| faceplate | 04-27-2003 09:54 PM |
How does racing line vary with AWD, RWD, and FWD; and some other non-newb questions
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Hello, I was wondering how racing line is affected by AWD, FWD, and RWD cars. I also wanted to know how is the line taken in AutoX and Rally different from road racing line. Lastly, I have a question for those of you who road race imprezas. Do you use the normal approach, or do you try and pitch the car into the turn and power slide out of it? (all wheel drift) I remember seeing a video of Tommi Makenin testing the 04 sti and he was power sliding it all over the place on a road course. I have always heard sideways is not fast, but why do they drive that way in WRC tarmac stages? Does it have to do with not knowing the road or all wheel drive or lots of torque? Thanks
BTW the guys on the top gear videos like to power slide cars on road courses too.
BTW the guys on the top gear videos like to power slide cars on road courses too.
| Ultralight | 04-28-2003 01:10 AM |
Holy Moly! It takes a dissertation to just qualify the question. The optimum line, what I will term "effective line" or the actual path the car takes, will be the same for all types if all else is equal. The all else is things like power to weight ratio, handling bias (oversteer, understeer), acceleration traction, lateral tire adhesion, braking capability, size of car and so on. Now what you do CONTROL WISE to achieve that optimum line will differ from type to type. I'm just beginning to explore AWD technique but I've hill climbed, rallied and autoxed RWD and FWD for 40 years. I do not know if the WRX is typical of AWD but it's combination of peaky power (I sometimes call it turbo lag but it's not, the WRX just has no torque below 3500), and understeer make it a piece of work to drive fast. I have to fight 40 years of conditioning and just let the #@%& thing push. What would be thrashing on any other car I've driven is, I think, how it must be driven. Perhaps I will learn different over the next year.
| ITWRX4ME | 04-28-2003 02:23 PM |
Re: How does racing line vary with AWD, RWD, and FWD; and some other non-newb questions
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[QUOTE][i]Originally posted by faceplate [/i]
[B]Hello, I was wondering how racing line is affected by AWD, FWD, and RWD cars. I also wanted to know how is the line taken in AutoX and Rally different from road racing line. Lastly, I have a question for those of you who road race imprezas. Do you use the normal approach, or do you try and pitch the car into the turn and power slide out of it? (all wheel drift) I remember seeing a video of Tommi Makenin testing the 04 sti and he was power sliding it all over the place on a road course. I have always heard sideways is not fast, but why do they drive that way in WRC tarmac stages? Does it have to do with not knowing the road or all wheel drive or lots of torque? Thanks
BTW the guys on the top gear videos like to power slide cars on road courses too. [/B][/QUOTE]
My impression is that the rally drivers use the slide to carry speed deeper into a turn. The slide is occuring more on the entry to the turn, not as much on the exit. Turning the car sideways scrubs off speed in a shorter distance, negates understeer and gets it pointing in the right direction all at the same time.
[B]Hello, I was wondering how racing line is affected by AWD, FWD, and RWD cars. I also wanted to know how is the line taken in AutoX and Rally different from road racing line. Lastly, I have a question for those of you who road race imprezas. Do you use the normal approach, or do you try and pitch the car into the turn and power slide out of it? (all wheel drift) I remember seeing a video of Tommi Makenin testing the 04 sti and he was power sliding it all over the place on a road course. I have always heard sideways is not fast, but why do they drive that way in WRC tarmac stages? Does it have to do with not knowing the road or all wheel drive or lots of torque? Thanks
BTW the guys on the top gear videos like to power slide cars on road courses too. [/B][/QUOTE]
My impression is that the rally drivers use the slide to carry speed deeper into a turn. The slide is occuring more on the entry to the turn, not as much on the exit. Turning the car sideways scrubs off speed in a shorter distance, negates understeer and gets it pointing in the right direction all at the same time.
| slim speedy | 04-28-2003 06:09 PM |
Re: Re: How does racing line vary with AWD, RWD, and FWD; and some other non-newb questions
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[QUOTE][i]Originally posted by ITWRX4ME [/i]
[B]
My impression is that the rally drivers use the slide to carry speed deeper into a turn. The slide is occuring more on the entry to the turn, not as much on the exit. Turning the car sideways scrubs off speed in a shorter distance, negates understeer and gets it pointing in the right direction all at the same time. [/B][/QUOTE]
Thats part of it, the other reason is that the roads rally drivers are on are typically much narrower and sharper than anything you will see at the track. In order to take the turn as a track driver would you would have to be going very slowly through the corner. Sliding the car is also very slow, but you can go into the turn with more speed. I'm sure part of it is also because thats what the drivers know best, on gravel, dirt, and snow sliding often is the fastest way around a turn. So they tend to do it on tarmac as well.
[B]
My impression is that the rally drivers use the slide to carry speed deeper into a turn. The slide is occuring more on the entry to the turn, not as much on the exit. Turning the car sideways scrubs off speed in a shorter distance, negates understeer and gets it pointing in the right direction all at the same time. [/B][/QUOTE]
Thats part of it, the other reason is that the roads rally drivers are on are typically much narrower and sharper than anything you will see at the track. In order to take the turn as a track driver would you would have to be going very slowly through the corner. Sliding the car is also very slow, but you can go into the turn with more speed. I'm sure part of it is also because thats what the drivers know best, on gravel, dirt, and snow sliding often is the fastest way around a turn. So they tend to do it on tarmac as well.
| ShockWave | 04-28-2003 06:10 PM |
A lot will be decided by what tires you are using. If you are using racing slicks you do not want to waste energy by sliding. Wasted energy appears in the form of heat and cooks the tires, making them greasy. Once you've done that you need to slow down and cool off your tires or end up mowing the grass. Street tires can be a little more forgiving or may even require some push to get through a turn carrying the maximum amount of speed.
