Helps to lag the right pipe
Turbo Mini Forums

I'd reported before that lagging the exhaust pipe made no difference to when my boost came on in the back door turbo. However when I looked under the car I discovered that the shop lads had lagged the boost pipe (turbo outlet) instead of the exhaust! Acck. They're quite competent turbo tuners all round, though they don't know carburetors. They said they thought I told them to put the wrap on that one.

Now that's sorted, the boost curve has dropped 500RPM. This makes a very different feel as you can imagine. Now 5psi comes up at 3000RPM instead of 3500RPM.

Next up: the evil water injection. In my continuing quest to get power without taking the motor apart, I'm fitting a water injection system and electronic boost control. Will go to 11-12psi, whatever is needed to produce 80 wheel horsepower here at altitude. That will exactly double the power it had naturally aspirated, and is probably near the limit for the stock clutch.

What power at the wheel have you all run with a stock A+ clutch?

1275 with Back Door Turbo