I have a couple of ? to ask.I don't know much about high Compression piston.I know stock Compression is 9.2:1.I was think of go with one at 11.1 .What kind of power and performance would i get from that?I was thinking that it will give me great all around HP.I was looking at the new DirtWheels Mag and saw in the back of the mag where it says hotstuff They have JE Raptor piston kit for $154.00 is that a good piston kit or what other kinds of piston kits are out there that are good.one more thing how much you think a dealer would charge to put in the piston kit.What are they cazy Z-400 BEAT the Raptor in the shoot out.Suzukl must be pay off the people from DirtWheels.

 

Big55- The JE is good! Dealer will charge at least 250 to install plus ream you on gaskets etc. JE also sells gaskets for the raptor.

 

I can't give you exact numbers, but I can give you my "guesstament" from what I know about the Rap and 4 strokes in general.

Regarding HP increase when "JUST" upping the comp from 9.2:1 to 11:1, probably 2-3 hp. More importantly, you will probably get twice that number in tourque 4-6 ft lb, which is good.

When using a higher comp piston you will notice most of the increase in the bottom end, which if your a trail rider, would be good for you.

JE is a good piston and is used by many of the top 4-stroke engine builders across the country. Although, many of these same builders will have JE custom make the pistons to that particular builders certain specifications.

Regarding what a dealer will charge you for labor, I can't say. I'm sure the price would differ from one to another. I would suspect they would charge atleast a couple hours worth of labor, so? What are the going rates now for dealers, $50-$60 per hour?

Also, don't forget to include the price of new gaskets too!

If you decide to do this or have your dealer do it, make sure you have them look at your valves and the seats of the valves. The Rap is prone to go through seats very quickly and has a tendancy to beat the valves up pretty bad. If the valves themselves look like they have some damage to them. I sugest you change them with stainless steel valves, which are much more durable (reliabilty), but more costly too.

 

my drag times dropped from 6.10 to 5.56 with my set-up.(read below)and contrary to popular belief it is the stock bore.

 

Thanks guys 4 info.

 

I agree with SWYTAK, $50-$60 per hour would be a good guessing range to figure for the labor plus gaskets, and go ahead and figure in valve replacent just in case(better to be expecting it).

One thing though. I talke to Trinity myself, and they said they would be glad to sell me a high-compression piston, but (and I quote) " Unless you have some work done on the head so it will flow more air and flow better, you probably won't gain any more power, infact you might even lose a little."

This may not sound correct, but that is what they told me, so I took their advice and have decided to wait until I can get it ported also, and replace the valves.

If this is infact a false statement, please correct me. Thanks.

 

I am currently running a JE piston without a cam or head work. I can tell you adding the piston did make a noticable difference, mostly felt on the bottom end as stated before. My bike was apart getting the 02 gears at the time, so I decided to drop the piston in. Money well spent IMO!

 

So that statement is not actually correct?, Thank you

 

ryen- I would say a piston by itself would improve somewhat but probably not worth the money to do by itself. Now port and polish the head, cam it and shove that piston in it.[img]i/expressions/face-icon-small-happy.gif[/img]

 

I am looking into it possibly. Until I broke down and bought a pipe, and then vilnrk hooked me up with some info, I really didn't think the raptor could be as fast as it is now. And now is nowhere near where it can go. thanks