dubseven

Application is a 2L Saab. 25-30psi on E85. Not looking to sacrifice spool. Turbo came with the small inlet 2 bolt compressor cover. Would like to switch to a 3" or 4" inlet compressor cover.

So, T04B or T04S cover, and why? Anti surge? Or, should I just leave the 2 bolt inlet?

http://www.atpturbo.com/mm5/merchant...egory_Code=GCH
http://www.atpturbo.com/mm5/merchant...egory_Code=GCH
http://www.atpturbo.com/mm5/merchant...Category_Code=

TheShodan

iTrader: (14)

The two bolt inlet is more of an option than standard, and you use the to4b standard inlet. 25-30psi of boost is in the upper range of what a GT2871R can do so depending upon your power goal you may want to look to something a little better in your efficiency range. (Again, just suggesting here, as you didn't express what year / engine of the SAAB or a power goal)

A T04S absolutely makes no sense for that compressor wheel, and you would do exactly what you didn't want, which was to loose recovery of pressurization between shifts. Ported shroud would be a better option considering the boost pressures that you're trying run to help with reversion. But that's not an option on the T04B until you get to the GTX28 series of turbos. Using a To4S cover as a ported shroud is just much a waste as going T04S in the first place..

Again, with more engine/ power level information, we can be of more precise help to you

dubseven

Goal is 350-400whp. 95 Saab 900, 2.0T. E85 is the fuel. Revving to 7500RPM.

So the T04B with the 3in inlet is the way to go? Decent gains over the 2 bolt housing?

TheShodan

iTrader: (14)

For that power goal, you're going to get perhaps 350whp, but not 400whp, not by a long shot. You need to step up to either the GTX2876R or GT3071R (in the 56.90mm turbine wheel) to do that. Doesn't matter how you slice it. "spool" will be fine.

And no. Stay with the T04B, in either case. No 2 bolt.