rocket256

Ok; I have done more then enough searchs. I have found good info on my topic. Im still looking for more. But: no really hit the nail on the head ( ) a far as what is better for street. Some people swear by 9:1, some swear by 10:1. Keeping in mind that when it is time to go to the track turn up the boost a lil' and not worry. Also is there that much of a difference from 9:1 CR to 10:1 CR if the turbo is a SC-34? Granted that 10:1 will yield out more power and torque then 9:1 at the same psi.

All comments/ .02$/ info is welcome!!!!!!


Modified by rocket256 at 3:30 PM 12/27/2003

0xenocron

I think 9:1 is generally safer, but if your tuner is competent he should be able to dial in a very safe 10:1 compression motor.

mrx

Hi,

that is my problem to, i have a stock b16 and want the car daily driven... but on the track i want to turn on the boost and i'am affraid that the thing blast with a 10,2:1 cr...

my problem is that everyone tells me another thing and thats the problem... i think i must try it out and maybe buy another engine...

Bye
Malte.

rocket256

well I was going to have Autologic in Houston do it.

rocket256

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

that is my problem to, i have a stock b16 and want the car daily driven... but on the track i want to turn on the boost and i'am affraid that the thing blast with a 10,2:1 cr...

.</TD></TR></TABLE>

I agree because I have a B18C.

DRP SHP TECH

10:1 is ok for anything from 8-10 psi with proper timing. if you want the most out of your engine i.e. longevity and power i would go with 9.4:1 to 9:1 comp ratio. some say no 10:1 will make more power but i dont believe that. with proper timing dialed in 9 to 1 will make just as much if not more power than the higher compression.timing maximum cylinder pressure and minimizing cylinder temps is the name of the game.

*Boostwerks*

It's all about the tuning.

If you have a good relaible tuning setup (Hondata, EMS...ect) I would go with the 10:1 ANYDAY.

I'm a big fan of Engines with a high CR, and a large laggy turbo for a street car. You will end up having good power straight from Idle, and the large turbo allows you to stay under 4K RPM for relaxed driving. Then once you feel the need to go insanly fast, just rev it past 4K...

HOWEVER...

If you don't have a very reliable source for tuning...I would stick with the 9:1 for a little more detonation insurance. The benefit from 9:1 is that you can have a little more power from pump gas.

It's all up to you...and what you think would be better for how drive and what you intend to do with the car.

mrx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bryson &raquo;</TD></TR><TR><TD CLASS="quote">
I'm a big fan of Engines with a high CR, and a large laggy turbo for a street car. You will end up having good power straight from Idle, and the large turbo allows you to stay under 4K RPM for relaxed driving. Then once you feel the need to go insanly fast, just rev it past 4K...
</TD></TR></TABLE>

Did i understand you right, that with a high compression engine, a bigger Turbo will spool up quicker than a smaller tubro?!

i personaly running a Garret T3 at the moment and wan't to run 7psi everyday and min. 10psi on the track with a 10.2:1 B16A engine.
currently my t3 is setup up for aprox. 18psi of boost... do you think thats a disadvantage when i run higher compression and less boost?

might be a T25 quicker spool up?

Thanks
Malte.

*Boostwerks*

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

Did i understand you right, that with a high compression engine, a bigger Turbo will spool up quicker than a smaller tubro?!

i personaly running a Garret T3 at the moment and wan't to run 7psi everyday and min. 10psi on the track with a 10.2:1 B16A engine.
currently my t3 is setup up for aprox. 18psi of boost... do you think thats a disadvantage when i run higher compression and less boost?

might be a T25 quicker spool up?

Thanks
Malte.</TD></TR></TABLE>

Hehehehe...NO.

A higher compression engine will spool up a turbo FASTER compared to a lower compression engine with the SAME turbo. It's doesn't matter what the turbo size is.

rocket256

Ok will it be that noticable of a difference from 9:1 to 10:1. After searching some more I found that some people say that you can not feel the difference from those to.

because I have both.


Modified by rocket256 at 5:27 PM 12/27/2003

*Boostwerks*

Every setup is different.

Some people may not feel it because they've pulled a little more timing for the increased CR compared to the 9:1.

If I were to just build a nice car for the street...10:1 would be my choice (IMO).

sharkcohen

I'm very partial to 10:1 myself.

QCKGSR

TUNING!!!!!!!!!!!!!!!!!!!!!!!!!!!!

RenoRacing

I had the same decision to make and I went w/ the 10:1. Figure it's easier to get 15psi out of a kit than 20psi and with the 10:1 it'll make comparable power to the 9:1 at 20psi.

rocket256

So you say high CR + low boost = good power + more torque.
And low CR + high boost = good power + less torque.

JDMs1eeper

10:1 should make more power on lower boost.

9:1 you may be able to get a decent tune on lower octane levels

i dunno... its your plans. Flip a coin

1SlowSi

Well why not go with a 9.5:1 thats my best guess, in between right? I myself was thinking the same thing today. 10:1 will always make more power than 9:1 at any given amount of boost, but how high can you actually go with a 10:1 before you start having problems? 9:1 you can obviously boost a little higher, and some of that being to compensate for the lower CR.

Ri5e

My friends running 9.5:1, made 463 WHP @ 14 lbs with a big fatty turbo on an H22 on 93 octane. He's running 16 Lbs daily ....

11psiTurboSI

I have 8.8:1 on my B16a2 with a Precision SC50 and it spools late has hell ... I don't like it... Next time I'm going with 9.5:1 or 10.0:1cr

danl

I like making as much power as possible with boost, not compression. Boost does more to make power than compression does. Else a high compressin n/a motor would be the ultimate in power. I personally don't have a problem with 8.0:1 compression in a civic or crx. They are light enough that any more low end torque is just annoying at low speeds in my opinion.

1SlowSi

Would the 10:1 CR setup be able to make as much HP as the 9.5:1? just with less boost? I guess that's the question to ask.

rocket256

I have a CTR valve tran and high CR. Now; as for my tuning window is what Im looking at. Is it going to be very small taken the fact of my setup. B18C(rings goin) + SC34 +CTR valve tran + high CR. Also look at its daily driven.

DynamicCK

For a street car, go 9:1. You can still make plenty of power w/ that compression. Its better safe then sorry for a street car. You dont need huge amounts of HP to run on the street, you'll spin the tires easily w/ mid 200's hp. And now horsepower isnt the issue but traction. now if u went w/ a track car, f*ck it. Go 10:1.

intekragsr

simple solution:

power on pump gas = low comp
power on race gas = high comp

xtremehondaex

I'm trying to decide what pistons to go with myself. I have decided to go with the 9.1 CR cuz I think its keeping my options open and has more potenial in the long run. What brand though? JE? JET? never bought pistons before.... kinda lost here...

-Danny