Well it is a Ford Coyote after all is said and done.

 

xkr = fuerte!!!

 

The AJ133 is not a Coyote, not a single shared part between them and a totally different head, camshaft, injection, etc. In no way related.

 

xkr 4.2 (420hp)- 12.9 @110mph
Xkr - 5.0 (510hp) - 12.6 @ 115mph
Xkr-s 5.0 (550hp) - 12.0 @122mph

On average ever .1 or 1mph on your et should equate to 1 car length so no wonder the 5.0 pulls so hard against the 4.2

 

Does the upper pully do that much for the xkr? How much horsepower does it add

 

I have not done the tune yet, I have it, as the software for first one was not correct and I was sent a replacment, I just haven't had any time over the last few weeks to spend the time loading it. Depending upon which tuner company you use (ie; ETG, Eurocharged, Vmax) the claims are anywhere from 80-105hp gains over the stock 510hp. Some have suggested that tweaks in the exhaust system (such as the X-pipe of the XKRs) are necessary to extract the maximum gains. I hope to have some time this week, and then I'll report what I "feel." I have done just the pulley, and I'm not sure I can tell the difference.

 

Tberg
For the tune to stick to a x-pipe is a necessity that is if you are loading the tune remotely.

However if it's a custom dyno tune no x-pipe is technically required however it's recommended due to the simultaneously firing of the left bank , plus it's good for a few extra hp & torque

 

It's true!