Need new turbo... advice on size

[Logan1994]

Ok so I just bought a turbo 535i and the turbo is shot. Called turbonetics to have it rebuilt and they said that the turbo is to old to rebuild. Anyway I am looking at getting a turbonetics t4 62-1 or 60-1 both have p trim turbine wheel. Now I am wondering what size A/R to get they have .58, .68, .81, .96.. I don't know much about turbo sizes only a little from google search so I figured I would ask you guys. Power wise I would like to make around 400+ and run e85 too. Main reason I am going with turbonetics is due to the fact my dp has a 4 bolt on center flange. And they are the only ones that have it that I can find. And treadstoneperformance has them for $747. ANY advice would be appreciated. Thank you guys ahead of time.

[Mark 88/M5 Houston]

I would bounce your question off Todd at TCD; He is the E 28 turbo guru.
http://turbochargingdynamics.com

[marc79euro645]

I'm bumping this ,because I'd really like to hear the answer as well. I'm just using a k27/745 turbo, and I don't know enough to give a good answer.

[Cjames570]

I am running the .68 on my 6266 and im hitting full boost (16lb) right on 3500. I ran a .58 for a short time, but honestly I think the difference in boost response was minimal, maybe 300rpm sooner. IMO our engines don't really spin the rpm's to need anything bigger than a .68 either, although there are people running over 1.01 on m30's

[Logan1994]

Sorry for not updating in awhile. Todd got ahold of me and is hooking me up with a comp turbo. T04e 61mm comp wheel p-trim with a .58 ar.