One week ago we found the XKR of our dreams at Jaguar of Waterloo. I picked it up on Friday, registered for the year's last track day at Calabogie Motorsport Park that evening, and arrived at the track with helmut, driving shoes and gloves the next morning.



I hoped the 6 hour drive there was going to offer some opportunity to get a feel for the car's handling under aggressive cornering and braking before getting it out on the road course with other high performance and race cars with advanced level drivers. Unfortunately it was mostly straight and flat freeways and secondary roads that provided minimal insight, with finally a little excitement just over the last few miles. Lots of tight bends and short straights that required aggressive braking, steering and acceleration when driven quickly. I tried paddle shifting for the first time (other track cars have always been manuals), but with such a capable automatic, and such limited time, I put it back into auto mode and focused solely on handling.



I quickly registered at the local motel, dropped off the non-essentials and continued on to the track. A couple of track buddies were already there, and as I checked in at the office they took the XKR for a spin. They were just getting back to the paddock area with grins ear to ear as I returned. They shared my initial impressions...the XKR has a very structurally solid feel to it, with a well-dampened suspension that keeps body roll in check, confidence inspiring brakes, supportive seat, good driving position, and enormous torque that's instantly and effortlessly available.

Preparation for running on the track was limited to removing all loose items from inside the vehicle, checking for sufficient brake pad thickness, checking the torque of all wheel lug nuts, and adding a few psi to each tire to help save their edges under the high cornering loads. I had driven the track twice a few years, so I thought I'd have a pretty good idea of the track layout, and the 22 corners. Helmet on, seat lowered to provide adequate clearance, and on to pit lane where the cars were being staged to be released for the first of three 30 minute sessions.

I staged at the back of the pack knowing that I'd be slower as I learned the car's handling capabilities and progressively probed the limits of tire adhesion. Part way into the session one of my friends with a lot of seat time at this track came up behind and then passed to tuck himself in front for me to follow. He demonstrated the best driving "line" around the track, which is essential so you can enter a corner from the right position to "turn-in" towards the apex at the right place, hit the apex, and then "track-out" to the corner exit...all in a fluid motion that doesn't require the mid-corner steering correction that can cause upsetting the balance of the car, loss of tire grip, and loss of car control. Hitting the apex correctly also allows you to get on the throttle sooner.

Optimizing the line through the corner allows the car to carry more speed through it, minimizing braking before the corner, and maximizing corner exit speed through it. Those three elements combine with acceleration from apex to the next corner's "turn-in" to reduce lap times. The faster cars around the track are generally those that are driven better, and that are fastest in the corners. The advantages of a powerful motor like the XKR's is quickly lost if the car handles like a pig!

Well I didn't expect to leave with a trophy, which is good because they don't hand them out at track lapping days! These aren't races...they're an opportunity for car owners to enjoy their high performance cars, and to develop their high performance driving skills. They're "test and tune" opportunities for those making modifications to their cars. Race car owners use them to prepare for races. I was at an event at Mosport International lapping with the Ranger Motorsports Porsche 997 one Monday and watched him drive it on TV in a race at Daytona the following weekend, and in a west coast race a week later.

Track Impressions:

So now we get to the point of going to the track, and this thread discussing it. This is what I learned, along with a few pointers for others that might like to do this as well:

-While I'd only driven the track twice before, and had certainly not discovered the ideal race "line" through all 22 corners in that short time, I'm surprised how much I had forgotten. The lead and follow session with my more experienced friend was invaluable. I was mentally prepared to drive this new and unfamiliar car well below my normal track pace to use the time to learn the car in a safe manner. I also hadn't been on a track for two years, despite annually spending 15-20 days on track for a number of years before that.

Vehicle balance is superb. There is negligible body lean under high "g" cornering loads. The car stays flat, which means its suspension is keeping the tire well-aligned with the pavement, and maximizing the tire's contact patch to maximize grip and vehicle speed while maintaining control. Dive under braking is well controlled as well, again benefiting grip. Fast transitions from aggressive cornering in one direction to the other is drama-free. There's a hard right followed immediately by a hard left leading onto the front straight and exit speed out of that last corner is important to taking advantage of the straight. The transition between them is prone to upsetting the car's balance more than any other spot on the track, and the suspension's electronically variable adjustable shock dampers do a wonderful job of using the steering input changes to adjust the dampers in anticipation of the lateral load reversing to minimize vehicle pitch through this section.

The suspension is also very well-dampened, meaning it's able to absorb uneven road surfaces in stride and keep the tires well-planted on the pavement. Most cars with suspensions stiff enough to drastically limit body roll are not compliant enough on uneven road surfaces, and tire grip and vehicle control is compromised.

