Twin Turbo Fabrication on F-Body
Thread Starter
Joined: Sep 2004
Posts: 2,552
Likes: 12
From: Visalia, California
Twin Turbo Fabrication on F-Body Me again, to run 5-7 psi using twin turbo's for quick spool, would two t3/t4's with .50/.70 do the trick? This is in a 99 TA with 6 speed, and 4.10's. Need opinions on wastegates/BOV's, shoot me your opinions, but don't shoot me! Appreciate any positive feedback. 
You would not need two turbos to get quick spool... just use a small turbo in a single setup.
Not 100% sure on this, but I think running twins for only 5-7psi would be sort of a waste... especially when you can get the same spool with one turbo.
Just my $.02, however I am curious to see what other people think!
Not 100% sure on this, but I think running twins for only 5-7psi would be sort of a waste... especially when you can get the same spool with one turbo.
Just my $.02, however I am curious to see what other people think!
Originally Posted by 67Firebird455
Me again, to run 5-7 psi using twin turbo's for quick spool, would two t3/t4's with .50/.70 do the trick? This is in a 99 TA with 6 speed, and 4.10's. Need opinions on wastegates/BOV's, shoot me your opinions, but don't shoot me! Appreciate any positive feedback.
Thread Starter
Joined: Sep 2004
Posts: 2,552
Likes: 12
From: Visalia, California
I had thought the same thing, like 1 60-1, but t3/t4's are inexpensive and fabrication is not a problem. The t3/t4's I'm looking at have a 2.54" exducer/2.89" mayor on the turbine wheel, and 2.23" exducer/3.31" mayor on the compressor wheel. Not sure if just one of those will do the trick... Appreciate the response!
I am actually considering a similar setup.... check out the post on KKK turbos from yesterday I believe, it has some decent info. There were just some recent posts about using smaller turbos like T3/T4 hybrids and the general consensus was that a stock Grand National turbo would get the job done just fine. It is a T3/T4 hybrid... not sure on the A/R housing or wheel specs, but I bet they wouldn't be to tough to dig up somewhere.
What I still really think though is that you're going to have potential to make way more than 5-7psi!
Going just from the exducer bore, I am going to guess those turbos are good for around 400hp? each and that you will be able to easily get the 5-7psi you are looking for. I know this is probably a lousy estimation tool, but just using the turbine exducer bore suggests you're going to be able to spin the compressor fast enough to get your power without creating too much back pressure on the hot side. I would still calculate your CFM of airflow and pressure ratio, etc and check out some compressor maps to be sure on the compressor side.
Where do you plan on getting your turbos from?
What I still really think though is that you're going to have potential to make way more than 5-7psi!
Going just from the exducer bore, I am going to guess those turbos are good for around 400hp? each and that you will be able to easily get the 5-7psi you are looking for. I know this is probably a lousy estimation tool, but just using the turbine exducer bore suggests you're going to be able to spin the compressor fast enough to get your power without creating too much back pressure on the hot side. I would still calculate your CFM of airflow and pressure ratio, etc and check out some compressor maps to be sure on the compressor side.Where do you plan on getting your turbos from?
Originally Posted by 67Firebird455
I had thought the same thing, like 1 60-1, but t3/t4's are inexpensive and fabrication is not a problem. The t3/t4's I'm looking at have a 2.54" exducer/2.89" mayor on the turbine wheel, and 2.23" exducer/3.31" mayor on the compressor wheel. Not sure if just one of those will do the trick... Appreciate the response!
Thread Starter
Joined: Sep 2004
Posts: 2,552
Likes: 12
From: Visalia, California
Not exactly sure where I plan on getting them from, just heard a few buds talkin about the GN t3/t4 hybrids and was very interested. I'm also looking for probably a twin turbo setup for my 7.6L Pontiac in my 67 bird, it's built to handle 15:1 or massive boost, currently running 10:1 with ported E-heads and JE pistons, H beams, steel crank, studded billet 4 bolt caps. Like I said, fabrication is not an issue.
Yeah, to be realistic, 400 or so horsepower should come from each t3/t4, but they are advertised at over 500 and I see a lot of 4 and 6 banger cars using them or small 8's, hence me wanting to twin turbo it, at the going price of around $300! I plan to install the turbo's at the collector on my LT's or rear mount, not sure, that's why I wanted to run such small turbo's, and run twin CA's to the front of the car, or twin filters on the *** end, not sure yet, just kind of doing the paperwork now before I start this project. I would imagine I would need injectors bigger than 42's for this setup, what do you think?
