Geez! chassis plots from events this season
03-07-05, 02:20 PM
#101
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The 2005 season is here!
The car has had no real changes to it over the winter except for usual maintenance and a new alignment to take advantage of the new Hoosier AS03's which I have never run. Thanks to turbojeff I got a deal on one of the last sets of AS03's and will run them until they wear out and replace them with Kumho V710's. The 710 is not available in 245/45/16 until April.
I figured I'd stick Hoosiers on the car and instantly go faster but the tires are certainly more different to drive than I expected and I'm still adjusting from the Victoracer. One of my Z06 competitors (who always beat me) is building a B-Mod car that isn't ready yet so he co-drive my car the first two events of this season and we had a lot of fun. We both know the Z06 is the faster car in SS but he says driving the RX-7 is a blast, it's smaller and more nimble than the Vette. He couldn't believe the difference in the two cars when going through slaloms. He tells me the Z06 really hates braking or accelerating through them and was astonished the first weekend as I turned into the entry of a 6 cone slalom and then accelerated all the way through. He claims the Z06 would not do that without becoming a real pig.
I'll get this out of the way first: my co-driver's fastest times were quicker than my own on both weekends even though he'd never been in an RX-7. He made fewer mistakes than I both weekends and went faster, that's how it works folks. Our times have been close though. Last weekend he turned an 88.3 to my 88.7 and this weekend he turned a 34.5 to my 34.9. It wasn't until my last run after the second event yesterday on the Hoosiers that I really began to come to terms with how to drive the tire and how hard you can push them. Tire pressures were my best guess given what others have used but the car was setup the same as last season other than the car now runs a full 2 degrees of negative camber front and rear. The Victoracer didn't need quite that much but everyone said the Hoosier would and I think I'll prove them right once I'm finished setting up the car for the new tires. I expected the Hoosier to just have more grip. While that is true they are different animals than the Victoracer and seem to demand different techniques to take full advantage.
Our first event last week was very fast with a slightly damp and chilly surface that was quite dirty in some sections. My co-driver and I saw right off the bat that we are more alike than different. We drove the course the first weekend exactly the same with the exception of one corner. My co-driver has Geez! installed in the Z06 and so is very familier with the system and its use. I emailed him the raw files from all our runs and he tells me there was only one corner where he was consistently making time on me (we used different lines there). We both made enough mistakes on our fast runs to know there was more time out there but he certainly made fewer than I did. I haven't had the chance to go through that weekend's runs personally so I'll post them up later and show comparisons.
I know I drove poorly that weekend. The surface was damp and dirty and the car seemed squirrely. I got bad out of shape and spun the car after 3 big oscillations through a fast section on my first run and nearly spun it again on my second. The car just didn't seem to correct as I am used to but I wrote it off as me making mistakes and not understanding the tires and alignment. At the end of the day I found I had a bad left rear wheel bearing and when I thought back every corner where the car felt poorly was a fast right hander. I replaced the bearing and as of yesterday the car feels normal again.
The car has had no real changes to it over the winter except for usual maintenance and a new alignment to take advantage of the new Hoosier AS03's which I have never run. Thanks to turbojeff I got a deal on one of the last sets of AS03's and will run them until they wear out and replace them with Kumho V710's. The 710 is not available in 245/45/16 until April.
I figured I'd stick Hoosiers on the car and instantly go faster but the tires are certainly more different to drive than I expected and I'm still adjusting from the Victoracer. One of my Z06 competitors (who always beat me) is building a B-Mod car that isn't ready yet so he co-drive my car the first two events of this season and we had a lot of fun. We both know the Z06 is the faster car in SS but he says driving the RX-7 is a blast, it's smaller and more nimble than the Vette. He couldn't believe the difference in the two cars when going through slaloms. He tells me the Z06 really hates braking or accelerating through them and was astonished the first weekend as I turned into the entry of a 6 cone slalom and then accelerated all the way through. He claims the Z06 would not do that without becoming a real pig.
I'll get this out of the way first: my co-driver's fastest times were quicker than my own on both weekends even though he'd never been in an RX-7. He made fewer mistakes than I both weekends and went faster, that's how it works folks. Our times have been close though. Last weekend he turned an 88.3 to my 88.7 and this weekend he turned a 34.5 to my 34.9. It wasn't until my last run after the second event yesterday on the Hoosiers that I really began to come to terms with how to drive the tire and how hard you can push them. Tire pressures were my best guess given what others have used but the car was setup the same as last season other than the car now runs a full 2 degrees of negative camber front and rear. The Victoracer didn't need quite that much but everyone said the Hoosier would and I think I'll prove them right once I'm finished setting up the car for the new tires. I expected the Hoosier to just have more grip. While that is true they are different animals than the Victoracer and seem to demand different techniques to take full advantage.
Our first event last week was very fast with a slightly damp and chilly surface that was quite dirty in some sections. My co-driver and I saw right off the bat that we are more alike than different. We drove the course the first weekend exactly the same with the exception of one corner. My co-driver has Geez! installed in the Z06 and so is very familier with the system and its use. I emailed him the raw files from all our runs and he tells me there was only one corner where he was consistently making time on me (we used different lines there). We both made enough mistakes on our fast runs to know there was more time out there but he certainly made fewer than I did. I haven't had the chance to go through that weekend's runs personally so I'll post them up later and show comparisons.
I know I drove poorly that weekend. The surface was damp and dirty and the car seemed squirrely. I got bad out of shape and spun the car after 3 big oscillations through a fast section on my first run and nearly spun it again on my second. The car just didn't seem to correct as I am used to but I wrote it off as me making mistakes and not understanding the tires and alignment. At the end of the day I found I had a bad left rear wheel bearing and when I thought back every corner where the car felt poorly was a fast right hander. I replaced the bearing and as of yesterday the car feels normal again.
Last edited by DamonB; 03-08-05 at 10:14 AM.
03-07-05, 03:10 PM
#102
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So here are the side by side results with my co-driver from the second event, he on the left and myself on the right. The start line was at the far left. From the start you go hard into a 3 cone offset slalom before having to move the car back over to the right to enter the first left hander. You head down a short chute with a single cone "kink" that you have to dodge before entering the second left hander and into an optional 3 cone slalom. You exit that and position the car for a fast 180 degree left hander, keeping your exit tight to set you up for the tighter 180 degree right that sends you on your way to a long, fast right hander where the pavement changes to downhill and off camber about midway through. Slow the car down and bend it into a left hander where the surface goes from off camber to level to "good" camber and into the finish.