The outside-inside-outside method of road racers, hitting the apex of the turn, is far and away the fastest way around a corner. But that method only works if you know exactly what the conditions of the track are. For that matter, you need to know exactly what the path and make up of the turn are. Rally stages have a habit of changing from time to time, and the conditions change constantly. Road racing is a more controlled environment so its turn style is better for absolute on the limit driving where a few pieces of gravel that you didn't anticipate will put you in the grass.
At least in my opinion.
The outside-inside-outside method of road racers, hitting the apex of the turn, is far and away the fastest way around a corner. But that method only works if you know exactly what the conditions of the track are. For that matter, you need to know exactly what the path and make up of the turn are. Rally stages have a habit of changing from time to time, and the conditions change constantly. Road racing is a more controlled environment so its turn style is better for absolute on the limit driving where a few pieces of gravel that you didn't anticipate will put you in the grass.
At least in my opinion.
| IXLR8 | 04-28-2003 07:26 PM |
At the most basic level:
The objective of drving fast is to have the car pointed in a direction where the driver can apply the most power for the longest time. In other words, to be fast means spending the most time possible going "straight".
In general, rally guys slide so they can get pointed in the right direction and put down the power earlier. For both road racing and rallying, the main measure of this is exit speed (not entry speed). All things being equal, the guy with a highest exit speed (turn is finished earlier) will have spent more time going "straight" (and under power) and will get to the next corner first...
The objective of drving fast is to have the car pointed in a direction where the driver can apply the most power for the longest time. In other words, to be fast means spending the most time possible going "straight".
In general, rally guys slide so they can get pointed in the right direction and put down the power earlier. For both road racing and rallying, the main measure of this is exit speed (not entry speed). All things being equal, the guy with a highest exit speed (turn is finished earlier) will have spent more time going "straight" (and under power) and will get to the next corner first...
| mch | 04-28-2003 09:00 PM |
You might find "Secrets of Solo Racing" by Henry A Watts useful. He does spend some time discussing racing line and the logic of going fast. Not all that in depth but a useful start.
mch
mch
| ITWRX4ME | 04-28-2003 09:05 PM |
[QUOTE][i]Originally posted by IXLR8 [/i]
[B]At the most basic level:
The objective of drving fast is to have the car pointed in a direction where the driver can apply the most power for the longest time. In other words, to be fast means spending the most time possible going "straight".
In general, rally guys slide so they can get pointed in the right direction and put down the power earlier. For both road racing and rallying, the main measure of this is exit speed (not entry speed). All things being equal, the guy with a highest exit speed (turn is finished earlier) will have spent more time going "straight" (and under power) and will get to the next corner first... [/B][/QUOTE]
That's kinda what I was getting at, but since I'm not speaking from experience, I didn't want to go too far. While I understand the concept, I have not the cojones for that style of driving(yet).
[B]At the most basic level:
The objective of drving fast is to have the car pointed in a direction where the driver can apply the most power for the longest time. In other words, to be fast means spending the most time possible going "straight".
In general, rally guys slide so they can get pointed in the right direction and put down the power earlier. For both road racing and rallying, the main measure of this is exit speed (not entry speed). All things being equal, the guy with a highest exit speed (turn is finished earlier) will have spent more time going "straight" (and under power) and will get to the next corner first... [/B][/QUOTE]
That's kinda what I was getting at, but since I'm not speaking from experience, I didn't want to go too far. While I understand the concept, I have not the cojones for that style of driving(yet).
| mch | 04-28-2003 09:17 PM |
Did I hear anyone say "friction circle"?
| ITWRX4ME | 04-28-2003 10:31 PM |
[QUOTE][i]Originally posted by mch [/i]
[B]Did I hear anyone say "friction circle"? [/B][/QUOTE]
<<----runs away screaming in fear of exposure to more physics theory.
That theory stuff is interesting. But eventually, it comes down to feeling it in the seat of your pants. In practice, all of the elements that come into play when taking a turn at high speed require feeling, experience and coordination. It's not like you can calculate, and then execute, the precise, optimal deceleration, steering and acceleration rates for any given situation. There are too many variables.
I'll bet Mikka doesn't give any thought whatsoever to slip angles when he executes a pendulum turn.
[B]Did I hear anyone say "friction circle"? [/B][/QUOTE]
<<----runs away screaming in fear of exposure to more physics theory.
That theory stuff is interesting. But eventually, it comes down to feeling it in the seat of your pants. In practice, all of the elements that come into play when taking a turn at high speed require feeling, experience and coordination. It's not like you can calculate, and then execute, the precise, optimal deceleration, steering and acceleration rates for any given situation. There are too many variables.
I'll bet Mikka doesn't give any thought whatsoever to slip angles when he executes a pendulum turn.
| Soon2Bgreat | 04-28-2003 10:44 PM |
Mikka or Makinen...;)
| IXLR8 | 04-28-2003 10:54 PM |
[QUOTE][i]Originally posted by ITWRX4ME [/i]
[B]I'll bet Mikka doesn't give any thought whatsoever to slip angles when he executes a pendulum turn. [/B][/QUOTE]
Actually I can almost guarantee he does...
Racing at his level (and pretty much all levels) is a team effort. While the execution may be seat-of-the-pants he has to be able to communicate to the crew in precise terms what the car (and each individual component) is doing in order to make adjustments. (Telemetry helps, but ultimately it's the driver, not data acquisition devices, that have to pilot the car.) That's one reason driver/crew chief "chemistry" counts for so much... gotta speak the same "vehicle language" to wring every bit out of it.
