whats this mean exactly.

[Screamin99]

I hear people all the time say im gonna up the compression in my engine just a lil bit..

I ask if it will help it in any way they say yes some but not alot depending on how much or something..

what is it am I able to do it? and how do you do it?

[Mogobs30th]

That all depends on what you are trying to do with your car. "Upping the compression" means basically someone is taking the stock 9.4:1 compression of a 3.8l, and changing it so it will be higher, to say for example, 10:1. By changing the compression to either higher or lower, you change how the air/fuel mixture in compressed withing the combustion chamber, resulting in either a bigger or smaller "explosion" within the chamber. You can change compression by milling heads, thicker or thinner head gasket, longer or shorter connecting rods, custom pistons, things like that.

I could explain a little better if I knew what exactly they were doing to your engine.

[Screamin99]

you got it with what your talkin about!! by going from 9.4:1 to 10:1.

I was thinking going to 10:1 or 11:1 but do I need to change things or what?

['94firebirdv6]

if you want to stay NA you would want to up your compression. however if you wanna go forced induction, you actually need to drop your C/R because a lower CR allows you to run a higher psi of boost without detonation. most boosted applications run a CR of about 8:1 or 8.5: most NA CR are around 9.4 upt to 12:1

[Mogobs30th]

Originally posted by '94firebirdv6:
if you want to stay NA you would want to up your compression. however if you wanna go forced induction, you actually need to drop your C/R because a lower CR allows you to run a higher psi of boost without detonation. most boosted applications run a CR of about 8:1 or 8.5: most NA CR are around 9.4 upt to 12:1

I didn't want to say this because this is a VERY common misconception. By dropping the compression, it HELPS with detonation when applying boost. BUT, you can raise compression and add boost, seen it done many times on a few V8 engines, just never been done on a 3.8l to my knowledge. If you have the right equipment, resources, and knowledge, then applying boost to an engine with a raised compression is possible, without the detonation. Now if you factor in driveability, street legallity, light to moderate internal work, on pump gas, then no, I wouldn't raise compression on a boosted car.

If you plan on keeping your car NA, then I think 11:1 is possible, you will have to do a helluva tune on that PCM, or order one that will suit your needs. Running on pump gas will be iffy at best, might have to go with a higher octane than what can be provided at a neighborhood pump. I am also not sure about how you will get 11:1 compression. I can't see thinner head gaskets and milled heads being enough, you might have to get a custom set of pistons made for that compression, but I could be a little off with that.

[98Camaro3.8]

If you really wanted it, the ZZP stroker kit gives you ~10.2:1 with stock heads. Milled heads and thinner gaskets would raise that even more. But I think it's more work/money than you realize.

[tdz16]

TURBO IT!!!

[tWiStEdBird]

Originally posted by tdz16:
TURBO IT!!!

Everyone has a turbo now. Procharger! [img]tongue.gif[/img]

[T-Punk]

Not everyone has twin turbo though ;)

[Screamin99]

Just seems like to much money to do all this stuff. seems as tho now that I have drove some V8 Fbodys and stuff that it would be easier to do the V8 swap or wait and sell it and buy a V8 car?

because I have no Idea about the HP Tuners and DHP stuff I just dont really understand the products how you get them and stuff. Mainly I want the best bang for the buck.

also how does one go about upping compression, say to 10:1 and if you did what do I need to do to my Engine and if anything what kind of gains will I pick up?!?

[Ender2664]

Just to give you an idea of how important tunning is in the equation, i have friends with nice little honda motors that are running around daily driven with 12.5 CR...they just have DAYS of tunning to make sure everything is perfect. You need to make sure that when you are going to the max that everything in your car is set up so that it can take it, or that one little part IS going to go, and with it the whole engine.

[Screamin99]

alright so how do you up your compression?

[98Camaro3.8]

Originally posted by Justin B.:
alright so how do you up your compression?

Thinner head gaskets, milled heads, stroker kit, etc. If you're asking questions like that, it's probably not a good idea to do such a serious mod.

[stuffy236]

Originally posted by Mogobs30th:
</font><blockquote>quote:</font><hr />Originally posted by '94firebirdv6:
if you want to stay NA you would want to up your compression. however if you wanna go forced induction, you actually need to drop your C/R because a lower CR allows you to run a higher psi of boost without detonation. most boosted applications run a CR of about 8:1 or 8.5: most NA CR are around 9.4 upt to 12:1

I didn't want to say this because this is a VERY common misconception. By dropping the compression, it HELPS with detonation when applying boost. BUT, you can raise compression and add boost, seen it done many times on a few V8 engines, just never been done on a 3.8l to my knowledge. If you have the right equipment, resources, and knowledge, then applying boost to an engine with a raised compression is possible, without the detonation. Now if you factor in driveability, street legallity, light to moderate internal work, on pump gas, then no, I wouldn't raise compression on a boosted car.

If you plan on keeping your car NA, then I think 11:1 is possible, you will have to do a helluva tune on that PCM, or order one that will suit your needs. Running on pump gas will be iffy at best, might have to go with a higher octane than what can be provided at a neighborhood pump. I am also not sure about how you will get 11:1 compression. I can't see thinner head gaskets and milled heads being enough, you might have to get a custom set of pistons made for that compression, but I could be a little off with that. </font>[/QUOTE]i hate to keep posting with links to the grandprix site, but this is also a good read about FI with higher compression: http://www.clubgp.com/newforum/tm.as...mode=1&smode=1

[Turbo V6 Camaro]

i have been running a ~8.5:1 N/A for 2000 miles, i havn't dynoed n/a yet but i know for a fact the my car is stronger then it was... also i have head works and a cam wicth lets more air flow and make up for the c/r loss.....

now my city milage suck A$$ major A$$ i got 16 MPG if i'm lucky.... but highway milage when i drove from ohio to florida was 33-36 MPH

also if i just drive around base and the 2 minute drive from work i get about 100 miles a tank :eek: :eek: [img]graemlins/rofl.gif[/img] [img]graemlins/rofl.gif[/img] yah she's running a bit rich right now...... lol