Most of the manufacturers producing turbos do a pretty good job. Your choice of turbo should not be decided based on one manufacturer over another just because you like their brand or the name better. What really matters is which turbo is best suited for your engine. I’ll give you an example. When I first built my RB25DET I was using a Bullseye Power (Borg Warner) S362 Turbo with a .85 a/r. This same turbo was producing 650hp on a Toyota Supra, but it was maybe hitting 400hp on a good day. When the turbo seals blew I went with a .70 a/r and had a bit better spool but still only about 421hp. So I started looking at compressor maps a little more closely and with a little help from a friend and some additional reading I determined that a smaller turbo like a GTX3076R by Garrett would be better matched with the RB25DET engine based on the math. Sure enough, the planning paid off because I hit 534hp with a SMALLER turbo that was spooling quicker.
So the key here is that a bigger turbo does not always automatically mean more power. Yes, if I would have continued to push the limits of my Bullseye Power turbo with race fuel and tons of boost, it would eventually make more power than the smaller Garrett. But that is just not practical for a street/track car hybrid and that power is not in the usable RPM range.
Be smart when selecting your turbo. I highly recommend reading this book and running the numbers yourself. Maximum Boost
