You can type here any text you want

How Much Boost Without Tune?

Welcome!

By registering with us, you'll be able to discuss, share and private message with other members of our community.

SignUp Now!

TT/Ameasap

The White Blur
Joined
Jan 31, 2002
Messages
5,374
How much boost were you old timers willing to go without a tune? I know this is a weird question to be asked of today, but I always wondered how much the Stock MAF window could take before Fuel was needed.

Over the years, I always thought 1-2psi and then you needed to squish the FPR to squeeze more fuel?
 
The Buick GSX-tra newsletter mentioned if you spent any time at 23 psi boost you would blow head gaskets.
I think that was with the stock chip, injectors and fuel pressure regulator.

I think it boils down to what fuel you're running and what chip.
You would either run out of fuel and get knock or run out of octane.

In '88 I had the ATR Pitbull street chip (92 octane) running 20 psi boost on 100 octane with a slight knock at the 2- 3 shift.
I had a knock detector so I knew how much was too much.

Hopefully you get more answers based on experience than theory.
 
I was at 19-20 psi on 100 octane in 87 . An engineer at the GM plant I work at now , cloned the HyperTech chip and sold them cheap . He also had a set-up with a T fitting that went to the waste gate . The T had a plug in it with a very small hole in it to bleed off waste gate pressure . You would select the plug with a larger hole for more boost . If I remember right I think the bleed hole size I used was around .015" . Never blew a headgasket with this set-up , but you could get the high octane fuel at the pump .
 
What do you mean without a tune? In the 90’s I ran the Bosch Pintle 36/lb/hr injector on a KB hi/lo chip with 110 octane and it would take whatever I threw at it on a stock turbo. Probably mid 20’s. The car ran hard and I crushed hundreds of Mustangs with it. Then I started watching 02 millivolts on a multimeter at WOT and added methanol injection and continued to pound on a lot of cars. The car dead hooked on the street with the original BFG drag radials. 4-5psi foot brakes and flat foot as soon as I let off the brake.


Sent from my iPhone using Tapatalk
 
Back
Top