The turbo is a diesel turbo used on merceds and volvo commercial trucks. I don't have all the measurements with me right now, but internally it measures like a holset hx35, maybe a tad more flow. It's a Journal bearing K27 with a billet compressor wheel. It looks huge because the housing are just so damn big. The exhaust housing is an 11cm^2 I belive. It's internally gated. The stock actuator was set at 30psi, so I threw an 11psi Garrett actuator on it til I gate it externally. It is a twin scroll exhaust housing, on a non divided cheap manifold which I have reinforced and mad a support for. No BOV. My plan is to do a sound performance quick spool valve, but surprisingly, this turbo is kinda spooling alright. Here is a link to it. http://eng.turbo3k.com/catalogue/d-37/ I have just gotten everything together on this car. A lot of diy fabwork for me to fit everything... Right now I need to get a few more things (injectors, rail) so I can get it on the dyno and get the Haltech PlatPro Plugin tuned. For now I'm only running about 13-14 psi which is on around 4000 rpm, but it feels like it could really spool faster when I can turn up the boost with a good tune. BTW, did I mention that I bought it brand new (Genuine KKK turbo. They get a ton in to bench test motors. This one hadn't even been used yet.) from a friend that works at the Volvo truck plant for 100 bucks?! My RB sounds ballistic with this turbo. Sounds like a Mack truck in fast forward, lol