What my co-driver understands about the Hoosier that I just began to realize is just how fast you can make the tire transition. In long corners I could not accelerate the Victoracer too aggressively at mid corner or the front would begin to push as the weight transferred off of it. On the Victoracer I tended to trail brake in very late and turn the car most of the way before going to the throttle. On the Hoosier I can begin accelerating the car earlier without the front end pushing. I really had to talk myself into using the throttle so early because I am conditioned not to. I couldn't believe the car would just hang on and keep turning. At the same time my co-driver was rotating the car down into the corners much more abruptly than I. The Victoracer would never allow you to have done that as it would have tried to turn in but as soon as it loaded up it would have pushed. The Hoosier doesn't seem to really care. The Victoracer is not a bad tire, but the Hoosier certainly has some advantages.
First thing you notice on the track maps is that my co-driver was much more aggressive in the first slalom. I'm flat not used to the car sticking that well and wasn't pushing it hard enough. The next area was the kink in the chute after the first left hander where I also under drove the car. Other than that we look nearly the same for the rest of the course. I didn't really begin to drive the car correctly until after the kink in the last run when I finally started to get the tire figured out. To me the real difference is I'm now able to brake earlier and slow the car down a little more for entry but then be able to speed the car up through the entire corner and down the straight whereas I couldn't often do that on the Victoracer. I'm braking earlier and turning in at a slightly lower speed but I get to accelerate the car before the apex without the front end trying to give up; the Vic wouldn't do that without pushing. Since I couldn't accelerate the Victoracer around the apex I always kept my entry speeds as high as possible, trail braked heavily, held the throttle steady and just gathered the car up in the turn if it started moving around. Anything to keep speed up since I couldn't accelerate hard before the front end was most of the way around. On the Hoosier I could trail brake in and immediately begin speeding the car up again without having to wait for more of the turning to be done.
What my co-driver understands about the Hoosier that I just began to realize is just how fast you can make the tire transition. In long corners I could not accelerate the Victoracer too aggressively at mid corner or the front would begin to push as the weight transferred off of it. On the Victoracer I tended to trail brake in very late and turn the car most of the way before going to the throttle. On the Hoosier I can begin accelerating the car earlier without the front end pushing. I really had to talk myself into using the throttle so early because I am conditioned not to. I couldn't believe the car would just hang on and keep turning. At the same time my co-driver was rotating the car down into the corners much more abruptly than I. The Victoracer would never allow you to have done that as it would have tried to turn in but as soon as it loaded up it would have pushed. The Hoosier doesn't seem to really care. The Victoracer is not a bad tire, but the Hoosier certainly has some advantages.
First thing you notice on the track maps is that my co-driver was much more aggressive in the first slalom. I'm flat not used to the car sticking that well and wasn't pushing it hard enough. The next area was the kink in the chute after the first left hander where I also under drove the car. Other than that we look nearly the same for the rest of the course. I didn't really begin to drive the car correctly until after the kink in the last run when I finally started to get the tire figured out. To me the real difference is I'm now able to brake earlier and slow the car down a little more for entry but then be able to speed the car up through the entire corner and down the straight whereas I couldn't often do that on the Victoracer. I'm braking earlier and turning in at a slightly lower speed but I get to accelerate the car before the apex without the front end trying to give up; the Vic wouldn't do that without pushing. Since I couldn't accelerate the Victoracer around the apex I always kept my entry speeds as high as possible, trail braked heavily, held the throttle steady and just gathered the car up in the turn if it started moving around. Anything to keep speed up since I couldn't accelerate hard before the front end was most of the way around. On the Hoosier I could trail brake in and immediately begin speeding the car up again without having to wait for more of the turning to be done.
Last edited by DamonB; 03-07-05 at 03:25 PM.
03-07-05, 03:55 PM
#103
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The single red line in the charts on the pic above is the instant we were rounding the single kink in the chute after the first left hander. You can see that not only did my co-driver carry more g here he was also accelerating much harder than I. My peak cornering g is lower and my acceleration is much lower. Again I'm used to the front end wanting to push if I accelerated too hard there and so was more timid with the throttle. After making it through there I started to realize what I needed to do differently and so our maps look much the same after that point.
The pic above also has a portion of the lateral acceleration chart as well as a portion of the track marked in green. This was a long right hand turn that had a single cone which you had to dodge on your way around the corner. Looking at the lateral acceleration chart between the green bars you can see my co-driver on the left basically drove up to that cone while in the right turn and whipped the wheel to the right and back to the left to miss it, a very quick and abrupt turn of the wheel in each direction. I on the other hand steered around the cone much slowly with a smaller peak in g and a slower transition as that's what I'm used to doing. I don't have to do that on these tires! You can see by the slope of the lines at each turn in that I don't turn in or out as sharply as he. You wish to make the car change directions as quickly as possible so if the car will allow it then his way would be better. I see no reason to be smoother like I was if you can just yank the car around without it coming loose.
The pic above also has a portion of the lateral acceleration chart as well as a portion of the track marked in green. This was a long right hand turn that had a single cone which you had to dodge on your way around the corner. Looking at the lateral acceleration chart between the green bars you can see my co-driver on the left basically drove up to that cone while in the right turn and whipped the wheel to the right and back to the left to miss it, a very quick and abrupt turn of the wheel in each direction. I on the other hand steered around the cone much slowly with a smaller peak in g and a slower transition as that's what I'm used to doing. I don't have to do that on these tires! You can see by the slope of the lines at each turn in that I don't turn in or out as sharply as he. You wish to make the car change directions as quickly as possible so if the car will allow it then his way would be better. I see no reason to be smoother like I was if you can just yank the car around without it coming loose.
Last edited by DamonB; 03-07-05 at 04:00 PM.
03-08-05, 08:46 AM
#105
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Looking at the time splits my co-driver made all his time on me (about .4 seconds) through the first slalom and the kink in the chute after the first left turn. I lost time in the slalom because I just went too slow and I lost time in the kink because I breathed the throttle more and thus didn't have as much speed up heading towards the second left hander. It was pretty much a dead heat between us after the first quarter of the course. Losing by .4 seconds means I was off by 1.1% compared to the winner. We should be looking for small advantages all the time because driving only 99% as well as the winner will find you back in the pack!
