1980 Indy 500 TTA

[Radge]

I have a 1980 turbo T/A. 4.9 V8 301 with the garrett tb0305. I am only getting 5psi off the turbo. I have shortened the wastegate actuating rod as much as possible and removed the vacuum line (vent) below the actuator which gave me 2 - 3 psi. (If I lengthen the rod psi drops exponetially).

just to be clear (as i wasn't) i only get 5 psi AFTER i removed the vent and shortened the rod.

I tapped into the actuator's inlet to run a boost gage. It does not come stock with a boost gage only 3 lights (low, med. High) 2 of which do not light anymore.

Anytime I ask someone they shake their head and say I cant help you or just swap that motor out for a 400. Well I just want to keep it original as much as possible and no one wants to help. No one has seen a TA like this, let alone want to work on it. I even went to the Pontiac dealer, and they could not help!!! Useless, needless to say. I bet if i had a GN it would be a lot easier!!!

Here are my questions:

I think I should be getting between 9 psi and 11 psi, how can I troubleshoot the problem? (Vacuum lines are good, turbo is working, wastegate actuator is new).

Carb. is new vaccum non-electric (exact match Q-jet from GM), new coil, new springs, plugs, cap, wires, rotor, altenator, belts, vaccum lines, set timing, etc.

Having a choke problem, cant seem to set it right it right. Takes a long time to warm up but once it does, no stalling or hesitation.

Will a rebuild kit (bushings, seals, etc.) help restore my boost or is it not worth it as opposed to trying to locate a new one? Is there any other turbo's that can be substituted since this one is hard to find.

The boost lights do not light up anymore. Bulbs are good, I think it is because of the lack of boost pressure. At what psi intervals should the boost lights activate? Normal is on all the time, how much psi for the medium light and high light? Again people I talk to say "I doubt this model turbo make the gage light up." Well why would it be there if it was not possible? Plus, I know it used to light up years ago, but the response I get is "that's impossible" with this car. Well i know it is not the fastest motor, but it aint bad.

To be honest, I can chirp the tires when it shifts from 2nd to 3rd and so on. Brake stands too. Once again not a GN, but not too shabby.

Hopefully someone can help and not tell me to rip that motor out and swap it for a 400. As of yet no one has helped. so i guess all I can say is
HHHHHHHHHHHHHHEEEEEEEEEEEEEELLLLLLLLLPPPPPP!

Thanks in advance!!

Roger

 

[Roc87]

Can't really give you much help, but I test drove an '80 Turbo and all 3 lights on the hood lit up. Took a while, but eventually they did. There's a few guys that have some fast older birds, maybe they can help.....

 

[1badTTA]

I would start with your exhaust, if you have an exhaust leak like mine did, then you wont see much boost. Second is the cat, if you still have the old flat bead type, it is a major restriction that will also limit your boost. (go for a test pipe if you change it)

The other thing is try running your boost gauge off the manifold, I was able to get 9psi bone stock with a mild exhaust leak that limited it to 9psi.

Also check your turbo and make sure it is in good shape (the last thing to try, not the first) and spins freely and doesn't blow lots of oil. Make sure there isn't excessive endplay.

Also, if it is running extremely rich, your turbo won't spool for crap.

The best place for advice on your car will be the "Before Black" section of this board as they are the ones that run the carb'd turbo engines.

 

[webleyaz]

I know two guys with those 301 ttas. One guy lived out in the sticks where pack rats had taken over his muffler making his slow car extremely slow. Little or no boost, bad gas mileage, fire hazard, etc. The other guy had exhaust leaks at the heads that I'm sure were larger collectively than the wastegate opening and he had no boost, ever.
Can those things run more than 9PSI w/o exploding?
BTW, both of these guys are currently different than stock motors. Best thing for 'em, really.

 

[1badTTA]

Chris, Those things are just like any other turbo motor, if you don't detonate them, they won't explode. 12psi is possible with good exhaust, and I have seen 15psi but it was a timebomb.

 

[Radge]

Flowmaster

I am going to attempt a removal of the Cat's guts (appearance of a cat, basically a straight pipe). i had dual flowmasters put on recently. any thoughts on that? what do you think- good, bad, ugly? next step is to check clogs in the turbo's exhaust, etc.....

hey you guys are a big help. no one else i have talked to cares!!! keep the ideas coming!!!!


Radge

 

[2QUIK6]

As mentioned above, I've heard of tons of people blowing head gaskets very easily on those motors. The key is to not let it detonate. YOu may want to investigate the possibility of a standalone type of knock gauge/detector for tuning. I test drove at least half a dozen '80 Indy Pace cars before I ended up finally buying my current 10th anniv TA. They are very sharp looking cars, and all the ones I drove, all the turbo lights lit up on the hood. Also, and as a car ages, less and less people know what they are or know how to work on them, especially the dealer, I think they only know how to work on cars that are less than 10 years old. Even with a GN, no one knows how to diagnose and work on them. Try locating some other tech forums that specialize in the 80 series TTA's, a good one I use for 2nd gen TAs is www.performanceyears.com and go to the tech forum.

 

[Radge]

clog/leaks

check turbo exhaust and intake piping. No blockage found.

I have a detonation sensor on the motor that seems to work just fine. but i do not know how to officially test it. that part is still available from the dealer for $100. i would rather not replace it unless mine is not functional.

does anyone know if i have an O2 sensor? i cant find it. Maybe they satrted in 81 with all the other electrical advancements......

 

[2QUIK6]

Does your knock detection sensor cause a light or gauge to display something when it detects knock? If so, you can test it by taking a piece of pipe or crowbar and tap the block with it near the knock sensor and it should register several degrees of knock or if a light, it should light up when detecting knock.
As far as an O2, I don't think any cars had O2s until the advent of fuel injection or electronic carb.

 

[Radge]

knock knock

theres no indicators to my knowledge. now if it is working fine maybe i just never saw the light, but in all the manuals and diagrams i have never seen any kind of knock indicator. i know i cant hear a knock, but that does not mean it works.

any other ideas?

 

[2QUIK6]

I was thinking of an aftermarket type knock detector, like the one www.casperselectronics.com sell for the GN and '89 TTA. You can always check with John at Caspers and ask him if it would work on the 80 TTA's. The spark control on those cars was the first of its kind for GM and is not real realiable. He may be able to make one for you, he's very knowledgable when it comes to electronics so he may have some ideas. But I'd definitly look into getting something to help notify you of knock because if the knock is loud enough to hear, then you're getting well over 7-8 degrees at least which is way too much for that motor to take for very long.

 

[smooth87]

i have an 80 tta, i pulled the engine and swapped in..... oh wait..