i've been searching these forums to find what pistons i should go with, but it really matters what i have on my car, and here it goes...i have a 99 LS b18b motor with skunk 2 intake manifold, aem intake, full cat back, aem fuel pressure regulator, aem adjustable cam gears, and im planning to get the crower cams, the stage II with the valve springs and retainer kit, oh btw i plan on getting turbo in december, will it hurt my car to run turbo design cams without turbo? so please help me out, and yes, i am a noob. thanx guys. -stanson

 

i run arias on my boosted b18b...they are badass. i used to have ross pistons, but didn't have good luck with them....

 

i want to go with FI, which cams will go good with it? i searched and people say are saying you dont want to go low comp for turbo becase all ur doing is lowering the power and getting it back, and people are saying you should get hi comp with FI to get higher power, im not too sure, on which one, can u explain to me why u would go with low comp as opposed to high.

 

stock gsr cams. when we were building a monstrous boosted b-series at the shop i work at.. we ran stock gsr cams. if I were you I would look into endyn roller wave pistons for your bottom end.. around about 9.5-9.7 compression depending on the head.

but the key to all of it is proper fuel management and tuning. thats one part of building a turbo car that you cant cut any corners on

 

yea, you dont want to drop the compression below stock but at the same time you dont want to run high compression pistons with an FI setup either. If you go with a high compression piston on a turbo setup you run the risk of detonation because your using a piston that will compress the air/fuel mixture at a high rate on top of forcing compressed air into the cylinder as well. Higher octane gas helps fight detonation at high compressions but you probably dont want to be running race gas on a daily basis. As NSXtcy21 suggested your probably gonna want to run in the range of 9.5-9.7. Hope that helps, good luck!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NSXtcy21 &raquo;</TD></TR><TR><TD CLASS="quote">stock gsr cams. when we were building a monstrous boosted b-series at the shop i work at.. we ran stock gsr cams. if I were you I would look into endyn roller wave pistons for your bottom end.. around about 9.5-9.7 compression depending on the head.</TD></TR></TABLE>

wouldn't he have to have a vtec head in order to utilize gsr cams?

 

You can run high compression, but the only thing is you gotta get that tuned. High compression just gives less room for error.

getting low compression pistons would allow more room for error when tuning. Dont bother with pistons, save that cash for a quality tune.

 

Before getting pistons i would suggest getting some new sleeves if you're going FI. But the answer to your question, it all depend on how much boost you want, if you're planning on boosting very high like 12psi+ it'll be better to stay below or near 9.5, but if you plan on boosting less then 10psi you might get away with 10.0 compression with good tuning. The reason why you want lower compression on turbo cars is because the turbo is pushing all those high pressure into your motor already to make power during the compression and with the higher compression pistons w/ turbo your piston is already high and by adding more pressure w/ the turbo to it, it will be too much pressure with no room. With higher compression all-motor setup, it doesnt have anything that would add more pressure to the motor like a turbo would, instead it uses wild cam shafts and other NA stuff w/ higher compression piston to make the power. Lower compression pistons save more room for the turbo pressure, higher compression w/ turbo will take some space and could causes denation. This is what my teacher with 45+yrs experience with high performance knowledge told me, " The more air and fuel you can jam into your motor and burn it right, that is what you call horsepower!" So with the lower compression pistons you can push a lot more air into the combustion camber to compress, less chance to denate and of course you would have to build it right, its either straight up NA or FI.
Damn its 3:40am in the morning im trying to think, but i hope that'll help you a little bit. Good luck.

-Bruce


Modified by sPaRk'iT at 3:41 PM 7/16/2005