You can see my low usage score by the red and blue just before and after the kink in the chute. I slowed down more than I needed to for the kink and didn't accelerate afterwards as early or as hard as I could have. If you look at the friction circle graphs you can see the same difference. The red cursor on the friction circle corresponds with the white cursor on the map at the instant we're rounding the kink. You can see my co-driver on the left is way out at the edge of the circle and accelerating hard. I on the other hand am not at the edge of the circle. The chart shows me that I'm not cornering or accelerating as hard as I could be given what I did elsewhere on the course.
On another note I can launch harder on the Hoosier. My first couple launches were poor because the tires wouldn't spin up. With the Vics on this surface I normally launched around 3500 and modulated the clutch just enough to control wheelspin, fully burying the throttle as soon as they began to hook up. I have to launch now at just over 4000 or the car will bog off the start since anything less than that and the tires just stick.
You can see my low usage score by the red and blue just before and after the kink in the chute. I slowed down more than I needed to for the kink and didn't accelerate afterwards as early or as hard as I could have. If you look at the friction circle graphs you can see the same difference. The red cursor on the friction circle corresponds with the white cursor on the map at the instant we're rounding the kink. You can see my co-driver on the left is way out at the edge of the circle and accelerating hard. I on the other hand am not at the edge of the circle. The chart shows me that I'm not cornering or accelerating as hard as I could be given what I did elsewhere on the course.
On another note I can launch harder on the Hoosier. My first couple launches were poor because the tires wouldn't spin up. With the Vics on this surface I normally launched around 3500 and modulated the clutch just enough to control wheelspin, fully burying the throttle as soon as they began to hook up. I have to launch now at just over 4000 or the car will bog off the start since anything less than that and the tires just stick.
Last edited by DamonB; 03-08-05 at 08:59 AM.
04-26-05, 08:46 PM
#106
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umrswimr came into town once again with his ASP C5 so we have data to compare. It seems our style and attack on this course was much more similar than last time yet there was about a half second difference in our times. I'm going to establish some time splits within Geez! and then can figure out exactly where on the course the difference in time was made.
I just got to thinking tonight about usage scores vs. lap time and realized something fairly profound (to me anyway) I should have paid more attention to before now. What I realized is that lap time wins the competition, not Geez scores. If the race is from Point A to Point B then the guy who covers that distance in the least amount of time wins, regardless of his Geez values. If one guy drove from Point A to Point B in a straight line he's going to get there much more quickly than a guy who weaves all over the road at terrific cornering and acceleration forces the entire time. Geez tells us how well we operate at the limits of the tires, but that doesn't necessarily mean we're covering ground as quickly as possible.
First a quick overall comparison of our charts. umrswimr on the left, myself on the right.
The couple things that jump out at me is that over the first 3/4 of the course or so I didn't brake as hard as he did, this is fairly opposite of us the last time we competed together. The other thing is that on these runs I spent more time at the edge of my friction circle as mine is more rounded and more fully developed. I think most of that is due to the fact that my cornering forces are more fully developed on the graph; even so that doesn't prove one is faster than the other.
I just got to thinking tonight about usage scores vs. lap time and realized something fairly profound (to me anyway) I should have paid more attention to before now. What I realized is that lap time wins the competition, not Geez scores. If the race is from Point A to Point B then the guy who covers that distance in the least amount of time wins, regardless of his Geez values. If one guy drove from Point A to Point B in a straight line he's going to get there much more quickly than a guy who weaves all over the road at terrific cornering and acceleration forces the entire time. Geez tells us how well we operate at the limits of the tires, but that doesn't necessarily mean we're covering ground as quickly as possible.
First a quick overall comparison of our charts. umrswimr on the left, myself on the right.
The couple things that jump out at me is that over the first 3/4 of the course or so I didn't brake as hard as he did, this is fairly opposite of us the last time we competed together. The other thing is that on these runs I spent more time at the edge of my friction circle as mine is more rounded and more fully developed. I think most of that is due to the fact that my cornering forces are more fully developed on the graph; even so that doesn't prove one is faster than the other.
Last edited by DamonB; 04-27-05 at 08:48 AM.
04-26-05, 09:10 PM
#107
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First the basic track map. This map is from my run and so the color is plotted in my usage values but we're going to ignore all that and focus on segment times. The start of the course is roughly in the middle of the screen where the white bullseye is. In my car this was a hard launch before immediately braking hard and making a very tight left turn. Accelerate uphill into a right hander and then head downhill into a two cone slalom, shifting to second gear just before entering the slalom. Out of this slalom still heading downhill and then begin rotating to the right. The car enters going downhill and then apexes on level ground before heading uphill as the right turn continues. Car heads into a Chicago box and exits the box in a slight right turn heading uphill again. The car now is re-tracing the exact same course as before but the track map doesn't overlap perfectly because of all the camber changes of the course surface (this could be corrected but for our use this time I think it's easier to follow along by leaving it as is). As the car exits the box and heads uphill it goes through the same right hander as before and through the same two cone slalom as before. After the 2 cone slalom the right turn isn't a full 180 this time but merely a 90 degree turn which then heads uphill again into a 5 cone slalom (the surface of the slalom itself is fairly level as is the remainder of the course from this point onward). Car brakes hard into a 180 right hander before heading into another large box that is essentially a smooth 180 left. Car exits this into a smooth 180 right and then dodges one kink into the finish.
The numbered markers are the splits I'm going to compute for our two runs. umrswimr's quickest run was a 52.0. My quickest run was a 51.3 but that one had a cone; my quickest clean run was a 51.5 so I'll use that one to compute my own splits. These splits will only be accurate to a couple tenths since I have to pick places maually and compare them. Since the overall difference in our times is about half a second though we should still be able to accurately figure out where on the track the difference occured.
The numbered markers are the splits I'm going to compute for our two runs. umrswimr's quickest run was a 52.0. My quickest run was a 51.3 but that one had a cone; my quickest clean run was a 51.5 so I'll use that one to compute my own splits. These splits will only be accurate to a couple tenths since I have to pick places maually and compare them. Since the overall difference in our times is about half a second though we should still be able to accurately figure out where on the track the difference occured.
Last edited by DamonB; 04-27-05 at 08:52 AM.
