NyBlankets
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- Joined
- Mar 17, 2003
Turbo took a schit, pulled it off and found this. Is a t4 setup supposed to look like this? It looks like there are provisions for a stock turbo on this flange along with the T4 bolt holes.
Take a look at this flange..
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NyBlankets
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- Mar 17, 2003
Pic of the turbo and the adapter that was used laying next to it. D'Alassandro handy work.. He used the adapter with the round hole on the turbos T4 housing blocking off a decent amount of area.
NyBlankets
Active Member
- Joined
- Mar 17, 2003
I'm pretty sure they are hooker, its been about 18 years since I purchased them.
NyBlankets
Active Member
- Joined
- Mar 17, 2003
Yes they are M&A. Before I went with the stage2 D'Alassandro put the turbo on my stock setup in 1994/5 and it looks like he just put a 3 bolt to T4 flange on.
Question is, is this a real T4 setup, is the exhaust supposed to be round where it meets the T4 flange or should it be a square end that matches the openeing of the T4 housing on the turbo? If it isn't I would like to make the necessary changes to make it a true T4 setup.
Question is, is this a real T4 setup, is the exhaust supposed to be round where it meets the T4 flange or should it be a square end that matches the openeing of the T4 housing on the turbo? If it isn't I would like to make the necessary changes to make it a true T4 setup.
- Joined
- May 26, 2001
That is a 3-bolt to T4 adaptor flange that was installed on those headers. Allowing the owner to run either a T4 turbine housing equiped turbo, or a Buick 3-bolt turbine housing equiped turbo.
Just for reference, here are the flanges.
T4 inlet flange.
http://www.precisionturbo.net/turbo...recision-Turbo-and-Engine-T4-Inlet-Flange/331
This is a copper 3-bolt gasket, but the flange is the same.
And this flange looks very similar to the one that's welded to your headers.
http://www.cottonsperformance.com/proddetail.asp?prod=20245-1&cat=90
Hope this helps.
Patrick
Just for reference, here are the flanges.
T4 inlet flange.
http://www.precisionturbo.net/turbo...recision-Turbo-and-Engine-T4-Inlet-Flange/331
This is a copper 3-bolt gasket, but the flange is the same.
And this flange looks very similar to the one that's welded to your headers.
http://www.cottonsperformance.com/proddetail.asp?prod=20245-1&cat=90
Hope this helps.
Patrick
NyBlankets
Active Member
- Joined
- Mar 17, 2003
Thanks for the info, can I bolt a t4 turbo up to the header without using the adapter that is shown in the picture along with the turbo?
- Joined
- May 26, 2001
I would not advise it, mainly because the header inlet flange you have, has a round hole and the T4 housing has a rectangular inlet hole that is much larger. It would have significant turbulence and would be exceedingly difficult to seal up.
Also, there were two different types of T4 turbine housings.
On Center (which is what you have now) has been discontinued by all major turbo makers. T4 inlet, but a round and centered (IE: along the centerline of the turbo) 4-bolt downpipe flange. Typically offered in .69, .81 and .96 A/R.
Tangential (this is the standard style T4 turbine housing that all turbo makers produce today) T4 inlet, and 3 5/8" OD v-band flange. Typically offered in .58, .68, .81 and .96 A/R.
If your Hooker headers are 3-bolt, the only true bolt on replacement option you have, if you want to keep your headers, the adaptor flange and the downpipe, would be to call all of the turbo makers and see if they still have any T4 On Center turbine housings left in stock that could be used on a replacement turbo. And if they do, you would want a .69 A/R T4 On Center housing if this is used on a 231 - 235 ci motor with those Hooker headers. Just remember that the T4 On Center style housing is very VERY old technology and does not promote or allow efficient flow to the turbo. If you compare the inlet of a T4 On Center turbine housing to a T4 Tangential housing, you will see the dramatic difference in the two designs. Also, unless you are planning on making over 750 wheel hp, you do not need a T4 style turbine housing. The Buick 3-bolt style housings used in the current generation of turbos, can easily support 750 wheel hp.
