i know both pistons are a cp and that the venom piston is to mixxers specs and it comes with all the bells and whistles but how do they compare as far as performance? will .5 compression points make that big of difference? i have read a couple articles stating that you won't be able to tell by your "butt dyno". also what if you have a 13.5.1 piston and just take the middle layer out of your gasket kit wouldn't it make it a 14.1 compression piston? not trying to start anything,just trying to see if theres a difference or if i could save some cash since times are as tuff as they are. also one more thing the venom pistom comes with nitrated rings,do the regular cp's come with that also?

thanks guys for the help

here's my take.

The Venom piston is an absolute work of art form top to bottom. I feel it is well worth the few extra dollars that it costs. the way the valve pockets are machined with the venom and the way that relates to air flow is very good for a motor. i'll admit i'm speaking above my pay grade, but i know i was using the 14.25:1 piston with the hr+3mm crank (14.85:1 comp) and hot cams in my yfz and could start my machine with the e start all the time when just about everyone said this wouldn't be possible. i believe the hot cams helped, but also the piston design. again admitting i'm speaking above my pay grade.

back to your question. i don't think it wise to alter a gasket for such a tedious difference. why open yourself up to the potential headaches. that will cost you time and money to gain what? a .25hp on a dyno. no way. If you already have an "ebay special" cp piston laying on your bench and you saved a bundle getting it than by all means use it with joy. but if your buying new, get the Venom.

last point is John (mixxer) gives tech advice unlike any human i know on the planet. he has access to his own dyno and knows what all these components can do. that is worth something. quite frankly, it's priceless! just my $.02

If you want a thinner gasket pick up a cosmetic gasket. The thinner gasket will give you a tighter squish and helps with the mixture and burn of the air/fuel charges.

Being you have the 04-05 bike i would go with 13.0 or 13.5 piston and spend the extra coin on decking the head to shrink the combustion chamber. 13:1 and .030" off the head is a real good running combo. Put in a thinner head gasket and she'll be a good running machine.

The decking will also slightly retard the cam which works very well with the HC2.

when you get some time... check out some of the pinned threads i have on compression and piston details...

there is a lot more to power production from piston design than just the static compression ratio... :)

there's more to a piston than just the given compression points.

the way it disperses oil and lubes the pin, and most importantly the weight (while maintaining strength) and the flow, due to specific valve pockets and patterns..... there's more to it than that but believe me, the venom may be made by CP, but it's no shelf CP piston. never was a truer statement than, "you get what you pay for".

there's also more to it than 'butt dyno'. there's the response and snappiness, which the venom does a great job with, imo. this comes back to the flow design and weight.