[B]I'll bet Mikka doesn't give any thought whatsoever to slip angles when he executes a pendulum turn. [/B][/QUOTE]
Actually I can almost guarantee he does...
Racing at his level (and pretty much all levels) is a team effort. While the execution may be seat-of-the-pants he has to be able to communicate to the crew in precise terms what the car (and each individual component) is doing in order to make adjustments. (Telemetry helps, but ultimately it's the driver, not data acquisition devices, that have to pilot the car.) That's one reason driver/crew chief "chemistry" counts for so much... gotta speak the same "vehicle language" to wring every bit out of it.
| OnTheGas | 04-28-2003 11:29 PM |
Re: How does racing line vary with AWD, RWD, and FWD; and some other non-newb questio
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[QUOTE][i]Originally posted by faceplate [/i]
[B]...How is the racing line is affected by AWD, FWD, and RWD cars?[/B][/QUOTE]Good question... A car's setup, (whether the car is oversteering, understeering, or is neutral) will strongly affect a good driver's lines, in some cases more so than whether the car is AWD, FWD, RWD.
That said, you should take a look at this article which somebody scanned. (Note that this is a copyright violation, and may be pulled down from our servers soon!) It comes from a magazine published by SCCA, and not available on magazine stands.
[url]http://forums.nasioc.com/forums/showthread.php?s=&threadid=349825[/url]
Read thru that whole article for some experienced insight on your question.
[QUOTE][i]Originally posted by faceplate [/i]
[B]...How is the line taken in AutoX and Rally different from road racing line?[/B][/QUOTE]This is a good question! Does someone have a url which explains the driving techiques of rallying?
Regarding Auto-X vs. Racing, I would recomend reading some of the books in the bibliography provided in this link, [url]http://www.metronypca.org/autocross/StaticInformation/Resources/2003%20Autocross%20Book%20Review.htm[/url].
The Physics of Racing url in that bibliography is antiquated, and slow... Try this:
[url]http://phors.locost7.info/contents.htm[/url] instead, since it is only slow. :)
[QUOTE][i]Originally posted by faceplate [/i]
[B]...Lastly, I have a question for those of you who road race imprezas. Do you use the normal approach, or do you try and pitch the car into the turn and power slide out of it (all wheel drift)?[/B][/QUOTE]They use the normal approach... See race report posts from [URL=http://forums.nasioc.com/forums/search.php?s=&action=finduser&userid=2450]GarySheehan[/URL]...
[B]...How is the racing line is affected by AWD, FWD, and RWD cars?[/B][/QUOTE]Good question... A car's setup, (whether the car is oversteering, understeering, or is neutral) will strongly affect a good driver's lines, in some cases more so than whether the car is AWD, FWD, RWD.
That said, you should take a look at this article which somebody scanned. (Note that this is a copyright violation, and may be pulled down from our servers soon!) It comes from a magazine published by SCCA, and not available on magazine stands.
[url]http://forums.nasioc.com/forums/showthread.php?s=&threadid=349825[/url]
Read thru that whole article for some experienced insight on your question.
[QUOTE][i]Originally posted by faceplate [/i]
[B]...How is the line taken in AutoX and Rally different from road racing line?[/B][/QUOTE]This is a good question! Does someone have a url which explains the driving techiques of rallying?
Regarding Auto-X vs. Racing, I would recomend reading some of the books in the bibliography provided in this link, [url]http://www.metronypca.org/autocross/StaticInformation/Resources/2003%20Autocross%20Book%20Review.htm[/url].
The Physics of Racing url in that bibliography is antiquated, and slow... Try this:
[url]http://phors.locost7.info/contents.htm[/url] instead, since it is only slow. :)
[QUOTE][i]Originally posted by faceplate [/i]
[B]...Lastly, I have a question for those of you who road race imprezas. Do you use the normal approach, or do you try and pitch the car into the turn and power slide out of it (all wheel drift)?[/B][/QUOTE]They use the normal approach... See race report posts from [URL=http://forums.nasioc.com/forums/search.php?s=&action=finduser&userid=2450]GarySheehan[/URL]...
| ITWRX4ME | 04-28-2003 11:34 PM |
[QUOTE][i]Originally posted by IXLR8 [/i]
[B]Mikka or Makinen...;) [/B][/QUOTE]
:lol: :lol: Crap. I'm so bad with names. It's that guy...you know...the one that drives that car...How 'bout Colin. There's a name I can remember. ;)
[QUOTE][i]Originally posted by Soon2Bgreat [/i]
[B]Actually I can almost guarantee he does...
Racing at his level (and pretty much all levels) is a team effort. While the execution may be seat-of-the-pants he has to be able to communicate to the crew in precise terms what the car (and each individual component) is doing in order to make adjustments. (Telemetry helps, but ultimately it's the driver, not data acquisition devices, that have to pilot the car.) That's one reason driver/crew chief "chemistry" counts for so much... gotta speak the same "vehicle language" to wring every bit out of it.[/B][/QUOTE]
Okay. But is the vehicle language at such a technical level? Or is it more of a "understeering under such and such circumstances" kind of thing?
[B]Mikka or Makinen...;) [/B][/QUOTE]
:lol: :lol: Crap. I'm so bad with names. It's that guy...you know...the one that drives that car...How 'bout Colin. There's a name I can remember. ;)
[QUOTE][i]Originally posted by Soon2Bgreat [/i]
[B]Actually I can almost guarantee he does...
