I`ve now full-throttled my way through a tank and a half after installing the header and tuner file. Torque, power and crispiness is as good as can be without Forced Induction. But - My wife came home yesterday and asked me what was wrong with the Cooper. I went with her for a ride,and experienced a really annoying dip in power at 4.2 K and at 5.2K. At half throttle there is! - No wonder I hadn`t noticed. The stumbling is consistent and happens everytime. When trying to balance rpm at this range, the power comes on and off almost digital. Not good. Is the mapping to aggressive at half throttle? Could it be smoothened out? My standard MTH-file was not like this.
Edit: Came to think about it. Maybe if I let Wife drive some more, the ECU will adjust half throttle performance too?
Tormod

 

That is surely caused due to the very sensitive throttle response. One can call it a "stumble" but it actually isn’t.

We can however supply a file without the immediate throttle response.

 

I might ask for a file with less throttle response later. But I I`ll drive along for a couple of weeks first to see if me and ECU adjusts to each other.

Thanks

 

I've noticed what seems like the same problem. It struck me as more of a "cruise control" feeling, where the RPMs rise & fall... not that I use the cruise control. Not so much a "dip" in power, but just the RPMs going up & down. With the throttle perfectly still, the RPMs do that in that range while in 5th gear. It doesn't bother me too much, as I'm generally in the WOT position