That's correct I did have one, still unknown what caused the converter to fail but when it was working it was excellent. Gear changes and characteristics of the box remain unchanged unless you have a built box but you will launch quicker but also loose top end. I had a single setup and my 3800 stall could brake boost to 3000rpm. This made a dramatic difference to acceleration, with bpu on stock twins a 3800 will launch the car in the middle of the power band which will give a great launch. I since have a new converter which I'll be testing with my big singlex hopefully it was down to a dodgy batch of converters.