Originally posted by 930gt-40r
Porschefile, the only reason I am going with the 1.06 is because the motor is 9.5:1 3.4L and I really want this thing to pull to the redline (going to spin her to 7500). I dont think she will have too much problem spooling, I am hoping for 550-600 to the wheels and with the 35R that is right at the sweet spot, 22-26 psi. But you are right, I could have done the .82 or .83 housing and had a hell of a lot of bottom end. I dont know, we will just have to see when she is done, I will keep everyone posted.
Hmm, honestly I really don't think a 1.06 is necessary until you get somewhere above ~4.0L as with a smaller .82 on even a 3.4l, there won't be nearly enough backpressure or lack of exhaust flow on the hotside to necessitate the use of a larger hotside. Are you sticking with the 9.5:1 CR? If so, I hope you plan on using race gas!
If you really want flow, go with a .81 T4. A T4 hotside is quite a bit larger and will overall flow better. I'm running a .81 T4 hotside on my crappy 60-1 w/ a P-trim turbine. The 60-1 is ancient stuff, though w/ 964 cams my car pulls hard to 7k rpm. With a 35r compressor wheel and that T4 hotside, you will have more than enough flow and reduced backpressure that it will definitely pull hard to ~7.5k
Greglepore, with a stock CR motor, I really wouldn't waste the money converting to a GT series turbo. I'm not sure what size turbo you have on your setup. Do you have a T3 or T4 exhaust flange? I'd highly recommend checking out a turbo from Precision's "SC" series Precision Turbo
I believe someone was running one on Pelican and they were reporting some crazy quick spool. Anyways, Precision's SC series turbos are usually only ~$800-850 new and I believe you can even request a T4 hotside. Ultimately, you're going to be limited on total power by your CR, and I doubt if you could make much more than ~350whp.
Jim2, Garrett's GT series doesn't use anything related to Turbonetics. Turbonetics is a completely different company. Here's a link to their website
. On their website they have all of the info and compressor/turbine maps you could want.
Most of the stuff they are using is fairly conventional. Most of the turbos have your typical T25, T3, or T4 flanges. There are some unique and cool things about them though, such as divided exhaust housings like This
which help a turbo spool up more quickly. Other than that, the wheels have been redesigned using the latest stuff like advanced CFD software, so they are much more aerodynamically efficient. On top of that, I'm not sure exactly what processes they used though the GT series wheels are lighter than their equivalent T series counterparts, yet they are stronger. This equates to quicker spool and higher shaft rpm capability, meaning they can more easily withstand high boost pressures.