View Full Version : How much boost did you lose?....

11-14-2005, 02:13 PM
Just wonderin how much boost you guys lost when you put on a set of ported heads and/or a cam.

I am running about 16psi at 4K so I don't think I lost any boost. I'm also running a stock IC though.

David Neibert
11-14-2005, 02:26 PM
I didn't loose any. I'm on my 4th cam and boost was about the same with all of them.


11-15-2005, 09:59 AM
according to previous owner , mine went down almost 3 with the exhaust ( 5% OD gave it back ), which is basically straight pipes, im putting back some ok flowmasters on it though.

heads are ported, gasket matched, but saw no loss with that.

runs 12-14 PSI.

Blown 91 Bird
11-15-2005, 11:03 PM
from what i have read, stock 91's usually make like 12lbs of boost. Since the motor in my car was blown up when i bought it i dont know what it made with untouched heads & lower intake..

but right now i make on average 9-10lbs, so i guess i lost 2lbs or so from opening up the heads & intake. But who knows if the stock guage is even telling the truth.. i will find out for sure when i finally actually put the autometer guage i have sitting here in.

11-15-2005, 11:10 PM
I'm running only 12 pounds of boost on a stock 92 M90 with a 10% OD pulley.
I'm using a stock NA Cam, Stock SC heads. But I do have shorty headers and true dual exhaust.