What does 9/10ths Mean?
07-16-2009, 07:59 AM
#1
4th Gear Member
Thread Starter
Join Date: Oct 2007
Location: Harrisburg PA
Posts: 1,778
What does 9/10ths Mean?
From time to time on various forums I see guys post comments like: "I was only driving 7/10ths, once I get the car sorted out I'll take it up to 9/10ths".
I suspect that using terms like this is open to lots of interpretation and means different things to different people. So I thought about some possibilities on quantifying it. 10/10ths would mean there is absolutely zero room for error, one bobble and you are off track. One more mph in a corner or 1 foot too far into your brake zone and you are going to mow the grass. In reality this is something of an impossibility but the very best drivers can get darn close. So how do you quantify 90% of that, or for that matter 80% or 70%. Some thoughts:
- Lap times - on a given track look up the ave lap times (mylaps.com) of a race class using similar car to yours and compare to your lap times. If you are 90% of their times you are running close to 9/10ths. The assumption being the racers are running near 10/10ths
- Threshold brake method - on a given track, a number of corners will have brake zones where you can threshold brake (just barely get into the ABS). Hit 90% of them.
- Data Aquisition method - find the data for a few class leading racers or TTers on a given track (data overlays from youTube, Vimeo, StreetFire, etc) using same/similar car to yours. Compare corner speeds to yours. Again you have to assume the data you are comparing to is run at close to 10/10ths.
- Data Aquisition method 2 - in many software programs you can plot speed (y-axis) vs distance (x-axis). This creates a chart of peaks and valleys from left to right. The higher the peak, the faster you are going. The steeper the incline or decline the harder you are accelerating or braking. One of the keys here is ideally you want very sharp peaks, indicating you are going from gas to brake with zero coast (there are other ways to analyze the chart but I'm no expert at this, just sat thru a couple classrooms). So - a given track has a number of turns. One key to going fast is to reduce or eliminate the periods of coast (you should be on the gas or on the brake and seldom in between). If 90% of your transition zones are coast free, you are at 9/10ths.
What thoughts do you guys have, how would you measure 9/10ths?
I suspect that using terms like this is open to lots of interpretation and means different things to different people. So I thought about some possibilities on quantifying it. 10/10ths would mean there is absolutely zero room for error, one bobble and you are off track. One more mph in a corner or 1 foot too far into your brake zone and you are going to mow the grass. In reality this is something of an impossibility but the very best drivers can get darn close. So how do you quantify 90% of that, or for that matter 80% or 70%. Some thoughts:
- Lap times - on a given track look up the ave lap times (mylaps.com) of a race class using similar car to yours and compare to your lap times. If you are 90% of their times you are running close to 9/10ths. The assumption being the racers are running near 10/10ths
- Threshold brake method - on a given track, a number of corners will have brake zones where you can threshold brake (just barely get into the ABS). Hit 90% of them.
- Data Aquisition method - find the data for a few class leading racers or TTers on a given track (data overlays from youTube, Vimeo, StreetFire, etc) using same/similar car to yours. Compare corner speeds to yours. Again you have to assume the data you are comparing to is run at close to 10/10ths.
- Data Aquisition method 2 - in many software programs you can plot speed (y-axis) vs distance (x-axis). This creates a chart of peaks and valleys from left to right. The higher the peak, the faster you are going. The steeper the incline or decline the harder you are accelerating or braking. One of the keys here is ideally you want very sharp peaks, indicating you are going from gas to brake with zero coast (there are other ways to analyze the chart but I'm no expert at this, just sat thru a couple classrooms). So - a given track has a number of turns. One key to going fast is to reduce or eliminate the periods of coast (you should be on the gas or on the brake and seldom in between). If 90% of your transition zones are coast free, you are at 9/10ths.
What thoughts do you guys have, how would you measure 9/10ths?
07-16-2009, 10:28 AM
#2
2nd Gear Member
Join Date: Dec 2006
Location: Flanders, NJ
Posts: 408
I don't think you can exactly measure where your 10/10ths is compared to someone else's 10/10ths in the sake of times. I think 10/10ths is at the maximum of your personal ability. When we start out trying to drive at 10/10ths pushing our selfs to lets say 12/10th and only getting to 7/10ths, in essence overdriving. You push yourself beyond your capabilities and cost your self time and speed.
