Good turbo or not for DIY build?

[jdw]

Good day everyone, I know an idividual that has a used turbo off a 12.7L Detroit Diesel engine and I was wondering what the group thought of the turbo and if it would be a good one for a build.

Here are some specs I dug up on the net I have yet to see the Turbo but I think these numbers are right oh and it is a garrett with a waste gate and twinscroll, I know these features aren't ideal but I think I can get it cheap,



Exhaust (Turbo Manifold) Flange: Standard T6 Twinscroll
Exhaust (Downpipe) Flange: 4.25" (ID) / 4.75" (OD)
Intake Inlet / Outlet Size (IN): 5.00 / 4.25
Compressor Trim: 55
Compressor Inducer /Exducer (MM): 67 / 96
Turbine Trim: 135
Turbine Inducer / Exducer: 87 / 75

ETA: I think it is a .88 A/R but don't know for sure

[racket]

Hi

Should be OK , the turb exducer area is ~25% greater than comp inducer area , this is good .

A 67/96 comp is a 48 trim wheel, the 87/75 turb is a 74 Trim .

At the right price it'll be worth buying, the wastegate shouldn't be needed , so seal it shut .

Mass flow ~60 lbs/min - 1 lb/sec , thrust about 55 lbs , 77 with afterburner :-)

Cheers
John

[jdw]

Thanks racket for the quick reply guess i'll have to scoop it up!!

[jdw]

OK finally got the turbo it's a Garrett GT4294
Compressor Specs:
Inducer = 70.3mm
Exducer = 94mm
Trim = 56
AR = 0.60
Turbine Specs:
Wheel dia = 82mm
Trim = 84
AR = 1.28

So the question is did i do any good? How suitable will this turbo be for a engine?

Thanks guys JDW

[jdw]

MAP: www.full-race.com/store/images/full/garrett-gt4294-twinscroll-turbo-content-1.jpg

CGTF: www.full-race.com/store/images/full/garrett-gt4294-twinscroll-turbo-content-2.jpg

[racket]

Hi JDW

It should make a nice engine.

The turbine stage is a tad small by normal standards with the turb exducer only ~14% bigger area than the comp inducer , preferable to be ~25% bigger area , also the 1.28A/R housing will limit flow a bit , to offset these negatives the compressor wheel is quite efficient so there'll be less need for expansion in the turb stage , and the "smallish" 0.60 A/R comp housing is limiting airflow which should help balance the turbine stage ..............yep , go for it :-)

Limit your P2 to ~30 psi to start with , as this will keep you in the high efficiency island/s of the comp map and your temperatures at their lowest , once you're happy with the engines temperatures you can increase the rpm a bit to get a P2 of ~35-38 psi , comp efficiency starts to drop off after that and it generally isn't worth pushing the engine any further , especially with a 56Trim comp .

Cheers
John