Caster settings, Explain please |
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Caster settings, Explain please |
r_towle |
Aug 12 2007, 01:25 PM
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#1
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Custom Member Group: Members Posts: 24,574 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
How does the caster setting affect an AutoX car.
What is the best, and why. Rich |
J P Stein |
Aug 12 2007, 02:02 PM
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#2
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
How does the caster setting affect an AutoX car. What is the best, and why. Rich The more caster one has, the more it effects an AX car in a positive manner....2 areas. The first is as the wheel turns, the caster causes an increase in the negative camber on the outside wheel. This helps counteract the positive camber caused by body roll....if you have any (IMG:style_emoticons/default/biggrin.gif) Second is the steering centering effect.....big deal, one might say....what's that good for? The answer is catching tank slappers or limiting them to one "slap". I don't recommend letting go of the steering wheel (actually, letting it slip thru your hands) to novices, but the wheel will spin a hell of a lot faster than you can turn it.....ya just gotta grab it again at the right time. It takes some practice. (IMG:style_emoticons/default/happy11.gif) 5-6 degrees is good....I run close to 6. I understand more than 6 is not better, but dunno why. (IMG:style_emoticons/default/confused24.gif) |
r_towle |
Aug 12 2007, 02:04 PM
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#3
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Custom Member Group: Members Posts: 24,574 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
so, more caster would mean that the top of the strut would be as far toward the rear of the car as possible??
R |
J P Stein |
Aug 12 2007, 02:07 PM
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#4
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Irrelevant old fart Group: Members Posts: 8,797 Joined: 30-December 02 From: Vancouver, WA Member No.: 45 Region Association: None |
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Dr Evil |
Aug 12 2007, 03:05 PM
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#5
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Send me your transmission! Group: Members Posts: 22,995 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
Would it be recommended to do the 6 deg to a street car?
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brp914 |
Aug 12 2007, 03:43 PM
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#6
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Unregistered |
QUOTE Would it be recommended to do the 6 deg to a street car? 6 +/- 0.5 degrees is the stock setting. |
Dr Evil |
Aug 12 2007, 08:34 PM
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#7
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Send me your transmission! Group: Members Posts: 22,995 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
Ah, simple enough (IMG:style_emoticons/default/rolleyes.gif) I guess I would have figured that out once I got to that part of my operation. (IMG:style_emoticons/default/wink.gif)
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john rogers |
Aug 12 2007, 09:07 PM
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#8
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Senior Member Group: Members Posts: 1,525 Joined: 4-March 03 From: Chula Vista CA Member No.: 391 |
A rule of thumb we use is for auto-x, DE and other stadium events we would take caster out as the car turns quicker, sort of like toe out. On road racing course such as the CA Speedway, we put in as much caster as possible since we want the car to be stable on the high speed banking portion of the race track and the turns are not nearly as tight as an auto-x course. When I was racing bicycles, my road racing bike had more caster or rake in the front forks which made it easy to ride in long road races but the criterium and track bikes had very little rake or caster since they needed to turn very quickly in short races.
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Joe Ricard |
Aug 13 2007, 12:48 PM
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#9
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CUMONIWANNARACEU Group: Members Posts: 6,811 Joined: 5-January 03 From: Gautier, MS Member No.: 92 |
I am of the same thought as John on this one.
I used to have a lot of caster in my car. did not turn in as quick. much more stable at high speed. the one road course I run has tighter turns where I can excel so I keep the caster less than full. |
jhadler |
Aug 13 2007, 01:00 PM
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#10
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Long term tinkerer... Group: Members Posts: 1,879 Joined: 7-April 03 From: Lyons, CO Member No.: 529 |
I'm pretty firmly in the camp of caster is good for autox. And more is better. Granted, there's such a thing as too much of a good thing. But the dynamic camber gain more than makes up for the reduced turn-in if that is the ONLY thing you're doing.