04-26-05, 09:32 PM
#108
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The computed splits for both umrswimr and myself will be from start to 1, from 1 to 2, from 2 to 3, from 3 to 4 and from 4 to 5. I'm going to ignore from 5 to the finish because we both manually trim our runs and I can't guarantee the maps are trimmed exactly where the finish line was. Remember that umrswimr's time was a 53 and my fastest clean run was a 52.5
umrswimr:
start to 1= 13.5
1 to 2= 13.1
2 to 3= 9.1
3 to 4= 6.1
4 to 5= 7.8
DamonB:
start to 1= 12.9
1 to 2= 13
2 to 3= 9.3
3 to 4= 6.1
4 to 5= 7.6
Again I'm trying to be accurate but if any split is within a tenth of eachother I think it best to just call them the same. With that in mind I made the entire half second difference in lap time from the start to Point 1. Honestly I find that pretty incredible because that is a pretty slow and tight portion of the course. After that we trade a little; his 2-3 segment is .2 seconds quicker than I but I get those .2 seconds back on the 4-5 segment.
FWIW I think I should have been capable of running a mid to high 51 but couldn't get it done in our four runs that day. I'm sure umrswimr feels he left some time out there too. Interesting once again to compare with someone else in a different car on the same course that day.
In three weeks we both head to Texas Motor Speedway again to run an autox setup on the infield road course. Look for our next comparitive installment then. This coming weekend I run as well so if there's anything interesting to show I'll talk about it then. Until then keep going fast!
umrswimr:
start to 1= 13.5
1 to 2= 13.1
2 to 3= 9.1
3 to 4= 6.1
4 to 5= 7.8
DamonB:
start to 1= 12.9
1 to 2= 13
2 to 3= 9.3
3 to 4= 6.1
4 to 5= 7.6
Again I'm trying to be accurate but if any split is within a tenth of eachother I think it best to just call them the same. With that in mind I made the entire half second difference in lap time from the start to Point 1. Honestly I find that pretty incredible because that is a pretty slow and tight portion of the course. After that we trade a little; his 2-3 segment is .2 seconds quicker than I but I get those .2 seconds back on the 4-5 segment.
FWIW I think I should have been capable of running a mid to high 51 but couldn't get it done in our four runs that day. I'm sure umrswimr feels he left some time out there too. Interesting once again to compare with someone else in a different car on the same course that day.
In three weeks we both head to Texas Motor Speedway again to run an autox setup on the infield road course. Look for our next comparitive installment then. This coming weekend I run as well so if there's anything interesting to show I'll talk about it then. Until then keep going fast!
Last edited by DamonB; 04-27-05 at 10:33 AM.
04-26-05, 09:55 PM
#109
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Interesting... I'm not suprised you made up most of your time in the first section- I was fairly sure I left a LOT out there on the first downhill right hander... Looks like we were pretty close otherwise which doesn't bode well for my PAX!
What is intersting is the difference in grip, considering the size difference in the tires. I suspect those Hoosiers are worth at least a few tenths over my Victoracers. I would be curious to see what caused the difference in the acceleration forces... You definately launched harder than I did at the start, but still!
What is intersting is the difference in grip, considering the size difference in the tires. I suspect those Hoosiers are worth at least a few tenths over my Victoracers. I would be curious to see what caused the difference in the acceleration forces... You definately launched harder than I did at the start, but still!
04-26-05, 10:09 PM
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Luckily, it mostly confirmed what I already knew- I took the downhill right hander entirely too slowly on the first lap (magenta lines). I never got comfortable with how fast I could take this corner and still *make* the hard right hander. And since screwing this corner up put you in a terrible position for the "box" going back uphill, I never really pushed it. And it showed. Usage in the this 3-second secton was only about 70%. Blech.
Now, the Geez box also confirmed my previous epiphany: I don't accelerate through the slalom if I pass the cone on the passenger side. I'll flog the heck out of it on the driver's side, but I'm way too timid on the passenger side.... (Blue lines)...
Overall, I got beat pretty badly out there... Damon got me by at least half a second in raw time which will be much worse when it's PAXed out
One of the other things I noticed: the downhill corner was extremely rough in my car. I had quite a bit of tire "chatter" over the bumps which leads me to beleive I was running too much pressure up front. (35 psi). Looking at the Geez plots, it's easy to see: The corning trace (left side) at the lower magenta line should be a flat plateau of right-hand cornering (like the one directly above it). Rather, it's a jagged mess indicating that I was not able to maintain a steady line through the corner. The same thing happens just above the first light blue line: Instead of a smooth corner, it's extremely jagged.
I believe it's this rough patch that caused me to be too timid on the first loop.
Now, the Geez box also confirmed my previous epiphany: I don't accelerate through the slalom if I pass the cone on the passenger side. I'll flog the heck out of it on the driver's side, but I'm way too timid on the passenger side.... (Blue lines)...
Overall, I got beat pretty badly out there... Damon got me by at least half a second in raw time which will be much worse when it's PAXed out
One of the other things I noticed: the downhill corner was extremely rough in my car. I had quite a bit of tire "chatter" over the bumps which leads me to beleive I was running too much pressure up front. (35 psi). Looking at the Geez plots, it's easy to see: The corning trace (left side) at the lower magenta line should be a flat plateau of right-hand cornering (like the one directly above it). Rather, it's a jagged mess indicating that I was not able to maintain a steady line through the corner. The same thing happens just above the first light blue line: Instead of a smooth corner, it's extremely jagged.
I believe it's this rough patch that caused me to be too timid on the first loop.
04-27-05, 07:27 AM
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Originally Posted by Umrswimr
Interesting... I'm not suprised you made up most of your time in the first section- I was fairly sure I left a LOT out there on the first downhill right hander
Originally Posted by Umrswimr
One of the other things I noticed: the downhill corner was extremely rough in my car. I had quite a bit of tire "chatter" over the bumps which leads me to beleive I was running too much pressure up front. (35 psi).
Last edited by DamonB; 04-27-05 at 07:32 AM.
05-04-05, 08:55 AM
#112
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We had an event at the largest, fastest site in the area this past Sunday. Third gear and 80+ mph are not uncommon in my car at this site. Unfortunately I got my butt soundly kicked by all the Z06's and I'm still trying to figure out if it was my driving or the car. The vettes were running 88's all day and the best I could manage was a 92.3 which I did my third run out of six. My goal was to get into the 90's but I couldn't even get close while every vette there just seemed to have no trouble at all. It's days like this I really wish there were another fast FD around or umrswimr to be there with Geez! in his ASP C5 so I can see what everyone else was able to do.
