PDA

View Full Version : Piston Upgrade?


4LEAFCLOVER
06-12-2005, 07:07 AM
What's the biggest size piston you can upgrade to without having to run race gas or 93 octane or better in the 450R?
http://img.photobucket.com/albums/v651/tavaresclover/100_0686.jpg
Jersey450R
06-12-2005, 07:22 AM
12:1 prolly.
cals400ex
06-12-2005, 08:36 PM
the size of the piston won't matter nearly as much as the compression ratio of the piston. the cam you run has a lot to do with what compression ratio is safe on 93 octane. on a stock cam, 12:1 probably isn't safe. with a HRC (a lot of overlap) you could actually run around 13:1 on 93 octane.
4LEAFCLOVER
06-13-2005, 07:23 AM
Hey thanks alot fellas for the info. I'm running a stock piston now with the full HRC kit so I'm guessing I would be okay getting a 12:1 piston. Any suggestions on which brand to go with? And will changing this piston out along with getting a full exhaust make my 450R go any faster?
cals400ex
06-13-2005, 07:58 AM
oh you bet. a good full exhaust and a higher compression piston will help a lot. i am not sure what brand of piston to tell you to get. a 3 ring piston will be more durable in the long run but it has more friction. the 2 ring piston will have less friction and will rev quicker. but it will be a bit less durable. i don't know enough about either one to tell you which way to go.
dtzalba450r
06-13-2005, 11:30 AM
If you're running the hrc cam then a 13.1 can be used with 93 pump gas if you want to be safe mix pump gas and race gas or straight, fresh pump gas. The je pistons can be shipped to your door for like $150.00, I'll be getting mine in by the end of the week!
trost66
06-13-2005, 09:00 PM
I have sparks aggressive drop in cam and a 13-8-1 piston and sparks said nothing under 112
HUNTSALOT
06-13-2005, 11:35 PM
I have a 11:5.1 that I could sell you it will help you alot with your HRC kit. You can run pump gas with this piston. I looked into all this before and I know its bad to go any bigger then 11 and run pump gas.
4LEAFCLOVER
06-14-2005, 06:15 AM
Hey fellas thanks alot for all of the reply's. Your info really helped out alot. Hey HUNTSALOT, what brand is that piston and is it used or brand new and how much do you want for it? Just hit me back via this thread or via e-mail at tclover1@cox.net. Thanks again fellas.