I was wondering if there is such a flange that will allow the use of the stock wastegate but enable you to not have to use the stock elbow. It would make running the downpipe a lot easier and would save room.

Thanks for any advise.

Craig

 

I know one guy that took the stock elbow and cut the flange off it, and used that to make his own custom downpipe:
http://www.gnttype.org/techarea/turbo/JTDP.html

It ain't pretty, but it apparently works...

John

 

Thanks...that would work great, but I am going for looks at the same time. If worst comes to worst I can try and make that but have it look pretty good. Would a turbo heat shield cover that?

Thanks
Craig

 

Do a search. I posted how to modify GN wastegate housings a while back.

There is no company that makes a universal Flapper housing for GNs.

You have three choices:

1) Modify it like I specify.

2) Buy a Turbonetics GN turbine housing that mounts an external deltagate on the turbine housing. Then have a custome flange made for the down pipe.

3) Buy a .63 turbine housing for a standard T3 and use turbonetics gate and flapper assembly.

 

thanks for the info. I will look for the thread.

Craig

 

turbostangman: Using a ford 5 bolt style .63 housing on a EFI gn turbo will not work at all. The EFI gn uses a thin wheel specific to the GN only turbo. Its very much like a t4 wheel but smaller. Early carb GN t type regals have a even differant turbine wheel. They are most like a ford T3 but also do not interchange. The ford T3 standard exhaust wheel is a 72 trim i do beleive w/o measureing it. The Inducer of it is bigger than the 79 t type regal and the housings will not interchange... Basically what im trying to say here. Is there is no way to put any other exhaust housing on a EFI gn turbo unless you change the turbine shaft as well. The GN turbine wheel is propietary just like its compressor wheel. Where did i get this info from? I personally tried to put a t type regal turbine housing onto a EFI gn turbo. And it most certianly will not fit. Then i tried to put a ford CHRA (turbocoupe) onto a 79 t type housing which also will not work.
Philip

 

http://hv.hypermart.net/turbo/IM000769.JPG

I know this pic sucks. But the EFI gn is 3rd in from the top left. If you know what the dog dish looks like you can see the wheel is very short. Bottom 3rd in is a CHRA from a 79 t type. Its wheel is not compatable with the EFI GN or the ford 5 bolt. Though its compressor is a 60 trim and all that does interchange. Top right is what a T type or carbed GN housing looks like. This fits nothing normal but a T type and the turbo trans-am. Its exducer (smaller diameter on a turbine) is smaller than the 72 trim ford turbine. I know its pretty common to hear that ALL T3s have the same turbine but this is just not so. To boot there is no way at all to determine which one you have unless you measure it. Unlike the t4 family that has the letter system. hope this pic clears things up and keeps people from flameing me
Phil

 

Thanks Phil, I never tried it so I wasn't sure.

So are the shaft Diameters different also? I might have to disassemble the 87GN turbo I have here and find out.

I also have a TO4B T3/T4 here and I pulled the Compressor housing off and it does bolt onto the GN turbo, just with a huge gap around the inducer of the wheel cause this is for a 60-1 wheel.

The backing plates look the same also.

I will take a closer look at the Turbine side but it might not help me much since this housing is for a Stage 2 turbonetics wheel. But I would like to compare them for my own knowledge.

I was extremely pleased with the power production of the GN turbos on my car. A stock bottom end 302 w/ just heads and an intake going over 128MPH on 12-13psi is a very well matched set-up. So I am seriously wondering if I even need to go to these larger 60-1 Hi-fi's unless I am planning on making well over 700HP. Part of it was I believe from the combination of the .63 turbine housing and wheel combination. Plus the Compressor wheels had to be in a nice sweet spot since my AIT was only in the 120 deg range down on the intake runner.

Since I have a stock block and rotating assembly, I don't know how often I will go over 700HP. Kind of like playing russian roulette but with 5 bullets in the gun.......

 

the shaft is small shaft .310 i beleive is the decimal equal. The wheel is just smaller in height. it doesnt seem to have the large pattle like structre on the turbine inducer. blades also have less pitch.. There might even be 10 insted of 11. not sure on that. maybe thats why the pitch looks differant.... The compressor backplate is T4 sized from what i can remember. Im pretty sure i put a T4 S housing on that backplate. I know the EFI gn has a carbon seal but cant remember if its t3 or t4 backplate.. Do you have any pics of what modifications where done for a stage 2 wheel ? I think i can do it myself on the bridgeport and save 100$ from turbonetics. I could do it on the cnc, but the brigeport is prolly faster. If you housing is off the car and you could measure it you would most definately be the man..
-phil

 

I can mic it for you. So you would just get a Stage 2 wheel and hog out your turbine housing?

I have the wheel diameters in my catalog I could give you.

 

I see the wheel sizes too but ide need to know the clearance factor they mahined into the housing to make it fit.. Turbonetics bores housings so if they can i can. In fact i can probably do a better job beacuse i care more.
phil

 

Either of you 2 have a good conditioned spare '86-'87 GN turbo you may sell? I am not looking to buy immediatly since I don't have the cash at the moment, just looking around so I know where I can possibly find 1.

Thanks,
Brian

 

All i have is a 79 t type regal exhaust housing its the largest ar avaialbe at .82 and takes a early garret wheel. This turbo has the t ype swing gate on it and i beleve its new from the looks of it. No stipped holes and the internal bolt has the yellow paint on it still. Ill take $30 for it if anyone needs it.
Phil