TECH: Back-pressure and Exhuast sizing.......

[nashstyle]

This has probably been covered (I just skimmed the 2nd page of the thread). I dont see why you would want any back pressure at all??? If I could, I would run my car with no exhaust at all, I mean, I've run it with the wastegate plate off and I could feel the difference (much better spool up and better torque...and .002 sec better down the 1/4 but this is negligable as I also got a farking great start on that run).
The way I see it, back pressure just causes exhaust gasses to pass through the turbo (and therefore out of the engine) slower, why would you want that? Wouldn't it be better to have 0 back pressure, and if at all humanly possible a -ve value of back pressure i.e the exhaust being sucked out?

I know you want the INTAKE system to be pressure/restriction free, so why is this different for the exhaust?

[toysrus]

The only issue with going to '0' back-pressure is that the Turbine *MAY* operate below its efficiency temperature, now whether or not this has an effect on power is up for debate :P

But going back to what coop1er said, creating the biggest pressure difference will result in he greatest velocity of gases and since the volume of gas is related to its temperature, then having the Turbine nice and hot by either 1) small A/R 2) high back-pressure exhaust 3) balanced combination both should achieve just that, with each option resulting in the differing power outputs