Originally Posted by jebsleo
Why not? Looks like it would suit my goals just fine. Should hit 200ft/tq @3300 RPM and make upwards of 300rwhp and pull hard to redline. Not like its cousin, the GT28RS.
Basically what you just told me is you have a GT28R with a larger compressor wheel. The compressor is not the bottleneck on the GT28R, it's the turbine side. If you have the .64 housing you do not have the NS111 exhaust wheel.
Look at the compressor maps of the 28R and the 28RS...not much more total flow between them but the turbine maps show a LARGE increase on the exhaust side. That is where most of the power gain comes from. The VE of the motor is increased via the exhaust side which translates into HP.
The 2871R with the NS111 wheels is on the edge of being a mismatch between compressor and turbine, putting the smaller exhaust housing and wheel pushes it over that edge. The tip speed are off even more along with other factors. The 28RS is pretty much a perfect match between turbine and compressor which is why it's such a lethal street turbo.
The turbo kit developement we have done with the 28RS have shown full boost by 3000rpm (Full boost being roughly one bar) and hp in the 275-300whp range on 1.8-2.0 liter engines at that one bar boost level. You can push it further and easily get 325whp or a little more if the motor can take the boost. The added flow of the 71mm compressor wheel in the 2871 pushes the envelope a bit further to roughly 375whp and closer to 400whp if pushed as the larger exhaust side can support that without totally choking.
Run what you like, I was just trying to offer some advice as we work with all three turbos on a daily basis and have more data logging and dyno time than I can remember for all of them.
Good luck, feel free to write or call if you have any other questions or we can help you out in some way.