I would like a no bull opinion about converting my .63 AMS 37R turbo to a .82 A/R hot side. I am on E85 on a built 2.0, JM drag manifold, ported stage 3 heads with larger 1mm valves. My redline is 10K however my turbo will run out of steam by 9K. I expect maximum power to be around 700 WHP. I know with a .82 housing I can get another 50 WHP. Ams went with the .63 to help the 37R turbo spool while leaving some power up top due to the smaller housing. My question is by going to a .82 will it improve my 1/4 mile times. I know dyno and max power on the dyno does not automatically translate to better ET's. I read on the Buick forum some have found the P67 (AMS 37R) with a .82 had slow spool. Keep in mind that is with 3.8 L how will it respond to a 2 L motor? You drag result would be appreciated.

Bump for answers anyone

A .82 a/r would lag more correct? So it would come down to getting your 2 step and anti lag set right. If a .82 a/r is going to yeild more power mid-top range well that's were your going to be on the track is in a higher rpm.

I believe your out of luck when it comes to playing with different turbine housing a/r's because AFAIK you can only get the funky 5-bolt housing AMS uses in a .63 a/r.

There's a company out there that does that ATP or something.

I've been wanting to do the same but I'm going to end up changing the whole kit and go with something more modern.

correction I just found this post might help you out

https://www.evolutionm.net/forums/sa...76-turbos.html

If I understand what you are saying you are correct when you say the 5 bolt only comes in .63 only for the P67 (AMS 37R). To get .82 you will need to switch to a 4 bolt housing which would mean cutting the 5 bolt flange and welding the new 4 bolt on. That is not a big job but does require some fabrication.