Re: Don's 08 STI. STI Hatchback/Wagon or bust!
I like this turbo! It is perfect with my driving style or bad habits. It is easier to drive in stop and go traffic. The stock turbo was pretty close to an on/off switch and was sort of a pain to drive. The Tomei ARMS M8265 is a little laggy, but my engine has slightly higher compression, so engine response does not suffer. It actually is more responsive, most likely from the 9.0:1 comp pistons, Killer B manifold, and less back pressure from the new turbo. I am guessing volumetric efficiency has improved with this combo. My gas mileage has improved as I am able to stay off boost easier while cruising. The engine response is great. While on boost, it hits hard, even under 4k rpm, and the Synapse Engineering diverter valve assists with turbo response under boost and gear change. While I do not know what the actual numbers are, since the dyno calibration factors were lost due to the computer crashing and lack of support from the makers of the dyno, my tuner say this set up is good for over 400whp and it definitely feels that way. Thanks to Mike and Dylan of Infamous Performance for the quick turnaround, and Bill from Delicious Tuning for extracting the power out of the engine.
The Tomei ARMS M8265 would have been the perfect turbo for my application, but the oil line bolt leaked and needed to be replaced with an aluminum one from Blouch. The wastegate actuator spring was not the advertised spring pressure of 12.8lbs, but more close to 22lbs, as the dyno showed 22 psi of boost, my tuner had to work around this and told me he could have extracted more power on lower boost. Other than that, it performs to my expectations.