Track review of DSC modes, Sport mode, and paddle shifting
#1
07-08-2012, 10:25 PM
Track review of DSC modes, Sport mode, and paddle shifting
I did a third lapping day in my 2010 XKR this week, and the goal was to find the settings that worked best. This was a return to Calabogie Motorsport Park that I ran the day after taking delivery of the car. Being unfamiliar with it at that time, I had just left the tranny in Normal, and dynamic stability control in DSC On while I focused on keeping things shiny side up. I found the tranny did a great job of keeping me in the right gear, but the DSC would abruptly intervene and kill power at the apex of slower/tighter corners where some tire slip is inevitable…but often desirable. This intervention had to be reduced, or eliminated.
My second track day had been at Mosport, which is a high speed track with just one particularly tight corner, and the DSC ON was intrusive on that corner. Unfortunately that’s a critical corner that leads onto the long back straight where the benefit of a higher exit speed multiplies all the way down the straight…and killing forward thrust is an unforgivable sin. I had been getting pretty comfortable with driving the car near the limits of tire grip, and it was time to try out the less invasive TRAC DSC mode to see how a little tire slip would be tolerated. That was an improvement, allowing a little more aggressive cornering and throttle application, but not really very much. I then tried DSC OFF, and when I rounded that same tight corner and rolled on the throttle the rear stepped out slightly, tucked right back in with a bit of anticipated counter-steer, and the car sling-shot onto the straight to reach a personal best top speed before braking for the next corner. I was still in Normal tranny mode, no paddle shifting, and out of fuel and time to experiment with paddle shifters. While the auto selected 2nd gear, I anticipated that manually selecting 3rd would allow me to roll on the throttle earlier, and hopefully prevent the tendency to power-slide on exit.
So this third day is back at Calabogie and I’m starting with Normal and DSC OFF modes to get comfortable with that before selecting Sport Mode. There’s one really tight corner that benefited from DSC OFF to prevent a major power intervention, but I was getting too much tire spin as I squeezed on the power at the apex…just like at Mosport, and again the tranny was selecting 2nd. So I started using the paddle shifters, and when I got comfortable with them I selected 3rd gear for that corner and that made all the difference. Much less tendency to light up the rears, much better car control, a lot less drama. That’s probably the only corner I was able to improve by shifting myself, but it was the only corner that really needed fixing. I used the paddles exclusively for the last 25 minute session, and I can see that I will definitely choose to continue to use them on the track because I do want to know that I’m always in the right gear, and I won’t be sure of that so long as the tranny is making those decisions.
What will take a bit of getting used to though is the sensitivity of the throttle in Sport mode with the Dynamic setting on. This track has a number of really long corners where you balance the car at the limits of grip with maintenance throttle, slightly lifting and applying throttle to adjust the line of the car by transferring weight from one end to the other to cause under-steer or over-steer. Steering with the throttle can be more effective than adjusting your line with the steering wheel in many instances. But what I was finding was that it’s so sensitive that it was a bit difficult to just hold throttle steady when I wanted in some corners, and I don’t doubt that my body moving around slightly under high cornering loads was a factor. The other cars I track are turbos, and their throttles responses are definitely just slow enough to smooth out power delivery as the throttle was adjusted. So now I’m wondering if paddle shifting in Normal tranny mode with DSC OFF may be the Holy Grail...better register for another track day to find out!
Other quick notes:
It was a hot and humid day (85F) and I detected no engine heat soaking (power reductions caused by excessive heat).
Dunlop Sport Maxx tires held up well, gripped like crazy, but there was very little audible squealing noise to help me determine how close I was to exceeding their limits of grip. Probably a combination of pavement and temperature difference from Mosport where the tires screamed when pushed on a cooler day.
The car’s overall handling balance on this lower speed “club style” track was just as neutral as on the much faster Mosport track. Lift throttle steering is not as quick or effective as on lighter cars for tightening a line, but throttle over-steer is never more than a right foot twitch away…and that attribute demands your full attention as you approach the limits of grip while the car is cornering…and especially with the DSC turned completely off.
