Trying to get a pair of HKS 3037's with .73 turbines to work on a std bottom end 2JZ and there is literally no boost untill 4800-5000rpm and then its 5psi until 6000rpm, from then on its 25psi. The lack of boost is depressing I need advice if this can be made to work. I would like the boost to start at least 1000rpm sooner.

I am looking to change the turbines to .63, will this be noticeable. I have been told that a 1000rpm improvement would be unlikely.

Whilst this is a street driven car, its definitely not a daily and the ultimate goal is 1000rwhp for dyno glory and the drag strip, although I will be looking at a new bottom end for that power level.

Would a small shot of nitrous make a big difference?

I also can't find any actual compressor maps for this turbo??

 

Turbine A/R seems a bit large for the displacement. This is also depending on the size of the turbine wheels too. Besides that though, yeah Nitrous will make a huge difference in the spooling. Something else to consider is, how is your tune both out of boost and going into b boost? If it's like the Garrett GT30 1000 at the wheels should be possible with an efficient drive train but at the edge of the turbos assuming you're going to be at about a 3.0 pressure ratio.

 

Turbo Specs...


Brand: HKS
Product: GT30 Series Turbo - GT3037S Turbine
Part Num: 1401-RA126 (A/R 0.61)
Part Num: 1401-RA127 (A/R 0.73)
Part Num: 1401-RA128 (A/R 0.87)
Part Num: 1401-RA129 (A/R 1.01)

Available Sizes:
- A/R 0.61
- A/R 0.73
- A/R 0.87
- A/R 1.01

SPECIFICATIONS:
Turbine Model: GT3037S
Turbine Type: Ball Bearing Type

Compressor Wheel (mm):
- Trim: 56
- Inducers: 55.0
- Major: 76.2

Compressor Housing (mm):
- In Dia.: 100
- Ex Dia.: 50

Turbo Wheel (mm):
- Trim: 84
- Inducers: 60.0
- Major: 55.0


Turbo Housing:
- In Flange: GT25
- Ex Flage: GT30

A/R:
- 0.61: 8cm2
- 0.73: 10cm2
- 0.87: 12cm2
- 1.01: 14cm2

 

Where is the cheapest place to buy .61 turbine housings for these?