im currently running a y8 head and z6 block with a y8 headgasket which is pretty thin. i dont know what my compression is but i know i should lower it if im going turbo. are there aftermarket headgaskets that are thick? and how thick should i go to lower the compression to fit my turbo? its going to be garret t3.

 

Here you go bud.

http://www.knology.net/~jediklc/D.htm

 

SCE makes a d series .062 im useing it on my stock a6 block and head and i come out to a 8.85 cr and im going with about 9 psi so im in the gold.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHCV-TechRider &raquo;</TD></TR><TR><TD CLASS="quote">Here you go bud.

http://www.knology.net/~jediklc/D.htm</TD></TR></TABLE>


wow sweet site! thanks man!!! im at 9.4:1. how low should i lower it to so that turbo will love it? about how thick of a gasket would i need?


where can i get a SCE headgasket?

 

im using a cometic...i like it and it comes in many different thicknesses...got mine at nipponpower.com

 

1. you don't need to lower your compression

2. turbos "like" high compression motors

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by infinatenexus &raquo;</TD></TR><TR><TD CLASS="quote">

2. turbos "like" high compression motors</TD></TR></TABLE>


er??

 

the higher your compression the less lag yo have. People use lower compression to compensate for a lack of tuning.

 

in other words... lazy?

 

Hes right. High compression and turbo works great. You just better be ready to really feed that baby and tune her well.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crashtest Sonny &raquo;</TD></TR><TR><TD CLASS="quote">in other words... lazy?</TD></TR></TABLE>

that, and scared

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by infinatenexus &raquo;</TD></TR><TR><TD CLASS="quote">the higher your compression the less lag yo have. People use lower compression to compensate for a lack of tuning. </TD></TR></TABLE>

Not only that but you wont be a dog in the lower rpms and lowering the comp is just taking away power that you have to make up for with more boost. And that whole "tuning" thing.

 

ahhhhhh i c i c. all i read about is how much people lower their compression. so i think lowering the compression will be better for turbo.

 

It simply allows for a larger margin of error. Running a higher static CR lets you get the same power with less boost than a low static CR running more boost. Just a very general figure off the top of my head, I read that a 9:1CR motor running 10psi makes the same power as a 10:1CR motor running 7psi. They both equaled the same effective compression(static + boost). Plus the 10:1 has a broader powerband.

 

Your Cr should be good enough for Turbo 9.1 or 9.4 is right on.

 

sweet! tahts some good news for me!

 

there's less of a chance of detonation with a lower compression motor...that's why people are quick to say "lower your compression when doing turbo". it really isn't that a higher comp motor will blow up into flames, its a little saftey thing.

lowering compression lowers power...

-cody

 

thanks. i guess ill be leaving my compression alone then. what kind of power would i be expecting to get? would raising the psi be any safe? or its better of changing the internals?

 

All this is true but do any of you have or know how much is involved in tuneing a high compression turbo motor??????
Unless you have full acess to a dyno and have tuned manycars and have an awsome engine managment setup i would deff stay with the low compression.

low compression is also less stress on your motor why strain your motor when you can let your turbo (which is 1/4 the cost of your motor) do all the work for you?

high compression is very unreliable and is deff the route that should be taken for a everyday driver imo.

bottom line even experienced engine tuners have trouble tuneing and maintaining high compression turbo setups its deff not a easy route to take unless you have a ton of forced induction experience.

 

Dude.. the guy is at 9.4-1... thats hardly "high compression"

 

i never said he was

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spun Vtec &raquo;</TD></TR><TR><TD CLASS="quote">i never said he was </TD></TR></TABLE>

 

so is that consider normal comp? leave it or lower it? my mechanic keep telling me to lower it to about 8.4:1.

 

find a new mechanic

 

so whats the reason most factory turbo cars have 8.4 or below compression?

btw, if you're going t3, you'll probably get some lag, so the 9.4:1 cr will help you out when you're not in boost.

but if you want to be safe, get a cometic hp gasket.