Which brings me to this warning…Be extremely careful if you are turning off the Dynamic Stability Control. The XKR has enough power to break the rear tires loose at almost any speed while cornering. The car got a little sideways at 75 mph while accelerating though a slight bend. I stayed on the gas, dialed in a little corrective steering, and the tail pulled right back in line without any drama or loss of speed. A little panic and lift off the gas could have had a very different outcome…but that’s why some of us repeatedly recommend enrolling in high performance driver education events. Knowing what to do, and being trained to do it automatically, will make you a much safer driver on both the road and track!
First and second track day report threads:
https://www.jaguarforums.com/forum/x...erforms-62545/
https://www.jaguarforums.com/forum/x...-excels-73135/
Bruce
My second track day had been at Mosport, which is a high speed track with just one particularly tight corner, and the DSC ON was intrusive on that corner. Unfortunately that’s a critical corner that leads onto the long back straight where the benefit of a higher exit speed multiplies all the way down the straight…and killing forward thrust is an unforgivable sin. I had been getting pretty comfortable with driving the car near the limits of tire grip, and it was time to try out the less invasive TRAC DSC mode to see how a little tire slip would be tolerated. That was an improvement, allowing a little more aggressive cornering and throttle application, but not really very much. I then tried DSC OFF, and when I rounded that same tight corner and rolled on the throttle the rear stepped out slightly, tucked right back in with a bit of anticipated counter-steer, and the car sling-shot onto the straight to reach a personal best top speed before braking for the next corner. I was still in Normal tranny mode, no paddle shifting, and out of fuel and time to experiment with paddle shifters. While the auto selected 2nd gear, I anticipated that manually selecting 3rd would allow me to roll on the throttle earlier, and hopefully prevent the tendency to power-slide on exit.
So this third day is back at Calabogie and I’m starting with Normal and DSC OFF modes to get comfortable with that before selecting Sport Mode. There’s one really tight corner that benefited from DSC OFF to prevent a major power intervention, but I was getting too much tire spin as I squeezed on the power at the apex…just like at Mosport, and again the tranny was selecting 2nd. So I started using the paddle shifters, and when I got comfortable with them I selected 3rd gear for that corner and that made all the difference. Much less tendency to light up the rears, much better car control, a lot less drama. That’s probably the only corner I was able to improve by shifting myself, but it was the only corner that really needed fixing. I used the paddles exclusively for the last 25 minute session, and I can see that I will definitely choose to continue to use them on the track because I do want to know that I’m always in the right gear, and I won’t be sure of that so long as the tranny is making those decisions.
What will take a bit of getting used to though is the sensitivity of the throttle in Sport mode with the Dynamic setting on. This track has a number of really long corners where you balance the car at the limits of grip with maintenance throttle, slightly lifting and applying throttle to adjust the line of the car by transferring weight from one end to the other to cause under-steer or over-steer. Steering with the throttle can be more effective than adjusting your line with the steering wheel in many instances. But what I was finding was that it’s so sensitive that it was a bit difficult to just hold throttle steady when I wanted in some corners, and I don’t doubt that my body moving around slightly under high cornering loads was a factor. The other cars I track are turbos, and their throttles responses are definitely just slow enough to smooth out power delivery as the throttle was adjusted. So now I’m wondering if paddle shifting in Normal tranny mode with DSC OFF may be the Holy Grail...better register for another track day to find out!
Other quick notes:
It was a hot and humid day (85F) and I detected no engine heat soaking (power reductions caused by excessive heat).
Dunlop Sport Maxx tires held up well, gripped like crazy, but there was very little audible squealing noise to help me determine how close I was to exceeding their limits of grip. Probably a combination of pavement and temperature difference from Mosport where the tires screamed when pushed on a cooler day.
The car’s overall handling balance on this lower speed “club style” track was just as neutral as on the much faster Mosport track. Lift throttle steering is not as quick or effective as on lighter cars for tightening a line, but throttle over-steer is never more than a right foot twitch away…and that attribute demands your full attention as you approach the limits of grip while the car is cornering…and especially with the DSC turned completely off.