I felt I was giving up some time as far as my driving goes but as hard as I tried to concentrate and execute my plan I just could not go faster. I'll be the first to admit that if you have any doubt about your performance you're normally right in the fact that it wasn't very good. My problem is that I felt I was driving the car to the limit because I couldn't put power down any better or corner any faster; I concentrated on being smooth and really feeling the car out and I thought I was pushing pretty hard. When I look at the times my competitors in the vettes made though I got slaughtered; FD or not I should have been closer than that. I figure that means either I drove poorly, my car setup was off or somehow the course just suited the vettes more than the FD.
This site is hilly and so usage values in Geez tend to be slightly lower here because of off camber turns etc. Even so I feel my scores are much too low. Looking at the track map the start is just above the stats menu. The car accelerates hard into a two cone slalom, shifts to second as it passes the first cone and then continues accelerating hard into a dirty 90 degree left. Out of this into a kink and then a sharp left turn heading toward a medium speed right hander. Balance the car on the throttle around the right hander and dodge an offset gate to the right before braking hard and making a right turn uphill. Climb uphill and accelerate hard before braking hard and early to pivot the car into a very sharp 180 degree left turn around a single cone and head downhill again. Into a medium speed right hander that is dirty and being careful to setup for the fast section coming. Rotate the car to the right and head uphill into a few really big offsets, shifting to third gear as I enter the first and continue to accelerate uphill. At the end of the offsets is a 5 cone slalom with the distance between each cone decreasing as you pass through. Out of this into a medium speed right hand and still climping uphill. Crest the hill onto level ground and rotate the car through a quick right turn that heads downhill again into another offset. Accelerating hard in third downhill into a giant carousel turn to the left. The first third of this turn is downhill, the middle third level and the last third uphhill again. Slow the car hard for a sharp right turn while heading uphill and downshift back to second. Through a short chute and into a giant right hand carousel on level ground. Hard around this carousel and into the finish.
I felt I was giving up some time as far as my driving goes but as hard as I tried to concentrate and execute my plan I just could not go faster. I'll be the first to admit that if you have any doubt about your performance you're normally right in the fact that it wasn't very good. My problem is that I felt I was driving the car to the limit because I couldn't put power down any better or corner any faster; I concentrated on being smooth and really feeling the car out and I thought I was pushing pretty hard. When I look at the times my competitors in the vettes made though I got slaughtered; FD or not I should have been closer than that. I figure that means either I drove poorly, my car setup was off or somehow the course just suited the vettes more than the FD.
This site is hilly and so usage values in Geez tend to be slightly lower here because of off camber turns etc. Even so I feel my scores are much too low. Looking at the track map the start is just above the stats menu. The car accelerates hard into a two cone slalom, shifts to second as it passes the first cone and then continues accelerating hard into a dirty 90 degree left. Out of this into a kink and then a sharp left turn heading toward a medium speed right hander. Balance the car on the throttle around the right hander and dodge an offset gate to the right before braking hard and making a right turn uphill. Climb uphill and accelerate hard before braking hard and early to pivot the car into a very sharp 180 degree left turn around a single cone and head downhill again. Into a medium speed right hander that is dirty and being careful to setup for the fast section coming. Rotate the car to the right and head uphill into a few really big offsets, shifting to third gear as I enter the first and continue to accelerate uphill. At the end of the offsets is a 5 cone slalom with the distance between each cone decreasing as you pass through. Out of this into a medium speed right hand and still climping uphill. Crest the hill onto level ground and rotate the car through a quick right turn that heads downhill again into another offset. Accelerating hard in third downhill into a giant carousel turn to the left. The first third of this turn is downhill, the middle third level and the last third uphhill again. Slow the car hard for a sharp right turn while heading uphill and downshift back to second. Through a short chute and into a giant right hand carousel on level ground. Hard around this carousel and into the finish.
Last edited by DamonB; 05-04-05 at 10:11 AM.
05-04-05, 10:07 AM
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Looking at the track map the first third or so is at normal autox speeds; maybe up to 55mph. This was also the dirtiest section of the course as the asphalt breaks up and litters the course with gravel. Once I make the right turn uphill into the large offeset and shift into the third the course was very clean with excellent grip. It's just hold on and go fast from there. The course is fast enough that there are really no issues with building boost and power. The tight sections were tight enough that I wouldn't have been able to accelerate harder anyway. The track map says I do the first third of the course really well and the middle third poorly; the last third is mediocre. The parts of the course Geez says I perform the worst were also the fastest portion of the course; all in third gear.
The bullseye on the track map is where I shifted to third gear as I climb the hill. I make it through the offset fine but heading into and through the decreasing slalom my usage is terrible. At the same time even though the surface was clean here I could not put down any more power than I was because the video shows the rear end trying to wag all the way through here if I push it harder. The car and my backside say I had no grip left but Geez thinks otherwise. Once I get through the slalom I make a right turn with great usage and then it plummets again before making the second right hander and heading downhill. My gut told me I was under driving that decreasing slalom so through the day I tried to drive it harder and couldn't do it. The rear end of the car would not stay put if I tried to go faster. This is the first time I feel that regardless of what Geez thinks I know I certainly wasn't capable of going faster through there.
The second span of low usage (red) is as the car crests the hill and I set it up to rotate it to the right and head downhill again. This section was dirty and if you got caught out wide you'd be in the gravel and in trouble. I probably did drive that area very conservatively because it was important to get through there cleanly in order to get ready for the next high speed portion. Still in third gear I make a right turn and then head downhill where my usage plummets again. I honestly don't know why this section shows poorly. It was fairly straight and downhill and I'm accelerating in third gear. My only thought is that perhaps since the rate of acceleration here in third gear is slower than most everywhere else when I was in second Geez feels I wasn't pushing as hard as possible.
So where's all this leave me? Geez says I drove the decreasing slalom poorly but I couldn't get through there any quicker without the car moving around all over the place. I can't explain the big disagreement between Geez and I here. The surface there was "good" so that's not it. One thing I wanted to try since the course was so fast was to stiffen the rear shocks up to aid in the really fast sections. My feelings agree with the map in one important way: the handling of the car was excellent in the slow and medium speed stuff but in the really fast stuff (60+ mph) the rear of the car didn't seem to stick as well. The front would rotate through and point no problem but the rear seemed sluggish and slow to react and change direction at high speed. Stiffening the rear shocks should have sped up the rear end but when I looked at the times the vettes were running I felt the difference was so large that my real failure was in driving, not handling. Because of that I chose to stick it out and not change the car through the day; I was convinced it was me screwing up.
