Interesting point, I suppose that the additional heat buildup could damage the cat. I am running e85 so that may help but I'll be searching the web for someone that has tried this. If not I may just have to be the first. So strange how the quest for more power is never endingIdk about having a cat between the engine and turbo. The hotside piping can see up to about 3x boost pressure (meaning if boost is 10 psi, the exhaust upstream of the turbo might be 30 psi) and temps well into the 1200-1500 F range. Not sure how well a cat would live in those conditions.