Racing at his level (and pretty much all levels) is a team effort. While the execution may be seat-of-the-pants he has to be able to communicate to the crew in precise terms what the car (and each individual component) is doing in order to make adjustments. (Telemetry helps, but ultimately it's the driver, not data acquisition devices, that have to pilot the car.) That's one reason driver/crew chief "chemistry" counts for so much... gotta speak the same "vehicle language" to wring every bit out of it.[/B][/QUOTE]
Okay. But is the vehicle language at such a technical level? Or is it more of a "understeering under such and such circumstances" kind of thing?
| Soon2Bgreat | 04-28-2003 11:52 PM |
just to correct you again, i didn't post that last paragraph you quoted. hehe:) It's all good.
I agree with ITWRX here though i think mikka would give more of a feel, or subjective assessment of the car as opposed to talking about slip angles when talking to his crew. He will talk in precise terms only in terms of the front left tire needs more camber, but he won't tell you what slip angle the car was at in turn 3, like you said, that's where telemetery becomes handy.
Oh yea, tommi makinen is his name.:alien:
I agree with ITWRX here though i think mikka would give more of a feel, or subjective assessment of the car as opposed to talking about slip angles when talking to his crew. He will talk in precise terms only in terms of the front left tire needs more camber, but he won't tell you what slip angle the car was at in turn 3, like you said, that's where telemetery becomes handy.
Oh yea, tommi makinen is his name.:alien:
| Kostamojen | 04-29-2003 02:56 AM |
I find that Colin McRae 2.0 (PC Game) represents the various driving lines and styles between RWD and AWD (FWD as well with the MINI) rather realisticically :p I know, its not "real" driving but its the easiest way and accurate enough as to give you a good idea of what the differences are. (especially the ability to tweak the F/R distribution of the AWD systems in the rallys)
Anyhow, im just ranting, but try it anyway :p
Anyhow, im just ranting, but try it anyway :p
| IXLR8 | 04-29-2003 07:12 AM |
[QUOTE][i]Originally posted by ITWRX4ME [/i]
[B]Okay. But is the vehicle language at such a technical level? [/B][/QUOTE]
Now this is where generalization starts to fail.... the answer is: it depends on who the driver is.
For some drivers (and crew) the exchange of info is indeed that technical and often much more so... for others it's more as the modestly handled "Soon2Bgreat" suggests.
The bottom line is communications and whatever "vocabulary" is required to get all the necessary information across. It should be obvious that with the degree of technical sophistocation and sensitivity of race cars today, a simple "it's push'n off three" could point the crew in dozens of adjustment directions. For some team "chemistry's" that statement may be enough for the driver to get what they want. But you can see that at some point through testing, long-time experience, trail and error, etc. they've had a more technically precise "conversation" with their driver to understand what he meant by "it's push'n off three".
If you're really interested in this, take a "look" (sorry, I don't have any specific sources) at the role of test drivers, and the qualities that make them good... it's not so much about fast, as it is about an almost mechanical consistantcy, and the ability to communicate in technical terms far beyond "it's push'n".
[B]Okay. But is the vehicle language at such a technical level? [/B][/QUOTE]
Now this is where generalization starts to fail.... the answer is: it depends on who the driver is.
For some drivers (and crew) the exchange of info is indeed that technical and often much more so... for others it's more as the modestly handled "Soon2Bgreat" suggests.
The bottom line is communications and whatever "vocabulary" is required to get all the necessary information across. It should be obvious that with the degree of technical sophistocation and sensitivity of race cars today, a simple "it's push'n off three" could point the crew in dozens of adjustment directions. For some team "chemistry's" that statement may be enough for the driver to get what they want. But you can see that at some point through testing, long-time experience, trail and error, etc. they've had a more technically precise "conversation" with their driver to understand what he meant by "it's push'n off three".
If you're really interested in this, take a "look" (sorry, I don't have any specific sources) at the role of test drivers, and the qualities that make them good... it's not so much about fast, as it is about an almost mechanical consistantcy, and the ability to communicate in technical terms far beyond "it's push'n".
| ITWRX4ME | 04-29-2003 08:52 AM |
soon2begreat - Sorry for the misquote. Cut and paste error.
IXLR8 - I don't doubt you at all. The level of technical savvy at which test drivers, and a good many pro race drivers, operate is far beyond the vast majority of race drivers, if you include the grassroots motorsports folks. It'd be nice if we could all have that depth of understanding of handling dynamics.
In my post about the fear of the physics lesson, I didn't mean to diminish the value of that type of discussion. Merely pointing out that those discussions are made all the more difficult if you're not feeling it in the seat of your pants. I'd imagine that even those test drivers had to eventually feel effect of a given slip angle or camber adjustment or tire tempurature or whatever, to have it all gel. To reach the point of understanding where the "Aha" is uttered.
The really cool thing is, there's so much to learn in this sport. There is a never ending supply of questions and I'm having a great time finding the answers.
IXLR8 - I don't doubt you at all. The level of technical savvy at which test drivers, and a good many pro race drivers, operate is far beyond the vast majority of race drivers, if you include the grassroots motorsports folks. It'd be nice if we could all have that depth of understanding of handling dynamics.
In my post about the fear of the physics lesson, I didn't mean to diminish the value of that type of discussion. Merely pointing out that those discussions are made all the more difficult if you're not feeling it in the seat of your pants. I'd imagine that even those test drivers had to eventually feel effect of a given slip angle or camber adjustment or tire tempurature or whatever, to have it all gel. To reach the point of understanding where the "Aha" is uttered.
The really cool thing is, there's so much to learn in this sport. There is a never ending supply of questions and I'm having a great time finding the answers.
| HoRo1 | 04-29-2003 09:40 AM |
Racing line...hehehe
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Somewhere in this forum I have some in-car video of me racing and I have some more to upload as well.