Now that I study more and look back I think it really could have been more of a handling problem. The areas I scored poorly on are distinctly different than the areas I scored well on; namely in speed. Unfortunately my biggest failure all day was in not changing the rear shocks and giving it a try. Because I didn't do that I can't say for certain if I had a real handling issue or if I just plain sucked that day. Being about 4 seconds off tells me I sucked but I couldn't make the car go any faster either. That suggests to me that perhaps the handling was off; I was at the limit but the car was handicapped because I didn't dial in what it needed. I don't know. As much as I would like to think it was the car that day history has taught me that when you get beat that badly it isn't the car. On the other hand Geez shows there was a distinct difference in performance between the slow and fast sections and on the fast sections I was pushing hard; the car couldn't take any more power or cornering speed.
So now I'm sitting here and don't really know what my problem was. If I was only off a second or two on that huge course I would have undoubtedly messed around with the car setup. I was so far back though I figured the problem was in fact me; the gap in times was just too big. Studying now though perhaps I was wrong that day. The course was mostly fast and I had issues in the fast parts; it may be as simple as that. I should have changed the rear shocks so that I would know for certain because I had already established I was struggling. When I wasn't dropping big pieces of time on successive runs and thought I might have a handling problem I should have changed the car.
The bullseye on the track map is where I shifted to third gear as I climb the hill. I make it through the offset fine but heading into and through the decreasing slalom my usage is terrible. At the same time even though the surface was clean here I could not put down any more power than I was because the video shows the rear end trying to wag all the way through here if I push it harder. The car and my backside say I had no grip left but Geez thinks otherwise. Once I get through the slalom I make a right turn with great usage and then it plummets again before making the second right hander and heading downhill. My gut told me I was under driving that decreasing slalom so through the day I tried to drive it harder and couldn't do it. The rear end of the car would not stay put if I tried to go faster. This is the first time I feel that regardless of what Geez thinks I know I certainly wasn't capable of going faster through there.
The second span of low usage (red) is as the car crests the hill and I set it up to rotate it to the right and head downhill again. This section was dirty and if you got caught out wide you'd be in the gravel and in trouble. I probably did drive that area very conservatively because it was important to get through there cleanly in order to get ready for the next high speed portion. Still in third gear I make a right turn and then head downhill where my usage plummets again. I honestly don't know why this section shows poorly. It was fairly straight and downhill and I'm accelerating in third gear. My only thought is that perhaps since the rate of acceleration here in third gear is slower than most everywhere else when I was in second Geez feels I wasn't pushing as hard as possible.
So where's all this leave me? Geez says I drove the decreasing slalom poorly but I couldn't get through there any quicker without the car moving around all over the place. I can't explain the big disagreement between Geez and I here. The surface there was "good" so that's not it. One thing I wanted to try since the course was so fast was to stiffen the rear shocks up to aid in the really fast sections. My feelings agree with the map in one important way: the handling of the car was excellent in the slow and medium speed stuff but in the really fast stuff (60+ mph) the rear of the car didn't seem to stick as well. The front would rotate through and point no problem but the rear seemed sluggish and slow to react and change direction at high speed. Stiffening the rear shocks should have sped up the rear end but when I looked at the times the vettes were running I felt the difference was so large that my real failure was in driving, not handling. Because of that I chose to stick it out and not change the car through the day; I was convinced it was me screwing up.
Now that I study more and look back I think it really could have been more of a handling problem. The areas I scored poorly on are distinctly different than the areas I scored well on; namely in speed. Unfortunately my biggest failure all day was in not changing the rear shocks and giving it a try. Because I didn't do that I can't say for certain if I had a real handling issue or if I just plain sucked that day. Being about 4 seconds off tells me I sucked but I couldn't make the car go any faster either. That suggests to me that perhaps the handling was off; I was at the limit but the car was handicapped because I didn't dial in what it needed. I don't know. As much as I would like to think it was the car that day history has taught me that when you get beat that badly it isn't the car. On the other hand Geez shows there was a distinct difference in performance between the slow and fast sections and on the fast sections I was pushing hard; the car couldn't take any more power or cornering speed.
So now I'm sitting here and don't really know what my problem was. If I was only off a second or two on that huge course I would have undoubtedly messed around with the car setup. I was so far back though I figured the problem was in fact me; the gap in times was just too big. Studying now though perhaps I was wrong that day. The course was mostly fast and I had issues in the fast parts; it may be as simple as that. I should have changed the rear shocks so that I would know for certain because I had already established I was struggling. When I wasn't dropping big pieces of time on successive runs and thought I might have a handling problem I should have changed the car.
Last edited by DamonB; 05-04-05 at 10:14 AM.
05-06-05, 08:21 AM
#114
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Because I thought I may have issues with the car that day and the course was very long I took tire temperatures to see how they looked. Keep in mind the temps were read about a minute after finishing and that the last turn was a long, fast right hander. Temps taken with a probe.
LF..123..124..132..........127..117..109..RF
LR..132..136..135..........133..123..121..RR
LF..123..124..132..........127..117..109..RF
LR..132..136..135..........133..123..121..RR
05-06-05, 10:15 AM
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Damon-
Interesting discussion.
Some things I've noticed when I feel I did poorly:
1) I overdrove the car. This is extremely hard to tell yourself you're doing and it's usually a lot worse when I'm frustrated and getting clobbered by everyone out there. Based on a few of your comments, I think this might have been part of it.
2) Most of my poor utilization figures occur on fast portions of the track. This comes as very little suprise to me, given the potential for damage and my preivious encounter with immobile objects. To me, it looks lilke you were underdriving the car on the fast(er) parts as well.
Together on your run, based on the usage I see, this tends to indicate a combination of things:
1) The rear of your car was too loose.
2) You were getting frustrated whcih usually results in jerky, sharp movements in an attempt to make up time.
3) Combine 1 and 2 together on a 3rd gear slalom and you get a twitchy, unsettled car that you can't seem to go any faster through.
Of course, the "smoothness" and "aggressiveness" values you have indicate nearly the exact opposite. Based on those values, iI would say you had terminal oversteer. In the GEEZ plots, I've found that oversteer shows up as poor usage, low aggressiveness, and good "smoothness" because of the lack of jerky "transition". Or exactly what you show above.
