5/7 Jim Cooper’s PS1000 triple Skidoo asphalt racer, dialing in new MSD ignition last Friday had a bad timing pickup so were waiting for a new one. Before the pickup went bad, we had Megatron fuel flow inconsistencies (solid mount twins are usually the worst, solid mount stroker triples are almost as bad). Jim had trouble at the racetrack with this, usually dropping 500 revs from half track on regardles of clutching. I’m betting the carbs were foaming like they are doing on the dyno. Along with new MSD pickup, Jim’s getting larger, viton N&S’s to try. Looks like Thursday AM/ PM. Got the MSD working again, turned out to be a missing crankcase bolt allowed A/F mixture to escape into the flywheel area and foul the MSD crank trigger. But those carbs are still giving us fits, fuel flow is 86 lb/hr at HP peak must be milkshake in the float bowls. Will try agian Saturday, mess with adding weight to carbs, fuel pressure etc.
Thurs AM sliding Jim Cooper’s sled off the dyno, cameras off, private tuning session for another pro racer, Jim Cooper will be back on to finalize his tuning late thursday. Private session was Glenn Hall’s first crack at dyno tuning a Boondocker turbo system/ D&D F1200/ Firecat (he was concerned that we might fumble this and he didn’t want to goof on camera). Off the trailer it was effortless 325ish at 10 psi boost. So we spent the day cautiously tweaking boost/ fuel/ timing/ exhaust components, gradually working up to 286 lb/ft torque and 414 CHP at 15psi boost!!! This pretty good HP for a Firecat chassis. This AM I’m going to put that HP screen up on the dyno computer, set it up to contuously replay the 400 plus HP tuneup dyno run.
5/9 Justin Fuller with turbocharged Yamaha 1000cc streetbike, maybe an R1 using the Cycledyn eddy current roller dyno to dial in boost/ A/F ratio. Justin’s still not quite finished with kit, will reschedule.
5/10 Justin Fuller has the R1 turbo system done, will dyno tune this PM about 4:00 Easy to fine tune, same fuel management as Justin uses on Apex turbo kits, made 200 DJHP on pump gas at the rear tire at 5.7 psi boost. Everything is hidden under the fairing, stock mufflers are used.
5/12 Finishing Jim Coopers PS1000, then Steve Bennett from West Virginia with CS1710 asphalt sled with fueling issues once more. Short on time, pulled Jim’s sled off the dyno to redo fuel system and add 5 lb of mass to Lectron carbs and will be back. Since Steve Bennett’s last trip to dyno where we had bumped fuel pressure to 6.9psi to overcome foaming float bowls, then made 321hp, Steve was fine for most of the season. But then he added n2o and snapped a conrod, replaced crankshaft and vibration was worse and fuel flow became impossible once more. Back to Batavia. On the dyno carbs disappeared into a silver blur at 6500 and no juggling of fuel pressure could make carbs deliver usable fuel flow–either 140 lb of fuel flow and float bowls went dry or add 1/4 psi and fuel flow went to 250 lb/hr and drowned the engine. Frustration over a vibrating engine with solid motor mounts. Tomorrow AM Jim Cooper is dropping in a brand new CS1710 engine into the solid mount chassis, hoping this is smoother and if we can see the carbs, maybe we can get decent fuel flow for 8.5 seconds. We have difficulty with most solid mount long stroke engines.
5/13 Jim Cooper spent today dropping in the new 1710, after transferring carbs/ ignition from old engine. Tripod Dan brought some rubber mounts which we used to isolate the engine mounts from the chassis. After an hour of sputtering trying to start the engine (glad we have electric start) on the dyno we discovered the new engine’s keyway was about 100 degrees off from the old one. Jim would come back tomorrow with his degree wheel/ dial indicator and figure this out.
5/14 while Jim was indicating the old engine, we discovered the crank was out of phase. Could this have been the source of excessive carb-foaming vibration? Jim rotated the MSD flywheel to align it properly with the trigger, and we were running. Now from 6500-8000 we could actually see the carbs, and even though the mechanical fuel pump was inadequate the Holley pump was tweaked up and down to where we got smooth fuel delivery without drowning the engine. Fine tuning timing and jetting netted us 229 /b/ft at 7400 and 328 CHP at 7700. Smoother due to better crank balance and/ or rubber isolation of engine from the rigid chassis.
Just sold my 90 Exciter with Bender Avalanche triple/ IRS EFI, but my pipes are still missing after I loaned them to Mark Forte in NJ for testing at New England dyno service 15 years ago. Need to buy another set if anyone has some hanging on their garage wall please email me. I found out that Mark Forte still has his Avalanche with MY pipes on it (he said that to the fellow who bought my sled from me–he also said that his were lost in shipping to Jaws for modification). I plan on getting my pipes back.
.5/21-5/28 cameras off intermittantly for private test session with engine on my motor plate.