Which brings me to this warning…Be extremely careful if you are turning off the Dynamic Stability Control. The XKR has enough power to break the rear tires loose at almost any speed while cornering. The car got a little sideways at 75 mph while accelerating though a slight bend. I stayed on the gas, dialed in a little corrective steering, and the tail pulled right back in line without any drama or loss of speed. A little panic and lift off the gas could have had a very different outcome…but that’s why some of us repeatedly recommend enrolling in high performance driver education events. Knowing what to do, and being trained to do it automatically, will make you a much safer driver on both the road and track!
First and second track day report threads:
https://www.jaguarforums.com/forum/x...erforms-62545/
https://www.jaguarforums.com/forum/x...-excels-73135/
Bruce
#2
07-08-2012, 11:11 PM
Veteran Member
A little panic and lift off the gas could have had a very different outcome…but that’s why some of us repeatedly recommend enrolling in high performance driver education events. Knowing what to do, and being trained to do it automatically, will make you a much safer driver on both the road and track!
Of course it comes a bit more naturally in a Supra Turbo that's not trying to do your thinking for you.
#4
07-09-2012, 06:07 PM
Veteran Member
#5
07-09-2012, 08:10 PM
Thanks...but I really did buy it with the intention of enjoying it on the track as well as the street. I'll have the car figured out well by the end of the next track day, and then I can dial it back to a pace I'm comfortable with. I hope to then do some road trips to distant tracks that I haven't done yet, and return to the best that I have. If I feel like driving 9/10th I have two other track cars I can take, but setting personal best records is no longer of interest to me, nor is having a race car. I've always done this as a way to more fully enjoy and appreciate the high performance cars I`ve fallen in love with as opposed to having a desire to compete. It`s been a great hobby!
Bruce
Bruce
#6
07-09-2012, 10:44 PM
I have taken my XKR to Monticello Motorsports where I am a member. Hands down the car has beyond proved itself to me. When I start behind a good friend who has a slightly modified F430, I can't pass him and he can't pull away from me till we both boil over our street tires and pit. About 20 minutes worth. And when I start in front, he can't get around me and I wont pull away. If either one of us drive any harder, we will be rubbing paint. We get EXTREMELY close, but thankfully, never make contact. The Jags weak point is in the braking. They never fade at all, but under hard braking and the steering wheel anywhere other than straight, the ABS straight up sucks and the car will dance. I wish it was programmed better, as it's actually not safe. At least that's what I think the problem is. I'm also always DSC off, Dynamic on, in Sport mode, and no paddles. They turn with the damn steering wheel and it's a pain to find them at the right second.
All in all, the car rocks. AC seats and Sirius cranking on the way there and while on track!!!!!!!
All in all, the car rocks. AC seats and Sirius cranking on the way there and while on track!!!!!!!
#7
07-10-2012, 05:20 AM
John, I just checked out your track...very nice! Monticello Motor Club » The Track » Track Maps
That's a lot of corners, and a pretty tight layout like Calabogie. Managing tire temps is a real challenge on tracks like these, and my guess is you're getting a fair bit of tire spin out of a number of these corners where the tranny is surely choosing 2nd gear. That's where I needed to manually select 3rd in Sport mode to settle down the rears. To make things even more challenging, you have an ECU flash that's adding more torque in the rpm band that's causing you to struggle to find grip already.
I've really had to stand on the brakes a couple of times, but not engaged ABS. The "boiling over" tire temps would certainly account for your ABS issues. High power, heavy car, constant threshold braking, scrubbing through long corners, wheel spin on a number of tight corner exits...that's a tall order for street tires.
I don't need to move my hands about the steering wheel, even on tighter corners. I'm also not trying to paddle shift with the wheel turned very much, avoiding upsetting the car, so I find the paddles to be where I need them at all times. You can probably do the full course in just 3rd and 4th gear, grabbing 3rd in the brake zones, and not needing to upshift until corner exit. If you try 3rd going in to the slower corners you may find you don't need upshift with the wheel turned so much.
Are you able to store gear at the track, and do you plan to run a set of R compound tires?
Bruce
That's a lot of corners, and a pretty tight layout like Calabogie. Managing tire temps is a real challenge on tracks like these, and my guess is you're getting a fair bit of tire spin out of a number of these corners where the tranny is surely choosing 2nd gear. That's where I needed to manually select 3rd in Sport mode to settle down the rears. To make things even more challenging, you have an ECU flash that's adding more torque in the rpm band that's causing you to struggle to find grip already.
