possible boost leak

specops_SC

Registered User
ok. i have two questions:

1)i have a bone stock 90 AOD SC with 134,000 miles on it. if i stomp on the gas from a stop, the boost gage will jump to 6-7 then slowly climb up to 10 psi around 4000 rpm's but it wont go higher. is this normal? i remember hearing somewhere that if it climbs like that there could be a vacuum/boost leak somewhere. arent these cars supposed to run around 12 psi stock?

2)what can i do to help my engine react faster to having the gas pedal pushed in? mine is really bad. i hit the gas and you can hear the intake suck in the air, then the engine revs up. it takes almost half a second or maybe more before the car launches. i dont know if this is normal or not but any help would be appreciated.
 
#1 Sounds normal for a car that age, but you may improve it a little by removing the air silencer. The gauge isn't very accurate either.

#2 Start with 3.73 gears...how far you go from there depends on your goals and your budget.

David
 
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If you suspect a boost leak, I'd get tbird88's intercooler gaskets. (Look for the Texas Thunderbirds banner at the top right of the screen) I didn't suspect a boost leak as I was getting a strong 12-13 lbs of boost. Installed his gaskets and picked up 2 lbs of boost and fixed the off-line hesitation that I've had a big problem with in the past. Most vacuum leaks occur at the intercooler pipe joints. Particularly as the engine mounts become worn and there is more twist to the engine under load. But like Dave stated, those guages aren't that accurate to begin with. And age does start to play a big factor in the performance of the cars.

And yes, gears will make a big difference in you acceleration. And of course, open up the intake and exhaust. That will increase power. Look around on the boards and you will see a host of things to improve your SC.
 
all right. thanks. i hadnt even thought to look at the intercooler pipes. thanks for the heads up on the gaskets.
 
ok. i just put in tbird88's ic gaskets. went a lot smoother than i thought. however, im still peaking at a little past 10 on the boost gauge. it gets there a lot faster now though. the ic pipes had absolutely nothing sealing them when i tooke them off so i figured id see an increase in indicated boost even if the gauge is inaccurate. i've already clamped several hoses around the rear of the sc. btw, i found out i have an exhaust leak today. dont know how big. could this be the problem?

p.s. i removed my hood liner and my sc is a bit louder now.. god i love that sound.. :D :D :D
 
yea.. it is isnt it? i can launch at about 8 lbs which i love cuz all my friends have turbos. it's nice knowing that they're still spooling up.. cant wait for that whipple.. :D maybe i just need a blower rebuild to help me get higher boost numbers..
 
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