 big bore (snoX?) cylinders, touched up by HTG, with best (for this engine) single pipe boondockered perfectly made 167 HP but at low 7600 RPM even with stock timing. Maybe compression too high?
.Denny Richards, new 08 HD NightRod with Turbo Connection Aerocharger system.used the onboard boost power commander to tweak midrange A/F ratio, got rid of a few rich burbles by tuning with PC connected to power commander, did a few WOT sweep tests made 160 HP at rear tire on pump gas. Perfect tuneup.
4/15 Tuesday Bill Woodley H-D twin cam Delphi EFI, testing/ tuning several exhaust systems including stock, Screamin Eagle, V&H, also several intakes/ filters, all tuning by power Commander learned lots about mufflers, air filters, power commander tuning is easy, allowing quick alteration of fuel and timing maps (we need power commander-like piggy back devices for our efi two and four stroke sleds).

4/17 Thurs AM Bill Chesney, Engine Tech F7/F9 single pipe asphalt racer, tuning with N2O. textbook tuneup--started with someone's recommended boondocker settings 144hp then tweaked and tuned to 172 with fatazz single, added 60 hp with 10 boondocker n2o nozzle holes, fattened that up to a total of 226 at .60 plus lb/hphr.

4/19 Sat AM Richard Weiss, SkiDoo 800 twin hill-dragracer verifying [seemingly too-high] dyno numbers from the engine builder. Richard's intuition and his butt dyno were correct--the engine builder had it dynod for him for $350 somewhere east of here, 115 lb/ft and 185-190hp but it didn't run like 185 in the field. Today after optimizing Richard's carburetion my dyno [calibrated correctly as it always is] indicates 109 /b/ft 172 HP.

4/24 Tues AM Yam YZ250 flatracker, added 8% HP optimizing fuel and timing

4/25 Wed AM doing more EFI fine tuning on my Triumph Tiger turbo to improve cruising mileage

4/29 Tues AM Casey Mulkins (tentative) bringing the Dragon 800 back to try a production 09 ECU and SLP y pipe and can. We'll post on DTR compare fuel flow/ timing etc 08.5 preproduction vs 09 production. you Polaris Dragon 800 buyers who insist on leaving it bone bone stock might not be totally pleased, but those who will spend $200 on the BMP pipe mod will be thrilled with the 09 ECU programming which now appears fat enough to safely support 154 HP.

4/30 Greg Bennett one more time with Polaris twin with Aerodyne 66. this is about the third trip to the dyno in the current state of tune 930cc big bore, the last two  ended with seizures first clearance too tight (.001" doesnt cut it with a big bore forged pistons) second severe deto at 6500 on boost. Now with proper clearance (thanks to Carl McQuillen's diamond hone) and a proper midrange ignition timing curve, tuned up to 333 HP and 213 lb/ft (new HTG single pipe created higher RPM HP peak than what we had when engine was tested earlier and posted on subscriber pages) now the Aerodyne model 66 has its tongue hanging out at 560 SCFM.

here's a good short article on gasoline I lifted off of AmSnow.

Tuesday, April 01, 2008

DynoTech : A/F ratio comparison of Dragon 800 pipes

This data shows an implication of higher airflow CFM with the BMP and SLP pipes. Fixed fuel flow from EFI plus leaner A/F ratio = assumed higher airflow CFM. Adding HP with higher airflow is always good, and I should have noted that in the article. The day after the test session, Casey Mulkins was on Chautauqua Lake doing multi-mile blasts at 8200RPM with the Dragon 800 w/ BMP mod and no extra fuel. All is well and fast so far.