So yesterday I took the car back to Thor Racing for the remap.
We loaded the initial map and it made around 14bhp (at the wheels) more than it was running with just the mufflerectomy and the torque curve wasn't the best looking thing in the world! The fact that we were mapping using the dyno filled me with confidence because any "mobile mapper" would have loaded that first file on my drive and taken my money. But we were able to modify the generic map used by many companies and tweak it to get us to a place we were happy.
After three or four revisions to achieve the desired peak power and smooth out the torque curve we ended up with 287.2lbft and 168.2bhp which equates to approximately 195bhp at the fly.
I'll be driving the car for a week to see how it adapts and then probably taking the car back next week for a minor bit of fettling to further smooth out the torque curve between 2300 and 2800rpm, basically lowering the peaks a fraction and removing that valley and then shifting the whole torque curve across to make peak torque at 2500rpm which should give the clutch a slightly easier time.
The car is now a real animal to drive, it pulls like a steam train in all gears and the exhaust has taken on a rather brutal note at full power that is more turbo and whistling air than a typical exhaust drone. Inside the cabin however you'd never know it wasn't standard as the sound doesn't make it inside the cab.
I'll report back in a few days with the MPG which on first impressions seems to be the same.
Now excuse me, but I'm going out for a play in my tractor!
Here's the video of the who process: