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Garret GT2056 turbo for B230F+T

auto660

New member
Joined
Jun 26, 2020
Hello everyone,

I am in the procedure of getting all the parts lined up for a +T conversion, but i am still a bit in doubt about the turbo. This conversion is going to be for my daily driver with a M47 that could possibly be swapped for an AW71 in the long run. The 13C is nice because it spools almost instant, it feels like you are driving with a bigger engine. The 15G/16T is nice because it will actually keep performing after 4500RPM and still spools relatively quick.

But when i was browsing through the Garret turbo site, i found the GT2056 turbo which looks to be really nice. It's got the spool characteristics of a 13C down low and the flow characteristics up top of a 16T while having a higher efficiency all over the curve which would hopefully help with the somewhat high compression ratio on pump gas.
https://www.turbozentrum.de/turbozentrum/pdf/other/Garrett_GT2056_751578_2_1.pdf

Does someone have any experience with this turbo? The powerband needs to be around 1800-5500RPM with about 200~220HP up top with a broad torque band. And i would really like the instant spool for drivability in low revs with lazy shifting. I'm thinking about the following setup:

- B230F (of course...)
- V cam (2 to 4 degrees advanced)
- GT2056 Turbo @ ~10PSI on 90+ manifold
- KL Racing intercooler
- 2.5" exhaust without cat
- 3" AMM
- Chips and bigger injectors (need to look into this more)
 
The GT2056 looks to have a smaller T25 mounting, you would need a custom exhaust manifold or adapter for T3 to T25. I have always wondered about one of these turbos as they do seem to be a great daily driven turbo on paper. But I went with a 15G on my +T, and with the T-cam (in a 91 740 auto wagon) it spools almost as fast (i would say about 500 rpm later) as my factory stock 13c turbo car (91 740 auto sedan), but with a way fatter power band. I'm sure the GT2056 would be better than a 15G or a 16T, but when i did the dollar to dollar math between those options, the 15G looked waay better.
 
auto660 here, i made a new account because i wasn't happy with my user name

It seems indeed that the GT2056 takes a lot more effort to fit and the difference isn't THAT big with a 16T. So i just bit the bullet and bought a new MHI 16T from KLRacing, that should make the +T conversion a little easier.
 
Where are you from? I make 18T's new. They are the greatest of mhi td04hl.
The 19T is very rough and spiky, the 18T is more balanced.

You'll not regret it!

I'm from Den Helder, which is where the boat leaves for Texel. I am first going to try the 16T, my wallet wasn't all that happy already with this purchase. My power goals are modest, ~220ft/lb (300nm) and ~220HP at the crank to keep the high compression and M47 happy-ish.
 
auto660 here, i made a new account because i wasn't happy with my user name

It seems indeed that the GT2056 takes a lot more effort to fit and the difference isn't THAT big with a 16T. So i just bit the bullet and bought a new MHI 16T from KLRacing, that should make the +T conversion a little easier.

If you need a user name change, go to the website/forums, there is a stuck thread.
https://forums.turbobricks.com/showthread.php?t=340909

Deleting your old user profile will delete this thread, so I will wait.
 
If you need a user name change, go to the website/forums, there is a stuck thread.
https://forums.turbobricks.com/showthread.php?t=340909

Deleting your old user profile will delete this thread, so I will wait.
Ah, i didn't see that. I just looked in the user settings menu and couldn't find anything to change the username, since i haven't posted that much with the other account i decided to make a new one. I have donated $5 anyway for the account hassle and all the information i found here.
 
I'm from Den Helder, which is where the boat leaves for Texel. I am first going to try the 16T, my wallet wasn't all that happy already with this purchase. My power goals are modest, ~220ft/lb (300nm) and ~220HP at the crank to keep the high compression and M47 happy-ish.

16T and B230F is good for 260 hp/370 Nm with gasoline. About 1,2 bar boost, but it is close to knock.
 
Last edited:
16T and B230F is good for 260 hp/370 Nm with gasoline. About 1,2 bar boost, but it is close to knock.

I was thinking that the B230F/16T combo would probably start knocking around ~0.8 bar boost on normal 93 (or 98 in Europe) pump gas. So even though it has 9.8:1 compression, ~1.0 bar boost can be safely had on pump gas without extremely retarding the ignition timing?
 
If you're thinking of using an oddball production turbo like the older GT2056 mentioned by the OP, you'll have to go through a bunch of work to get it adapted to a Redblock. And if you don't mind doing all of that work, then it would follow that you should get results for your efforts, and it would really make sense to consider a newer gasoline passenger car turbo in that case.

The old 751578-0002 wouldn't be a bad match for a sub-300hp redblock and actually has a very nice compressor map. Better would be a modern MGT2256 or MGT2260 from a BMW S63 or N63 V8. These use higher temp capable materials in the turbine; Mar-M-247 for the wheel and austenitic stainless steel for the housing. Specific output will be higher (more power for the same size wheels) and turbine efficiency should be higher as well meaning reduced backpressure. The turbine housings use strong internal wastegate designs and v-band inlets & outlets. There is even a twin scroll version. And a single MGT20 or MGT22 is well matched to a 2.0 - 2.3L engine making ~250 to 300hp.

Here's an example - this is one is M5 spec: https://www.atpturbo.com/mm5/merchant.mvc?Screen=PROD&Store_Code=tp&Product_Code=GRT-TBO-193&Category_Code=SMPF

Found under the "small frame performance" category here: http://www.atpturbo.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=tp&Category_Code=SMPF
 
I was thinking that the B230F/16T combo would probably start knocking around ~0.8 bar boost on normal 93 (or 98 in Europe) pump gas. So even though it has 9.8:1 compression, ~1.0 bar boost can be safely had on pump gas without extremely retarding the ignition timing?

Yeah, that would be ok. We mapped B230 on static crank dyno so ping comes easier than on a rolling road inertia dyno.

It is smart move to upgrade intercooler.
 
@Duder:
Thanks for this writeup, this gives a good insight into the newer Garrett stuff.

@OttoB:
The bigger intercooler will be added, i have to buy one anyway and i like to have a bit more insurance against detonation. Later on i probably have acces to a dyno that can hold the wheel speed steady, so that will be great for finetuning the setup.
 
I was thinking that the B230F/16T combo would probably start knocking around ~0.8 bar boost on normal 93 (or 98 in Europe) pump gas. So even though it has 9.8:1 compression, ~1.0 bar boost can be safely had on pump gas without extremely retarding the ignition timing?

My buddy has a 16T setup with the 3" conical exhaust side. 1.2 bar (17-18psi),
original intercooler. No problems with knocking on 95 octane EU gasoline.
 
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