Thread: GT28RS 0.64 vs 0.86

Right, I'm planning to use a GT28RS on my future VE+T setup, but I'd like to know which trim will be best.

We all know that the lower number means better spool, but less power up top, and the higher means slower spool, but more power up top.

So the first would be better for DD, and the latter for racing. But what are the effects when combining the higher number with VVL?

Can anyone tell me what would be the best turbo for DD, in combination with the VVL? Is there any significant difference?

The trim has to do with the compressor and turbine wheels. What you are talking about is AR. If you are putting this on a VE get the .86 turbine housing. I would recommend getting the GT2871R over the GT28RS. You will get more HP at every given boost levek and the power band will hold to 8000 rpms.

The disco has an 84 trim wheel iirc. The GT2871r will hold power better, but I don't like the spool characteristics of that turbo, jmo. But it will rock if you can rev high. Otherwise, a .63ar GT3071r will work much better, but will require more work and money to use it.

really though, by the time you went with the 3071r, you would want the .82ar exhaust housing.

Does the disco/VVL combo work very well?

Ah, yeah, I meant AR, but I used trim in the same sense as using it to distinguish 2 cars of the same models, but with different spilers, skirts etc.

Anyways, I guess it would make more sense to have a turbo that delivers better at higher RPM when you have a motor which is limited at 8000. What AR would be recommended for the GT2871R? Or is that different for everyone? Cause there's like 10 different GT2871Rs listed on the site of Garrett.

Coheed, remember the vvl head will wake up the GT2871R and I like that over the 28RS in a VE application.

Brent

true, the VVL will prob spool it faster. I just really love the stellar response from the disco.

They have a bunch of different turbos from garrett rated up to 475hp or so for the GT2871r.

I too like the GT2871R idea better for what that's worth.

If you stick with the small turbo, get the larger A/R ratio.

Okay.

Now help me make my choice :P

I've been reading into the GT2871R, and it seems that there are a few models, each with 2 versions.

I think I should stay away from the "smaller" 5-bolt pattern flanges, as stated on the Garrett website.

In terms of boost and VVL, would I need to go high boost (12 psi and upwards) or low boost (6 and upwards)?

This is the only one for SR20 engines as far as I'm concerned.
TurboByGarrett.com - Catalog
Fitment is correct (although that might not matter much to you if you're going to fabricate everything else) and both wheels have the best size, trim and A/R. Nothing too big, nothing too small.

If this were me, I'd be aiming for and planning on 400 WHP around 12 psi but that's me. Maybe most people could expect 350 WHP at 12 psi so maybe plan on that to tell you how much boost you want to run. If you're wondering what kind of wastegate to get, get the weakest one you can afford if you're given a choice. It will make tuning easier.

How do you know that it's the only one for SR20 engines? What's different from the other ones?

EDIT: Off topic, but since we're on the subject: Does a T2 flange mean a flange for a (G)T25XX and (G)T28XX type turbochargers, and a T3 flange mean a flange for GT30XX and such turbochargers? And thus T4 stand for a flange for GT40XX?