Steering effort and feedback was great. The "lightness" that some reviewers have commented on was non-existent at track speeds, or at any speed for that matter. It also communicated the amount of tire grip, and more importantly, the approach of the limits of tire grip. As a tire reaches its limits you can feel a coarseness transmitted through the wheel... sort of a gravelly feel. Pushing beyond that the car is going to stop steering as sharply (understeering), so good car control requires the driver to not exceed the tire's limit, and since the highest cornering speeds and fastest lap times will be when driven at the limit, it's critical to know where the limit is at all times...and not push beyond it.

Throttle modulation is very direct and linear. If you need to add or reduce power slightly, the throttle reacts very well to pedal pressure.

The sensitivity of the throttle, the steering feedback and suspension combine to allow the driver to increase vehicle speed in longer corners right up to the threshold of grip, and hold it there by simply modulating the throttle. I was able to steer the car through a long sweeping corner, and as I exceeded the limits of the front tire's grip, and the car started to steer wide (understeering), a gentle lift of the throttle would shift a bit more weight onto the front tires to increase grip, and the nose of the car would tuck back in and resume the desired line through the corner. Slowly feeding in more throttle, or backing off, would adjust the line through the corner in a more effective manner than adjusting with the steering wheel...afterall, if the tire has lost grip and the ability to hold a required turning radius it won't turn better by steering more sharply...the opposite will result actually.

Brakes are fantastic, and haul the car's speed down very impressively...the best brakes I've experienced. Aggressive braking requires a comfortable amount of pressure on the pedal, and brake force is very linear with pedal pressure...no surprise. They are fade-free under hard, extended, and near constant use on the track. Track use can turn brakes that perform flawlessly in magazine tests into brakes that fade badly after a few laps and can no longer effectively slow the car. The massive brakes on the MY2010+ XKR was probably the single most important reason why I chose the 2010 over the '07-09 series, although the rare Portfolios with Alcon brakes would likely be suitable for the track as well.

Engine power is excellent. There really is no replacement for displacement, and combined with a supercharger, the 5.0L really puts out strong low rpm power for accelerating out of corners, and holds it well at high rpm for maintaining acceleration down the longer straigthaways. 510 hp sounds like a lot, but it is a relatively heavy car, and it puts every bit of it to good use with the assistance of the active limited slip differential.

The transmission is another huge highlight of the car. It's impossible to catch this tranny in the wrong gear, or have the vehicle's balance or handling compromised by a rough or abrupt shift. I left it in automatic mode and it performed brilliantly!



Final thoughts... to be continued...

Bruce

 

Traction control and dynamic stability contol are both wonderful things that really help keep the car from getting too far out of shape in every challenging circumstance...but they can really get in the way of an experienced driver who uses tire slip, lift throttle oversteer, power on throttle oversteer, etc to maximize grip and steer the car with his right foot along with steering wheel input. It also limits the ability to put power to the rear wheels to accelerate out of tight corners where even minimal tire slip is detected and power is halted.

DSC and TC would intervene on the same three corner apexes every lap, preventing application of power until it was sufficiently satisfied that all shenanigans had ceased, and that the driver reprimand had been effective. No sliding, no bringing the tail around with the throttle...driver gets a "time out" to reflect. I was lucky nobody ran into the back of me when that would happen!

I'm quite familiar with the limiting impacts of traction control while tracking the Toyota Supra, and with that car I pull its fuse to fully disengage it, which turning off the TC switch only partially does. I understand on the XKR that there may be a couple of stages of disengagement for those systems, but since I wasn't planning on driving it "***** to the walls" on my 2nd day of ownership, and the 1st time on track, I decided to leave it all on!

Here's an in-car video of one lap of Calabogie. The camera car is a friend's BMW 3 series track car, and he's recording for me our '93 Toyota MR2 Turbo with track modifications and upgraded turbocharger. I keep pulling out of camera range and have to slow down so he can catch up...ooops, now I'm bragging


One Lap of Calabogie Motorsports Park Oct '06 - YouTube


Suggestions for improvement

You always start with the most limiting and weakest aspect first, address that, re-assess, and move on to the next most significant item. In the case of the bone stock XKR that would be tire grip, and this factor would be the same for most high performance street cars as well.

The car comes with grippy Dunlop Sport Maxx performance tires, and while I was quite impressed with them on the street, and they even did an admirable job when pushed on the track, they really limited all-out performance on the track in every corner, as was completely anticipated. The harder I pushed them the hotter they got, and the less grip they had. I was however impressed that the tire edges didn't wear more than they did after all the hard cornering. The short, and stiff sidewall of the 20" size accounted for much of that, along with the additional 5 psi I put into all four tires to spread more wear across the entire face of the tire. The suspension design also gets credit for maintaining the wheel's camber under hard cornering loads, and that's no surprise either given its ability to prevent body roll.

