I had been considering purchasing the 5.0L XFR/XKR for occasional street and lapping day use. I bought a MY10 XKR convertible (wife's choice) last week, took it straight to the race track, and posted about my impressions there. Since the XFR and XKR share the same drivetrain and suspension, I suspect there are a lot more similarities than differences. In fact, I saw one reviewer say the XFR was actually better on track!

Here's the link to the XKR forum if any of you have ever wondered about just how good your car, and its driver, would be on your local race track...
https://www.jaguarforums.com/forum/x...erforms-62545/

Bruce

 

The professional instructors at the "R Performance Academy" told me that the XFR is just a bit easier to drive than the K variant.. a bit more stable and more predictable. Its not that its faster, its that its easier to drive faster.

At the Academy, we got to drive both cars one after the other all day and in all events. I found the XKR slightly faster, owing to the weight advantage it has, but it was also faster to kick out the back end. The XFR just seemed to stay planted a bit longer.

At the end of the day, the two cars are really cut from the same material. One just looks a helluva lot sportier! The difference in performance is really negligible.

 

Thank you for your feedback. I'm hoping you'll expand on it as much as possible.

Did they give you any recommendations about car preparation for using your own cars for tracking days? I'm thinking of tires and pressures, different engine oil viscosity or fill level, other fluids, brake system prep, settings, etc.

I'm interested in the DSC and tranny settings they used at the track, and any other modes they had you try. The manual indicates that Dynamic Mode would be selected for the track, and that experienced drivers would select TracDSC as opposed to the normal DSC ON mode.

Did they also have you try DSC Off, and once you got a bit used to the rear stepping out did you find it aided car control and speed around the track?

What did they recommend regarding use of tranny Sport mode, and Sport mode with manual gear changes with paddle shifters? I was reluctant on the first day out to use the paddle shifters for fear of over-revving it while being pre-occupied by learning its handling dynamics.

I hope you don't mind all the questions, but the high performance drivng knowledge base seems to be quite limited, and that makes you IT

Bruce

 

We ran in Sport Mode all day, with Dynamic Mode selected. The road course saw us in TracDSC, which gives you just a hint of play before the car reels you back in from an over exuberant application of the throttle.

Our instructors urged us to use the paddle shifters, but honestly Jaguar did such a phenomenal job with their software that I didn't see much difference running manually or through straight Sport Mode. To begin with, I'd recommend letting the car pick your gears and then once you feel comfortable with how it handles, perhaps after a few times out, experiment with the manual shifting.

We did turn off the DSC for the figure 8 portion of the training. In that exercise they took you around a figure 8 course and when they felt comfortable with your control of the vehicle they got you to goose the throttle when you were coming around the corner, kicking the rear out. This was actually my favorite exercise, as its not something that you get to do with a $100k car everyday!

I talked to the drivers about the maintenance and prep that the cars saw for the track. I don't know whether to believe him or not, but they said that other than checking that the tire pressures were set to factory recommended levels, they didn't do ANYTHING to the cars to get them prepped. They were insistent throughout the whole experience that these cars were basically bulletproof. We were running in hot, humid weather and we were pushing the cars very hard. I personally took three different cars (two XKR's and one XFR) to the overheat point. The neat thing about that is that the car is smart enough to protect itself. First it cuts out the A/C, which is your first indication that you're getting warm. If you keep on it, the car will pull back your rev limiter, keeping you in lower rpms. Finally it flashes the overheat warning and drops you back to a really low rpm ceiling until it cools down again. After a few minutes of "normal" driving on the course at low rpm, the car had cooled itself to allow all-out driving again for a while longer.

Remember, if you do take it out hard, don't pull into the pits and shut it down! The car needs to keep the oil moving throughout the car to keep things lubricated and cool down all of the components. Just let it idle for five minutes until its back to a semblance of normalcy.

 

Excellent info....thank you. It sounds like selecting TracDSC doesn't cause things to get too crazy which is great, and would likely have prevented the major intervention and loss of power I was experiencing while apexing tighter corners. I'll use that and Sport tranny mode next time out, along with Dynamic Mode again.

Stock tire pressures sound right also, as I found after adding 5 psi per tire that I had to let out about 5 psi after the tires warmed up to bring them down to 40 from well above that.

Impressive engine management to prevent overheating. I see in the manual that the active differential has a safeguard built-in as well. I haven't got to the part that discusses driver monitoring of fluids and temps, but I have a feeling checking oil level may be about all we can do.

I saw your thread about the R Performance Academy, and left a message for them to contact me about my participation. I don't know if Canadian buyers are eligible, but it's worth a try. Mosport has a driver development track I'll probably get out onto when the season opens next year, which is a safer place to do car control exercises than thehigh speed Grand Prix circuit we normally run.

Thanks again, and I hope others will chime in with their comments and experiences.

Bruce

 

I'm sure that you'll be able to attend. They run in a few different locations. You just need to get there somehow! Well worth it, trust me!

 

Anywhere, anytime...haven't heard back from them yet, but I'll keep on them!