Racing line is dictated by your desire to catch and overtake the guy in front while keeping the guy behind you, behind you. Ideally, you straighten all the corners by using all the track, driving as smoothly as you can. An AWD car will understeer, quite badly if you don't have the setup right, and as a rule will tend to not oversteer (depending on setup) - but if it does oversteer, an application of throttle will usually solve the problem. AWD helps you by enabling a slightly earlier application of gas exiting corners, and you might be able to (depending on the track), keep accelerating in long sweeping turns where RWD might have trouble. In the wet of course, AWD is just superior.
Racing is COMPLETELY different to autoX, time trialing etc. I've TT'd quite a lot, and line is KING in that sport, but for racing, you do whatever you can to get past the guy in front - turning in early, sitting on his ass (if you have the balls - no pun intended), outbraking to the point of severe pucker factor. What I'm saying is that in racing while line is important, esp. in clear track situations where you can take huge chunks of time out of guys in front who are dicing with each other and therefore losing time, when you've got someone 30 feet in front or behind, you do what you can to intimidate and/or block (within the rules) them.
Try it. You'll like it!
Racing line is dictated by your desire to catch and overtake the guy in front while keeping the guy behind you, behind you. Ideally, you straighten all the corners by using all the track, driving as smoothly as you can. An AWD car will understeer, quite badly if you don't have the setup right, and as a rule will tend to not oversteer (depending on setup) - but if it does oversteer, an application of throttle will usually solve the problem. AWD helps you by enabling a slightly earlier application of gas exiting corners, and you might be able to (depending on the track), keep accelerating in long sweeping turns where RWD might have trouble. In the wet of course, AWD is just superior.
Racing is COMPLETELY different to autoX, time trialing etc. I've TT'd quite a lot, and line is KING in that sport, but for racing, you do whatever you can to get past the guy in front - turning in early, sitting on his ass (if you have the balls - no pun intended), outbraking to the point of severe pucker factor. What I'm saying is that in racing while line is important, esp. in clear track situations where you can take huge chunks of time out of guys in front who are dicing with each other and therefore losing time, when you've got someone 30 feet in front or behind, you do what you can to intimidate and/or block (within the rules) them.
Try it. You'll like it!
| IXLR8 | 04-29-2003 10:01 AM |
[QUOTE][i]Originally posted by ITWRX4ME [/i]
[B] The level of technical savvy at which test drivers, and a good many pro race drivers, operate is far beyond the vast majority of race drivers, if you include the grassroots motorsports folks. [/B][/QUOTE]
Not to beat a dead horse, 'cause I think you accept the point, but don't short grassroots motorsports. I expect you'd be amazed at the general level of technical discussion/vehicle language vocabulary even in club racing.
While they may not have a shock dyno on the bench of the second semi-tractor/trailer, they know they have to translate the feel of not enough rebound damping in the right front while negotiating the climbing esses at VIR to the tech doing the custom valving at Bilstein. If for no other reason than, if you don't get it right, it's gunna cost you time and money for the re-re-build...
Enjoy your quest.
[B] The level of technical savvy at which test drivers, and a good many pro race drivers, operate is far beyond the vast majority of race drivers, if you include the grassroots motorsports folks. [/B][/QUOTE]
Not to beat a dead horse, 'cause I think you accept the point, but don't short grassroots motorsports. I expect you'd be amazed at the general level of technical discussion/vehicle language vocabulary even in club racing.
While they may not have a shock dyno on the bench of the second semi-tractor/trailer, they know they have to translate the feel of not enough rebound damping in the right front while negotiating the climbing esses at VIR to the tech doing the custom valving at Bilstein. If for no other reason than, if you don't get it right, it's gunna cost you time and money for the re-re-build...
Enjoy your quest.
| HoRo1 | 04-29-2003 10:44 AM |
race video
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Quicktime files showing just how all that stuff about line goes right out of the window when the flag drops. This was a real learning experience as have been subsequent races. There really is a thing called racecraft - and if you have it, you have a big advantage over those who don't...I don't - yet! :)
[url]http://www.skifreakz.com/horo1/[/url]
[url]http://www.skifreakz.com/horo1/[/url]
| toerag | 04-29-2003 11:55 AM |
Having done a day's rallydriving tuition I can offer some knowledge. The reason for sliding sideways into the corner is to give yourself more time to think. If you go in at the perfect angle then there is less chance of you altering your line. Rally corners tend to be blind, so going in sideways & wide allows you to 'open out' the view of the corner before committing to it. Sideways allows you to put the power down early if the corner isn't as tight as you thought, or to wait until you've scrubbed off speed if it's tighter then you thought.
| FuJi K | 04-29-2003 12:25 PM |
Re: How does racing line vary with AWD, RWD, and FWD; and some other non-newb questions
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[QUOTE][i]Originally posted by faceplate [/i]
[B]Hello, I was wondering how racing line is affected by AWD, FWD, and RWD cars. I also wanted to know how is the line taken in AutoX and Rally different from road racing line. [/B][/QUOTE]
If you just roll through the turn, the line would be the same for all drivetrains. Drive a little harder and you'll have to position yourself depending on the suspension setup.
EX: If you were to be accelerating hard out in a FWD car, you'd want to take the turn a little later so when you exit, your speed will be higher and there would be less turning involved when exiting the turn. The reason for this is a FWD will want to understeer because the front wheels are being driven (more slip angle).
EX: An AWD car you can take either line, but the fastest would have to be like the line I described above or a regular line (out - in apex - out).
The racing line will really depend HOW you race, the car's suspension setup, and the car's handling charateristics.
yay? nay?
