We were presented an opportunity by one of or sponsors, Cobb Tuning to test their new 20G TDO5 Turbo on our 2015 STI. Now that we have been able to put some miles on it we are in a better place to write a review and share our feedback with you guys sitting on the fence and or unaware of it.

Supporting Mods:


Cobb Accessport

Mishimoto TMIC

DeatschWerks Fuel Rails

DeatschWerks DW300C Fuel Pump

DeatschWerks DW1500cc Injectors

Stainless Fuel Lines

Fuel Pressure Regulator

Catless Downpipe

Dual N1 Exhaust

Stock EJ257 STI Block

Tuned by Clark Tuner at Goodspeed Performance in Scottsdale, AZ on a Maha AWD Dyno.

91 Dyno with stock Turbo vs. Cobb’s 20G:

We made 300WHP on 91 with the stock STI turbo. No other changes other than the Cobb 20G Turbo and a new tune and we got 350WHP. Full boost was hit at 3400 (Give or take) and held boost flat to redline. Both the stock and Cobb 20G were at the same boost pressure (19lbs).

Clark Tuner did back to back pulls on 91. 350, 350, and 352WHP.

The final result of the 91 tune was 356WHP at 19lbs of boost.

E85 Tune:

I wanted a conservative tune as we are on a stock block and I did not want to chance blowing a motor with 4K miles on it to have a few extra HP for numbers.

Clark Tuner was able to pull 400WHP out of the Cobb 20G still at 19lbs of boost with room to spare. Very safe and strong tune and has a lot of top end power. Based on Clark’s results, he was comfortable telling me that the Td05 seems to out power similar Td06 models. I know this will turn into a debate, but we are not here to get into that with other brand turbos. This is based off of experience tuning just about every brand turbo on the market.


With this being a semi daily driver, it performs well, and has held strong. We have put about 2500 miles on it and have not had a single issue. You can feel the power almost instantly and I don’t feel like I am loosing power when reaching redline. It is fun and inexpensive compared to competitive models. I would recommend this to anyone looking for a fun turbo upgrade. You cant go wrong with a turbo backed by Cobb. It included everything needed to install out of the box.

I do not yet have anything negative to say about this turbo except for the clearance with the upgraded TMIC, but I have seen clearance issues with past turbos on my older STI.

Great job Cobb! I will report more information as I continue to push this turbo! Did I mention we have been testing this in Arizona? 110+ degrees outside.

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