turbo identification
 

so im thinking about picking up this turbo buddy only wants 100 bucks for it. no shaftplay and spins freely now he said he doesnt know much about it other than he was told its a gt28 with a precision hotside. ive figured out it has a t3 flange and a ford 5 bolt for the downpipe. other than that im lost.

well i figured you guys know a hell of a lot more than either of us. so i wanted to see if you could ID it for me?

markings on the compressor side front ( first pic) 4 A/R.50 M-24 L and garrett.
on the side of the compressor near the outlet. reads: -3705


https://www.miataturbo.net/attachmen...ine=1342903128
https://www.miataturbo.net/attachmen...ine=1342903128
https://www.miataturbo.net/attachmen...ine=1342903128
https://www.miataturbo.net/attachmen...ine=1342903128

some sort of t3/t4. turbine is Turbonetics, looks stage III.


consider a gt28 has a 60mm exducer on the compressor and a small t25 turbine...

Awesome! thanks!

well im guessing a t3/t4 isnt going to be entirely too much overkill on my car then?
I was originally looking at a gt2871r but with the release of the gtx2867r i was really loving the thought of the sooner spool while still having the ability to hit around 350 whp.

That's actually a nice turbo for 100 bucks. "T3/T4" is possibly the worst thing you can say when asking for identification or specifications. T3/T4 turbos can range from 350hp to enough to spin the earth backwards. It's a huge shot in the dark to guess what sort of spool time/power you can get out of this thing just from the pictures.

I'd pass on it if you're willing to budget a GTX, though.

Edit: quick google search says common turbos that use the .50 compressor are 50 trims and 57 trims. Around 500-600~ new from most turbo suppliers depending on your turbine choice. Both will sail past your 350whp goal with ease and probably spool like sh!t. Without actual wheel measurements this is all speculation, of course. But, if you can budget a GTX, get that.

I wouldn't run that. even if I had a built motor.

You would likely be very unhappy with that turbo.

then I guess I am passing on it!

once again yall have saved me from disappointment and wasted money!!

so the GTX it is then
quick question, I have figured the 2867 is a good choice because i was originally looking at a gt2871. But for S&G and the fact i suck at reading compressor maps. Will the gtx2863 meet my goals? and what is the theoretical max hp for it on a built 1.8?

what sorta power goal? the 2867 and 2863 are pretty close in terms of peak output, but the 63 will have much better low end for sure.

a built 1.8L can be limited by the size of the turbo...all depends.

well im looking at at least 350whp. if not push the transmissions envelope towards 400.
but since its mostly a DD i dont want to risk replacing the 6 speed every year or more so over 400whp is never an option.

If you plan to DD the car, the 6speed will be fine for 400+whp. You will never put the same stress and torture on your transmission on the road as you will on the track.

The only person I've heard of breaking a 6 speed on the street was Faeflora, but he's special

Edit: the turbo you showed in the first post would be nice with a .48 housing, assuming it's a 50 trim and not a 57 trim. 350whp would be cake.