[B]Hello, I was wondering how racing line is affected by AWD, FWD, and RWD cars. I also wanted to know how is the line taken in AutoX and Rally different from road racing line. [/B][/QUOTE]
If you just roll through the turn, the line would be the same for all drivetrains. Drive a little harder and you'll have to position yourself depending on the suspension setup.
EX: If you were to be accelerating hard out in a FWD car, you'd want to take the turn a little later so when you exit, your speed will be higher and there would be less turning involved when exiting the turn. The reason for this is a FWD will want to understeer because the front wheels are being driven (more slip angle).
EX: An AWD car you can take either line, but the fastest would have to be like the line I described above or a regular line (out - in apex - out).
The racing line will really depend HOW you race, the car's suspension setup, and the car's handling charateristics.
yay? nay?
| sdecker | 04-29-2003 09:01 PM |
Re: race video
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[QUOTE][i]Originally posted by HoRo1 [/i]
[B]Quicktime files showing just how all that stuff about line goes right out of the window when the flag drops. This was a real learning experience as have been subsequent races. There really is a thing called racecraft - and if you have it, you have a big advantage over those who don't...I don't - yet! :)
[url]http://www.skifreakz.com/horo1/[/url] [/B][/QUOTE]
Horo:
The race footage was great, man! I mean, it's not Gary Sheehan or anything but I thought you did very well. I'm in the process of getting up to that level myself. Nice work! :D BTW, what was that that passed you?
Scott
[B]Quicktime files showing just how all that stuff about line goes right out of the window when the flag drops. This was a real learning experience as have been subsequent races. There really is a thing called racecraft - and if you have it, you have a big advantage over those who don't...I don't - yet! :)
[url]http://www.skifreakz.com/horo1/[/url] [/B][/QUOTE]
Horo:
The race footage was great, man! I mean, it's not Gary Sheehan or anything but I thought you did very well. I'm in the process of getting up to that level myself. Nice work! :D BTW, what was that that passed you?
Scott
| HoRo1 | 04-29-2003 10:19 PM |
Saleen Mustang - supercharged+brakes+suspension. I'm told something around 450HP.
I've since done 2 more races and learned a huge amount about how to be race. For instance, how to size up the guy in front and when I should be looking to overtake, how to be a little more flexible at the start and not over-commit, how to select the right tires and use the rules to my advantage. I have two more races coming up at Laguna Seca - 10-12 laps each and then a 2 hour enduro at Buttonwillow in early June.
I've since done 2 more races and learned a huge amount about how to be race. For instance, how to size up the guy in front and when I should be looking to overtake, how to be a little more flexible at the start and not over-commit, how to select the right tires and use the rules to my advantage. I have two more races coming up at Laguna Seca - 10-12 laps each and then a 2 hour enduro at Buttonwillow in early June.
| faceplate | 04-29-2003 10:23 PM |
Thanks for all your replys. I like what toerag said about rally driving on tarmac. I was thinking this was primarily why they slide on tarmac but was not sure.
[QUOTE]Having done a day's rallydriving tuition I can offer some knowledge. The reason for sliding sideways into the corner is to give yourself more time to think. If you go in at the perfect angle then there is less chance of you altering your line. Rally corners tend to be blind, so going in sideways & wide allows you to 'open out' the view of the corner before committing to it. Sideways allows you to put the power down early if the corner isn't as tight as you thought, or to wait until you've scrubbed off speed if it's tighter then you thought.[/QUOTE]
I have read the autocross book by watts. The primary thing I got from it was in autocross you want to take late apex. In a road racing high speed corner there wont be that much change in speed (relatively speaking), but since speeds are so slow in autocross the effect is more prominent. The slower the corner the later the apex.
I am currently messing around with autocross. I attended one autocross last season, and really got nothing out of it. I was really frustrated. It was the last event of the season. I tried it again at the beginning of this season, and now I am hooked. I got a hang of the car sliding and swaying. I was having fun!!! Unfortunately, chassis, suspension, and tires wise my car is stock. I am planning to change all that soon. I still have to use my current set up (or lack there of) for a few more autocrosses. I know the best drivers can drive the stock WRX and beat the crap out of everyone there, so I know there is more I can get out of the stock set up. I will describe my current driving method. I brake aggresively before the turn. Then I lift the brakes and begin turn in, then apply power at the appropriate time. I know the stock setup understeers really bad, so how can I with the back around and eliminate the understeering front from the equation. Tire Pressures? My main point is how do I use the brakes to get the back around; make oversteer to counter understeer. (Trailbraking maybe?) I know this creates big slip angles which scrub speed but it is faster than understeering.
Some one mentioned test drivers and the feedback they have to give constructors and engineers. I am really curious about this. I know Walter Rohrl is a test driver for porsche. I dont know much about him, but I heard he tackles things like a science expiriment, and thats how I do things. I know he is a road race and rally god. I wonder if his road race experience has helped his rally stuff. How in the heck to he master two greatly different arts. Please dont laugh, but how would one become a test driver? Could an engineer become a test driver? I am a very young guy looking at careers, and I am really thinking about the nerdly side of motorsports. (and dont worry my expectations of work and odd are realistic)
Hopefully my droning is interesting for someone to read and maybe respond to.
[QUOTE]Having done a day's rallydriving tuition I can offer some knowledge. The reason for sliding sideways into the corner is to give yourself more time to think. If you go in at the perfect angle then there is less chance of you altering your line. Rally corners tend to be blind, so going in sideways & wide allows you to 'open out' the view of the corner before committing to it. Sideways allows you to put the power down early if the corner isn't as tight as you thought, or to wait until you've scrubbed off speed if it's tighter then you thought.[/QUOTE]
I have read the autocross book by watts. The primary thing I got from it was in autocross you want to take late apex. In a road racing high speed corner there wont be that much change in speed (relatively speaking), but since speeds are so slow in autocross the effect is more prominent. The slower the corner the later the apex.