I've really had to stand on the brakes a couple of times, but not engaged ABS. The "boiling over" tire temps would certainly account for your ABS issues. High power, heavy car, constant threshold braking, scrubbing through long corners, wheel spin on a number of tight corner exits...that's a tall order for street tires.
I don't need to move my hands about the steering wheel, even on tighter corners. I'm also not trying to paddle shift with the wheel turned very much, avoiding upsetting the car, so I find the paddles to be where I need them at all times. You can probably do the full course in just 3rd and 4th gear, grabbing 3rd in the brake zones, and not needing to upshift until corner exit. If you try 3rd going in to the slower corners you may find you don't need upshift with the wheel turned so much.
Are you able to store gear at the track, and do you plan to run a set of R compound tires?
Bruce
Trending Topics
#8
07-10-2012, 08:10 AM
Veteran Member
Thanks...but I really did buy it with the intention of enjoying it on the track as well as the street. I'll have the car figured out well by the end of the next track day, and then I can dial it back to a pace I'm comfortable with. I hope to then do some road trips to distant tracks that I haven't done yet, and return to the best that I have. If I feel like driving 9/10th I have two other track cars I can take, but setting personal best records is no longer of interest to me, nor is having a race car. I've always done this as a way to more fully enjoy and appreciate the high performance cars I`ve fallen in love with as opposed to having a desire to compete. It`s been a great hobby!
Bruce
Bruce
#9
07-10-2012, 09:04 AM
I couldn't have either at your age. But I discovered it more by chance in my 40's when I could, and it's been a real passion ever since. My wife bought me a driving school gift certificate, and that led to the BMW club and doing autocross, and then to road course events. She actually ended up doing schools herself, including a HPDE school at Mosport, but after driving that track she took up golf!
#10
07-24-2012, 08:23 AM
Just had another INSANE track day at Monticello this last Saturday. I went with a friend in a 458 and another friend in a Carrera GT! Long story short, XKR IS UNREAL ON THE TRACK!
The 458 guys knows the track inside and out like I do. When he started directly behind me, he could never pass. We are basically rubbing front/back bumpers through the turns and straights. They don't black flag the 2 of us anymore. They gave up. lol. He never needed to slow down because he was too close. He said he was pushing as hard a possible and we kept about 10-30 feet between us at all times. When i start behind him, it's the same story... We also run about 25-30 minute sessions. We crank out over 1/2 a tank of fuel every session!!!!!!
Then the CGT!!!!!!!! It was his first time at Monticello, but he's a long time track junkie. He did learn the track surprisingly quick. About as fast as it took me the first time. Remember, there are 4.1 miles and 18 turns of track. Tons of elevation change, double apex's, all kinds of ****! So towards the very end of the day Mr. CGT was getting good with his instructor and he started behind me. The beginning of the session I started to pull away. In the middle or so, he made some ground up, and towards the end he was breathing down my neck!!!!!!!!!!! I held him for the last 2 laps!!! He did say after we got off the track, that he did need to slow up only once when he hit a bunch of turns perfectly. It shot up forwards and he started using his weapon to a higher degree. No doubt, the CGT driven properly should rape the XKR, but it was badass to see a $500,000 hypercar struggle to keep up for a while.
Either way, I don't think the CGT driven by a pro and XKR driven by a pro will be apart by more than 1.5 seconds on a 2.45 minute track!!!!!!!!! Bold statement there!!!!!!
Get your cars to the track poeple!!!!!!!!!!!!!!
The 458 guys knows the track inside and out like I do. When he started directly behind me, he could never pass. We are basically rubbing front/back bumpers through the turns and straights. They don't black flag the 2 of us anymore. They gave up. lol. He never needed to slow down because he was too close. He said he was pushing as hard a possible and we kept about 10-30 feet between us at all times. When i start behind him, it's the same story... We also run about 25-30 minute sessions. We crank out over 1/2 a tank of fuel every session!!!!!!
