| Thanks gang for the fast response. Cavitating turbos.....my field is not thermodynamics so I'm not the expert; A thermodynamicist at work suggested cavitation and he races Starions with huge turbos specifically so they don't cavitate. Could be he's using the wrong term who knows. Whether the term is correct or not, the process is that as the air gets thinner, the turbine has to spin faster to move more air. You can see the effect when you put your hand over a vacuum cleaner, the rpm's rise. Turbines create higher pressure on the leading side of their blades and lower on the trailing side. As they turn faster, the low pressure zone behind gets larger and eventually meets up with the leading edge of the next blade. The analogy is a little different between turbine and compressor but the principle is similar. Friend showed me an Ansys animation he did to model his turbos and you could see the pressure zones as the turbo reached its limits. But he builds his cars for high sustained track speed and horsepower regardless of response so his advice only goes so far for me. Turbocharged aircraft engines de-rate as altitude increases for the same reason. Anyway....I suspect that is the problem for me because my intake path is clear, no boost leaks and I can plug the boost jets completely so the waste gates are never opening, and still no more than about 9 PSI. I like the suggestion of an EGR leak so I'll either replace it or ditch it when I do the rebuild. Will also probably get a larger intake filter than the single K&N filter of the JWT stage III I have now. Please suggest more.... But....I still want to put ball bearing turbos in because I want them to last another 20 years. I'm seeing kits complete with downpipes for under $3K, and I'm willing to drop the cash but don't want to be disappointed with the new horsepower range so I need advice on which ones will give me the fast spool at no less than 2600 rpm but with more capacity. Some track racers I know are looking for more horsepower regardless of response, and that is not what I'm trying for because this is my daily driver. I have JWT stage 3 SS exhaust system....is the suggestion that I go bigger than that? Does anyone have experience with the GT2560, GT2860.....GT275's? When do they spool? Keep the advice coming...I need all I can get so the cash I drop lands in the right zone. Thanks all! Jameyguy
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