Yeah, to be realistic, 400 or so horsepower should come from each t3/t4, but they are advertised at over 500 and I see a lot of 4 and 6 banger cars using them or small 8's, hence me wanting to twin turbo it, at the going price of around $300! I plan to install the turbo's at the collector on my LT's or rear mount, not sure, that's why I wanted to run such small turbo's, and run twin CA's to the front of the car, or twin filters on the *** end, not sure yet, just kind of doing the paperwork now before I start this project. I would imagine I would need injectors bigger than 42's for this setup, what do you think?
Yea, I was leaning towards the T3/T4 setup myself, however the fact that I can't seem to find them readily available with water-cooled bearings is pretty unattractive to me... I'm looking into the KKK brand myself.. I'd check them out!
Buy and read "Maximum Boost" by Corky Bell if you haven't already. It's a fantastic book (250 pgs) that outlines everything you need to know about designing and building your own turbo system. It will show you how to do the math to figure out what compressor you need, etc. JUST BUY THE BOOK! It will be the best $25 you spend on your turbo setup, period.
A rear mount setup with GREATLY impact the A/R ratio you need on the turbine housing.
42's will prob get you by on 5-7psi.
Don't know much about your other setup, but I'd say the 10:1 compression ratio is going to limit you on the amount of boost and timing you can run.
Buy and read "Maximum Boost" by Corky Bell if you haven't already. It's a fantastic book (250 pgs) that outlines everything you need to know about designing and building your own turbo system. It will show you how to do the math to figure out what compressor you need, etc. JUST BUY THE BOOK! It will be the best $25 you spend on your turbo setup, period.
A rear mount setup with GREATLY impact the A/R ratio you need on the turbine housing.
42's will prob get you by on 5-7psi.
Don't know much about your other setup, but I'd say the 10:1 compression ratio is going to limit you on the amount of boost and timing you can run.
Originally Posted by 67Firebird455
Not exactly sure where I plan on getting them from, just heard a few buds talkin about the GN t3/t4 hybrids and was very interested. I'm also looking for probably a twin turbo setup for my 7.6L Pontiac in my 67 bird, it's built to handle 15:1 or massive boost, currently running 10:1 with ported E-heads and JE pistons, H beams, steel crank, studded billet 4 bolt caps. Like I said, fabrication is not an issue.
Yeah, to be realistic, 400 or so horsepower should come from each t3/t4, but they are advertised at over 500 and I see a lot of 4 and 6 banger cars using them or small 8's, hence me wanting to twin turbo it, at the going price of around $300! I plan to install the turbo's at the collector on my LT's or rear mount, not sure, that's why I wanted to run such small turbo's, and run twin CA's to the front of the car, or twin filters on the *** end, not sure yet, just kind of doing the paperwork now before I start this project. I would imagine I would need injectors bigger than 42's for this setup, what do you think?
Yeah, to be realistic, 400 or so horsepower should come from each t3/t4, but they are advertised at over 500 and I see a lot of 4 and 6 banger cars using them or small 8's, hence me wanting to twin turbo it, at the going price of around $300! I plan to install the turbo's at the collector on my LT's or rear mount, not sure, that's why I wanted to run such small turbo's, and run twin CA's to the front of the car, or twin filters on the *** end, not sure yet, just kind of doing the paperwork now before I start this project. I would imagine I would need injectors bigger than 42's for this setup, what do you think?
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Verdad Gallardo I'm curious too... but I already shared my opinion!
Recently (in the last two weeks or so) there have been a lot of twin turbo setup posts. Go back through the last few pages of listings and read them all.... they have some good info in them that you can apply to your setup.
Recently (in the last two weeks or so) there have been a lot of twin turbo setup posts. Go back through the last few pages of listings and read them all.... they have some good info in them that you can apply to your setup.
Originally Posted by 67Firebird455
Wish other people would respond, I could definitely use some opinions...
Originally Posted by 67Firebird455
Me again, to run 5-7 psi using twin turbo's for quick spool, would two t3/t4's with .50/.70 do the trick? This is in a 99 TA with 6 speed, and 4.10's. Need opinions on wastegates/BOV's, shoot me your opinions, but don't shoot me! Appreciate any positive feedback.
Call Tom Izzo at Speed inc for more info.
As far as Turbos, contact John Craig at Limitengineering.com professional, affordable and knowledgable.
probably bigger thanyou want to run, butim using master power t-70's, still a small frame turbo so spool is decent for its size, similar to sc-61's (said jose at forced inductions) each capable of about 700hp
