street ported 13B T2

the engine revs out just fine in 1st and 2nd gear(can start to feel it drop off...), but in 3rd above 6,500rpm the power just drops out...making it difficult to get to the rev buzzer.

boost starts off at 12psi and falls all the way down to 6psi by redline.

would it be worth it to upgrade to a bnr or is the hotside just choking it?

 

stock turbo? the hotsides are way to small on there. That's exactly what mine did. The BNR turbos push the stock hotside to the limit and are good for 12-14psi to redline, but that's it. The stage 4 is basically a Turbonetics T60-1/Garrett T04S, but choked down by a smaller compressor side and way smaller hotside. Expect a max of 350 or so on the BNR turbos. Street ported motors add more overlap and backpressure, so they are particularly held back by the stock hotside.

If you just want a reliable and inexpensive 300ish rwhp with the stock ECU/Rtek and mild mods, then the BNR stage 2 would be a good choice.

 

stock S5 turbo.

if my car made the same power all the way to redline i'd be happy.