But like Brad said, I do think it can depend on conditions; track, car or driver. For example last weekend my local club ran on a different lot then usual. After the first runs we all noticed that this lot did not have the same grip level as our usual lot. When speaking to some folks I run with we all kind of agreed that in order to get the most out of your autocross runs on this lot you are going to have to go at it at 8/10th. If you pushed it beyond that you were leaving time on the course and ultimately going slower. I dialed myself back and won my class for the event.
I had a big lesson on this while running the SCCA National Tour event watching Sam run while it rained. Besides the fact that he is in just another class of drivers out there, but seeing how he dialed himself back on his last run, full wet conditions, and ran a full second faster then the first few runs by other drivers in the dry.
I think that is another case where you measure out your personal limits.
But like Brad said, I do think it can depend on conditions; track, car or driver. For example last weekend my local club ran on a different lot then usual. After the first runs we all noticed that this lot did not have the same grip level as our usual lot. When speaking to some folks I run with we all kind of agreed that in order to get the most out of your autocross runs on this lot you are going to have to go at it at 8/10th. If you pushed it beyond that you were leaving time on the course and ultimately going slower. I dialed myself back and won my class for the event.
I had a big lesson on this while running the SCCA National Tour event watching Sam run while it rained. Besides the fact that he is in just another class of drivers out there, but seeing how he dialed himself back on his last run, full wet conditions, and ran a full second faster then the first few runs by other drivers in the dry.
I think that is another case where you measure out your personal limits.
Last edited by jayel579; 07-16-2009 at 10:31 AM.
07-16-2009, 06:05 PM
#3
1st Gear Member
Join Date: Dec 2007
Posts: 100
Ya, I don't think the concept of 10th's is intended to be quantified. I think you can see it and feel it, to be sure, and it's different for everybody. For instance, I'll bet many of us have seen this scenario:
You're driving along at an open track event and are catching up to a car in front of you. When you're further back, you can see that the driver's line is good, the slip angles are relatively low (or non-existent) and the braking is smooth and easy. Then as you get closer, the driver starts missing apexes, braking zones and operating at much higher slip angles. Then after a wild slide and nearly throwing it off track, points you by. I would say the difference between those two extremes is 7/10th's vs. 10/10th's.
Note: Not all drivers are like this of course, but some are. And, if I had to generalize, I would say it often comes from drivers in cars that should be faster than mine. I've noticed that many BMW, Porsche and Ferrari drivers don't like getting passed by the Mustang. :-) Corvette drivers have been remarkably civil about it.
Also, I do plenty of pointing these cars by - I'm just trying to make the 7/10's vs. 10/10's comparison.
You're driving along at an open track event and are catching up to a car in front of you. When you're further back, you can see that the driver's line is good, the slip angles are relatively low (or non-existent) and the braking is smooth and easy. Then as you get closer, the driver starts missing apexes, braking zones and operating at much higher slip angles. Then after a wild slide and nearly throwing it off track, points you by. I would say the difference between those two extremes is 7/10th's vs. 10/10th's.
Note: Not all drivers are like this of course, but some are. And, if I had to generalize, I would say it often comes from drivers in cars that should be faster than mine. I've noticed that many BMW, Porsche and Ferrari drivers don't like getting passed by the Mustang. :-) Corvette drivers have been remarkably civil about it.
Also, I do plenty of pointing these cars by - I'm just trying to make the 7/10's vs. 10/10's comparison.
07-16-2009, 07:47 PM
#4
4th Gear Member
Join Date: Dec 2007
Location: Ontario, Canada
Posts: 1,692
An iteresting discussion and here is my 2 cents worth.
My feeling is that at 9/10ths is you are driving at 90% of the cars limit on that day at that track. 10/10 ths would be doing a lap at the maximum limit of the tires and/or engine all of the way around the course. On a flat skidpad you would be circulating at what ever limit the car would give, say 1 G on my car which has high performance street tires.
