I thought I would update this in case anyone is looking in the future.
Essentially my car was mapped by Romain many years ago and it made 247 I think on his dyno. I then changed the intake from a Gruppe M to a Mugen and the exhaust from DC to RM01A.
The car then went on another rolling road before mapping.
The rev numbers are all skewiff, the mapper did explain why but it went over my head. But the torque and bhp curves are true. Here's the before dyno, as you can see it isn't overly smooth and a little lumpy, there's also flat spots which I sometimes noticed on the road.
Here's after mapping.
You can see that it's much, much smoother and the difference in the torque curve is night and day. Rich told me the previous map was too rich as well. So, a 10-15 bhp gain on the Owen Developments dyno, with a bit of man maths would suggest it's knocking on 260 bhp on Romains dyno.
Try and not read into the numbers too much.
To be honest, too many factors have changed and who knows, once a Gruppe M goes on and it's mapped again maybe that would make more numbers? I am not sure, but thought someone may be interested in an update.
