Garret Gt3071r Or Garrett Gt2871r For Rb20

[ryan_o_grady]

Looking at buying a new garret turbo for my rb20.

Ive been search for last 2 days on specs for these 2 turbos.

GCG will do the 2871R with a skyline T3 rear housing.

How much effort is it to fit a 3071R, has anyone got one of these with .63 A/R and a 2.75" inlet.

If anyone can point me in the direction of a thread covering the variations of these turbos that would be great thanks.

[tridentt150v]

See Nabil's thread on forced Induction http://www.skylinesaustralia.com/forums/in...=145752&hl=.

Also see Slide's prices on the trader section on SAU, good prices and http://www.skylinesaustralia.com/forums/in...howtopic=131709

[discopotato03]

Yep GT2871R series turbos use the high performance GT28 turbine with Garretts 71.1mm GT35 series compressors in 48 or 52 or 56 trim .

There are variations in both turbines and compressors in the GT3071R/GT2835 series cartridges/turbos . Don't be confused by HKS terminology - the 28 in 2835 does NOT mean it uses a GT28 turbine , they ALL use a cropped GT30 turbine in 84 or 90 trim .

The turbine takes one of three forms , cropped or 56.6mm OD in 84 or 90 trim . Unmolested in 60mm 84 trim . The real GT3071R uses the 60mm 84T turbine .

Compressors are same deal as the GT2871 or 71.1mm 48/52/56T .

Same old same old , drama is always getting a T3 flanged exhaust housing to suit the chosen turbocharger .

Three options with the GT2871R (or any GT28 series turbo with same turbine) .

1) Rat up the .64 A/R HKS housing from 2530/2540/2535 or GT-RS .

2) Reprofile one of the Nissan/Hitachi RB20/25/VG30 housings .

3) GCG's recent custom housing .

With "GT3071R's" there are some traps . Firstly some are made with the cropped GT30 turbine which would be sort of ok if the exhaust housing was GT30 based ie like HKS's T3 flanged ones . Sadly Garrett and HKS like to sell the things with bored out and butchered T28 flanged GT28 housings which don't work . Garrett call them "GT3071R-WG" and they are dogs . HKS also did it with GT2835's aimed at SR20/CA18's which have T28 flanged exhaust manifolds - note I mean the integral waste gated ones . HKS also have T28 flanged GT30 turbine housings that DO work just no integral waste gate .

IMO the ones worth using are the real GT3071R cartridge number 700177-5023 and one or two of the HKS custom combinations of the cropped GT30 turbine with the 52 or 48 trim compressor . The HKS option is expensive and may not get you the exhaust housing you want . The real Garrett 3071R can now be had with Garretts own GT30 integral waste gate exhaust housing so its reasonably easy , I would use the smaller .63 A/R housing if you do this .

RB20's have small ~ 330cc cylinders so not a mountain of torque at low/med revs . A bit of boost early on helps but if the compressor is a healthy one and steps are not taken to minimise it they surge badly once they get going . The old fix was to use larger A/R turbine housings but then you lose the bottom end torque . HKS gets around it by fitting port shrouded compressor housings ie to their RB specific GT-RS and possibly their RB type GT2530 which may have been called GT2530KAI . Some firms can do a ported shroud by machining the large boss type TO4B compressor housing like GT2860RS's and many GT2871R turbos come std with . Something like this or the RB type HKS GT-RS (GT2871R 52T with HKS housings) would probably be nice on a street RB20DET . Or if you know someone running the ball bearing Hi Flow get them to take you for a spin , you may like it .

Cheers A .

[ryan_o_grady]

So what would be the advice on either of these 2 turbo's?

Which one and which housing options etc?

Thannks