Anyone here have ever tuned their XK/XK-R? Since I’m getting a new Exhaust system I thought I’d might as well go “Full Monte” and get it tuned. I was recommended ECU tuning group as best in the business. Anyone here used them before? I was quoted $695, takes approx 2 hrs to upload and will see instant increase in power across the power curb.

 

There are dozens of people who have 'tuned' their XKs with dozens of tunes from a dozen places, and there are dozens of differing outcomes from No Noticeable Improvement, Worse than it Was, and the questionable Amazing Results.
Very few (if any) have actual measurements to document these increases, and usually are a 'seat of the pants' comparison.
The ONLY ways to have verified any possible power increases are Before & After dyno sheets from the same Dyno under the same conditions, and Several Drag Strip runs, both Before and After using Similar Conditions.

I take all claims of "Vast Improvement with a Tune" claims as 75% wishful thinking.
There are too many cases of tunes not actually doing a danged thing.

 

badincdog, you say you have a 2009 XK, so that's the 4.2L naturally aspirated?

 

What Cee Jay said. Been there done that. Lost HP with some gained minimal with other.
The good news a dyno developed my own tune and offer it to to others. Gained nearly 100 hp to crank Check my threads and send me pm if you have a 4.2 car

 

That is correct, naturally aspired.

 

With a shorter diff ratio , ecu tune , high flow cats and decent tread your probably good for a 13.5 e.t