TURBO TOO BIG? Slow/no boost

[MONSTER GN]

Hey there, as always my 87 has me chasing my tail. I have a slow/no boost issue. It just kinda sucks i feel it but not really. I have fuel and everything squared away (thanks to help from this forum) and vacuum taken care of. But the car just doesn't seem to boost like it should. I have run it in tuner mode and no difference in the way it half boosts. Is it possible my turbo is too big and its not able to boost the way i want? I have a turbonetics ar 63 T3/T4 Hybrid stage III. Or do i maybe have a boost leak? Any help would be greatly appreciated.

 

[NY_GN]

Hey there, as always my 87 has me chasing my tail. I have a slow/no boost issue. It just kinda sucks i feel it but not really. I have fuel and everything squared away (thanks to help from this forum) and vacuum taken care of. But the car just doesn't seem to boost like it should. I have run it in tuner mode and no difference in the way it half boosts. Is it possible my turbo is too big and its not able to boost the way i want? I have a turbonetics ar 63 T3/T4 Hybrid stage III. Or do i maybe have a boost leak? Any help would be greatly appreciated.

Any internal work? Heads? Cam?
Upgraded torque converter? Alkyl?
If not, stock internals and converter may not support that size turbo.

 

[MONSTER GN]

Any internal work? Heads? Cam?
Upgraded torque converter? Alkyl?
If not, stock internals and converter may not support that size turbo.

Hmmmmm i thought i had all that stuff in my signature. But yes bored .30 over with 478 lift cam with 266 duration. Heads have been drcked. All forged internals. 2,800 stall converter and the adjustable rockers and now the 255lph pump with a hot wire kit

 

[Pronto]

Does the turbo spin freely by hand? What size tire are you running with those 3.73 gears?

 

[MONSTER GN]

Yes it spins freely. It does have up and down play tho. And i have the 16×8 gta wheels

 

[NY_GN]

Hmmmmm i thought i had all that stuff in my signature. But yes bored .30 over with 478 lift cam with 266 duration. Heads have been drcked. All forged internals. 2,800 stall converter and the adjustable rockers and now the 255lph pump with a hot wire kit

Guess I missed that, not my fault, Oktoberfest is out.

Maybe boost leak, clogged cat/restrictive exhaust or wastegate.

Is the turbo red hot after running it?

 

[MONSTER GN]

Guess I missed that, not my fault, Oktoberfest is out.

Maybe boost leak, clogged cat/restrictive exhaust or wastegate.

Is the turbo red hot after running it?

I have the shield on it so idk if its piping hot. I fixed the exhaust leaks and smoke tested it. Its good and while i was in there i inspected the wastegate puck shes good. How would i go about checking a boost leak? I smoke tested the hose to the compressor housing of the turbo and it only comes out at the air filter

 

[MONSTER GN]

I was thinking of removing cat tho.

 

[TexasT]

Pull the cat and put on a "test pipe" you will think it is a different car if that cat has the substrate still in it.

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[MONSTER GN]

Ill do that tomorrow then and put a some clamps on it and see how she does. Maybe ill get my wrench back that i dropped in the down pipe years ago lol. So any thoughts on the turbo being too big? It is a 63mm

 

[TexasT]

You should be able to build boost. It will just take a little longer. Hard on trans and converter.
I think with a cat you are not able to get it spinning as it can't get the exhaust past the cat. It is a bottle neck.

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[MONSTER GN]

I mean it spins and pulls just not strong. Doesnt even rip the tires loose even from a dig at WOT

 

[TexasT]

Apply the brakes and start in with the gas pedal. Watch your boost gauge. It should rise. With street tires I would think you couldnt launch it with more than 1-3 psi without going up in smoke.

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[MONSTER GN]

Ive tried that the tires start spinnin without boost. Its not kicking in until about 3,000

 

[TexasT]

Are you sure your converter is a 2800 stall?
Do that power brake and note the rpm where the tires break loose and spin.

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[MONSTER GN]

Ill note the rpm for sure in the AM. The converter came from poston buick back in the day. So who freekin knows at this point, we all know how they operated

 

[MONSTER GN]

I do know its not much rpm tho they come loose fairly easily

 

[TexasT]

If it is pretty low I am doubting your 2800 stall converter is really a 2800 stall.

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[MONSTER GN]

If it is pretty low I am doubting your 2800 stall converter is really a 2800 stall.

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God Damnit POSTON BUICK! but even with lets say a factory converter could it really make that much of a difference?

 

[TexasT]

A factory converter would be pretty low compared to a 2800.

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