You won't be able to install a stock turbo on your current setup, because your turbo had a T4 On Center style turbine housing. Your header adaptor flange will allow you to bolt up a stock style 3-bolt turbine housing equipped turbo, but the downpipe won't bolt up. You will have to have a custom downpipe made for your car, if you keep that flange on your headers, as the mounting position of that setup is different then a stock Buick 3-bolt configuration. Or you can bolt on the 3-bolt turbine housing equipped turbo and buy a new stock style downpipe and see how off it will be. Then make modifications as needed to the rest of the exhaust.
If it was me, I would try that, as it would be easier to modify the downpipe to test pipe alignment, than it would be to try to modify your current downpipe. But that's just me. Then again, if you installed a set of stock headers and a 3" TH style downpipe along with a 3-bolt turbine housing equipped turbo, everything would be good to go. One other thing you will need to address, if you go back to factory style 3-bolt headers, would be to source a OEM turbo heat shield mounting bracket that bolts to the front of the block. This bracket, not only provides a mounting point for the factory turbo heat shield, but it also helps support the weight of the turbo, vs having all of the weight on the header and the downpipe pulling down on it. That would put a lot of undue stress on the header which will eventually lead to cracks. I would suggest you contact G-Body Parts for those items. One thing is for sure, your setup is very odd, as you definitely do not see that configuration today. More pics of what flange is welded on the header would really be helpful in better determining what the best course of action would be.
HTH
Patrick
Also, there were two different types of T4 turbine housings.
On Center (which is what you have now) has been discontinued by all major turbo makers. T4 inlet, but a round and centered (IE: along the centerline of the turbo) 4-bolt downpipe flange. Typically offered in .69, .81 and .96 A/R.
Tangential (this is the standard style T4 turbine housing that all turbo makers produce today) T4 inlet, and 3 5/8" OD v-band flange. Typically offered in .58, .68, .81 and .96 A/R.
If your Hooker headers are 3-bolt, the only true bolt on replacement option you have, if you want to keep your headers, the adaptor flange and the downpipe, would be to call all of the turbo makers and see if they still have any T4 On Center turbine housings left in stock that could be used on a replacement turbo. And if they do, you would want a .69 A/R T4 On Center housing if this is used on a 231 - 235 ci motor with those Hooker headers. Just remember that the T4 On Center style housing is very VERY old technology and does not promote or allow efficient flow to the turbo. If you compare the inlet of a T4 On Center turbine housing to a T4 Tangential housing, you will see the dramatic difference in the two designs. Also, unless you are planning on making over 750 wheel hp, you do not need a T4 style turbine housing. The Buick 3-bolt style housings used in the current generation of turbos, can easily support 750 wheel hp.
You won't be able to install a stock turbo on your current setup, because your turbo had a T4 On Center style turbine housing. Your header adaptor flange will allow you to bolt up a stock style 3-bolt turbine housing equipped turbo, but the downpipe won't bolt up. You will have to have a custom downpipe made for your car, if you keep that flange on your headers, as the mounting position of that setup is different then a stock Buick 3-bolt configuration. Or you can bolt on the 3-bolt turbine housing equipped turbo and buy a new stock style downpipe and see how off it will be. Then make modifications as needed to the rest of the exhaust.
If it was me, I would try that, as it would be easier to modify the downpipe to test pipe alignment, than it would be to try to modify your current downpipe. But that's just me. Then again, if you installed a set of stock headers and a 3" TH style downpipe along with a 3-bolt turbine housing equipped turbo, everything would be good to go. One other thing you will need to address, if you go back to factory style 3-bolt headers, would be to source a OEM turbo heat shield mounting bracket that bolts to the front of the block. This bracket, not only provides a mounting point for the factory turbo heat shield, but it also helps support the weight of the turbo, vs having all of the weight on the header and the downpipe pulling down on it. That would put a lot of undue stress on the header which will eventually lead to cracks. I would suggest you contact G-Body Parts for those items. One thing is for sure, your setup is very odd, as you definitely do not see that configuration today. More pics of what flange is welded on the header would really be helpful in better determining what the best course of action would be.
HTH
Patrick
NyBlankets
Active Member
- Joined
- Mar 17, 2003
You went above and beyond Patrick, thank you for taking the time and laying out all my options in simple terms. The engine is a 278ci stage 2 setup 9.5CR with race ported heads (Dutweiller). I will be weighing my options over the next couple of days and making some calls. I have a local fabricator that has helped me in the past, I'll geter done
