Vg30det Bb Turbo Info

[Cubes]

Hi ppls,

I've recently dropped a VG30DET turbo on my RB30DET to keep me happy until xmas.

I've just measured up the VG30DET and old S2 R32 RB20DET BB Turbo.

It appears the VG30DET and RB20DET S2 turbo's have an IDENTICAL compressor wheel.

Inducer - 46mm

Exducer - 63mm

The only difference between the two turbo's is the vg30's larger turbine and compressor cover.

The VG30DET turbo has smoothed out spool, increased bottom end off boost torque and made the car feel like a turbo car again, that being where the top end rushes, not dies off as the rb20det turbo did.

Hope you found it interesting, more so disappointing, I did.

Edited October 4, 2005 by Cubes

[JeeTeeEss25Tee]

how much was the gain from the rb20 unit? I'm thinking of doing a highflow with VG30 housing for my rb25 but not sure would get substantial gain to justify the $2K tag

[Cubes]

Its not tuned yet so I am unsure.

I'm however expecting a gain of around 20-30rwkw (~200rwkw) with peak power extended close to 6000rpm, the rb20det turbo with its small turbine housing had power reaching its peak and flattening out at 4400rpm then nosing over after 4900rpm. It wasn't much fun.

I initially bought the VG30DET in anticipation of having it machined to suit a GT30R -12 CHRA with the .6 comp cover.

This would make around 280rwkw possibly 300rwkw.

There is apparently a -14 that is simply a GT30R -12 with a GT35R compressor wheel. This 'may' surge on the 2.5ltr, it should be fine on the 3ltr.

Having the 3ltr I'm going to jump in and give the xr6t turbo a shot as it should be all in by ~3800rpm (the same as a VG30 Highflow on a 2.5ltr) and making some nice boost 8-10psi by 3000rpm.

The 3ltrs really need a big turbine to make use of the DOHC head.

The XR6T turbo I think is a really bad match to the RB30ET SOHC.

They spool the same ~3800rpm then makes its peak power around 4200rpm, flattens out then noses over.

Edited October 4, 2005 by Cubes

[JeeTeeEss25Tee]

Sounds very interesting. I thought that XR6 combo would be quite laggy even for your 3lt but as long as you have done all the homeworks and with nice tune it should bring impressive result (easy 300rwkw)