T4 s400 408
T4 s400 408 I'm looking to turbo my Trans Am it has a 408 lq9 10.7:1 with TFS 255 cc Ls3 heads and stock ls3 intake 6 speed. The car is a street car in its current form and will stay that way for a while so practicality is key. I've been looking into the huron speed v1/v2 t4 kits as I'm only looking for a beginner turbo kit and not looking to make crazy hp numbers I figure I'd have some room to grow later if I choose to go t6. From what I've gathered people are 50/50 on t4 408's especially with high flowing heads. Some say it can be done with the proper turbo and a huge A/R. I'm looking into the bw s400sx 1.25 A/R with a 92mm compressor wheel. Obviously the t4 flange will choke my motor but what could I expect from a set up like this? Could this turbo rev to 6300 rpm on my motor and not completely fall on its face? The biggest dilemma I have with going t6 is a 4-5 inch down pipe coming out of my fender and not being able to pass inspection.
yes that 92mm turbine can flow quite a bit of air. your 408 might choke a little earlier but that turbine has been 8.20s at 165 mph in jarrett's nova.
an etr-ho 76 or 80 with 92 turbine is more than a beginner turbo. should support 1000hp on your 408 if the setup is right.
an etr-ho 76 or 80 with 92 turbine is more than a beginner turbo. should support 1000hp on your 408 if the setup is right.
You mean a 92mm exh wheel?
You’ll still want/need a 4” DP on a healthy T4. IMO it makes no sense to not go T6 right from the start. Run a 4” DP reducer on it, and start with the basic $640 shipped 1.32 T6 S475. It comes with the larger “96mm” exh wheel. General DP size rule is 120% of the exh. wheel exducer. The 96/87 wheel does just fine with 4” exhaust. (120% of 87mm is 104mm or 4”).
4" T6 reducer ring.
http://www.liljohnsmotorsports.com/l...ges-30399.html
You’ll still want/need a 4” DP on a healthy T4. IMO it makes no sense to not go T6 right from the start. Run a 4” DP reducer on it, and start with the basic $640 shipped 1.32 T6 S475. It comes with the larger “96mm” exh wheel. General DP size rule is 120% of the exh. wheel exducer. The 96/87 wheel does just fine with 4” exhaust. (120% of 87mm is 104mm or 4”).
4" T6 reducer ring.
http://www.liljohnsmotorsports.com/l...ges-30399.html
Awesome good info. I'm leaning towards the t6 kit next question, I've read that it's possible to run a 4 inch downpipe with stock k member with spohn solid motor mounts is this true? Are there any other options to run a 4 inch down pipe with stock k member? If that were the case I'd like to run 4 inch dp off turbo to a 3.5 inch custom exhaust to my rear bumper with a 4 inch cut out right off dp. A/C has already been removed from the car.
Last edited by Shiftslow; Feb 16, 2016 at 12:15 PM.
Awesome good info. I'm leaning towards the t6 kit next question, I've read that it's possible to run a 4 inch downpipe with stock k member with spohn solid motor mounts is this true? Are there any other options to run a 4 inch down pipe with stock k member? If that were the case I'd like to run 4 inch dp off turbo to a 3.5 inch custom exhaust to my rear bumper with a 4 inch cut out right off dp. A/C has already been removed from the car.
