Im debating on gettin the piston and cam setup, along wit the tit valve kit of course, and dont know which cams are best. I see Web Racing cams- 110, 109/110, or 109 grind and the RWR cams - axtell, wood9, and wood7. What are the differences between them?
The only pistons i see are the RWR CP piston and the MR H JE piston, i would like to be able to run pump gas so im debatin between the stock compression or 11:5:1. Any reports on those that have these pistons would be greatly appreciated.

 

If your looking to run pump gas another option is the Mr HP trail kit. 11:1 piston and mild cams. Does not require aftermaket springs or buckets. THere are several on this board running this setup with good results.

 

The main thing is what kind of riding you do and what rpm range you want the power to be.

 

Well i think the tit valve kit is a must, if im gonna run over 8500 rpms at anytime i dont want to be worried about my valves, since i have the RWR cdi box.
Im mainly lookin for low end build up, acceleration is more important to me then top end, you can have the fastest quad in the world but if it takes an hour to get there it aint no good. Id like a crazy low end pick up with mid and top improvment as well, i dont want to lose any power along the band ya know.

 

I believe this is more a gearing issue then an engine design.

This is engine design, cams and head design have a huge influence of what the power band looks like. Sounds to me like would like a smooth linear power band with a lot of torque just off idle.

When you say pump gas, what octane is that? Here in S. Cali, our highest pump is only 91 octane.

 

I'm right along with him on this question. Wanting the same results. The highest pump we have here is 91 as well, As for gearing, I don't want to lose any top end, and end up winding out too fast. Like Nick said, biggest increase in the bottom end and mid, lessening off towards the top end. 11.5-1 comp piston should work, but the biggest confusion would be the cams..... which cams do what and for what rpm range?

 

How about stock cams with a 11.5-1 piston?

 

I run a 11:1 piston on 91 octane and it runs great. I did hear a light ping a couple of times after a fast and furious ride. It was around 98 degrees outside and I was in the sand. I think that is about some of the harsher trail riding out there. So now if the temps climb above 88 degrees, I splash in a little race fuel to raise my mix to 93-94 octane. Never happened again.

Now the temps are down, I run straight 91. 11:5 compression and higher has got to pushing the "cheap gas" especially if it warms up outside.

A couple of us run MR H trail cams and piston. They pull like a freak on tweak, top to bottom. I believe they produce peak power around 7,000rpm where as the stock cams stop around 6,300rpm.

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High compression and piston are (IMO) the best mods for the DS. You won't believe the power gain.

Basically, the more aggressive the cam, the more it acts like a two stroke (less power down low but, more power on top).

Decide what kind of riding you do and choose the set-up for it.

The higher the compression the more you off-set the losses down low from an aggressive cam.

If you ride at higher altitudes, you may be able to get away with a little lower octane on a higher compression piston.

Trail riders usually prefer less aggressive cams. . . Hill shooters generally look for more aggressive cams.

I suggest the valve springs.

 

The valves aren't a problm, i want high compression pistons, but unsure of what cams