Improved track performance requires R compound tires...plain and simple. They are designed to operate at peak performance at much higher temperatures, have even stiffer sidewalls to prevent the tire sidewalls from flexing under high cornering loads in order to keep the tires face firmly in contact with the pavement, and have tread faces made of much higher grip compounds. They are also designed to particularly maximize the lateral grip required for aggressive cornering. Wider tires would also help if they could be fitted within the fender wells.

Grippier tires would also reduce the number of DSC interventions, but as soon as the driver increases cornering speeds to the limits of the new tires he'd be back to the same problem. I know this sounds scary, but there will come a time that the DSC and TC systems need to be made less sensitive to tire slip, or turned off completely. Just make sure you are intimate with the vehicles handling characteristics at the limit of adhesion, and how to re-gain control if things get a little too sideways. If you are satisfied to drive within the tires limits, and at a novice or intermediate skill level, then leaving the "nannies" turned on won't adversely affect your enjoyment of track days, and they could save your car in the event of fluids being spilled on the track, or an accident avoidance maneuver that might otherwise stuff you into a wall or other solid structure.

Beyond using track tires and turning off the dynamic stability and traction control functions I think a track alignment to add negative camber, etc for better tire contact in the corners and vehicle weight reduction are the next on the list. Neither are required for the odd track day, but track junkies will likely at least do the alignment, although that will wear their street tires more quickly, and could perhaps also take away from its fine street performance slightly.

Almost forgot...MORE POWER. More, more more!

Now I do realize that even the 4.2 L normally aspirated XK has sporty power, and the 420 hp 4.2 L supercharged XKR is all anyone really needs on the street, and the new 385 hp 5.0 L XK might be closely matched with that, but you'll want all the performance you can get your hands onto for the gruelling demands of the track...and for that job the numerous performance upgrades on the MY10+ is the way to go...with the 550hp XKR-S being King of them all!

Conclusions

The Jaguar XKR 5.0L is a thoroughly modern high performance luxury sports GT straight from the factory. It needs nothing to run with that faster crowd, looking and sounding the part perhaps better than all but a few rare GT's. It's not going to be as fast as some of the hard core sports cars from the likes of Porsche, but my reality is that there will always be somebody faster than you so I don't worry about being the fastest, and the XKR packages its virtues in such a seductively elegant design that I just don't care.


Should you consider tracking your car?

BMW-CCA is a great organization to join for their excellent high performance driving education schools and track days. They accept members driving any marque. There may also be other high performance driving schools offered in your area, with lapping days booked at your local road course. Google is your friend.

I started with a driving school certificate that my wife purchased from a local newspaper advertisement. Before long I was touring around the eastern US driving as many tracks as I could including Road Atlanta, Virginia International, Watkin's Glen, Road America, Mid-Ohio, St. Jovie/Le Circuit Mont Tremblant, and of course Mosport and Calabogie. It's a great hobby, I've made a lot of friends, and I've seen parts of the country I never would have before.

Most importantly, I found a way to fully enjoy the high performance cars I had admired and purchased but very seldom ever drove, and certainly couldn't appreciate their high performance abilities on public roads.

Like I said before, they don't hand out trophies at lapping days, so bring what you own and have the time of your life... "It's the most fun you can have in a car with your clothes on"!

Bruce

 

Well, look at you! That's awesome you got out there that fast.

I've not had the chance to track mine yet, but I've been playing in the (wet) twisties a bit. I've been having trouble finding the limit of adhesion so far, but right now we're in our 'leaves are falling and the road is always wet' season, so I'm content to wait some of that out for spring.

I do like how strong the brakes feel, but in comparison to the StopTech's on my Z, they're a little hard to modulate smoothly. Part of that is just my Newb status with the car, and probably part of it is how aggressively the car will downshift on it's own with the Puck dialed all the way to the right on 'S'. I think the brakes may be a little bit soft on initial bite with them getting much stronger once engaged. I'm wondering if just a simple switch to braided brake lines might help that a bit.

I will comment on how much I simply LOVE the active differential though. It's bloody brilliant. It's quick to engage, but it engages smoothly and without drama. I have a small metal grate right in the middle of the right wheel track in the road that leads up the mountain to my house. Both my truck and Z have LSDs, but when they lose grip on the right side you can feel the 'jerk' of the diff kicking in. Then you get the drama of a bit of wheel spin, etc. But the Jag just has the tiniest bit of slip that has no accompaniment of the drama in my other vehicles.

