Im playing with the idea of adding a Trans am 4.9 turbo well turbo and putting it onto my 82 firebird, I know i will need to change the pipework and probably intake but does anyone know if doing this will actually work ? I cant find many pictures of a Turbo trans am detailed enough to see how its done. Can anyone help with saying what things i would need to change to make it work.

Any help will be fantastic or even a site i can look at to find the info i need ?

 

Yes, you can make it wor, however there are many other options for the turbo unit that are more efficient. Intalling a turbo requires a system approach, it will not be a bolt-on deal. Plan on some fabrication work.

Start by reading the turbo books: 'Turbochargers' by Hugh MacInnes, 'Maximum boost' by Corky Bell and 'Street Turbocharging'

 

yeah ive done work with turbos before but on JAP cars the older V8s should be simular idea but was wandering what type of intake id need ?Maybe one from an original TA turbo but again will that fit a 305 ?

 

No, the 301TTA manifold won't fit your 305. What intake you need depends on many things, but first and formost is this going to be EFI or carbureted? If carbed, blow through or draw through? Like I stated above, you are going to be building from sqaure one, so you have the freedom to choose which route you want to go.

 

This Chevy Truck has a 350 with a TTA turbo on it.

http://www.youtube.com/watch?v=rQpsan-9plw

 

It will be a carb set up, Im going to try and copy the original TTA setup.
Ohh does the TTA have an intercooler ? I cant seem to find one on an pictures i have and because im in England i cant find any TTA to go look at for myself which sucks to be fair.
So what would of the original setep of done ? draw i suppose, Ideally id like to keep it simular to the original setup, Would this involve custom pipe work or are there any parts i can get of the shelf to help fit it?

 

Sounds like a cool project, I was thinking of doing the exact same thing a while back with my '82 TA. The setup is a draw through carb, and the original 301T was not intercooled. You will need to get motor mounts for the 301, and I believe it was offset which is why there is a bulge on the hood to clear the air cleaner. There isn't much aftermarket for the 301T, you can upgrade the carb to a holley, but as far as better intakes...I don't believe their are any. as far as the pipe work goes, to a template in PVC pipe, then have a muffler shop re create it. Here is a site with more 301T info:
http://home.ripway.com/2005-1/240165/301shrine.html

Oh, there was also I guy I talked to a while back when I was thinking of doing this project, and he was running 12's in his '80 or '81 TTA with a pretty much stock motor. He told me all the mods he did, but unfortunatly I lost contact with him. So far there hasn't been anyone telling you not to do the project because the motor is junk, which is surprising. This engine has potential if you are willing to make it work

 

The turbo motor in the old Trans Am used the horrible short-deck 301 Pontiac V8 motor. Nothing will fit a Chevy V8, if that's what you had in mind. If you want to drop the whole engine package under the hood of your 3rd gen I suppose it's possible (with a lot of work), but you'll still have stock 350 TPI cars blowing past you when you're done.

If you're going turbo with a carb I'd suggest a kit to fit your 3rd gen, or go with an even simpler blow-through centrifugal supercharger setup. Cheaper and you'll go faster in the end.

 

If you really want to do the turbo I would suggest the chevy motor with a custom /home made turbo set up. It would have much more potential. That is unless you are stuck on having a Pontiac motor.Then go with a 400. The only difference in the block size is the 400 has a 1" taller deck. Now a 301T can be made to run if you want ,but don't expect a strip killer. Not unless you want to go real custom ie: billet crank,forged chevy rods and pistons along with custom made intake. So if you plan on doing the fab work great. If not, buy a Viper. It will be cheaper. They can run 12's and 13's with some work. Camshaft,turbo mods, and exhaust mods. Neil Smedley is who you are speaking about and I can put you in touch with him if need be. He set the class record for his division in NHRA. Don't get me wrong I'm all for doing something differen't ,after all I have a pretty modded 301T Pace car, but if you want more ultimate power potential cheaper then go with the other powertrains.

 

I done it on a 89 camaro.Pm me and i can give you the details.