One more thing to consider:
The elvation changes affect the utilization figures as you mentioned. But if the track does not have uniform grip, that will also affect your score. Though I find it odd that two of the areas with low utilization are those UPHILL areas with good grip.... Usually it's the other way around.
Interesting discussion.
Some things I've noticed when I feel I did poorly:
1) I overdrove the car. This is extremely hard to tell yourself you're doing and it's usually a lot worse when I'm frustrated and getting clobbered by everyone out there. Based on a few of your comments, I think this might have been part of it.
2) Most of my poor utilization figures occur on fast portions of the track. This comes as very little suprise to me, given the potential for damage and my preivious encounter with immobile objects. To me, it looks lilke you were underdriving the car on the fast(er) parts as well.
Together on your run, based on the usage I see, this tends to indicate a combination of things:
1) The rear of your car was too loose.
2) You were getting frustrated whcih usually results in jerky, sharp movements in an attempt to make up time.
3) Combine 1 and 2 together on a 3rd gear slalom and you get a twitchy, unsettled car that you can't seem to go any faster through.
Of course, the "smoothness" and "aggressiveness" values you have indicate nearly the exact opposite. Based on those values, iI would say you had terminal oversteer. In the GEEZ plots, I've found that oversteer shows up as poor usage, low aggressiveness, and good "smoothness" because of the lack of jerky "transition". Or exactly what you show above.
One more thing to consider:
The elvation changes affect the utilization figures as you mentioned. But if the track does not have uniform grip, that will also affect your score. Though I find it odd that two of the areas with low utilization are those UPHILL areas with good grip.... Usually it's the other way around.
05-06-05, 11:02 AM
#116
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^ What doesn't add up for me though is the fact the on the dirty part of the course my usage values are great and on the clean part they are poor. By coincidence the dirty section was also the slow section and the clean section was the fast section. The red sections are my lowest usage overall and those are also the steepest sections of the course so I can buy scoring lower there because of the non-level surface. But the whole 4 second difference behind the vettes just isn't right. The course should have suited my car pretty well and though I wouldn't have expected to beat all the vettes I did expect to be no more than a couple seconds back over 90 seconds.
Overall handling through corners was the same as usual for the way I keep the car: slight understeer to neutral in slow to medium stuff which heads toward oversteer the faster you go. Mostly this is because of using a big front bar in combination with the soft stock springs. Overall the car felt good, it just seemed to be going much too slow when I look at others' times.
Overall handling through corners was the same as usual for the way I keep the car: slight understeer to neutral in slow to medium stuff which heads toward oversteer the faster you go. Mostly this is because of using a big front bar in combination with the soft stock springs. Overall the car felt good, it just seemed to be going much too slow when I look at others' times.
05-17-05, 09:27 AM
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Geez
Well, Damon and I once again did battle on the TMS infield road course. This course was a similar layout to the previous year's race, though the details were significantly different. This course flowed much nicer than the previous year's event, although it still had several extremely tight sections to control speed.
The course started with quick offfset gate (1-2 gearshift) into a 3 cone slalom. This dumped into a Chicago box (first braking spike) which went into another set of ofset gates and ANOTHER Chicago box (second braking spike). This box opened into a 50 yard long straight which resulted in the 2-3 gearchange (~69 MPH here).
Stand on the brakes to enter the sweeping righthand banked corner which was constant radius into a 5 cone slalom with a catch: the first two cones were straight, then a 30 degree angle to the next three. I worked this corner and 75% of the cars clipped one of these cones. It was an extremely difficult section to do cleanly because of the speed, the transition off the banking, and the offset nature of the slalom.
Exit the slalom and roll onto the throttle as you clear the fourth cone, pass the fifth, then a 30 yard straight which enters the "how big are your nutz?" section of the track. A sharp righthander (which required a substantial braking section for me, but my competition in the ASP Lotus could do this flat out) into a sweeping left which was modulated with your foot. If done correctly, it was a nearly constant left corner which topped out at 76 MPH for me. To say I was a little nervous would be an understatement.
HARD braking (be sure to do it in a straight line here or you'll swap ends in a hurry -ask how I know!) into a right hand four cone slalom which is decreasing distance. WOT again before another brake stand into a deceptively tight right hander. This corner was dificult because it was a deceptively tight entry, wide in the middle, then a very tight exit into a VERY tight offset slalom before the finish. I blew this slalom on the second run and cost me my 54.8 with three cones.
...continued...
The course started with quick offfset gate (1-2 gearshift) into a 3 cone slalom. This dumped into a Chicago box (first braking spike) which went into another set of ofset gates and ANOTHER Chicago box (second braking spike). This box opened into a 50 yard long straight which resulted in the 2-3 gearchange (~69 MPH here).
Stand on the brakes to enter the sweeping righthand banked corner which was constant radius into a 5 cone slalom with a catch: the first two cones were straight, then a 30 degree angle to the next three. I worked this corner and 75% of the cars clipped one of these cones. It was an extremely difficult section to do cleanly because of the speed, the transition off the banking, and the offset nature of the slalom.
Exit the slalom and roll onto the throttle as you clear the fourth cone, pass the fifth, then a 30 yard straight which enters the "how big are your nutz?" section of the track. A sharp righthander (which required a substantial braking section for me, but my competition in the ASP Lotus could do this flat out) into a sweeping left which was modulated with your foot. If done correctly, it was a nearly constant left corner which topped out at 76 MPH for me. To say I was a little nervous would be an understatement.
HARD braking (be sure to do it in a straight line here or you'll swap ends in a hurry -ask how I know!) into a right hand four cone slalom which is decreasing distance. WOT again before another brake stand into a deceptively tight right hander. This corner was dificult because it was a deceptively tight entry, wide in the middle, then a very tight exit into a VERY tight offset slalom before the finish. I blew this slalom on the second run and cost me my 54.8 with three cones.
...continued...
05-17-05, 09:59 AM
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My time for this run was a 56.284 with no cones. But my fastest time was a 54.8 with three cones.
So what caused the huge time disparity?
The obvious one: on the 54.8 run, I upshifted to third before the sweeping lefthand pucker corner, then downshifted back to second at the end of the corner to finish in second gear. For the plot above, I shifted to third before the banked righthand corner and ran the whole course in third. This DRAMATICALLY affected my accelleration as shown on the above plot. The sections bracketed in red lines are areas where I was WOT in third gear, but the car was below the power band and acceleration G force was HALF that in second gear on the previous run.