Many before seem to have commented on the XKs propensity to understeer. I imagine with your tire pressures pumped up that issue would be exacerbated. Any additional comments on that? Typically one messes with sway bars and camber a bit to dial out understeer. I'm not sure we have many options to mess with either of those, as the XK aftermarket is a little... um... non-existant. (wry chuckle)

At any rate, huge props again for getting out so fast. I'm jealous!

 

Would I have any issues putting my XKR on the track?? I have 20" wheels ?? I do have larger Vented disc and six piston Calipers .

 

Really you can track any car that you like. If you've never done it before, then before you go there are a couple of things to consider.

1 - No insurance at the track (for the most part). If you screw up, the repair bill is going to be out of pocket. Don't take anything to the track that you're not willing to pay for. Having said that, I've done quite a bit of tracking and while I've seen bad things happen, I've managed to avoid it so far. Mostly it's about being careful and keeping space between you and those around you.

2 - HPDE days (like what Bruce is talking about) are about having fun. It's not racing. It's not competitive. You drive the car fast, you learn the car, you have fun in ways that are illegal on open roads. If your cars brakes (or whatever) are not up to snuff, the car will tell you by becoming less responsive. Listen to the car and do what she tells you to do. Life works better like that. I had one instructor tell me "Always listen when the car talks to you. Because if you wait until it's screaming, it's too late."

3 - Be prepared for consumables. Not just the obvious terrible gas mileage (My Z goes from 27mpg on the highway to about 8mpg on the track), but brakes and most especially tires. If you do it more than once or twice, you'll likely want to get another set of rims with race rubber to abuse instead of street rubber. Abused street rubber makes horrid noises on the road and your quiet XK will sound a bit like a Jeep on mud tires.

4 - Prepare your car. Check fluids. Check air pressure and tread depth on the tires. Make sure all the loose items in the cabin are secured. You may want to switch out/flush your brake fluid. A stock car can easily boil the brake fluid and putting in a higher temp fluid may be a good idea. I say may as you'll have to change that stuff out more often than the street version as it has a greater tendency to absorb water.

But at the end of it all, this entire oversized post is just here to say "yes, you can track yer car!" If you've not done it, it's a lot of fun. Just be sensible and stay in control -- it's easier to work your way up to fast than to start out too fast and need a flatbed!

 

Interesting thread. Tent set up.

Some more pictures would also be good.

 

The only thing I do right now is drag race a MINI on a 1/4mile track

 

Page #2 now posted above to complete the initial post



Thanks Brian,

My buddies told me about the event mid last week while I was waiting to get the car. I was praying it would be ready in time on Friday...and that's when I had to really hustle.

Once you get on the track your brakes might feel different under those conditions, and I wasn't in Sport mode so I don't know if that would have affected my impression. I just couldn't fault them even for the late braking and trail braking techniques I was using to compensate for my street tire weaknesses.

Most cars are of course designed to understeer from the factory so when people drive too fast and experience it, the corrective action is the one they do naturally...lift off the gas. I'm sure part of my understeer was a result of the DSC and trac control not letting me balance the rear with throttle. I needed to stuff 285/30/18's under the front fenders of the Supra to get the balance I wanted, and it's a much lighter car at 3480#. I'd need at least that much tire under the front of the XKR to accomplish something similar, and maybe running 285's on all four corners would be a solution for that, allowing rotating to even out tire wear. That, and adjusting front/rear tire pressures might be enough. I can't see me getting into different suspension components, but I'd go for a little more negative camber if I could. That should balance the car and make it very neutral...with the driver able to control/induce both understeer and oversteer as required.

Bruce

 

Video on Pg. 2 showing the track layout just for you. My MR2 track car, but gives you an idea of the joy of tracking. I wish I had a wide open throttle sound clip down the front straight. My friend said when I passed him on the highway the sound was fantastic with the exhaust dampers open, and different from what you hear inside the car. He said you could feel the car passing.

Bruce

 

Yeah, figuring out how much rubber can be stuffed under the stock fenders would help a lot. I managed to get 275s on all 4 corners of the Z. Between that and new sways it's pretty decently balanced now. I'm thinking a visit to a rim MFG is in order. Fikse is HQd not far from me, but I don't think they even do 20s right now. At least they haven't historically -- they were a little slow to adopt any trendy things. Not sure what else to do for that though. My knowledge of figuring out how that'd work is pretty limited.

 

FastCat2011 shared his experiences at the R Performance Academy in this thread shared on the XFR forum where he noted how similar the two models handled and added this...

"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 tirepressures 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."

Hopefully others will contribute their experiences as well, and who knows...maybe we'll get a Motorsports Forum here one day!!! Hint, hint

Bruce


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Thanks, you need to buy your friend a telephoto lens though.