MoscowLeaper,

Since you have intimate knowledge concerning the 2007/2008 xk engine and transmission controls I assume (hope) you can answer several questions related specifically to the NA 2007/2008 xk150, 4.2.

When the selector is put in S is there a change to the CATS controls? And if so could that change be programmed into a 2008 xk as the default setting?

Is there much HP to be gained by reprogramming the NA XK without any other changes?

Thanks for your time



wj

 

1. Yes, diffrent curve is selected, CATS are at stiff setting (however may switch to soft on a bad road for example)
2. No, can't be programmed. Pull the CATS fuse.
3. No, there's not much reserves in NA engines. Approx 15-20hp, nothing more, nothing less.

 

short and to the point!

thank you very much

wj

 

Moscow leaper tune with 100 cel cats

 

Steve,
I would be thrilled with that performance! You should be proud.
I'm not going to spend $ trying to make my xk into a wanna be xkr. I will optimize it as much as I can to fulfill my driving style until I can replace it with an XKR. No money at the moment to pursue this desire. I need to finish quite a few things on my 2005 XK8 and then decide whether to keep it or possibly sell both to fund an XKR. In the back of my mind I'm considering selling the xk8, purchase another older, low mileage XK8 coupe and install an LS engine with a twin screw. Sell the 2008XK replacing with a lower mileage 2013-14 XKR convertible.
We'll see, I'm getting old might not happen.
Have you gone to the strip with the 4.4 installed?
wj

 

Factory supercharged 5l you can't go wrong , with the right tune your deep into the 11s

The 4.4 xk is no faster still trapping 101.5mph , in hindsight I should have swapped the cams over with the 4.2 and would have most likely picked up a few tenths down the strip