Nate Jung

Hey guys. Me and my dad are about to pull the engine out of my 91 Trans Am GTA 5.7L in the next few weeks to replace the gaskets, rod bearings, and such due to a slight engine knock and a vacuum leak. (We caught it early so don't worry). We are about to pull the engine and I wanted people's input on what the best ways were to increase power once the engine is pulled. Willing to spend a few hundred or so. Thanks!!!

Orr89RocZ

iTrader: (20)

Update the runners and base with big tube tpi stuff or delete tpi entirely and go a different efi intake

A cam really wont do a whole lot for the money especially still using stock tpi. Could do 1.6 rockers on stock cam to make a few more hp

83 Crossfire TA

iTrader: (2)

the problem is "a few hundred..."

TPI upgrades will cost more than a few hundred unless you find a good deal used. A cam, if carefully chosen can work with what you have, give you the advantages of the 1.6 rockers + cam timing that will make more power for "a few hundred" but to really take advantage of it you're likely talking about at least tuning, and likely springs and related that will take that few hundred up a few hundred.

If you can do it yourself porting the heads will cost nothing and can add quite a bit. If I was going to pick one performance upgrade to a 5.7 car while the engine is out for "a few hundred" it would be a torque converter and possibly a shift kit, that will make more of a difference in how the car feels and runs than any of the other performance mods listed here. If the car doesn't have headers already then they'll be pretty much necessary for you to get much out of any of the performance mods we're talking about.

If it's more like $1000, then I'd start with the converter and the cam, porting the heads if you can. The rest of this can be done without pulling the engine or trans and can be added later.

Orr89RocZ

iTrader: (20)

X2 on torque converter with 2500-2800 stall

And i did a cam only plus long tube header L98 that only made 226 whp 330's wtq. Torque was strong but i was hoping for more hp. Stock L98's with exhaust mods cars have done 205-230 whp so not sure the cam really does alot.

Hell my L98 with stock cam and 1.6 rockers with a stealth ram made 254 whp.

83 Crossfire TA

iTrader: (2)

I'd go higher on the converter stall (I like a 3200), but that's just me, and I guess I'd only be doing it if I was going to spend money on a good lockup converter.

Stealth ram is not a bad option... cheaper than upgrading runners and crap on a TPI.

Cams are a tough one with the TPI intake. You need something that will try to make a torque peak right in the mid 3000rpm range and then there is enough airflow in the runners/base to make close to 400bhp. The head is the restriction as soon as you mess with anything there which is why I was suggesting porting. Really, things are so well matched between the throttle body and the exhaust port that if you're going to mess with anything there you might as well mess with everything because whatever you don't touch will become your restriction.

How fast did 226hp go in that car?

Orr89RocZ

iTrader: (20)

Do not know. I dont think the owner ever took it to the track but certainly would have been in the high 13's based on how my old L98 ran, but he needs a converter.

Cam i believe the machine shop picked out was a comp xe 218/224 .495/.502 or something like this. Sounded good, might have been 110 lsa. Felt it was a good cam, i just did the tuning