I know that running higher compression pistons yeilds more power and so does running boost. But i notice that some people that run boost usually run LOWER compression pistons. Why would they want to do that, does the engine explode if you run higher compression pistons and boost together or something?

 

NO,
people just dont generally have the ability to tune their cars (standalone)

I would run 12.5+boost if its daily driver and maybe up 13-13.5 if u run race gass or propane though the motor all the time

Its all about getting the correct tune on your car to utalize the maximun potential out of your car without being unsafe

on my mr2 we went with 10:1 but i run 22psi on pump gass (gotta love the 50trim) however i wish i would have gone higher

if you have the ability to correctally tune your car then i would go high...if you plan to half azz it and run on a stock or chipped ecu and run a FMU or some cheezy setup then stay low compression

 

It's not a simple topic. First, do a search as I recall there was a thread on it.

In a nut-shell, with lower compression pistions you can have higher boost than if you have high-compression pistons and low boost. The usual reason is that having high compression by whatever means (pistons or boost or both) puts the engine near self-ignition/detonation/pinging... a very bad thing.

If you use very high octane gas then yes, you can have both pistons and boost.

Like what was said above, tuning makes an enormous difference, either good or bad depending who's doing it.

 

yeah, detonation....what he said.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ItalynStylion &raquo;</TD></TR><TR><TD CLASS="quote">I know that running higher compression pistons yeilds more power and so does running boost. But i notice that some people that run boost usually run LOWER compression pistons. Why would they want to do that, does the engine explode if you run higher compression pistons and boost together or something?</TD></TR></TABLE>

a friend of mine that is a nissan fan and is very well knowledgeable and have done a lot of auto&gt; manual conversions, engine swaps, engine building, tranny swaps, and even electricals told me this ( everything i said doesnt constitute that he knows what he is talking about, but it helps to justify the validity of his point). he said that boost alone will increase the compression, and having higher compression pistons with it should yield even more power theorectically.

so why do we lower the compression when going turbo? known as a fact, the more o2 you cram into a cylinder, the more fuel the computer will spray in as well at stoichiometric rates. the reason you lower the boost is b/c the gasoline you put into it will only hold up to a certain compression before it detonates.

so how do achieve a safe, but high compression, with the most o2 and fuel you can get into it?
you lower the compression, and you up the boost. this will yield even more power than high compression pistons, and a low boost due to the added air and fuel.

low compression, high boost.
pros: you get more useable power
cons: you waste more gas

high compression, low boost
pros: you save gas.
con: overall power is lower.

 

the only reason people run lower compression is to boost more on pump gas safely. if u plan on puttin in race gas at the track u might as well just go with higher compression. you can still get 350+ on pump gas with higher compression