I've done a search on this and have gotten a lot of great info form all the Raptors. But I can't find any info on how much low end I'll have. I have an EPI clutch kit for large tires, 26" Titan 589s, and jetted/muffler/filter so now I lookin at a Wiseco 11:1 High-Compression Piston(not a big bore) and HotCams (Stage 1) cam. I've read that the cam is great at mid and high range, but lacking in low. That's where the piston comes in, right? But will it be enough? I've heard that HotCams is looking at doing a 660 Grizzly cam for low end, but one of the reasons I'm lookin at a cam is so the Grizzly doesn't fall on it's face on in high range, but I still want more low end then I have now. Will the piston give me that?
My next question is about my valves. I've heard that a lot of 660s are having problems with valves and head damage caused by weak springs. I have a late model 02 and I'm wondering if I should replace me springs with some Kibblewhite Springs that are recommitted for the Stage 2 cam to prevent the damage. ?

 

Anybody?

 

I am not sure about the accual spec the the typical four stroke should behave the same. With the bigger cam you do loose low end becase they valves are opening up later, with this you will probly want a set of stronger lifter springs, or do the 660's have those? The higher comprssion piston will add some all round power, and may take up some of the low end that was lost. Even though, it would be hard to get it all back. With that big of tires and an after market clutch, you should have no problem lugging that beast anywere. Be ware, with that high of comprssion, you will be puttimg more strain on the crank, may want to check into a crank.