And the comment about pulse turbos making unlimited boost makes sense.
I do want to point out one more thing about the wastegate/non discussion.
Boost is a factor of expanding gasses from burned fuel, passing through the turbo at high velocity, and driving the wheel which compresses incoming air. There is no boost at idle because there is next to no fuel being delivered.(Remember, our engines are nothing more than big air compressors, air in the front, air out the back) At full throttle, the MAX boost is determined by the amount of fuel being delivered by the injection pump.
In a non-wastegated turbo, you can limit boost by having the injection pump turned down to only deliver a certain amount of fuel at full throttle.
The wastegate is there to route
excess boost away yes. The high boost off the line is achieved by sizing the compressor wheel smaller, so it spins faster/sooner as driven by the exhaust gasses, but therefore can also produce more than the desired max boost, especially with high throttle low rpms situations, thus the wastegate. And although the boost is being wasted down the pipe, the exhaust gasses are still hot, so you can still have way high egt's especially at lower rpm's.
I haven't done it yet(although I'm currently getting the parts together to get it running) with my ATS wastegated turbo, but I'm assuming that the boost on a wastegated turbo can also be limited in a similar fashion by turning down the fuel, so that the wastegate essentially never opens(I've heard of guys that have disconnected them, so they can't open), and egt's will remain within reason, and you'll get the benefit of the turbo and boost, but lacking the inefficiency at higher rpm's.
I also assume that the higher backpressures associated with a wastegated turbo would only be when the boost is so high that the gate is open, and exhaust (efficiency) is being "wasted".
Zigg