Result for you. ATR43ss2 ballbearing version compared to Garrett GTX 3076 gen 2. Same 0.82 externally gated housing used on both, and the turbo was the only change to the setup. Forged RB25, Supertech valvesprings, 256 Poncams, topmount steampipe ex.manifold with Turbosmart 38mm external gate, 3.5in intake pipe, 3.5in turbo back exhaust, Apexi PFC. P98 fuel.
Disregard the pink line; that was the GTX running an EBC that overboosted, run aborted. The blue line is the ATR43, no boost controller, just running wastegate pressure. The red and green lines are the GTX, also just running wastegate pressure....crappy ex.manifold resulted in spiking a much higher boost pressure, another story so disregard that aspect of the higher HP when it hits 24psi.
Important part to note is the ATR making more HP through the entire run right up until the boost creep on the GTX. Also to note, the R35 afm in a 3.5in pipe was hitting 5v at the peak of the red run.
Here's the run of just the ATR.
Just under 400rwhp. Note this was also with an inadequate boost controller; now running a Greddy MAP controller allowing for boost to come on stronger earlier without overshooting at higher rpms, so the midrange is now stronger.
Same dyno and tuner for both, just done at different sessions.