Hey guys, i got the 2010 M8. Run ussually 3000-6000. Running 70 gram weights right now. on flat im pulling 8100-8200 rpm. But as soon as i hit the hill my rpms start bouncing anywhere from 7900-8300?? Even in untouched powder i cant hold a steady rpm.. Anyone else having this issue? or anyone have a explanation as to why its doin this?
2010 M8 RPM unstable
- Thread starter Soly
- Start date
You might be over revving. It sounds like max hp is at about 7900rpm. You should add some weight to bring it down
I run my m8 2010 at 8150 all day long and it don't drop off any on rpm's
H
hatchers
Well-known member
sounds like a stock sled to me
the primary spring is too weak on the finish....its a 140/290 i think....a 120/340-160 will work, get a shift assist also
lol yeah its stock other than a cpc intake and cpc adjustable weights. Thanx guys ill try the Helix and adjust the weights from there.
Try the Spring*** haha
who's dyno chart is this ? cat recomends 8100 to 8300 peak rpm its on the sticker for the clutch and gearing set up. also look at slp dyno chart for the 2010 stock there dyno chart says 8200 rpm
I was wondering this same thing. I looked at D&Ds web site and with their y pipe the peak hp is at 7,950. Why does AC recommend 8100 to 8300?
I'm with Hatchers on his spring recommendation. I've got a 120/340 and I'm using 67 grams in Cutler adjustable weights and holding 8200 up to 12,500 feet. As of right now, I'm completly stock engine wise other than spring and weights in the primary. I've tried more and less weight and max rpm's. It pulls super hard when maxing at 8000 but I've found better riding results when it holds 8200. Also as clutches heat up and you ride it really hard for an extended amount of time, your peak rpm may drop 1 or 2 hundred rpm. Are you still using the stock spring? Any chance it's broken, cause that will effect performance.
The spring doesnt seem to be broken from what i can see, i think i might try the heavier spring, and maybe try throwing some weight in it.
H
hatchers
Well-known member
whatcha mean by "better riding results"??
i get 7900-8000 in the deep and 8150 on the hard.....a sticker on my sled that reads 8100-8300 does not impress me, WTF does it mean, a quality product would have a number not a range.....seems weird
G
geo
Well-known member
Dirty secondary (bushings) will make the RPM wander. One extra spring shim or keep the clutches clean,or put the stock weights back in, will keep it steady but maybe not the quickest.
As for power band peaks and dynos, a safe pipe (read not the best possible for max power) will show big rpm peak swings. Cold pipe lower rpm, hot pipe higher rpm. Combine that with the variables of engine coolant temps and AC programing safeguards and you will see the dynos showing different peaks depending on the operator and their run times and loading technique.
Makes perfect sence to me.
My `10 M8 likes 8050 to 8150 with my clutching and riding. Feels pretty close to torque peak at 8050.
Geo
As for power band peaks and dynos, a safe pipe (read not the best possible for max power) will show big rpm peak swings. Cold pipe lower rpm, hot pipe higher rpm. Combine that with the variables of engine coolant temps and AC programing safeguards and you will see the dynos showing different peaks depending on the operator and their run times and loading technique.
Makes perfect sence to me.
My `10 M8 likes 8050 to 8150 with my clutching and riding. Feels pretty close to torque peak at 8050.
Geo
