Reduce understeer: Did I over do it?
10-14-2003, 09:40 PM
#31
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Originally posted by Radical Racer
It is really hard to talk about under/oversteer as everyone has a different idea of what a loose car is or one that pushes. For example, I like a car that is a little loose, based on my definition of loose. Maybe DJ will chime in here and give his description of what I call a 'little loose'.
It is really hard to talk about under/oversteer as everyone has a different idea of what a loose car is or one that pushes. For example, I like a car that is a little loose, based on my definition of loose. Maybe DJ will chime in here and give his description of what I call a 'little loose'.
I always thought that I preferred a car to be a little loose. I like to hang the tail out, get it a little sideways, stuff like that. After driving Mark's car, I decided that I don't like loose. I like the car to be a little tight--at least, compared to Mark's cars. I think there's a pretty wide disparity between what some people think is loose, and what other people think is loose.
That said, first things first: change your shock settings. The PSS-9s are softest at 9 and stiffest at 1. With your settings of 8 front and 6 rear, you've got the car set up biased toward being loose. Especially if you've gotten used to driving the car on stock suspension, this will be a big swing in the understeer-to-neutral-to-oversteer ball park. I would suggest setting them at 4 or 3 (front and rear the same), and try it again. It will be markedly firmer, but it will also be more neutral.
Next things next: the best advice has already been given. Get thee to the track. POC's short track series (do they still call it that?) at Streets of Willow Springs is the perfect venue for getting a better handle on what your car will do when you do this, or when you do that. They've got some good instructors too.
I wouldn't change your alignment settings, nor your tire pressure settings, but you may want to change what you do.
Last edited by DJ; 10-14-2003 at 10:20 PM.
10-14-2003, 10:05 PM
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hn and others,
When you change suspension and lower your car, then you NEED to adjust the kinematic toe. Most shop will lie to you because 1) they are too stupid to know what it does or 2) they are hoping you are too stupid to understand and they really don't want to spend the money for the tool.
Until your car is in proper specs, all this talk on tire pressures which is a tuning aid is not relevant. Kinematic tries to keep the rear end toe at a constant setting as the suspension moves up and down but ONLY for a range of motion. So if you lower your car 1-1/2"s and now the suspension travels up and down guess what? You will probably be out of the range of adjustment on this setting. So you need to recalibrate the initial setting to the new ride height.
When you change suspension and lower your car, then you NEED to adjust the kinematic toe. Most shop will lie to you because 1) they are too stupid to know what it does or 2) they are hoping you are too stupid to understand and they really don't want to spend the money for the tool.
Until your car is in proper specs, all this talk on tire pressures which is a tuning aid is not relevant. Kinematic tries to keep the rear end toe at a constant setting as the suspension moves up and down but ONLY for a range of motion. So if you lower your car 1-1/2"s and now the suspension travels up and down guess what? You will probably be out of the range of adjustment on this setting. So you need to recalibrate the initial setting to the new ride height.
10-14-2003, 10:05 PM
#33
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DJ: Yup it's still called the Short Track Series. I've got the paperwork right here in front of me. I'm signing up for the next one which is November 8th and 9th.
Contact person is Laurie Taylor (949) 360-6475
By the way, does anyone have any video of the small track at Willow?
Contact person is Laurie Taylor (949) 360-6475
By the way, does anyone have any video of the small track at Willow?
10-14-2003, 10:23 PM
#34
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Originally posted by viperbob
When you change suspension and lower your car, then you NEED to adjust the kinematic toe. Most shop will lie to you because 1) they are too stupid to know what it does or 2) they are hoping you are too stupid to understand and they really don't want to spend the money for the tool.
When you change suspension and lower your car, then you NEED to adjust the kinematic toe. Most shop will lie to you because 1) they are too stupid to know what it does or 2) they are hoping you are too stupid to understand and they really don't want to spend the money for the tool.
I purposely ignored the K-toe question because he said he took the car to Johnson Alignment, and they definitely know what they're doing with Porsches.
