I am taking the plunge. I connected with RSC Tuning out of Miami, FL. They have extensive experience tuning exotic cars, including Jaguars. They even work with several Jaguar dealers to tune customer cars.

On Monday, I am planning to get an ECU tune and new supercharger pulley. RSC is predicting an increase of 80-90 HP. The shop that is installing the pulley will do a before and after dyno, so I'll be able to document the improvement. The tech from RSC is actually flying in from Miami to reprogram the ECU at the same time that the pulley is being installed.

I've been interested in finding more HP ever since I bought the Jag. Quite honestly, I purchased the SC rather than the SS because I thought I could find a less expensive way to add 40 HP.

I spent a lot of time over the last couple of weeks researching RSC and the mods that we are doing. I must admit that I've been close to chickening out over the last few days for fear that I would screw up the car, the warranty or the resale value. After having spoken to several knowledgable people who have experience with these types of mods, I've concluded that the the only real risk of damage to the car is if the pulley install is not done correctly, the manufacturer has to prove that the mods directly caused a warranty claim to deny it, and if I have a problem at resale I can spend a few dollars to restore the car to stock.

So, what do you guys think? Am I crazy? Have I missed something? I'd appreciate any and all advice.

BTW, I have absolutely no affiliation with RSC. I am just excited to have found a cost effective way to realize the true performance potential that has been engineered into these engines.

 

Can one tune the 385hp Portfolio? My last car was N/A but I added over 30K in mods and had it tuned more than once to make everything flow well together. The ride after the tune was like night and day.

 

(Damn, I wish I had money like that!)
Good luck with the tune!
Sounds like an adventurous way to get more horses out of the stable.
I like the reversible approach.
Your efforts are a vanguard for the rest of the tuners, seeking an alternative means of improvement.
Please let us know how it goes.

 

RSC is an great choice! I've been throwing around the same idea. RSC also has a nice exhaust system. I was actually going to go through Eurocharged here in Houston. They have a pulley and tune package, and seem to have a good reputation. I really wanted the use of the MyGenius hand held programmer. It allows you to store the factory tune and up to 5 other tunes, so then you can flash it to stock when you bring the car in for service. However, it is not compatible with the Jag computer yet. I was told the same gains as you, 90 extra hp would put the Jag XJ-S at the top of the luxury sports car food chain! Can't wait to hear the results and reviews! Good luck!

 

If you haven't followed the threads of those who have done a 5L S/C ECU tune and pulley you really should. BigCat09 on the XF forum has posted extensively and would be a good source of info for what you're doing. There's others on the XJ and XKR forums who have gone through this as well, and results vary from tuner to tuner.

Bruce

 

Bruce, thanks for the tip. I searched the XJ forum, but not the others.

 

Did you ever send the car off to RSC? If so, what were the results? Dying to hear!

 

I actually decided to keep the car stock for now.

 

I connected up with RSC Tuning out of Miami. I've got a 2011 XJL (NA). Was a little leary about doing it, "bang for the buck" on a non SC vehicle but figured what the heck and now intial impressions is that is was a good decision.

Took a few hours, Ninja was great and spent quite a bit of time just chatting.

Actually does have a little different (lower or throaty) rumble in the exhaust note. Still early but seat of the pants feel "appears" to be a little more responsive, rpm and shifting. Purely subjective of course, (and might be psychological), don't have any before and after 1/4 mile or dyno times... but just trying to give an honest impression of how I feel about this mod.

Still in the learning phase so we'll see after a few days... but so far so good and very happy!!!!!!

-Jason

 

Jason,
Can you please us know how the changes have impacted your gas consumption?
Thanks,
Thierry

 

So Barry, you didn't go for it in the end up?

What was the deciding factor in your decision?

 

While I was excited about the idea of more power, I had some nagging doubts about whether I would have problems down the road. Since I wasn't 100% comfortable, I decided to hold off.

 

Thats ok Barry, better safe than sorry I guess.

Its always something you can revisit at a later time if / when you feel more comfortable about the whole thing I guess.

 

Sorry for the delay in posting. Wanted to get as much data as possible.

All of the info is based on the trip comp.

Crusing at 80 mph gets me 28 mpg, pretty even. On average, highway mileage is mid 26 mpg. If I recall I was getting around the 23-24 mpg before, same type of driving. I usually cruise at 80 mph or so.

Depending on how much stop and sit and go driving, city mileage is low 22 mpg. If I get a little more aggressive with the throttle I'll be around 21 mpg or just under. I was getting around 18 mpg or just under before.

Bottom line mileage has definitely improved as well as seat of the pants feel.

Glad I did the mod!!!!

 

Jaser35x is your engine any louder when the car is idling??

 

Maybe a 'slight' lower rumble, I'm sure nobody else would notice but me though. When revving, there is a difference... for sure.... didn't really believe them when they told me it would happen but I guess it is true!!!