hatemi said:

I believe that the rise of EMPs is caused by more air going through the engine with less backpreasure after the turbine. This is clearer if the turbine is small and at its edge already. With less backpresure after, the total preasuredifference and available energy for the turbine is grater. With small turbo youll end up overspinning the shaft and might get the whole thing out of its operating range.

Didn't think of that! Actually it looks like 4 psi emp more at 3600 rpm, and 2 psi more at 5000. I would think that restriction would go up with revs? Now, if only we could get a comparable test with OEM DP w/o cat, to see whether the cat or the DP is the bigger restriction.

Some data from the graphs, as close as I can see from the graph zoomed in:

At around 5000 rpm:

The 3" DP w/o cat is at N75 72% , EMP 35 psi, IMP 25 psi.

The stock DP w cat is at N75 74%, EMP 37 psi, IMP 25 psi.

At 3600 rpm:

3"- N75 75%, EMP 28 psi, IMP 26 psi

stock DP w cat- N75 71% EMP 32 psi, IMP 26.5 psi

Acceleration: 3" does from 3000 rpm to 4800 rpm in 6 seconds.

Stock dp w cat does 3000-4800 rpm in 6 seconds.