But it's all a system. Caster alone is not the end-all-be-all. You need to dial the rest of the car in around it. And a truly hot setup for autox, is not going to be a hot setup for track or street. Having a lot of caster allows you to run less static negative camber, giving you a better contact patch for braking. Turn-in won't be as light, but the car will have more front end grip when you need it (mid turn). Turn-in then can be played with by toe, or spring rate, or just compensating with the steering nut. I think I'd rather have a little more effort for turn-in if it meant I could carry an extra .15 G around a turn. -Josh2 |
woobn8r |
Aug 13 2007, 08:54 PM
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#11
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Senior Member Group: Members Posts: 607 Joined: 7-January 07 From: Newmarket, Ontario, Canada Member No.: 7,435 Region Association: None |
I'm pretty firmly in the camp of caster is good for autox. And more is better. Granted, there's such a thing as too much of a good thing. But the dynamic camber gain more than makes up for the reduced turn-in if that is the ONLY thing you're doing. But it's all a system. Caster alone is not the end-all-be-all. You need to dial the rest of the car in around it. And a truly hot setup for autox, is not going to be a hot setup for track or street. Having a lot of caster allows you to run less static negative camber, giving you a better contact patch for braking. Turn-in won't be as light, but the car will have more front end grip when you need it (mid turn). Turn-in then can be played with by toe, or spring rate, or just compensating with the steering nut. I think I'd rather have a little more effort for turn-in if it meant I could carry an extra .15 G around a turn. -Josh2 You had me right up to the point where you say you set up with less negative camber and have more grip in a corner....not in my experience...but I also don't run max caster on my race cars...I do use a pyrometer to maximize all test set ups though....I'm also not sure your more caster/less neg camber theory is correct...but if it works for you...who am I to argue. |
alpha434 |
Aug 13 2007, 10:31 PM
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#12
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My member number is no coincidence. Group: Members Posts: 3,154 Joined: 16-December 05 From: Denver, CO Member No.: 5,280 Region Association: Rocky Mountains |
F=uW
Whatever makes the tires stick best. |
jhadler |
Aug 13 2007, 11:33 PM
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#13
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Long term tinkerer... Group: Members Posts: 1,879 Joined: 7-April 03 From: Lyons, CO Member No.: 529 |
You had me right up to the point where you say you set up with less negative camber and have more grip in a corner....not in my experience...but I also don't run max caster on my race cars...I do use a pyrometer to maximize all test set ups though....I'm also not sure your more caster/less neg camber theory is correct...but if it works for you...who am I to argue. Absolutely. The pyrometer tells all. With more caster, you don't need radical amounts of static negative camber. The negative camber grows as the wheel is turned. Now, a track car doesn't see as much steering angle as an autox car does, and as such, you don't get as much of a camber benefit from caster. For a fictional example: You have a 1982 hupmobile. You can, fictionally speaking, come off a hypothetical skidpad with identical tire temps. Two different setups. Car 1: 6 degrees of caster, -1.5 degrees of camber. Car 2: 4 degrees of casetr, -3 degrees of camber. Car 2 will have lighter, more responsive turn-in, but will be more prone to locking up a tire under braking, and if there are a lot of high speed straights, the inner edge will wear more. Car 1 will have heavier turn-in, but will have more contact patch on the ground when the wheel is straight. What's good on the track, is not necessarily good for autox, and vice versa. -Josh2 |
alpha434 |
Aug 14 2007, 01:01 AM
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#14
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My member number is no coincidence. Group: Members Posts: 3,154 Joined: 16-December 05 From: Denver, CO Member No.: 5,280 Region Association: Rocky Mountains |
And if you've ever driven a Hupmobile, you know how important this can be!
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Joe Ricard |
Aug 14 2007, 05:58 AM
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#15
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CUMONIWANNARACEU Group: Members Posts: 6,811 Joined: 5-January 03 From: Gautier, MS Member No.: 92 |
Like Josh said it all about the whole set up.
Since I run 11" wide slicks up front and they don't like a lot of camber my set up is going to be different. Tire pyrometer readings vary as little as 5 degrees inside to outside when up to temp of 120 degrees. Lots of caster makes them big tires a real bear to turn. If I remember right John Rogers runs slicks too. |
jhadler |
Aug 14 2007, 12:40 PM
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#16
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Long term tinkerer... Group: Members Posts: 1,879 Joined: 7-April 03 From: Lyons, CO Member No.: 529 |
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degreeoff |
Aug 14 2007, 01:11 PM
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#17
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I like big butts and I can not lie! Group: Members Posts: 1,622 Joined: 9-February 03 From: Booowieeee MD (near DC) Member No.: 275 Region Association: MidAtlantic Region |
(IMG:style_emoticons/default/hijacked.gif) OK I am almost to a point where I will need an alignment.....can I do this at the shop (mine!) or do I NEED a alignment machine??
Sorry to hijack but..... (IMG:style_emoticons/default/hijacked.gif) |
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