Because my posterior and experience level are not high enough yet to know how many 10ths I am at on a given point on the track I used the "data acquistion" method to help me out. My brother, who has thousands of laps at Mosport, drove my car, which he does not have a lot of laps in. The data from his best run, incidentally while he was chasing a Nissan GT-R on a clear track, showed that he was probably running between 9.5 and 10 ths of the cars capability. By comparing his data to my best lap I could easily tell what the car was capable of and where it was near the ragged edge. This was then converted into corner entry speeds for the 5 main corners and later in the month I did my best to make sure that I entered the corners at those speeds. I also made sure that my right foot stayed on the floor in 4th all the way up the back straight to the braking point.
Looking at the data afterwards showed my best lap time dropped almost 8 seconds, to 1:52 so the strategy worked. His best time was 1:42 so that puts me at about 9/10 ths of the cars limit.
I'm back again at Mosport again on Aug 3 and will have slightly higher corner entry speeds targets so it will be interesting to see how much of an improvement there will be this time.
Hopefully I won't go to 10.1 ths because Mosport can be pretty unforgiving
My feeling is that at 9/10ths is you are driving at 90% of the cars limit on that day at that track. 10/10 ths would be doing a lap at the maximum limit of the tires and/or engine all of the way around the course. On a flat skidpad you would be circulating at what ever limit the car would give, say 1 G on my car which has high performance street tires.
Because my posterior and experience level are not high enough yet to know how many 10ths I am at on a given point on the track I used the "data acquistion" method to help me out. My brother, who has thousands of laps at Mosport, drove my car, which he does not have a lot of laps in. The data from his best run, incidentally while he was chasing a Nissan GT-R on a clear track, showed that he was probably running between 9.5 and 10 ths of the cars capability. By comparing his data to my best lap I could easily tell what the car was capable of and where it was near the ragged edge. This was then converted into corner entry speeds for the 5 main corners and later in the month I did my best to make sure that I entered the corners at those speeds. I also made sure that my right foot stayed on the floor in 4th all the way up the back straight to the braking point.
Looking at the data afterwards showed my best lap time dropped almost 8 seconds, to 1:52 so the strategy worked. His best time was 1:42 so that puts me at about 9/10 ths of the cars limit.
I'm back again at Mosport again on Aug 3 and will have slightly higher corner entry speeds targets so it will be interesting to see how much of an improvement there will be this time.
Hopefully I won't go to 10.1 ths because Mosport can be pretty unforgiving
Last edited by Sleeper_08; 07-16-2009 at 08:01 PM.
07-16-2009, 08:16 PM
#5
2nd Gear Member
Join Date: Jan 2009
Location: Texas
Posts: 162
i agree with all of the responses on this 9/10ths. but truly believe it is a way to measure ones ability and fear of pushing just a little to hard. i constantly am questioning my approach to all areas of a track and can sometimes feel that i am holding back a bit, weather it's cause i know i have several more years of payments on this car or that i still have several more years of learning to do. in either case, i know when i could have pushed more or even sometimes should have let up. i do find it funny to quote "zero2sixd" on the lines taken by the car infront of you and watch them fall apart as you gain (push) on him/her. those are my most treasured moments. 
Argonaut thanks for the parts, will be using them for the 1st time on 9/19.
Argonaut thanks for the parts, will be using them for the 1st time on 9/19.
07-16-2009, 08:32 PM
#6
4th Gear Member
Join Date: Dec 2007
Location: Ontario, Canada
Posts: 1,692
i agree with all of the responses on this 9/10ths. but truly believe it is a way to measure ones ability and fear of pushing just a little to hard. i constantly am questioning my approach to all areas of a track and can sometimes feel that i am holding back a bit, weather it's cause i know i have several more years of payments on this car or that i still have several more years of learning to do. in either case, i know when i could have pushed more or even sometimes should have let up. i do find it funny to quote "zero2sixd" on the lines taken by the car infront of you and watch them fall apart as you gain (push) on him/her. those are my most treasured moments.
Argonaut thanks for the parts, will be using them for the 1st time on 9/19.
Argonaut thanks for the parts, will be using them for the 1st time on 9/19.
+1 gaining on the car in front.
My other objective next time out is to get to where my laps are more consistent, even when there is someone pushing me.