So why did I go up to third? Well, entering the sweeping righthander at the top, I needed third gear. Even with the upshift to third, I was at 69 MPH which is redline in second. Had I stayed in second, I would have been in the limiter for sure. I also needed third for the sweeping left pucker corner, so I felt it was not worth it to downshift to second in the middle of the slalom. This was a judgement call and I'm still not sure what the right decision would be, based on the difficulty of the offset slalom.
Now, there is no quesiton that I should have downshifted after the lefthand pucker corner. The car was well below the powerband for third (2800 RPM, looks like) and my acceleration suffered.
So what caused the huge time disparity?
The obvious one: on the 54.8 run, I upshifted to third before the sweeping lefthand pucker corner, then downshifted back to second at the end of the corner to finish in second gear. For the plot above, I shifted to third before the banked righthand corner and ran the whole course in third. This DRAMATICALLY affected my accelleration as shown on the above plot. The sections bracketed in red lines are areas where I was WOT in third gear, but the car was below the power band and acceleration G force was HALF that in second gear on the previous run.
So why did I go up to third? Well, entering the sweeping righthander at the top, I needed third gear. Even with the upshift to third, I was at 69 MPH which is redline in second. Had I stayed in second, I would have been in the limiter for sure. I also needed third for the sweeping left pucker corner, so I felt it was not worth it to downshift to second in the middle of the slalom. This was a judgement call and I'm still not sure what the right decision would be, based on the difficulty of the offset slalom.
Now, there is no quesiton that I should have downshifted after the lefthand pucker corner. The car was well below the powerband for third (2800 RPM, looks like) and my acceleration suffered.
Last edited by Umrswimr; 05-17-05 at 10:19 AM.
05-17-05, 10:05 AM
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Originally Posted by DamonB
Dave, post a pic of your friction circle. My usage was low too and I think I know why...
Notice the two heavy right hand corners had considerably higher G forces.... They were both banked.
05-17-05, 11:30 AM
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Here's my data from the same event umrswimr posted above. The fastest I was able to run all day was a 57.1 but that run carried a cone. In fact, all my runs carried cones; it was one of those days. The course was smooth, fast and in order to maintain speed you had to be aggressive with placing the car. I hit different cones on every run while pushing hard but I knew my raw times had me in the hunt and didn't want to back off too much. On my final run I hit the very last cone before the finish. That kind of stuff irritates the hell out of me; nobody's fault but my own.
First off a map of the course. This event was held on the infield road course at Texas Motor Speedway. It is mostly level except the two large 180 degree turns at either end which are banked and a section of turns with elevation changes. Geez grades you on how well you maintain maximum grip at all times but this course fools it a little. Since the banked turns are both long right handers you can of course corner harder there than elsewhere. This skews your readings a little but it's still perfectly acceptable to compare numbers as long as they are from the same course.
Below is a map of the course as well as friction circle graphs from umrswimr and I. You can see our friction circles are much more developed in the right turns than the left; that's due to the banking in the long right handers. Because of those turns Geez feels we didn't turn left as hard as we could have and grades us lower than we would like to normally see. That's why you shouldn't focus so tightly on just the numbers, you need to evaluate everything together.
First off a map of the course. This event was held on the infield road course at Texas Motor Speedway. It is mostly level except the two large 180 degree turns at either end which are banked and a section of turns with elevation changes. Geez grades you on how well you maintain maximum grip at all times but this course fools it a little. Since the banked turns are both long right handers you can of course corner harder there than elsewhere. This skews your readings a little but it's still perfectly acceptable to compare numbers as long as they are from the same course.
Below is a map of the course as well as friction circle graphs from umrswimr and I. You can see our friction circles are much more developed in the right turns than the left; that's due to the banking in the long right handers. Because of those turns Geez feels we didn't turn left as hard as we could have and grades us lower than we would like to normally see. That's why you shouldn't focus so tightly on just the numbers, you need to evaluate everything together.
05-17-05, 11:42 AM
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Here's an overall view showing the course, lateral and accel g's and scores. This is the same color scheme I always use with 90%+ usage in light blue, 80%-90% in dark blue, 70%-80% in violet and anything under 70% in red. You see at the opposite ends of the course two long right handers that score pretty well, these are the banked turns. The slalom complexes off the start I felt I drove well but since it was on flat and level ground the car naturally didn't corner as hard as on the banked turns, so the entire complex shows as lower usage. Same with the downhill portions of the course. The downhill sections were during cornering and of course you had to back off a little (those of us with power anyway 
) to keep the car from shooting off the pavement.
) to keep the car from shooting off the pavement.
05-17-05, 12:07 PM
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Looks like Damon took the two banked corners better (especially the entrance to the offset slalom) than I did and I took the center "pucker" corner a little faster... Given the speed and elevation change here, I can't really fault him for that!
Did you run the exit to that corner in second gear? Based on the acceleration trace, it looks like you were able to do the front half in second until the entrance to the "pucker" corner where you grabbed third. (the dip in the accel trace about halfway through the run right before the huge brake spike).
I'm really curious why we both show low utilization for the are marked "2" on my map... I'm at WOT here and it looks like Damon is too (with a gearchange in the middle for Damon right around the second red bracket line on my trace). I guess this is a situation where Geez is telling me: you should've been in a lower gear, dipchit.
Did you run the exit to that corner in second gear? Based on the acceleration trace, it looks like you were able to do the front half in second until the entrance to the "pucker" corner where you grabbed third. (the dip in the accel trace about halfway through the run right before the huge brake spike).
I'm really curious why we both show low utilization for the are marked "2" on my map... I'm at WOT here and it looks like Damon is too (with a gearchange in the middle for Damon right around the second red bracket line on my trace). I guess this is a situation where Geez is telling me: you should've been in a lower gear, dipchit.
05-17-05, 12:08 PM
#124
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Here are the lateral g and accelration g charts from umrswimr and myself placed side by side. Each pair of charts shows lateral g on the left, and acceleration g on the right. I also labled our upshifts on the acceleration charts. Upshifts are easy to spot if you know what to look for as you'll see sharply rising acceleration and then a sharp dip to zero before acceleration rises again. The sharper that spike the faster the shift was accomplished. Downshifts normally can't be spotted because there is no tach input, this chart merely shows acceleration. Since you normally downshift while braking hard you can't pinpoint the shift, whereas when accelerating hard you can easily notice because the dipping of the clutch on the upshift shows as acceleration momentarily stopping.