I am currently messing around with autocross. I attended one autocross last season, and really got nothing out of it. I was really frustrated. It was the last event of the season. I tried it again at the beginning of this season, and now I am hooked. I got a hang of the car sliding and swaying. I was having fun!!! Unfortunately, chassis, suspension, and tires wise my car is stock. I am planning to change all that soon. I still have to use my current set up (or lack there of) for a few more autocrosses. I know the best drivers can drive the stock WRX and beat the crap out of everyone there, so I know there is more I can get out of the stock set up. I will describe my current driving method. I brake aggresively before the turn. Then I lift the brakes and begin turn in, then apply power at the appropriate time. I know the stock setup understeers really bad, so how can I with the back around and eliminate the understeering front from the equation. Tire Pressures? My main point is how do I use the brakes to get the back around; make oversteer to counter understeer. (Trailbraking maybe?) I know this creates big slip angles which scrub speed but it is faster than understeering.
Some one mentioned test drivers and the feedback they have to give constructors and engineers. I am really curious about this. I know Walter Rohrl is a test driver for porsche. I dont know much about him, but I heard he tackles things like a science expiriment, and thats how I do things. I know he is a road race and rally god. I wonder if his road race experience has helped his rally stuff. How in the heck to he master two greatly different arts. Please dont laugh, but how would one become a test driver? Could an engineer become a test driver? I am a very young guy looking at careers, and I am really thinking about the nerdly side of motorsports. (and dont worry my expectations of work and odd are realistic)
Hopefully my droning is interesting for someone to read and maybe respond to.
| sdecker | 04-29-2003 11:06 PM |
[QUOTE][i]Originally posted by HoRo1 [/i]
[B]Saleen Mustang - supercharged+brakes+suspension. I'm told something around 450HP.
I've since done 2 more races and learned a huge amount about how to be race. For instance, how to size up the guy in front and when I should be looking to overtake, how to be a little more flexible at the start and not over-commit, how to select the right tires and use the rules to my advantage. I have two more races coming up at Laguna Seca - 10-12 laps each and then a 2 hour enduro at Buttonwillow in early June. [/B][/QUOTE]
Well, this it totally OT, but I'm pullin' for you man! Best of luck and sorry to hijack this thread. :D
Even further OT: would you care to digress on some of your learning? Feel free to PM if you'd like. I'm interested in your opinions...
Scott
[B]Saleen Mustang - supercharged+brakes+suspension. I'm told something around 450HP.
I've since done 2 more races and learned a huge amount about how to be race. For instance, how to size up the guy in front and when I should be looking to overtake, how to be a little more flexible at the start and not over-commit, how to select the right tires and use the rules to my advantage. I have two more races coming up at Laguna Seca - 10-12 laps each and then a 2 hour enduro at Buttonwillow in early June. [/B][/QUOTE]
Well, this it totally OT, but I'm pullin' for you man! Best of luck and sorry to hijack this thread. :D
Even further OT: would you care to digress on some of your learning? Feel free to PM if you'd like. I'm interested in your opinions...
Scott
| ITWRX4ME | 04-30-2003 12:34 PM |
[QUOTE][i]Originally posted by faceplate [/i]
[B]Unfortunately, chassis, suspension, and tires wise my car is stock. I am planning to change all that soon. I still have to use my current set up (or lack there of) for a few more autocrosses. I know the best drivers can drive the stock WRX and beat the crap out of everyone there, so I know there is more I can get out of the stock set up. I will describe my current driving method. I brake aggresively before the turn. Then I lift the brakes and begin turn in, then apply power at the appropriate time. I know the stock setup understeers really bad, so how can I with the back around and eliminate the understeering front from the equation. Tire Pressures? My main point is how do I use the brakes to get the back around; make oversteer to counter understeer. (Trailbraking maybe?) I know this creates big slip angles which scrub speed but it is faster than understeering.
[/B][/QUOTE]
I can make one suggestion that may help. You said that you lift off the brakes as you turn in. Instead, try trail braking. Stay on the brakes while you turn in, while the back end is still light. Let the rear end break loose and oversteer briefly passed the apex and then smoothly lift off the brakes and transition to throttle. You may have to lift of the brakes at turn in ever so slightly so that the tires will have some traction left for turning. But, as the car takes a cornering attitude, use the brakes to get the back end to rotate.
I have done this with some degree of success at the track in tight corners, though I can't say I can do it every time. When I get it right, the feeling is pretty :cool:. I was also able to do it with the stock suspension, though I have since added a rear anti-sway bar.
I know how difficult it is at an autocross to practice a technique because you only get a few trys at a given corner. But give it a shot.
Not a pro, just play one in this forum. :lol:
[B]Unfortunately, chassis, suspension, and tires wise my car is stock. I am planning to change all that soon. I still have to use my current set up (or lack there of) for a few more autocrosses. I know the best drivers can drive the stock WRX and beat the crap out of everyone there, so I know there is more I can get out of the stock set up. I will describe my current driving method. I brake aggresively before the turn. Then I lift the brakes and begin turn in, then apply power at the appropriate time. I know the stock setup understeers really bad, so how can I with the back around and eliminate the understeering front from the equation. Tire Pressures? My main point is how do I use the brakes to get the back around; make oversteer to counter understeer. (Trailbraking maybe?) I know this creates big slip angles which scrub speed but it is faster than understeering.
