88 305 TPI
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Car: 1988 Pontiac TA
Engine: 305 TPI
Transmission: 5 Speed Manual
Axle/Gears: 3.43:1
88 305 TPI
I am new to the forum and just purchased a 1988 Firebird Trans Am with 39K miles, 5 Speed Manual and 305 TPI. I hope this is the right section of the forum. This car is 100% original so any changes need to be easily reversible. My question is if there are any simple ways to add power? (Note: my state does not do emissions tests on 20+ year old cars).
As far s I know, the cat has been gutted (I have the original) and Flowmaster exhaust are the only items changed. Any suggestions? Power is OK for daily driving but need more anyway. (Is there ever enough?).
If I decided to to any major changes (remove emissions, change heads and cam) or such, does it hurt the value? I see these cars holding or slightly increasing value over the next 5 years. Thanks
Larry in CT
As far s I know, the cat has been gutted (I have the original) and Flowmaster exhaust are the only items changed. Any suggestions? Power is OK for daily driving but need more anyway. (Is there ever enough?).
If I decided to to any major changes (remove emissions, change heads and cam) or such, does it hurt the value? I see these cars holding or slightly increasing value over the next 5 years. Thanks
Larry in CT
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Car: 1988 IROC Z Convertible
Engine: 305 TPI (LB9)
Transmission: 700 R4
Axle/Gears: G80 GU2
Re: 88 305 TPI
There’s a dyno from a guy with a 305 Automatic with 2.73 rear end who had a stock motor and exhaust but switched the cam to an LT1 cam.
Those 305 auto TPI 2.73 cars supposedly had only 195hp, but this guy got about 225hp just by switching to the LT1 cam.
The other problem with the 305s is the heads. They don’t flow as good as the L98 heads. If your car blows a little blue smoke on startup and you need the valve seals done, you might as well get the heads ported and polished. It’s not great to switch the heads to the L98 ones since the 305 needs the compression that those heads give.
The TPI is actually better matched to the 305 than the 350 so you might as well leave that stock.. (and it looks so cool)
My 87 5-speed I had back in the 90s could beat my friend’s 96 Camaro SS which was rated at 305hp and did 13.3 1/4 mile time. It had a cam from the previous owner and a power pulley with the smog disconnected. He also told me he bumped the timing. When I got the car it appeared stock and was slightly quicker than my friend’s twin 5.7L
-I had the heads done when I got my valve seals fixed,
-had a hollowed cat with Flowmaster exhaust
-cut out the air box and MAF screens and installed K&Ns
-switched the chip to a Hypertech thermomaster
-installed a 160 thermostat
-centerforce dual friction clutch
-Hurst shifter
-upgraded suspension and switched to poly bushings
-MSD Ignition, Accel wires and supercoil
That car was a G92 and had the performance 3.45 axle.
I don’t know that I’d cut or modify anything you can’t put back to stock. If you have the factory exhaust and it’s not rotted out I’d keep that stock too, but basically you can get a lot more power getting the car to breathe better, get the exhaust out quicker, and beef up the cam and heads. That way you can make noticeably more power and not ruin the looks..
There are people that use power adders like turbos and superchargers and can put the car back to stock anytime as well.
There’s a lot of folks that probably have all types of other advice as well..
Those 305 auto TPI 2.73 cars supposedly had only 195hp, but this guy got about 225hp just by switching to the LT1 cam.
The other problem with the 305s is the heads. They don’t flow as good as the L98 heads. If your car blows a little blue smoke on startup and you need the valve seals done, you might as well get the heads ported and polished. It’s not great to switch the heads to the L98 ones since the 305 needs the compression that those heads give.
The TPI is actually better matched to the 305 than the 350 so you might as well leave that stock.. (and it looks so cool)
My 87 5-speed I had back in the 90s could beat my friend’s 96 Camaro SS which was rated at 305hp and did 13.3 1/4 mile time. It had a cam from the previous owner and a power pulley with the smog disconnected. He also told me he bumped the timing. When I got the car it appeared stock and was slightly quicker than my friend’s twin 5.7L
-I had the heads done when I got my valve seals fixed,
-had a hollowed cat with Flowmaster exhaust
-cut out the air box and MAF screens and installed K&Ns
-switched the chip to a Hypertech thermomaster
-installed a 160 thermostat
-centerforce dual friction clutch
-Hurst shifter
-upgraded suspension and switched to poly bushings
-MSD Ignition, Accel wires and supercoil
That car was a G92 and had the performance 3.45 axle.
I don’t know that I’d cut or modify anything you can’t put back to stock. If you have the factory exhaust and it’s not rotted out I’d keep that stock too, but basically you can get a lot more power getting the car to breathe better, get the exhaust out quicker, and beef up the cam and heads. That way you can make noticeably more power and not ruin the looks..
There are people that use power adders like turbos and superchargers and can put the car back to stock anytime as well.
There’s a lot of folks that probably have all types of other advice as well..
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