Thread: Questions about GT2871R Turbine Housings and A/R..

Hey,

So I'm looking at the options for turbine housings for the GT2871R and am not really clear what application each config is for.

The choices are:

- T25 Turbine, 5 bolt GT discharge
- T3 Turbine Inlet Range, 5 bolt T3/T4/Ford Style Discharge
- k24/k26
- T3 4-bolt
- Tial Stainless V-Band Turbine Housing

Can someone please explain to me what application each turbine housing is used for?

And how much difference is there between a .86 A/R and .64 A/R Turbine Housing?

Thanks,
-G

p.s. link to gt2871R: Garrett GT2871R: atpturbo.com

First off what exhaust manifold are you going to use?

Yea basically the housing depends on what type of manifold you are using. If you are using a T3 manifold then get the T3 housing in either 5 bolt(internal wastegate) or 4 bolt. I am almost sure the vband is also a T3 housing(no bolts just a vband for easy removal/install), and then there is the T25 which will bolt up to our stock gtir/vet manifolds maybe even avenir. k24/k26 I believe is Volkswagen flange.

Now for the Turbine housing the difference would be spool time and top end. The smaller .64 housing will have a quicker boost onset and may lack top end pull in comparison to the .86 housing which will spool a little later and more top end. This is in general I am speaking. I have seen a lot of dynos where the .64 housing actually made 400 whp but have not seen the .86 housing in action/(240 forums). Also the turbo is super responsive so I am really not sure the spool time will be a big difference.

cool. I think you answered all of my questions.

I plan on running an Avenir manifold, so I should go for the T25 turbine housing.

What turbine style would I use if I wanted to do an external wastegate w/the Avenir by getting the external wastegate flange welded onto the manifold? Would I basically have to weld the internal wastegate shut on the T25 housing?

Also, it seems the .64 housing is more popular than the .86 for the 71R

If you are gonna go external wastegate, I would ditch the t-25 housing. I would personally go with the t3 4 bolt exhaust housing. If you are gonna have someone weld an external wastegate, you could probably get them to weld the t3 flange on it also. This would make upgrading in the future a bit easier.

If you are cheap and impatient, like me, Just bolt the t-25 housing on and go.

As for the popularity of the .64 vs .86. Alot of times you have to specify when you order, otherwise they just send you a [standard] housing. I would go with the .86 personally, I had the .64 and it was almost useless from a stop till 3rd gear. The bigger ar should create a bit more lag, but can asure you would be happier with the result. Unless you just like to smoke tires.

Get

T25 Turbine, 5 bolt GT discharge with .86 AR

Compressor housing .60 AR with 3 inch inlet

i disagree with this, get a .64, much more responsive

FWD car spins tires already, this combo could use a little later spool

^^meh get the 3071r then in .64 i think its a better set up than the .86 2871r

but i suppose fwd is a different game, however if going .86 to induce lag to help with traction does seem silly to me as all you are doing is prolonging the inevitable, its just gonna bog down a little more then spin 200-300rpm latter

LOL- i know but it does help keep out of spinning tires driving on the street