[/B][/QUOTE]
I can make one suggestion that may help. You said that you lift off the brakes as you turn in. Instead, try trail braking. Stay on the brakes while you turn in, while the back end is still light. Let the rear end break loose and oversteer briefly passed the apex and then smoothly lift off the brakes and transition to throttle. You may have to lift of the brakes at turn in ever so slightly so that the tires will have some traction left for turning. But, as the car takes a cornering attitude, use the brakes to get the back end to rotate.
I have done this with some degree of success at the track in tight corners, though I can't say I can do it every time. When I get it right, the feeling is pretty :cool:. I was also able to do it with the stock suspension, though I have since added a rear anti-sway bar.
I know how difficult it is at an autocross to practice a technique because you only get a few trys at a given corner. But give it a shot.
Not a pro, just play one in this forum. :lol:
| jprowland | 04-30-2003 02:31 PM |
All race cars are a little sideways, even on a "clean" corner. The road racers call it slip angle, and they typically run a slip angle of around 15 degrees. But their idea of slipping is a little bit different from the sideways in rallying...
The idea behind slip angles is to keep the force on the rear tires the same as the front tires, since hopefully that's what the car is set up to take advantage of. With zero slip, the rear tires will track on a smaller radius than the fronts in the same amount of time, meaning they're not going as fast and not taking as much of the force of cornering. The front tires are doing all the work.
Slipping the rear tires means that you're transferring some of the cornering force from the front to the rear and bringing the rear tires up to 100% of their capability (actually a little beyond...they're starting to lose grip, but not to the point where they break free.) Much of the "slipping" really isn't slipping, but rather the tires just flexing. But some of it really is the tire sliding, just a little.
But this isn't "drifting", the way the rally guys do it. Like it was mentioned, it's at least 50% so that they have more time to see what the outside of the corner looks like. By taking a wide, late apex and drifting into it, they get a better view of what's on the other side. In rallying, you don't have time to dissect each turn. It's a lot easier to just carry a lot of speed into the corner and scrub it off while deciding what to do next. Not to mention that AWD cars typically don't lose as much time as the 2WDs do when drifting through a turn.
Gilles Villenueve was an F1 driver in the 70s that was the fastest on the road and well-known for hanging the tail waaaay out on nearly every turn. His driving style rewarded him with a fatal racing accident that took his life, I believe in 1982 (but don't quote me on that). It's a lot easier, and usually faster, to drive a "clean" turn on a race track.
And as far as the top drivers that you mentioned drifting, well, when you're not racing, it's a heck of a lot more fun...
The idea behind slip angles is to keep the force on the rear tires the same as the front tires, since hopefully that's what the car is set up to take advantage of. With zero slip, the rear tires will track on a smaller radius than the fronts in the same amount of time, meaning they're not going as fast and not taking as much of the force of cornering. The front tires are doing all the work.
Slipping the rear tires means that you're transferring some of the cornering force from the front to the rear and bringing the rear tires up to 100% of their capability (actually a little beyond...they're starting to lose grip, but not to the point where they break free.) Much of the "slipping" really isn't slipping, but rather the tires just flexing. But some of it really is the tire sliding, just a little.
But this isn't "drifting", the way the rally guys do it. Like it was mentioned, it's at least 50% so that they have more time to see what the outside of the corner looks like. By taking a wide, late apex and drifting into it, they get a better view of what's on the other side. In rallying, you don't have time to dissect each turn. It's a lot easier to just carry a lot of speed into the corner and scrub it off while deciding what to do next. Not to mention that AWD cars typically don't lose as much time as the 2WDs do when drifting through a turn.
Gilles Villenueve was an F1 driver in the 70s that was the fastest on the road and well-known for hanging the tail waaaay out on nearly every turn. His driving style rewarded him with a fatal racing accident that took his life, I believe in 1982 (but don't quote me on that). It's a lot easier, and usually faster, to drive a "clean" turn on a race track.
And as far as the top drivers that you mentioned drifting, well, when you're not racing, it's a heck of a lot more fun...
| OnTheGas | 04-30-2003 04:29 PM |
Re: The Nerdy Side of Motorsports
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[QUOTE][i]Originally posted by faceplate [/i]
[B]Could an engineer become a test driver? I am a very young guy looking at careers, and I am really thinking about the nerdly side of motorsports. (and dont worry my expectations of work and odd are realistic).[/B][/QUOTE]Spend time on this web-site, [url]http://www.motorsportsengineering.sae.org/jsp/jsps/motorsports.jsp[/url], if you're considering "nerdly" motorsports careers... Some folks do make their living this way, so it is possible for you to walk out of a college or university w/a bachelor's degree and go knock on some cool doors.
If you have the opportunity to do what you love, jump into with both feet... some folks don't... they're the ones who don't smile as much.
:)
edit: changed the url, which was wrong...
[B]Could an engineer become a test driver? I am a very young guy looking at careers, and I am really thinking about the nerdly side of motorsports. (and dont worry my expectations of work and odd are realistic).[/B][/QUOTE]Spend time on this web-site, [url]http://www.motorsportsengineering.sae.org/jsp/jsps/motorsports.jsp[/url], if you're considering "nerdly" motorsports careers... Some folks do make their living this way, so it is possible for you to walk out of a college or university w/a bachelor's degree and go knock on some cool doors.
If you have the opportunity to do what you love, jump into with both feet... some folks don't... they're the ones who don't smile as much.
:)
edit: changed the url, which was wrong...
| ITWRX4ME | 05-01-2003 11:06 AM |
Thanks for posting that site. Lot's of interesting reads.
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