Then the CGT!!!!!!!! It was his first time at Monticello, but he's a long time track junkie. He did learn the track surprisingly quick. About as fast as it took me the first time. Remember, there are 4.1 miles and 18 turns of track. Tons of elevation change, double apex's, all kinds of ****! So towards the very end of the day Mr. CGT was getting good with his instructor and he started behind me. The beginning of the session I started to pull away. In the middle or so, he made some ground up, and towards the end he was breathing down my neck!!!!!!!!!!! I held him for the last 2 laps!!! He did say after we got off the track, that he did need to slow up only once when he hit a bunch of turns perfectly. It shot up forwards and he started using his weapon to a higher degree. No doubt, the CGT driven properly should rape the XKR, but it was badass to see a $500,000 hypercar struggle to keep up for a while.
Either way, I don't think the CGT driven by a pro and XKR driven by a pro will be apart by more than 1.5 seconds on a 2.45 minute track!!!!!!!!! Bold statement there!!!!!!Get your cars to the track poeple!!!!!!!!!!!!!!
The following users liked this post:
amcdonal86 (07-24-2012)
#11
07-24-2012, 10:27 AM
#12
07-24-2012, 03:42 PM
Veteran Member
Just had another INSANE track day at Monticello this last Saturday. I went with a friend in a 458 and another friend in a Carrera GT! Long story short, XKR IS UNREAL ON THE TRACK!
The 458 guys knows the track inside and out like I do. When he started directly behind me, he could never pass. We are basically rubbing front/back bumpers through the turns and straights. They don't black flag the 2 of us anymore. They gave up. lol. He never needed to slow down because he was too close. He said he was pushing as hard a possible and we kept about 10-30 feet between us at all times. When i start behind him, it's the same story... We also run about 25-30 minute sessions. We crank out over 1/2 a tank of fuel every session!!!!!!
Then the CGT!!!!!!!! It was his first time at Monticello, but he's a long time track junkie. He did learn the track surprisingly quick. About as fast as it took me the first time. Remember, there are 4.1 miles and 18 turns of track. Tons of elevation change, double apex's, all kinds of ****! So towards the very end of the day Mr. CGT was getting good with his instructor and he started behind me. The beginning of the session I started to pull away. In the middle or so, he made some ground up, and towards the end he was breathing down my neck!!!!!!!!!!! I held him for the last 2 laps!!! He did say after we got off the track, that he did need to slow up only once when he hit a bunch of turns perfectly. It shot up forwards and he started using his weapon to a higher degree. No doubt, the CGT driven properly should rape the XKR, but it was badass to see a $500,000 hypercar struggle to keep up for a while. Either way, I don't think the CGT driven by a pro and XKR driven by a pro will be apart by more than 1.5 seconds on a 2.45 minute track!!!!!!!!! Bold statement there!!!!!!
Get your cars to the track poeple!!!!!!!!!!!!!!
The 458 guys knows the track inside and out like I do. When he started directly behind me, he could never pass. We are basically rubbing front/back bumpers through the turns and straights. They don't black flag the 2 of us anymore. They gave up. lol. He never needed to slow down because he was too close. He said he was pushing as hard a possible and we kept about 10-30 feet between us at all times. When i start behind him, it's the same story... We also run about 25-30 minute sessions. We crank out over 1/2 a tank of fuel every session!!!!!!
Then the CGT!!!!!!!! It was his first time at Monticello, but he's a long time track junkie. He did learn the track surprisingly quick. About as fast as it took me the first time. Remember, there are 4.1 miles and 18 turns of track. Tons of elevation change, double apex's, all kinds of ****! So towards the very end of the day Mr. CGT was getting good with his instructor and he started behind me. The beginning of the session I started to pull away. In the middle or so, he made some ground up, and towards the end he was breathing down my neck!!!!!!!!!!! I held him for the last 2 laps!!! He did say after we got off the track, that he did need to slow up only once when he hit a bunch of turns perfectly. It shot up forwards and he started using his weapon to a higher degree. No doubt, the CGT driven properly should rape the XKR, but it was badass to see a $500,000 hypercar struggle to keep up for a while.
Either way, I don't think the CGT driven by a pro and XKR driven by a pro will be apart by more than 1.5 seconds on a 2.45 minute track!!!!!!!!! Bold statement there!!!!!!Get your cars to the track poeple!!!!!!!!!!!!!!
Thread
Thread Starter
Forum
Replies
Last Post
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)