We're all going to be driving 640+ hp bad *** Jaguars.

Quote of the day right there...

I take it the Jaguar Active Exhaust and Jaguar Performance Active Exhaust...are they not "Cat Back Exhausts"? Is the QUicksilver exhaust a cat back?

A "cat back" exhaust is just an exhaust system that replaces exhaust components from after the catalytic converter and back. So it is not a full exhaust system, since you are retaining the original cats and the headers/exhaust manifolds.

A full exhaust system would change everything from the motor back to the muffler.

"PS- i did hook up a battery tender recently and felt like a man... I accomplished something on my car!!!!

Loth "

Loth..That cracked me up! LOL!! I'm the same way.

" I didn't have the high RPM cut off as before and spun the tires at 60MPH.."

Holy Crap!!!! Spun the tires at 60mph?! You guys have all the fun!!!!! Dagg Nabitt!

On a Ferrari Testarossa flat 12cylinders, I had, I replaced the cats with a by pass pipe or sometimes called "Test Pipes". Gave it more power and sounded fantastic, since I also removed the muffler! But you do smell more raw gas smell because the Cats aren't burning the excess fuel off. Kinda Nasty smell. They do have 02 sensors that you weld into the test pipes that trick the cars computer into thinking the cats are still there. The best part it only cost me like $100 to do at a local speed/muffler shop. Just need the right couplings on the end of standard muffler pipes welded together. Nice and smooth flow. Like having headers.
$1000 per Jag cat scares me. Yikes!

LOL HP is contagious!

There are ways to bypass the oxygen sensors on xkr and I suppose xkrs, electronically. Look at "Toyota oxygensensor bypass" on you tube. If you want the fake sensors then go to Big daddies garage O2 simulator cel fix or homemade rear oxygen sensor bypass on google. In the future I would suggest that other members give exact places to look, as I did, rather than telling folks it is available 'Somewhere" on the net. From your friendly Polish hooligan with motorcycle baffles in the pipes and no mufflers!!!

Hey Max, How's the reflash holding up? Are you experiencing similar power loss at the high end? Are you still interested in the Eurocharged tune?

Car felt a bit slower today but verify it tomorrow morning.

ok today the car felt good, yesterday might have just been me as I had my mind on a 100 other things.

I have a call with RSC at 11am to discuss the tune and cats. If I can get the RSC tune dialed in the way I want then I'll stick with it.

We are also going to discuss high low cats so anyone interested in high flow cats please let me know as I'm sure they will be under the Milltek price.

I'm in on the hi flow cats depending on price.

I just spoke with him and the tuner is working on the boost and he will call me about the cats this evening.

Nameless Performance has XK8 200 cell high flow cats for ~1100 so I'm hoping he can come in around that price.

Hey Max, What's the word on the 200 cell cats? How's the RSC remap working? Are you still considering an Eurocharged map?

So after some emails with the brtis who wrote my tune it was discovered that it was reverting back. There seems to be an issue with their tune tool and 2013+ models where the ECM sets the maps back to stock after a few hundred miles. The fix was to apply the tune shut the car off immediately and disconnect the battery. Wait 5 minutes then reconnect. This seemed to help until I went to the Dyno Saturday and got horrible results.

I'm going with Eurocharged hopefully this week if Jerry is ready with the tool.

Also does anyone know how to clear the "service alert" you get when you disconnect the battery? I did the parking brake reset but I remember there was something else that needed to be done.

One other thing Dynoing these cars is a pain.. You need to remove fuse 20 for the DSC pump but also after you get it in started you have to remove fuse 3 for the ABS pump. If you remove it before you start the car it will not start.

sorry to hear your trouble with your tune. Llooks like a standard XKR-S dyno run. Good luck with Eurocharge.

Exactly look like a XKRS tune thats it, and the part that gets me is that I have an exhaust and 3LBS pulley(so they say). Looks like this tune just caused the throttle to activate quicker giving the illusion of more power but easily explains the power drop off at higher RPMs.. My higher trap speeds are solely due to the exhaust

At least this vs the wheels was paid with me CC so I can get the money back today.

between your trouble, although with a different tuner, and the guys who did F types and not show a real improvement at the drag strip this is starting to leave me wanting. I had all my P cars remapped, tuned and even turbos added with significant hp gains.
This car already can spin the tires in normal mode with DSC on into third gear. Not sure I am still sold and hot on some extra 80-90hp. Again not likely you can feel it, it is for my ego only for sure but has anybody else gone back to dyno their car to see if the tune sticks?
What if the ECU rolls everyone back, would you actually be able to feel it or accurately measure it with smartphone apps?

After speaking with a few high performance car owners, Porsche, BMW M & Audi RS and I have been advised that any flash based tune is worthless. I am told the only way to properly tune an ECM & TCM is via a LIVE dyno tune. Also noted, intake & exhaust may need modification to take full advantage of the tune and a smaller pulley won't hurt either.