Enlighten me, peak rpm and pipe design.

[Wheel House Motorsports]

I have a new project rolling for next year. its a turbo'd doo 600 motor and swapping to the race ignition setup next year which doesnt rev limit till 8700. Because i am using a stock pipe with just a turbo on the end, what is it that regulates rpm?? this year i had far to light clutching and the RPM just hung at 8k rpm and fluctuated, no matter how light it was, 8k was my peak rpm and i wasnt on the rev limiter.

just curious about piped design, etc and what actually controls the peak rpm of the motor?

 

[vendetta]

pipe tunning is huge for rpm. i dont know it all but i just had a custom pipe built and he had all the specks for a turboed 670.




Rob

 

[djm]

8000 RPM Limit

What year engine and sled were you running.. You weren't by any chance running an 600RS crankcase with stator and fly wheel from the RS were you? With the production ECU???

I built two of the 700HO XP, with 600RS lower end. Figured I would be trick, pulled the connector off and was able to stick the second pick up in. The RS fly wheel pickups are in the same place and it has two sensor strips on the fly wheel just like the 800R and 500ss only they are shorter. Since they don't have reverse in the 600RS I assume that they count twice for each revolution... whatever.. Reverse worked fine with those fly wheels. But in my case I was limited to 7500 - might have been 7600 rpm but no more. I lightened pin weight as far as 6 grams.. still 7500 rpm.

I jetted up and down.. 7500 rpm was all it would do. Then I remembered the length of the metal trigger on the fly wheels, pulled one of the fly wheels and put an 800R fly wheel on.. instant 8800 rpms (oh, if you send your ECU in to Skidoo Wausau, you can have it recurved and the rev limiter removed - I was able to run 23 grams of pin weight to get it back down to 8150 rpm after changing fly wheels. You can't run an RS flywheel with a production 800R or 500ss ECU and get RPM. I switched and put a 500 ss fly wheel on my second XP 700HO... and walla ... I could run the same 23 grams of pin weight with DJ QR11 Helix.

Don't know if that is your issue but... from what you describe it sounds similar to the issue I had. A 600RS is speed rev limited by the short triggers on the RS flywheel when used with a production ecu. I wasted 2/3rd of the season getting over that stumbling block. Again, you don't have to run the 600RS ECU, you can send you current one in and for $80 get it recurved. I am running the hot 700 trail curve in both sleds with the rev limiter removed.

Man I love these two sleds now .. at a recent hill drag, I was running more mph then a good tuned stock 800R on radar.

 

[Wheel House Motorsports]

I am running all the electronics that belong on it currently, they all came off the running stocker i have ran forever, and when i switch the ignition setups i will be going to the full race setup, pickups, flywheel, etc, not going to try to mix and match, and thanks for the reassurance not to!!!

im wondering if the stocker just limits rpm to around 8100 or so which would have been right at the wall i was running into. i guess i was more or less curious before i got wild next season.