10-14-2003, 10:24 PM
#35
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Originally posted by ScottMellor
DJ: Yup it's still called the Short Track Series. I've got the paperwork right here in front of me. I'm signing up for the next one which is November 8th and 9th.
Contact person is Laurie Taylor (949) 360-6475
By the way, does anyone have any video of the small track at Willow?
DJ: Yup it's still called the Short Track Series. I've got the paperwork right here in front of me. I'm signing up for the next one which is November 8th and 9th.
Contact person is Laurie Taylor (949) 360-6475
By the way, does anyone have any video of the small track at Willow?
Cool, Scott. Do it.
What class will your car run in? NP?
10-15-2003, 12:12 AM
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Originally posted by DJ
I purposely ignored the K-toe question because he said he took the car to Johnson Alignment, and they definitely know what they're doing with Porsches.
I purposely ignored the K-toe question because he said he took the car to Johnson Alignment, and they definitely know what they're doing with Porsches.
10-15-2003, 02:38 AM
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Originally posted by DJ
I always thought that I preferred a car to be a little loose. I like to hang the tail out, get it a little sideways, stuff like that. After driving Mark's car, I decided that I don't like loose. I like the car to be a little tight--at least, compared to Mark's cars. I think there's a pretty wide disparity between what some people think is loose, and what other people think is loose.
That said, first things first: change your shock settings. The PSS-9s are softest at 9 and stiffest at 1. With your settings of 8 front and 6 rear, you've got the car set up biased toward being loose. Especially if you've gotten used to driving the car on stock suspension, this will be a big swing in the understeer-to-neutral-to-oversteer ball park. I would suggest setting them at 4 or 3 (front and rear the same), and try it again. It will be markedly firmer, but it will also be more neutral.
Next things next: the best advice has already been given. Get thee to the track. POC's short track series (do they still call it that?) at Streets of Willow Springs is the perfect venue for getting a better handle on what your car will do when you do this, or when you do that. They've got some good instructors too.
I wouldn't change your alignment settings, nor your tire pressure settings, but you may want to change what you do.
I always thought that I preferred a car to be a little loose. I like to hang the tail out, get it a little sideways, stuff like that. After driving Mark's car, I decided that I don't like loose. I like the car to be a little tight--at least, compared to Mark's cars. I think there's a pretty wide disparity between what some people think is loose, and what other people think is loose.
That said, first things first: change your shock settings. The PSS-9s are softest at 9 and stiffest at 1. With your settings of 8 front and 6 rear, you've got the car set up biased toward being loose. Especially if you've gotten used to driving the car on stock suspension, this will be a big swing in the understeer-to-neutral-to-oversteer ball park. I would suggest setting them at 4 or 3 (front and rear the same), and try it again. It will be markedly firmer, but it will also be more neutral.
Next things next: the best advice has already been given. Get thee to the track. POC's short track series (do they still call it that?) at Streets of Willow Springs is the perfect venue for getting a better handle on what your car will do when you do this, or when you do that. They've got some good instructors too.
I wouldn't change your alignment settings, nor your tire pressure settings, but you may want to change what you do.
Besides that do not expect to have the aswers revealed to you even after your first event... What I thought was a "neutral car" a year ago seems to be a dog understeering car now. With more experience you discover new limits for your self and develop your driving technic. So in essence you develop as a driver and your taste does change. Therefore playing with tire pressures, sway bars, etc is a never ending story and a very frustrating quest. To complicate further the matter, a setting that seemed ok at the beginning of the weekend, as you get faster it suddenly needs adjustment!
So don't sweat over it, do get on the track and if you still have your tail hanging out at the end of the weekend, next time around change. If you are running street tires I have found that keeping hot pressures no more than 40 psi is best. For reference my street tires pick up around 6 pounds after a hot run. By comparison the MPSC's have picked up even 8 pounds ending up 32-34 F/R Hot. You got some great advise here, go out and have fun!
10-15-2003, 12:55 PM
#38
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Thanks guys, good stuff. I'll leave my car alone for now.