 

Just watched the truck vid.After all the flaming i got,it looks like i might've started something.

 

The turbo isn't optimal for making super power sure, but for a stock motor it'd probably work very well since the displacement and N/A HP are similar. How much past low-mid 200 hp it'll get you is an issue of speculation since the size/hp parameters are the same as the N/A motor. Theory says that draw through cools the air charge with fuel, however If you actually use it as designed I'd be looking into methanol injection. You can not use a draw through setup with an intercooler because of puddling issues with the fuel. If you used the turbocharger in a blow through configuration however, intercooling becomes a non-issue. If you already have the stuff my thoughts are go for it, if not get a different turbocharger or turbochargers to use in a blow-through configuration.

 

True ,but you used a Chevy motor. I think he wanted the Pontiac motor. So he could keep it all Pontiac. Still no one here saying don't do it. Something differen't is great. Just don't expect to go 11's with that turbo set up. Not ganna happen. It would be cool to see it though under the hood since your cars has the turbo humpjust like the 80-81 TTA cars.

 

You'd be surprised

 

I already know. Not gonna happen with the bone stock 301T turbo. I should know I have a very modded 301T. 12's yes. 11's needs more exoctic work. Unless you can show me and Neil Smedley(NHRA record holder) and a couple of us other 301T die hards something new?

 

what exactly did you do with your engine? I didn't know you had a modded 301T. I would be happy with 12's with that engine, that's a major improvement considereing what it runs stock.

 

I must've misunderstood then.But how he wrote it "Trans Am 4.9 turbo well turbo and etc...", i figured he meant "Trans Am 4.9 turbo,well the turbo anyway".

Oh and thats an old pic of my car.Ive cleaned it up alot since.Looks and performs alot better now.

 

You know, lets start with that it’s basically a 60 trim T3 turbo, which will only really push about 300-maybe350hp worth of air at higher boost levels. The original cars, considering the et’s and mph’s that they ran and the weight of the late second gen cars were probably making around 190hp at the crank. That takes into account the induction (carb…) setup and the turbo…

Whether you rigged it up to work on a 305 chevy or left it on a 301 poncho, your limitation will still be the turbo, the available airflow, meaning that you’ll never have a fast setup without a bigger turbo, carb… basically reengineering the whole deal, and if you’re going to go that far you might as well go blowthrough instead of drawthrough (will give you a much greater choice of turbos…).

The one interesting thing is that you will make that power at whatever rpm that you get the turbo spooled up enough to pump that amount of air, looking at a T3 60 trim chart…, it will move the most air at a pressure ratio of about 2.25:1, or about 18psi.

Assuming that we’re talking about something roughly 5L (305, 301…whatever), to get that airflow at that boost level at 85% VE, the engine would have to be at around 3000rpm, and this is where things get interesting… assuming that you tune the rest of the setup to actually do this, and actually match the parts in the engine so that the hp peak actually came at about that rpm and that you were able to control detonation at that level, you’d be making roughly 640lb-ft of torque at that point, and all though the engine power would fall off quickly after that, most of the usable range of the engine would have torque numbers somewhere in the 600lf-ft range as long as the turbo is spooled.

Stupid torque numbers do tend to = stupid fun on the street, and does make for a car that feels very fast off the line (this thing would be a terror from a stop light, but even with the best gearing and matched parts would never run faster then a mid/high 12 in a light 3rd gen)

 

That is an interesting way of looking at it. That is how I went about choosing the two 45 trim, .48 A/R turbine T3s for the bone stock 1986 305ci TPI with TPI stock log manifolds in the 4500lb truck. Stock TPI is about 92% VE at 3200 RPM, at 10 PSI intercooled that is about 470 ft-lb of torque....not bad for a 305ci which I am told can't make any power.

What do you have to lose? Try the 60 trim T3. Just make the turbine flange and orientation such that you have room for a T4 turbo if you want to go faster later on.

