'79 - '81 Turbine Housing A/R ratio.

[Nascar T/A]

Hello
I just read this on the "Before Black" web site. "1982 - First year for the 0.63 Turbine housing. Quicker spool/Less Lag." . I was wondering what the A/R ratio was for the 1979 to 1981 turbos. On another note, is there any way of getting different Turbine Housing with different A/R ratios that will swap on to these turbos. I know Garrett doesn't only make turbos for Buick V6's and Pontiac 301's. Wonder if there is another app that turbo parts could be borrowed from. By the way new to the draw through turbo thing. Just trying to figure out ways to reduce turbo up pipe back pressure.

Have a good day

 

[mat231v6]

You can always bolt up a 86/87 Grand National hot side. On my 301 build i used a 86/87 housing and Reed provided me the blades. I just had to use a 84/85 doughnut adapt (not sure what its called) which allowed me to run the stock up pipe.

 

[Nascar T/A]

You can always bolt up a 86/87 Grand National hot side. On my 301 build i used a 86/87 housing and Reed provided me the blades. I just had to use a 84/85 doughnut adapt (not sure what its called) which allowed me to run the stock up pipe.

Hello, you have my attention!! Do you have pictures of the 86/87 turbine housing on your 301T. Also what it the A/R ratio on the 86/87 Turbine Housing. What about the 84/85 turbine housing? why did you use the 86/87. By the way who is Reed?
Thanks in advance.

 

[Nascar T/A]

Hello Is there a chart somewhere that has all the 231 turbo specifications and model numbers by model year.

Have a good day

Lee

 

[buick83-T]

The 82-87 buick turbine housings are .63 ratio. 78-81 are .82 ratio. Reed at work turbo has good knowledge on the drawthru turbos. I have the 301 compressor housing with 83 t-type turbine housing upgraded done by Reed.

 

[Nascar T/A]

The 82-87 buick turbine housings are .63 ratio. 78-81 are .82 ratio. Reed at work turbo has good knowledge on the drawthru turbos. I have the 301 compressor housing with 83 t-type turbine housing upgraded done by Reed.

Thanks for the reply. I didn't know they keep the A/R that common through all those years. I thought the changed the A/R ratios more often. Like I said new to this. That kind of makes sense with what I read "Quicker spool/Less Lag". Has anyone measure the back pressure before the turbine compared to the boost pressure. Thanks again.

 

[buick83-T]

Is your car stock?..301 v8 turbo ...you are basically looking to gain faster spoolup?

 

[b4black]

What year-model do you have? What are you looking to do?

 

[Nascar T/A]

Thanks for your replies, You are correct, I have a 301 Turbo Trans Am. I want better performance for my T/A. and I am on a hunt for more information. I am trying to put together parts that I would need to make this combination work. Unfortunately Pontiac didn't have the sense to continue working on this engine like Buick did. I recently read some information that indicated the turbo back pressure on the 301 is twice the boost pressure when you start to increase boost. I read a way of reducing the back pressure was to increase the Turbine Housing A/R ratio, I figured Garret would have an interchange chart for the housing but haven't been able to find anything. That is why I came here to see what your group does about A/R ratios and back pressure. I was amazed to find out that Buick actually reduce the Turbine A/R ratio from '81 to '82 and carried it all the way to '87. I hope you don't hold it against me that I have a Pontiac and educate me.

 

[Nascar T/A]

Is your car stock?..301 v8 turbo

Right now Most of the 301 parts I have are stock. I am in the process of adding a 200 4R to my car and it has 3.70 rear axle. Currently the car has a SBC with a 278 Energizer Cam Dynamic Cam with aluminum Corvette Heads and Performer Intake. I want to go back to the Pontiac Engine but don't want to give up the performance.

 

[buick83-T]

Turbo 301 - Performance/Mods

Turbo 301 - Performance/Mods

www.301garage.com

This forum has alot of build info on the 301 Turbo. Free flow air intake, larger up-pipe and downpipe,full exhaust will help alot & Higher stall torque convertor. If still running q-jet reduce spring tension on the secondaries.

 

[mat231v6]

The 82-87 buick turbine housings are .63 ratio. 78-81 are .82 ratio. Reed at work turbo has good knowledge on the drawthru turbos. I have the 301 compressor housing with 83 t-type turbine housing upgraded done by Reed.

I didn't know you did the 301 upgrade. Do you have it on the car? Just wondering if you went the route of modifying the turbo or the intake. On my build i re-drilled the intake and made a spacer rather than change the turbo body.

 

[buick83-T]

I didn't know you did the 301 upgrade. Do you have it on the car? Just wondering if you went the route of modifying the turbo or the intake. On my build i re-drilled the intake and made a spacer rather than change the turbo body.

Yes I had the ears moved on housing instead of modding intake manifold. Also milled down the inlet on housing. Fits like the stocker with using my stock .63 turbine housing off the 83. I havent got to much time playing on it yet...i need to open up the plenum more and get rid of stock carb bonnet.