Twin Turbo Sizing Question
Twin Turbo Sizing Question Curious about what you guys think about this turbos specifications for a 408 forged stroker setup. Going twins.
gt35 turbo charger .82ar
Intake :4 inch
Outlet: 2.5 inch
Compressor trim: .70 ar
Compressor Wheel diameter: 66.36 /81.87
Turbine wheel diameter : 64.50 /73.60
Exhaust trim: .82 ar
Turbine flange type: t3 flange
Twin scroll turbine housing
gt35 turbo charger .82ar
Intake :4 inch
Outlet: 2.5 inch
Compressor trim: .70 ar
Compressor Wheel diameter: 66.36 /81.87
Turbine wheel diameter : 64.50 /73.60
Exhaust trim: .82 ar
Turbine flange type: t3 flange
Twin scroll turbine housing
you may hear alot of people say that T3 turbos are too small for your motor but they are wrong. there are many people here who make great power from twin T3 setups. I am in the middle of building a kit for a buddy's 280Z that will use two 60-1s on a 5.3. looking for 700+hp with that setup
Curious about what you guys think about this turbos specifications for a 408 forged stroker setup. Going twins.
gt35 turbo charger .82ar
Intake :4 inch
Outlet: 2.5 inch
Compressor trim: .70 ar
Compressor Wheel diameter: 66.36 /81.87
Turbine wheel diameter : 64.50 /73.60
Exhaust trim: .82 ar
Turbine flange type: t3 flange
Twin scroll turbine housing
gt35 turbo charger .82ar
Intake :4 inch
Outlet: 2.5 inch
Compressor trim: .70 ar
Compressor Wheel diameter: 66.36 /81.87
Turbine wheel diameter : 64.50 /73.60
Exhaust trim: .82 ar
Turbine flange type: t3 flange
Twin scroll turbine housing
A 408 is a big motor. I myself am using T4 .81 housings on my 403. T3 would probably be good if you want insta spool and want peak power at 5800-6200. I want to spin 7500, so I went T4. This is if we are talking front mount. Rear mount those T3 would probably do well. If you already have the turbos, then try them. Give yourself room when you build your kit to fit the T4 just in case you want to try them.
Actually I am going to use the GT45 turbos. After some research today a GT45 is essentially a T67. Many people are doing T67 twin turbo setups on these bigger cube motors and seem to be a proven setup. Also the GT45s utilize a T4 flange. I will be running 3" downpipes and 38mm wastegates.
GT45
Intake :4 inch
Outlet: 2.5 inch
Compressor trim: .70 ar
Compressor Wheel diameter: Inducer 66.71 / Exducer 84.20
Turbine wheel diameter : Inducer 73.60 / Exducer 63.56
Exhaust trim: 1.00ar
Turbine flange type: T4 flange
Downpipe flange type : 3.25" v band flange
Cooling type: oil cooled only
Precision PT6776H turbocharger specs
compressor wheel: Inducer 2.620" (67mm) Exducer 3.310" (84mm)
exhaust wheel: Inducer 2.920" (74mm) Exducer 2.542" (64.5mm)
As you can see the ebay turbo is very very very close to the Precision turbo.
Not only that but I am spending less for the entire setup than I could buy one Precision turbo for. Curious as to how much I am spending? Try $700 shipped. That includes both turbos, both wastegates, all gaskets required, T4 flanges, 2 -4an oil feed lines and 2 -10an oil return lines. Did I mention I have a 1 year warranty on parts? Thats the same warranty that Precision Turbo gives you.
So...$250 for an ebay GT45 turbo
Or...$989 for a Precision 6776
GT45
Intake :4 inch
Outlet: 2.5 inch
Compressor trim: .70 ar
Compressor Wheel diameter: Inducer 66.71 / Exducer 84.20
Turbine wheel diameter : Inducer 73.60 / Exducer 63.56
Exhaust trim: 1.00ar
Turbine flange type: T4 flange
Downpipe flange type : 3.25" v band flange
Cooling type: oil cooled only
Precision PT6776H turbocharger specs
compressor wheel: Inducer 2.620" (67mm) Exducer 3.310" (84mm)
exhaust wheel: Inducer 2.920" (74mm) Exducer 2.542" (64.5mm)
As you can see the ebay turbo is very very very close to the Precision turbo.
Not only that but I am spending less for the entire setup than I could buy one Precision turbo for. Curious as to how much I am spending? Try $700 shipped. That includes both turbos, both wastegates, all gaskets required, T4 flanges, 2 -4an oil feed lines and 2 -10an oil return lines. Did I mention I have a 1 year warranty on parts? Thats the same warranty that Precision Turbo gives you.
So...$250 for an ebay GT45 turbo
Or...$989 for a Precision 6776
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Im all for saving money and budget builds but the Ebay stuff is typically trouble.
Good luck on your build, I hope you get it to last five years and prove everyone wrong, but I kind of doubt it.
Good luck on your build, I hope you get it to last five years and prove everyone wrong, but I kind of doubt it.
