Hey,

I was just wondering what effect would be had by changing my stock piston to a 10:1 or a 10.5:1 higher compression piston? What else has to change along with the piston? Is there much of a gain by changing just the piston?

Any opinions welcom [img]i/expressions/face-icon-small-smile.gif[/img]

Thanks,

Trev

 

i noticed a big diff in mine but i have a much higher comp than that and i did all my
mods at the same time

 

Half a point of compression, not much at all. Sure you will pick up some power, but very little. It's hard to do just one mod and pick up a bunch of power. To get more O2 to the engine you have to do a bunch of mods at the same time to work well.

Look at it this way, if you put a big carb on to flow a bunch of air, you still have a stock pipe and cam with restrictions.

Nitrous and super/turbochargers are two exceptions to the rule.

 

Yeah, I figured as much. Not really worth it to me.

 

plaining the head will get you farther power wise then going to a 10.5

 

Planing the head is not really a good idea on a 4 stroke (timing chain). More compression actually compresses air and fuel more for a more efficient and powerful burn.
Gary

 

RULE OF THUMB FOR 4 STROKERS >>>>>1 point of compression is worth about %.04 in power ( torque). So if you have 20 LB FT of torque going up 1/2 point will give you almost an extra 1/2 LB FT!!!

 

HP is a form of torque. If you are gaining torque at any RPM, you are gaining HP. More compression is almost always a good thing. Some 2 strokers do not like too much compression because the RPM ceiling is lowered for that application.

 

HP = torque(lbs-ft) x rpm/5252

So if that rule of thumb is true about compression .. then going from stock compression on the warrior at 9.2 up to a 10.5 is a gain of 1.3 ...

20.3lbs-ft stock .. I would gain roughly 1.05 pounds of torque. Which, at 6000rpm equates to ... 1.2hp at the crank.

What about reliability issues? And where rougly would I be I wonder once I've installed my new filter, rejet correctly with my FMF pipe? Questions questions questions [img]i/expressions/face-icon-small-happy.gif[/img]

 

Reliability? Any time you ask more from an engine (power wise) reliability will lower.