89IROCZZ4

Does anyone run this? If so, how much boost? I have been talking to people that say don't run anymore than 6 psi but the ads from ati say 9lbs of boost because of intercooling. This also has a 3 core intercooler, by the way. Images are here:





[This message has been edited by 89IROCZZ4 (edited December 09, 2001).]

maniacc

89IROCZZ4,

The ads from ATI do say it's okay to run 9lbs of boost on a STOCK 9.3:1 compression using no less than 92 octane.
You are far from stock compression at 10:1 with your ZZ4.

Personally i would lower your compression to 9:1 by either replacing your pistons with a set of dished blower pistons(forged) or by replacing your cyl. heads with cyl. heads that have a bigger combustion chamber, either way it will be costly, but cheaper than if you blow up your engine

You do want you want, but i would do alot more research and talk to some of your local speed shops and see what they have to say.

later
larry

------------------
MÅN¡ÅÇ ©
88 IROC 5.7 TPI
ATI procharger D1sc 10#'s boost, edelbrock TES, complete MSD ignition, Borla cat-back, KB subframe connectors, accel 24# injectors...and a few other go fast goodies

Best E.T. 13.417 @ 106.89 mph on worn out street tires
http://maniac.megamania.com

[This message has been edited by maniacc (edited December 09, 2001).]

Dan91Z

heck.. just use 100 octane then :-)

89IROCZZ4

lol...I would if they offered that at gas stations! Well, with my engine having a 10:1 compression ratio, what would the highest psi I could run? I have a feeling I won't be able to spend anymore money on the car whatsoever after this...sooo...should I sell my superram, keep the stock tpi and get better heads or what? Maybe just run 7 psi? Help is greatly appreciated!

Here is something I found from the L98 F-body page for ATI's:

"However, because intercooling removes the heat which causes detonation, intercooled boost is so reliable that you can safely run up to 15 psi of engine-friendly intercooled boost with full timing, virtually no threat of detonation, and without any band aids."

I also found this:


It looks like I would be fine from this graph - if, after looking at this graph, and you still have problems w/it, please let me know. Thanks for the reply!

[This message has been edited by 89IROCZZ4 (edited December 09, 2001).]

PETE

iTrader: (1)

just my .02 in order to get that cr down to where you need it(a rough est. is 1cc=around .1)that means you'd have to go to a 68cc combustion chamber.keep in mind that when you go to a larger head like that you destroy the quench area of the combustion chamber.going from 64cc's to say 58cc's tightens up the quench area which isn't that bad.and since you are planning on force feeding it this might wreak havoc on the burn rate and cause improper combustion events.just because it's rated for 9 psi doesn't mean it will push 9 psi.the 9 psi is the restricton the air has to overcome on a stock motor.by adding a better flowing intake(superram)and better heads(l98's are still better than the cast iron's as far as intake runner volume goes and the aluminum castings help with octane tolerance)you may only be able to push 6 or 7 psi with that setup anyway.in any rate you'll definately need to see what the o2 sensor is telling you,not to mention if the ecm is pulling out any timing(which means a scanner or laptop to tune)93 octane should get you started then you could always tweak the prom to increase the pulse width and take out some timing for higher in the rpm band where detonation will really hurt you under boost.

Dan91Z

hmm.. there's 2 gas stations within 5 miles of me that carry 100 octane

maniacc

I agree with pete, if it were my engine, i would keep the superram, and replace the pistons with a dished blower piston, this should not hurt the quench area as bad, plus the piston is forged (can withstand some slight detonation), and the ringlands are usually lower set on the piston crown. all are good insurances when running a forced induction unit.

plus you probably don't want to run 100 octane all the time at $3.50 a gallon.

later
larry



------------------
MÅN¡ÅÇ ©
88 IROC 5.7 TPI
ATI procharger D1sc 10#'s boost, edelbrock TES, complete MSD ignition, Borla cat-back, KB subframe connectors, accel 24# injectors...and a few other go fast goodies

Best E.T. 13.417 @ 106.89 mph on worn out street tires
http://maniac.megamania.com

vortecfcar

I dont know how accurate that graph is. My dad was running a roots blower at 6psi on his zz4 without problems on 92 octane. That graph shows that he should have blown that thing sky high