Originally Posted by
onehundred80
It is always puzzling to me when I see people with problems on the change to the 74mm TB. I did it along with the larger air box and intakes and had no problems at all, I did not even notice an adjustment period or a hiccup. There must be an explanation though, is it because the air is insufficient without the air box and intakes? I thought everyone was changing the whole set up.
I think that the changes are quite subtle anyway, it took the tune to see a real difference and that definitely took a couple days of driving to feel the full benefit.
Max and I talked about this at length and had some theories, but just that, theories.
I would say a solid 30%, if not more, have had surging idle issues with the swap. After spending a day doing every test in the book on mine and knowing it was correct I finally said screw it and left for the Dragon with it surging. It did it once or twice while I was there, but I think I flogged it hard enough to beat the ECU into submission...