TECH Enthusiast
Joined: Sep 2010
Posts: 580
Likes: 0
From: North Central Ohio
So basically your feeding each turbo with about 204 cubic inches. A T3/T4 would work but a T4 is probably better suited to the combination. They use twin GT35Rs on supras which are 181ci total. Use good quality componets, make sure you try to make the system work as one, use the T4s and dont look back. This just goes back to the definition of "Works"...What works to the guy down the street may run like crap to you or I.
Actually I am going to use the GT45 turbos. After some research today a GT45 is essentially a T67. Many people are doing T67 twin turbo setups on these bigger cube motors and seem to be a proven setup. Also the GT45s utilize a T4 flange. I will be running 3" downpipes and 38mm wastegates.
GT45
Intake :4 inch
Outlet: 2.5 inch
Compressor trim: .70 ar
Compressor Wheel diameter: Inducer 66.71 / Exducer 84.20
Turbine wheel diameter : Inducer 73.60 / Exducer 63.56
Exhaust trim: 1.00ar
Turbine flange type: T4 flange
Downpipe flange type : 3.25" v band flange
Cooling type: oil cooled only
Precision PT6776H turbocharger specs
compressor wheel: Inducer 2.620" (67mm) Exducer 3.310" (84mm)
exhaust wheel: Inducer 2.920" (74mm) Exducer 2.542" (64.5mm)
As you can see the ebay turbo is very very very close to the Precision turbo.
Not only that but I am spending less for the entire setup than I could buy one Precision turbo for. Curious as to how much I am spending? Try $700 shipped. That includes both turbos, both wastegates, all gaskets required, T4 flanges, 2 -4an oil feed lines and 2 -10an oil return lines. Did I mention I have a 1 year warranty on parts? Thats the same warranty that Precision Turbo gives you.
So...$250 for an ebay GT45 turbo
Or...$989 for a Precision 6776
GT45
Intake :4 inch
Outlet: 2.5 inch
Compressor trim: .70 ar
Compressor Wheel diameter: Inducer 66.71 / Exducer 84.20
Turbine wheel diameter : Inducer 73.60 / Exducer 63.56
Exhaust trim: 1.00ar
Turbine flange type: T4 flange
Downpipe flange type : 3.25" v band flange
Cooling type: oil cooled only
Precision PT6776H turbocharger specs
compressor wheel: Inducer 2.620" (67mm) Exducer 3.310" (84mm)
exhaust wheel: Inducer 2.920" (74mm) Exducer 2.542" (64.5mm)
As you can see the ebay turbo is very very very close to the Precision turbo.
Not only that but I am spending less for the entire setup than I could buy one Precision turbo for. Curious as to how much I am spending? Try $700 shipped. That includes both turbos, both wastegates, all gaskets required, T4 flanges, 2 -4an oil feed lines and 2 -10an oil return lines. Did I mention I have a 1 year warranty on parts? Thats the same warranty that Precision Turbo gives you.
So...$250 for an ebay GT45 turbo
Or...$989 for a Precision 6776
I can agree that I should probably use some TiAL wastegates. If you know someone that has them for that price used let me know
As far as the turbos go if one does come apart I would expect it to hit the intercooler first long before it got to the engine.
If either of these turbos start burning oil it will be shipped back for replacement.
I believe the turbos would be fine for a 383ci engine. The person building my setup thinks the GT35s might be a tad bit small for my 408ci engine
As far as the turbos go if one does come apart I would expect it to hit the intercooler first long before it got to the engine.
If either of these turbos start burning oil it will be shipped back for replacement.
I believe the turbos would be fine for a 383ci engine. The person building my setup thinks the GT35s might be a tad bit small for my 408ci engine
TECH Fanatic
Joined: Feb 2006
Posts: 1,025
Likes: 1
From: CT/NJ
I can agree that I should probably use some TiAL wastegates. If you know someone that has them for that price used let me know
As far as the turbos go if one does come apart I would expect it to hit the intercooler first long before it got to the engine.
If either of these turbos start burning oil it will be shipped back for replacement.
I believe the turbos would be fine for a 383ci engine. The person building my setup thinks the GT35s might be a tad bit small for my 408ci engine
As far as the turbos go if one does come apart I would expect it to hit the intercooler first long before it got to the engine.
If either of these turbos start burning oil it will be shipped back for replacement.
I believe the turbos would be fine for a 383ci engine. The person building my setup thinks the GT35s might be a tad bit small for my 408ci engine
here's some threads to look at. GT35s will work just fine. APS and INCON use GT35 style turbos and 1000 hp has been seen with those. GT35s on a 408 will be just fine. use the search button and find a new builder. lol
https://ls1tech.com/forums/forced-in...-1004rwhp.html
https://ls1tech.com/forums/forced-in...1040-rwhp.html
https://ls1tech.com/forums/forced-in...in-turbos.html
https://ls1tech.com/forums/forced-in...-1004rwhp.html
https://ls1tech.com/forums/forced-in...1040-rwhp.html
https://ls1tech.com/forums/forced-in...in-turbos.html
