Top end power?

[RedDesert450R]

If I have an exhaust the is for low end power. How do I get more out of the top end without swapping pipes? I already have the HRC Kit.

[sandmanblue]

I don't know how well the M7 performs, so you're faced with a piston, porting and an intake change to get more out of it. The HRC cam is already a top end cam....

If you don't mind running race gas, buy a 14:1 piston and that will make a world of difference. Stock compression on the 04/05 is only 10.5:1. For every 1 point in compression, you can pretty much add 2 hp. So, you could expect a 7 hp increase for the $250 that the piston will cost. Best part is that the power is across the board - all rpms will see an increase.

[RedDesert450R]

Thanks for the response. So if I change the piston do I need to port the head and change the intake too, or can I just change the piston? If I change the piston will this compromise any reliability?

[nowukno]

Originally posted by RedDesert450R
Thanks for the response. So if I change the piston do I need to port the head and change the intake too, or can I just change the piston? If I change the piston will this compromise any reliability?

I have had my 13:1 JE for almost 1 year and i love it. No other stuff needed just put the new piston in with new rings & gasket.

[RedDesert450R]

Great! What was the cost? Do you have to run race fuel or just a mixture?

[nowukno]

Originally posted by RedDesert450R
Great! What was the cost? Do you have to run race fuel or just a mixture?

The piston was around $140 i think and they recommend running at least a 50/50 mix. I got mine from C&D.

[RedDesert450R]

Thanks for the info.