 

83 Crossfire brings up some important points. In reality the T-3 turbo for the 80-81 TTA's is pretty small. It will ONLY flow so much. Yes the design of the 301T is of a LOW rpm beast. Meaning you have to get it all in early as the head and intake design run out of steam early. At most 4500-5000rpm. So yes it's a bottom feeder. The most boost I know of that has been run out of the stock turbo is 20 psi , but that resulted in blown head gasket after a couple of runs and really didn't make any difference in times from running 15 psi. Reason being that at max capacity you really get less true usuable boost. If you want the best of both worlds it would be a T3/T4 combo. You still get the down low spin up , but also get some more breathing up top. Really when those cars were produced that particular turbo was too small., but we all know how GM l likes to save $$ and just throw what ever out there. . In stock form those cars were really strangled. So it's understandable about thier bad rep. I agree that a Blow-thru set up would account for easier install, as the draw-thru requires some ackward carb mounting. Really just a point of where you are going and what you like.


Someone asked about the mods on mine which include complete custom hand made exhaust. All mandrel bends and I mean every piece of pipe like intake pipe and redsigned down pipe with 2 1/2" diameter. Custom ground Isky Turbocycle camshaft. Original turbo polished along with a special trim wheel built John Craig if Limit Engineering. Roller rockers, 700r4 trans and some other small stuff. Every little bit helps. This year I will have ALKY injection and a new carb done up by Jet performance. My current carb as always give me some problems that I just can't see to fix. That and the computer set up for the 81 is so slow and antiquated. That may go away soon.

Back to the original topic I've seen a picture somewhere on the net with a 301T in a third gen so it can be done. Just take it's draw backs into consideration when building it so you are not disappointed. I did it because I want to see how far I can take the stock internals , intake and heads. Then I will move to the next level.

 

Heh, it’s all about getting the right numbers in the right places…

Are you sure about that VE at 3200? I’d expect the tpi to actually get max VE at around 34-3600rpm… I’ve considered slapping one of the TPI’s that I have sitting around onto my K1500 blazer, but driving it around, it doesn’t see over 2500rpm unless I’m really beating on it, and the TPI is a bit lost below 3000rpm. Instead I’m adapting a modified old crossfire setup to mine which makes monster torque just off idle, but I expect to be all done by 4000rpm.

I’ve also had similar ideas about building up a turbocharged 305 to replace the 350 when I wear it out… seems like the obvious answer… get the boost in soon enough and you have more torque then you realistically know what to do with, the 305 can be built to do much better mileage wise then most v8’s, and add boost in specific areas and you can save mpg by not having to downshift…

Though my current truck tinkering was served a bit of a wake up call when I destroyed the rear gear in it last month. 3.42’s + 8.5” ring gear + 33” tires you can still find the torque to strip all the teeth off the pinion.

 

When you think about it, it’s really an obvious approach for Pontiac to take to build a performance car with some respect for MPG. Traditionally poncho engines are all about low end torque, and are usually done by 5000 or so rpm, so why not take that same basic layout, make it lighter, take away some cubes and add the torque back with a smallish turbo?

The problems with this (and a lot of similar vintage designs that caught a lot of flack from the owners and was because no one at the time knew much about the care and feeding these oddball setups. Well, that and it was somewhat a primitive beginning to modern engine controls.

Yea, it will fit… besides the obvious mounts and bellhousing bolt pattern issues, you’ll run into exhaust issues with the poncho’s W I D E oil pan.

 

Brother you are the first person I have run into as of late that UNDERSTANDS the real issue of what those and other early cars had to go through. Instead of just implying that the are junk because you don't know how they work. After all the TTA's and early Turbo buicks(same design) paved the road for the later GN's and so on. It was a neat idea ,just the excecution and technology was not quite there yet. When you have a TTA and tear it down to go through it, you really wonder how that thing even moved at all with the restrictions it was hampered with. Every time I took something off and studied it during the resto I just shook my head.

 

Considering we're talking the years of the 180hp 350 in the Corvettes, 200hp in ANY factory engine was a pretty big deal. Probably one of the reasons people think a 305 is a dog too. Yes it's overall limited by bore size, but at the same time most of them came with swill gas compression, small port heads and tiny camshafts.