What is the difference between POC and PCA? I think I know what they stand for (Porsche Owner Club and Porsche Club America?) but not sure what they do. Which one coordinates more DE? Any links ? I haven't planned to join any of these yet, but I guess the sooner is the better.
What is the difference between POC and PCA? I think I know what they stand for (Porsche Owner Club and Porsche Club America?) but not sure what they do. Which one coordinates more DE? Any links ? I haven't planned to join any of these yet, but I guess the sooner is the better.
10-15-2003, 01:05 PM
#39
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hn,
www.porscheownersclub.com
POC is more track oriented than PCA as far as the available events for the membership. PCA has many other types of event (auto-x. DE, TT, social, rally, etc..).
Good luck!
www.porscheownersclub.com
POC is more track oriented than PCA as far as the available events for the membership. PCA has many other types of event (auto-x. DE, TT, social, rally, etc..).
Good luck!
10-15-2003, 01:37 PM
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DJ: As far as I can see, my car would be classified as N Production with perhaps 9 points added for the modified turbos/computer/exhaust and wider wheels and the Bilsteins.
Why do they want to classify me? I PROMISE that I am not going to race or Time Trial. I don't want to void my insurance.
Why do they want to classify me? I PROMISE that I am not going to race or Time Trial. I don't want to void my insurance.
10-15-2003, 04:01 PM
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Originally posted by hn
Thanks guys, good stuff. I'll leave my car alone for now.
Thanks guys, good stuff. I'll leave my car alone for now.
Thats going way too far! You need to EXPERIMENT on your car. Make some small changes to your PSS-9s or tire pressures and see what they do. Keep a little log book. Don't worry about whether or not you are doing what the best racers would do in that situation, the important thing is to learn how your car reacts to the little things you can do that affect handling.Chip
10-15-2003, 04:20 PM
#42
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Hoan,
I was at 5 front and 5 rear for the fun run. My tire pressure was 34 front, 36 rear. Granted, I drive a C4S, have wider tires (at least in the rear), and my alignment was set up for aggressive canyon driving.
I echo what others have said, experiment with your car and learn to drive it.
Look forward to seeing you on the next one.
Addison
I was at 5 front and 5 rear for the fun run. My tire pressure was 34 front, 36 rear. Granted, I drive a C4S, have wider tires (at least in the rear), and my alignment was set up for aggressive canyon driving.
I echo what others have said, experiment with your car and learn to drive it.
Look forward to seeing you on the next one.
Addison
10-15-2003, 05:36 PM
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Thanks guys for the encouragement. What I meant was to leave it until I do another drive and pay more attention before changing anything. I am thinking of going to the Street of Willow like Scott mentioned above but not sure when. $125 (non member) for the whole day is not bad. I'll find out more once I get the brochure from POC. I am not sure which event that lets you drive with an instructor. Can the instructor slap you around if you mess up? 
Addison, If a 67 911 can keep up, it can't be the cars
Thanks Kary for the link.
Wait until I tell my wife I am going to take a whole day to learn how to drive
Addison, If a 67 911 can keep up, it can't be the cars
Thanks Kary for the link.
Wait until I tell my wife I am going to take a whole day to learn how to drive
10-15-2003, 05:44 PM
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hn,
As I instruct for PCA I recommend that the instructor not slap the student around. It tends to discourage them ;-) All kidding aside, I have found most instructors to be quote helpful and if they are any good will work at the level that you are at providing you instruction that stresses the fundamentals first and then progressing at your own speed. Don't expect too much out of your first event as you will be "busy" becoming accustom to a large track. Remember to always have fun and if you are not getting along with your instructor in terms of personality or learning, ask for another one. No questions asked, no need to explain, just get another one.
As I instruct for PCA I recommend that the instructor not slap the student around. It tends to discourage them ;-) All kidding aside, I have found most instructors to be quote helpful and if they are any good will work at the level that you are at providing you instruction that stresses the fundamentals first and then progressing at your own speed. Don't expect too much out of your first event as you will be "busy" becoming accustom to a large track. Remember to always have fun and if you are not getting along with your instructor in terms of personality or learning, ask for another one. No questions asked, no need to explain, just get another one.