07-16-2009, 09:10 PM
#8
4th Gear Member
Thread Starter
Join Date: Oct 2007
Location: Harrisburg PA
Posts: 1,778
Thanks for the responses guys. Sounds like Colin and I are of the same feeling - using DA to compare your times with those of a known near 10/10ths driver in same car is one way to quantify it. I guess you could make the argument that doing it this way makes the measurment heavily dependent on equipment. IOW, if the car is capable of doing corner X at 100 MPH and I'm doing it at 90, then I am making the car go 9/10ths of its capability.
On the other hand Jason and Zero sound a little more skill level focused. For example - if two drivers drive the same car back to back and each drives at what he feels is 9/10ths and then you compare lap times and driver 1 is 10 seconds faster than driver 2...well thats ok, they were still both driving at 9/10s. So, looking at it this way I can see where you don't think it can be quantified.
So you prove my assumption - using a phrase like "I was driving at 9/10ths" is pretty meaningless. I don't know if the guy means he was driving the car at 9/10ths of the cars ability or he thought the he personally was driving really hard.
Regarding the "pecking" order that Zero points out. You know, its really funny you say that some guys who drive Vettes, Porsche, etc don't like to point Mustangs bye. That is so true. Last year in the Mustang I had that happen a lot. I remember one day in particular. I was at Lightning in New Jersey and the event was sponsored by a Corvette shop. The majority of cars there were Vettes. In a couple session I was dicing it up with a 911. We were turning identical lap times. There were a number of times when we'd come up on the six of a Vette and the guy would point the 911 by but not me. I'd really have to get in his mirrors before he'd do it. Flash forward to this year. Doesn't happen anymore. Driving the Vette a lot of tiimes, guys see me coming and give me the point by instantly, I don't even slow down.
On the other hand Jason and Zero sound a little more skill level focused. For example - if two drivers drive the same car back to back and each drives at what he feels is 9/10ths and then you compare lap times and driver 1 is 10 seconds faster than driver 2...well thats ok, they were still both driving at 9/10s. So, looking at it this way I can see where you don't think it can be quantified.
So you prove my assumption - using a phrase like "I was driving at 9/10ths" is pretty meaningless. I don't know if the guy means he was driving the car at 9/10ths of the cars ability or he thought the he personally was driving really hard.
Regarding the "pecking" order that Zero points out. You know, its really funny you say that some guys who drive Vettes, Porsche, etc don't like to point Mustangs bye. That is so true. Last year in the Mustang I had that happen a lot. I remember one day in particular. I was at Lightning in New Jersey and the event was sponsored by a Corvette shop. The majority of cars there were Vettes. In a couple session I was dicing it up with a 911. We were turning identical lap times. There were a number of times when we'd come up on the six of a Vette and the guy would point the 911 by but not me. I'd really have to get in his mirrors before he'd do it. Flash forward to this year. Doesn't happen anymore. Driving the Vette a lot of tiimes, guys see me coming and give me the point by instantly, I don't even slow down.
Last edited by Argonaut; 07-16-2009 at 09:13 PM.
07-16-2009, 09:29 PM
#9
4th Gear Member
Join Date: Dec 2007
Location: Ontario, Canada
Posts: 1,692
Here is a video I've posted before but it is a good example of the "pecking order" and/or ego problem. Most people feel the Z06 should have waved my brother past
http://www.youtube.com/watch?v=HtwXgKPy5hY
http://www.youtube.com/watch?v=HtwXgKPy5hY
07-17-2009, 07:08 AM
#10
4th Gear Member
Thread Starter
Join Date: Oct 2007
Location: Harrisburg PA
Posts: 1,778
That is a classic example! Yep, should have been a point by. If I'm the car in front, I hate having guys on my bumper like that. I'd prefer to let them by and then see if I can hang with them. I have to admit though, I did the same thing to a Miata one time and really cursed myself afterword, even apologized to the guy. He was an advanced driver running in the intermediate group and a far better driver than me. On the tight Shenandoah circuit he stayed right on my tail when we were in traffic. I kept thinking to myself - when I clear the traffic I will leave him in my dust. Didn't happen, he kept on my tail and I kept thinking "this can't be". Learned a lesson there, put the ego aside.
OK - back on topic - any more thoughts on what 9/10ths means?
OK - back on topic - any more thoughts on what 9/10ths means?