DAVE Sz

iTrader: (2)

I keep hearing that you should lower the CR to 8:1 or 8.5:1 when boosted but I barely see anyone here with lowered compression. I know a few guys do but most I don't think are.

mtcookson

iTrader: (2)

i have low compression pistons however they came with the engine. if you're wanting to go with high boost you'll want low compression pistons, however... if you are good at tuning you can actually run high compression and high boost. i've heard of cars running something like 12:1 compression and still pushing 20+ psi of boost. its all in the tuning.

jkklim

i believe turbo95max has lower CR pistons also

maxlinegtr

iTrader: (3)

u know where and how much it would cost to do CR pistons

jkklim

http://forums.maxima.org/showthread.php?t=255096

meccanoble

iTrader: (22)

stock compression pushing 10 psi....

DAVE Sz

iTrader: (2)

Really? I heard the opposite. Running 8:1 or 8.5:1 is supposed to be optimal for boost. The chances for detonation are very slim and you get most power from that. That also makes using street gas safer.

desertmaxima

iTrader: (5)

Uh nope those are mine already, the whole thing, block rods and pistons. Will be in my garage in about a month.

jkklim

congrats, but i just wanted to give him an idea of how much it costs

Stephen Max

iTrader: (59)

Low CR is good for high boost, but may not be optimal for what you want. The lower the CR, the less responsive your car is going to be at partial throttle. The engine gets very mush feeling and you only have good power at WOT.

I like keeping the stock CR and limiting my boost. That way I have a car that feels great driving around town but still has some ***** when I need it. Some day I might raise boost and lower the CR to 9 or 9.5:1, but not any lower than that.

mingo

iTrader: (4)

9:1 is a good compromise. aks turtle what he's running.

HitManSE

iTrader: (1)

IMO, id say no lower then what mingo suggested. Its not like your going to go out and run 20+psi but with a 9:1 you should be safe to run as high as 15 or so.

What really matters is how strong your bottom end is, you can run 10.1:1 compression pistons with 15psi, but thats only if your bottom end can handle it. It would be great if you can build your bottom end & get stronger rods...which reminds me that the 3.5 bottom end does fit into the 3.0block does it not

That combined with 9:1 pistons might just be a good budget build to satisfy to boost happy guys on here. Especially the turbo guys. Just a suggestion.

matty

iTrader: (54)

Your pretty much safe running a 10-12 psi supercharger kit on stock CR correct with 130K miles on the engine with good compression ??

-matt

HitManSE

iTrader: (1)

Shouldnt be much of a problem, besides the S/C isnt pumping out 10-12 psi until your pretty much near or at redline. So your only boosting a few psi on the low end, so if you drive like a sane person 99% of the time your not putting too much excessive stress on the motor.
The turbo however is a diff story, depending on the turbo it can reach full boost as early as 2.5K so your putting the stress of boost on the motor from that point on. So a turbo is definetly harder on the motor.