Well, I was going to hold off on this post until I was actually getting into my project, but Im bored on my lunch break and Ive had this on my mind for the past 3 days now, so here it goes.

Im building a BMW with an LS2/T56 swap. Im not building a drag car, nor an auto-x or road course car. Its going to be a high power FUN street car that has the ability to do all those things, but will not be built with anything specific in mind other than to put a smile on my face.

My background is mostly with Syclones, Typhoons and Turbo Buicks. Ive owned my Typhoon for 8+ years now and it currently has a PTE-52 turbo, custom downpipe, chip, ect ect.

Being that Im mostly familar with single turbo automatics and I haven't found exactly what Im looking for in terms of someone elses build to go off of reguarding street friendly twin turbos with a 6-speed. Ive read most every thread by searching "twin turbo" and "twin turbos" on the forum, as well as the stickies and checking out some of the vendors kits that are available for F-bodies and GTOs.

So with that, Ill get the nitty gritty already.

My goal is 700 - 800 BHP running 15 - 20 PSI.

I've already bought HP Tuners Software since I needed it for another project already, and meth injection is not out of the question.

I definately want to go with a ball bearing turbo and I have been eyeing up the GT35R with either .82 A/R or 1.06 A/R (this is something Im not 100% sure about, but I was feeling the .82 A/R would be the right one).

If I was going single turbo Id probably be a little more confident in my decision making, but Im not sure if I should read things like I have 1 turbo on 3.0L of engine or not.

So would Twin GT35R's be a good pick for a street 364 CID / 6-Speed combo? Or are they going to choke out in the higher RPMs on track days?

I plan on going with 6.0L truck manifolds, dished pistons and larger combustion chamber heads, upgraded rods, ARP fasteners, ect ect. Ive seen a number of people run high HP numbers on stock crank, and others who have steel cranks running lower numbers, so Im up in the air on that right now, but this turbo selection will help me get the ball rolling in the other departments.

Ok, lunch is over but I think I got the main points out there. Again I hate making posts like this but its been driving me crazy and Im sure someone here can put my mind at ease.

Thanks in advance.

 

Maybe this will put things in "perspective" - my mechanic ran two GT 35Rs on his 3.8L '98 Firebird with heads/cam and laid down somehwere in neighborhood of 773whp. Once they got to that range they said they were running out of turbo. I would think if you went with the 1.06A/R GT35Rs you should get your 700hp goal (intercooled, that is).

 

one to go ...2 fo' sho'...and double the trouble shooting...
just something to consider...either way it will be a fun build.
best of luck in all your future endeavours. ciao' roberto'

 

well 773whp is I guess in the neighborhood of 840bhp so thats more than what Im looking for.

Ive considered it, honestly I was going to go with a Magnuson MP122 but I couldnt bring myself to go with a S/C. Its been suggested to me a couple times by my friends to go with a single and I had contemplated a GT45R but there is something that is worring me about lag time on the street with a large single that keeps bringing me back to the smaller twins.

Yes, one to go and two for show, but I already states pretty clearly that I wasnt building a track monster and yes I do plan on showing this car, keeping the AC and cruise control and taking the family out to dinner once in a while.