Turbo sizing and a/r question.

[ZeroNine]

Zilvians,

I am currently running a Garrett gt3582r with a 1.03 a/r on my single turbo 350z and it is rather laggy. I was planning on selling the current turbo and downsizing to a gtx3076 with .82 a/r for quicker spool and a bit less horsepower. Car is currently making 430 wheel on 110 octane and 14psi. Looking to go down to around 375 on pump gas. In your educated opinions, would I be better off with the turbo downsize or simply replacing my housing to a .63 a/r on the 3582r? Comments/shit talk/advice welcome.

[fullthrottle]

Do they make an .82 housing or something similar? I think that would be helpful.

[e30gangsta]

Yes they make an .82 3076 is too small step down to a gtx3576r if you going to go down a bit.

[PoorMans180SX]

A .82 or .63 would be a big improvement. If you're really desperate for faster spool, go with a GTX3576R, same size turbine as your 35R but with a 3076 compressor wheel. The 35R turbine is probably already too small for the VQ.

[Mitsubayati]

gtx will not increase spool time noticeably and in an affordable manner. Running a .82 AR exhaust housing would be a smarter bet.

If you don't plan on ever making more power than 400-450hp then a gt3076r would be a good bet to get faster spool. Your top end will be more limited though.

[ZeroNine]

There is a .82 and .63 housing available for the 3582. If I were to opt for the housing swap rather than an entire turbo swap, what would be the pros and cons of both or those a/r sizes in my situation? Would the .63 be too small?

[PoorMans180SX]

There is a .82 and .63 housing available for the 3582. If I were to opt for the housing swap rather than an entire turbo swap, what would be the pros and cons of both or those a/r sizes in my situation? Would the .63 be too small?

A general rule of thumb is that the turbo is restricted by the turbine itself, so you can usually run a tight A/R without too much restriction in the top end. That's why .82 2871's suck on SR's.

I would however, go with the .82 to be safe, as that's already a small turbine for the engine size. It'll definitely spool faster than that 1.02 housing.

[Def]

For a single turbo on a VQ, you'd see huge gains going to a twin scroll setup with a proper manifold/crossover pipe.

That said, I'd not go to a GT30 turbine - freakin' way too small for a 3.5L.

I'd just go to a slightly tighter turbine if you're not wanting to spend much money.


If you go TS, I'd go with something like a BW EFR 7670. Their TS turbine geometry is generally better, as they're not using old diesel housings that were never meant to run on the turbines they're used on (unless you buy the $$$$$ Garrett Ni-resist housings which are fairly new and expensive).

[ZeroNine]

For a single turbo on a VQ, you'd see huge gains going to a twin scroll setup with a proper manifold/crossover pipe.

That said, I'd not go to a GT30 turbine - freakin' way too small for a 3.5L.

I'd just go to a slightly tighter turbine if you're not wanting to spend much money.


If you go TS, I'd go with something like a BW EFR 7670. Their TS turbine geometry is generally better, as they're not using old diesel housings that were never meant to run on the turbines they're used on (unless you buy the $$$$$ Garrett Ni-resist housings which are fairly new and expensive).

When i have the cash later down the road this was always the plan. I think for now I'm going to go to the .82 A/R housing and add an EBC. That should make enough difference. I hope.