1980 Turbo Trans Am

[ben47xbox]

Hey i'm new here, and just have some questions. I'm getting ready to start on my T/A and was just gonna get some input. First off i'll tell you my plans, I wan't to keep it looking original but i want to put in an LS3 Crate in it. I don't know what tranny to go with, i need an automatic so my dad can drive it. and i was wonderin if anybody knows what gears would work in it, i'm thinking a 12bolt chevy but if anybody thinks a ford 9" would be better tell me why. I won't be swapping gears it will be a pro touring car, not a dragster. and i'm thinking about making a three link suspension or fourlink. anyway thats all for now let me know what you guys think out there.

[andrewb70]

Welcome!

I suggest you look in the Project Update forum and read through some of the build threads. Your questions about transmission, gear, and rear end selection has been covered by many people and many builds.

Andrew

[NOT A TA]

Welcome! Like Andrew said have a look around in the different sections. Questions like "12 bolt or 9 inch?" lead to personal preferance replies where more specific questions with lots of background info about your car and expectations will get more specific answers related to the function, ease of install etc. for your application.

Always nice to see another 2nd gen come aboard! Post up some pics if you have them.

[Takid455]

nice to see another fellow t/a. search around the forum to find answers to your questions as they have been asked before. here are my thought based on the info provided.

I prefer to keep them poncho powered, but its your car. Your stock 10 bolt will handle the crate LS3 without problems. Maybe add an aftermarket posi (tru trak) and some 30 spline axles if you want to modify it. Weld the axle tubes to the center section. A nice leaf & watts link setup will hang with the best of them. no need to spend $$ if you dont have to. a 200r4 will fit and give you an OD. gears from 3.23-3.73 will suite your application nicely. Of course, if you want to go nuts on the build..skys the limit. there are afew 2nd gens in teh project sectin for ideas.




where the 'wink' smiley????

[79-TA]

Welcome aboard! Any modern electronic transmission (4L60 and such) will require that you make your transmission tunnel larger to accomodate it. If you do go that route, one of the new 6L80's would make for an amazing combination.

The 9 inch vs 12 bolt argument seems to be summed like this: the 9 inch is stronger, but less efficient than the 12 bolt. I say the 12 bolt should be plenty of beef and it'd keep your car more GM.

What gears you use all depends on what transmission ratios you have. You might also consider the older 4 speed automatics (700R4 and 2004R.)

Any overdrive transmission will allow you to easily run 3.42's with a very low freeway cruising rpm, assuming your wheel-tire combo isn't ridiculously small. Good luck with the project!

[ben47xbox]

thanks guy's, i'll take a look around here and see what i can find, i like hearing from other car guy's. I'm a bodyman by trade and the mechanical end of things is a little harder for me. luckily the T/A is in good shape and won't need much body work. I just don't want to stick with the turbo 301, 3-speed. it's kinda pathetic expecially without the turbo on it. It still runs very good, but not as good as I need it to. I will just have to check out everything and see whats right for me i guess. Thanks again, and keep comments comeing.

[WS6]

Keep the 8.5 10 bolt if you can build your suspension around it. It's very strong when built correctly like TAkid says.

Since you're looking at an LS3, you should stay with a trans that the PCM can control. That will give you better tuning abilities than going with anything thing else mechanically controlled.

Welcome and good luck. Start a project thread when you can.

[critter]

I'd disagree on enlarging the transmission tunnel for an electronic transmission. A 4L80e will fit and I've been told that the 4l60e will fit.

Welcome to the forums.

[MonzaRacer]

As for the keep it real theme, take a 6.0L add in a 3 in stroke crank(302)L92 heads, keep it FI, add in a turbo(aka turbo TA), use a beefed up 4l65E and paddle shifter set up, switch to a good LSD centersection, some Moser axles, a good rear preload cover and its road racing at its best.
And dont ever let anyone tell you an 8.5 or 12 bolt or even an 8.2 diff is weak. Local machinst ran a 400 Pontiac, large by huge Lunati cam, Crane Superflow heads, banging a 4 speed and never lost an axle, most shrapnel came from cheaper branded(street only) ring gears shedding teeth after season of running a 400 cube engine/4 speed in 11 1/2 lb class(*ie thats 11.5 lbs per cubic inch(thats 4600lbs!!!!) all with a 8,2 inch pontiac 10 bolt!.

Just an idea.

[ben47xbox]

Thanks again, I think the idea of taking a 6.0 out of a gto would be good, keepin the valve covers pontiac.lol. My only prob with turbo on LS anything is cost. keep ideas come'n.

[HIOSILVER]

as the rear goes is it a ws6 with rear disc if so keep it i have a ta putting 500hp and the rear has done fine.

[ben47xbox]

Yes it is a ws6, although i put regular snowflakes on it instead of ws6 snowflakes, for looks. What motor do you have put'n 500hp, HIOSILVER?

[MonzaRacer]

Why s ogun shy of turboing a lsx. Cant be too hard when a guy pulls an upgraded one off a turbo TA and actually just made it blow through the stock intake, he simply added in a 4 bar map and upgraded the computer to handle boost, less than a grand in whole conversion,,, it only made 4 1/2 boost till he got bigger turbo,, but it ran awesome for low boost.
If its 8.5 10 bolt with disc, get a preload cover and some good synthetic gear oil and maybe add in some good axles after engine is nearly done.
I also have made a few lsx 327s with 3.25 stroke cranks in 6.0 blocks, they used L92 heads and had cheap hot rod engines.

[BanditDave]

Welcome aboard! Any modern electronic transmission (4L60 and such) will require that you make your transmission tunnel larger to accomodate it. If you do go that route, one of the new 6L80's would make for an amazing combination.

The 9 inch vs 12 bolt argument seems to be summed like this: the 9 inch is stronger, but less efficient than the 12 bolt. I say the 12 bolt should be plenty of beef and it'd keep your car more GM.

What gears you use all depends on what transmission ratios you have. You might also consider the older 4 speed automatics (700R4 and 2004R.)

Any overdrive transmission will allow you to easily run 3.42's with a very low freeway cruising rpm, assuming your wheel-tire combo isn't ridiculously small. Good luck with the project!


The first statement here is untrue. I have a LS1 4L60E in my '78 TA...no tunnel mods necessary. If I can take a pic of the darn thing when it isn't raining out I can show you. I definitely agree though that the 6L80E would be an amazing tranny swap in these cars...first gear is ridiculous in those things!

The ten bolt rear is more than sufficient for something in as much as 450 horse if you aren't running slicks. At that point a posi, gears and axles are a wise decision.

As many of them said, there are a TON of things available for these cars now...PM me or post up here if you have any questions. TONS of info available!

Take care and good luck!
Dave