GTM Performance Engineering: MHI Twin Turbo Official Release

esfourteen

you wont get boost creep with the .86 AR (stage 2). originally I had .64 AR (stage 1) with internal wastegates and I had trouble running less than 13psi, I got custom 2" restrictor plates made up to put in my exhaust at the time and it worked great, basically adding back pressure prevented exhaust gasses from bypassing the small wastegate opening. I was able to run 10psi on that setup. Now i'm trying to dial in 17psi

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Alkatraz

Sounds like you are going with the exact same setup as myself

Is anyone else here going to need to have the BOV's recirculated (plumbed back)?

I know that I mentioned this to Mike a while back and he said that they would have an option for it because others had already asked about it but he didn't elaborate on what it would be. I don't believe that the standard Tial Q or Turbosmart Raceport BOV's can be recirculated so I would assume that they will send either the Tial QR or the Turbosmart Plumb Back.

Does anyone know more about this?

BlkNismo

will there be boost creep issues with the .64ar running 2.5" all the way back, no cats?

Chuck33079

It's entirely possible if you're planning on using internal wastegates. Either go external or step up a turbo size and you won't have to worry about it.

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megalapagas

By step up a turbo size your reffering to like from .64 to .84?? Don't flame me I'm still in the learning process lol

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Chuck33079

That's correct.

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megalapagas

Yesss!! Everyday you learn something and I finally got it right lmao so then I'm fine with my Exhaust setup that I have in my Signature its all Non-Resd with the .84 internal no need to change to external or would there be a liability on boost creep still? Reason I ask is I rather have room for safety than having trouble down the road

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GTM 34 Row Oil Cooler | K&N Drop Ins w/ Z1's Post MAF Tubes | F.I Non-Res'd 2.5" T.P w/ CF CBE | Axis Wheels | Piecing together My Own Custom T4 Top Mount Single Turbo Kit *Still in the works* |

elperuano

Boost creeping is fun! More boost!

megalapagas

More Boost More POOWWAA! Said No Blown Engine Ever

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GTM 34 Row Oil Cooler | K&N Drop Ins w/ Z1's Post MAF Tubes | F.I Non-Res'd 2.5" T.P w/ CF CBE | Axis Wheels | Piecing together My Own Custom T4 Top Mount Single Turbo Kit *Still in the works* |

G37sHKS

Go with external wastegate. my boost gauge was reading 8.8 PSI while the internal wastegate spring was 7 PSI.

1.8 PSI of boost creep is a lot if you ask me. Im not so sure if going with .86 housing will eliminate the boost creep or will just minimize it (which is still not good)

So just to be in safe side. go with external wastegate. you will have better boost response, better flow, more power, and last but not least, it will extend the life of turbo.

Yes you heard me right it will extend the life of turbo and will give better power and more power.

Please watch this video to learn more about external and internal

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Chuck33079

Yep. Other than cost, external is always better.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

megalapagas

Thx now I'm SET FOR SURE.

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GTM 34 Row Oil Cooler | K&N Drop Ins w/ Z1's Post MAF Tubes | F.I Non-Res'd 2.5" T.P w/ CF CBE | Axis Wheels | Piecing together My Own Custom T4 Top Mount Single Turbo Kit *Still in the works* |

showme99

Very informative video. Thanks for sharing.

Dzel

How much is it for external $400.00 more I'm guessing?

That video was very informative. Thanks x

Sent with TapAhoe now Free

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esfourteen

Every factory turbocharged car in the world comes with internal wastegates, for the obvious reasons of: cost, weight, and clearance/space issues, so aside from those, I would say its a good idea to run externals just because internals have certain limitations.

Since the volumetric efficiency of our engine is so high, I would say if you have the extra money just go external so you avoid any boost creep issues with our engine. However, claiming that external wastegates are safer and give "better power" (whatever that means) and more power is just a joke.

The biggest problem typically encountered with internal wastegates is controlling higher amounts of boost (> 20psi). Theres 2 reasons for that, first most factory actuator springs are in the range of 7-14psi, so with an EBC solenoid at max duty cycle (about 90%) that would mean a maximum of 14-28psi. The second issue is the size of the wastegate openings. Internally gated turbos wastegate opening is limited by the size of the turbine housing itself, external wastegates do not have this limitation. This is why the .64 AR suffers from creep issues while the .86 does not.

I currently run 15psi and have no issues holding that to redline on internal gates with .86 housings.

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