Clutching suggestions for '10 M8 10,000' riding

[Jorgy]

I posted this in SW as well.....

I ride in the Snowies mostly (10,000+). I tried the AC gold spring which is great at dropping the initial engagement. Now my problem is the top end. I could only pull 7,850-7,900 rpms. I'm running the stock 68g weights. My only mods are a y-pipe and can from D&D. I think my culprit is the gold spring since it's lower on the top end (275 vs 290). Any magic spring out there that'll give me both lower engagement plus keep my peek hp more in the 8,100-8,300 that it's supposed to run? Should I be dropping weight? I know my chart says to use 63g at that elevation, but will I get my top end where it needs to be. I've also got the yellow white spring I could try. Someone mentioned an SLP spring (I think it was) that is 120-310. Maybe that's worth a try.

[metaltwister162]

i think that i would try and drop your primary weights down to closer to the chart that is on the sled and see where that gets you. I know that my 08 M8 loses a lot of power once you start going over 9k feet and if I dont drop weight off my primary i cannot pull the rpms out of it. still pulls but not like it should be.

[dmkhnr]

Drop a little weight and add a stiffer primary spring.
My 10 is running 67# at 7-10k and will barely hold 8k r's. I've got a 340 primary spring coming, and would drop another gram of weight, except that the slp pipe should be coming this week so I'll clutch for that.

AC says to run 63# for your altitude!!! 66# and the stock spring might do it for you.

[Jorgy]

Originally Posted by dmkhnr

Drop a little weight and add a stiffer primary spring.
My 10 is running 67# at 7-10k and will barely hold 8k r's. I've got a 340 primary spring coming, and would drop another gram of weight, except that the slp pipe should be coming this week so I'll clutch for that.

AC says to run 63# for your altitude!!! 66# and the stock spring might do it for you.

I have the yellow/white AC spring, so I might try that. I'm worried that the 63s are too much of a drop from 68s that come stock.

[dmkhnr]

I ran it today with 2' of heavy fresh.
SLP blue/pink and 67# weights. It held 8100+ all day long. Very impressive, completely different sled when the r's are singing.

[newtrout]

Originally Posted by Jorgy

I have the yellow/white AC spring, so I might try that. I'm worried that the 63s are too much of a drop from 68s that come stock.

There are a few other options out there. The D&D white is rated at like 130-330 or something, but it has a lower engagement than the AC yellow-white. Acts like a 100-300, which is about what you're looking for. Speedwerx makes a 120-310 and 125-340, which are also a bit over-rated compared to AC springs. In my opinion, you'll have more consistent RPMs if you stick with heavier weights and a stronger finish spring. Don't drop to the 63s if you don't have to.

[Jorgy]

The other thing that throws me a little off is that I put a D&D y-pipe on. Their web site claims that peak hp with the y-pipe is at 7,950rpms. I've also seen a dyno chart of a stock CFR 800 and it peaked at 8,000 or less (I don't remember the exact number). Why does AC say to run 8,100-8,300?

[dmkhnr]

SLP pipe will be here Monday, they say 8200.