z6 motor, rebuilt, crower rods, stock sleeves for now, cp pistons and a garrett t3/t4, hondata, injectors
-->now if i were to use 10psi and 11:1 c.r. i would get a 18.48 effective c.r.
-->if i used the lower c.r. of 9:1 and 15psi i would get a 18.18 effective c.r.
the higher static c.r. will allow mush faster spool up time but the lower statis c.r. will be less likely to detonate. how much is detonation a big problem? i dont read too many topics about detonation not being curable with tuning...so is it a good idea to use a higher c.r?or not? the S2K is 11:1 cr and they do it all the time!!
ALL OPINIONS WELCOME

 

first vote! well, from what i have read here, a lower compression ratio is desirable because it allows a larger margin of error. the tuning window is larger with a smaller c/r and more boost, as opposed to a higher c/r and less boost.

basically, the setup becomes easier to tune, and less prone to blowing up when you make a mistake

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdmsiR20 &raquo;</TD></TR><TR><TD CLASS="quote">first vote! well, from what i have read here, a lower compression ratio is desirable because it allows a larger margin of error. the tuning window is larger with a smaller c/r and more boost, as opposed to a higher c/r and less boost.

basically, the setup becomes easier to tune, and less prone to blowing up when you make a mistake </TD></TR></TABLE>

yeah what this cat said!!!

 

I'll be bulding mine pretty soon for 10.5:1 and higher boost as well.

Lower boost is just a shitty idea IMHO. If you're going to spend the money to do it, spend the money to get it tuned well.

A car with a higher CR off of boost will be faster with less boost.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ricey McRicerton &raquo;</TD></TR><TR><TD CLASS="quote">I'll be bulding mine pretty soon for 10.5:1 and higher boost as well.

Lower boost is just a shitty idea IMHO. If you're going to spend the money to do it, spend the money to get it tuned well.

A car with a higher CR off of boost will be faster with less boost. </TD></TR></TABLE>

i agree 100%, why even try forced induction if you dont run over 10lbs???

 

because 8PSI will still give me a bit more "umph" on my D16Z6?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dyzee &raquo;</TD></TR><TR><TD CLASS="quote">because 8PSI will still give me a bit more "umph" on my D16Z6? </TD></TR></TABLE>

If you just want an 8 psi umph get nitrous, it's a hell of a lot cheaper and a hell of a lot easier

If you go turbo crank that boost 15 PSI

 

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

If you just want an 8 psi umph get nitrous, it's a hell of a lot cheaper and a hell of a lot easier

If you go turbo crank that boost 15 PSI </TD></TR></TABLE>


STFU, bro.

damn you guys are harsh. Well your really going have to calculate out which setup with yeild more power and also put more stress on your walls, piston-rings....

On a dseries I would do lower psi (9.1:5) since it already has a crapy r/s ratio... hehe


Boost is good even at 5psi... start out small amount then slowly crank it up.
Don't instanly turn into a boost-attic..... you'll messup and burn out quickly

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ricey McRicerton &raquo;</TD></TR><TR><TD CLASS="quote">A car with a higher CR off of boost will be faster with less boost. </TD></TR></TABLE>


Ans spool faster+ have more power when out of boost

 

When choosing a C/R for boost you need to decide what kind of fuel you plan on using. If its going to be a daily driven car and you get to crazy with the compression you'll be stuck running low boost or having to mix with race gas, which gets pretty expensive. But if your looking for big hp numbers for x amount of boost the more cr the merrier.

My vote 9:1 (streetmotor)
10.5:1 (drag motor)



Modified by Rusty Shackleferd at 2:33 AM 4/9/2004

 

9:1.

Higher compression will really not spool faster, that 95% myth. It just feels better, because it makes more power out of boost.

It also makes less power in boost, don't forget that people.