JDM VF37 Twin Scroll Turbo

I was recently looking at turbo upgrades (just for fun) for the STi and I found a site which says the JDM GD EJ20 version 8 engine uses a IHI VF37 twin scroll turbo. I was wondering if that is the same type (twin scroll) used in the USDM car and what exactly a twin scroll turbo is. Also as i try to broaden my knowledge of the STi I would like to know what other differences diferentiate the JDM car from the USDM. Thanks all

USDM does not have a twin scroll turbo. It has a vf39. A twinscroll turbo has 2 entries for the exhaust. On a 4 cylinder the 2 shortest pipes in the headers come togeter and the 2 longest pipes come together. so you will have 4-2 headers instead of 4-1 or 4-2-1. It allows the turbo to spool up much faster. I've heard claims from 800 to 400 rpms sooner compaired to the vf34. I have pic of mine on clubwrx so i'll try to find the thread.

found it. In the 2nd pic you can see how where the uppipe connects is much different. then in the 3rd pic you can see how different the rest of the turbo is. http://www.clubwrx.net/forums/showthread.php?s=&threadid=53345&highlight=twinscroll

did you ever get it in?

next week I had to wait for my oil pan cuz it was on back order for a few months. The guys I'm getting it installed by are taking their show car out to california and will be haning out with guppes.com guys, got the turbo from them, and they're going to pick up a turbo bracket, gaskets, and a fuel pump. Gets installed on tursday morning, drive around w/ dp only till I go to the muffler shop and get the exhaust made later that day or the next, finaly to the dyno to get utec tuned on friday, and to top it off drive to cali on sat. morning