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Author Topic:   Bump Steer,Roll Center, Camber Gain
nw15x
Dirt Maniac

Total posts: 129
posted April 16, 2002 12:18 AM  
Bump Steer,Roll Center, Camber Gain...

If you had to rate them which one is the most important for proper handling.

nw15
Dirt Full Roller

Total posts: 28
posted April 16, 2002 12:04 PM  
Any takers on this subject...????

jammin
Dirt Administrator

Total posts: 6243
posted April 16, 2002 12:15 PM  
I'm with you jammin, SLEEPY

dode
Dirt Forum Champ
Total posts: 613
posted April 18, 2002 09:29 AM  
If the is a order of importance (I THINK THEY ARE ALL IMPORTANT) I will say that roll center location on any car is the most important, if you use a full size frame then the camber gain, but if you use a small metric I say bump steer is the next in line....the bump steer on the full size cars isn't tooo bad, but the bump on the small metric is sooooooo far off it becomes almost as important as roll center location....

When locating the front roll center you can use different parts that correct 2 or 3 of these things at the same time..........mostly roll center and camber gain........then the bump steer can be corrected after, that is isolated from the roll and camber anyway..........

Jeff

racnfool
Dirt Forum Racer

Total posts: 89
posted April 23, 2003 03:49 PM  
So what changes would you say are needed or would help to correct roll center on a stock stub?
Upper a arm angle
Lower a arm angle
(in order of importance)and what would the roll center target be?
Racnfool

longracing25
Dirt Freak

Total posts: 217
posted April 23, 2003 08:35 PM  
I added the AFCO lower ball joints(tall) to my metric on both sides(because i noticed they didn't make easy replacement ones for the top)...does this help anything? Is that how you help the roll center?

SBS
Dirt Roller

Total posts: 13
posted October 14, 2005 12:17 PM  
We have some software that calculates roll center and shows how the suspension moves during dive and roll.

Check it out: http://www.sbsmotorsports.com

Thanks,
Sal

SBS
Dirt Roller

Total posts: 13
posted October 14, 2005 12:19 PM  
We have some software that calculates roll center and shows how the suspension moves during dive and roll.

Check it out: http://www.sbsmotorsports.com

Thanks,
Sal

enduro80
Dirt Roller

Total posts: 12
posted October 14, 2005 10:02 PM  
So in a stock metric chassis how do you set bump steer?I used to have IMCA adjustable ends with heim joints for tie rod ends but kept snapping them off.How do you guys set bump steer??Any pictures??Thanks in advance Enduro 80

sc1 racing
Dirt Freak

Total posts: 419
posted October 15, 2005 10:27 AM  
roll center and caster..wtf is bump steer...LMAO never messed with it so it must not be to important...

enduro80
Dirt Roller

Total posts: 12
posted October 15, 2005 03:49 PM  
roll center and caster..wtf is bump steer...LMAO never messed with it so it must not be to important...
Now thats funny right there i don't care who you are.......

[This message has been edited by enduro80 (edited October 15, 2005).]

[This message has been edited by enduro80 (edited October 15, 2005).]

SBS
Dirt Roller

Total posts: 13
posted October 17, 2005 10:17 AM  
Bump steer is very important. Pick up one of the Steve Smith books to read more about it.

Basically, when your car rolls in a turn the angles of your A Arms and tie rods change. If things are not correctly set up, simply putting the car into body roll will cause the wheels to steer in or out. This will also happen when your tire rises or falls (bump). So the car would seem to wander from side to side if you were going down a bumpy road.

To correct for this (and achieve more reliable steering through body roll and wheel bump) you need to modify/adjust your centerlink and tie rods. How much you can do this will be limited by your rules and how closely your tech man looks at things.

-Sal


CLBaker25
Dirt Maniac

Total posts: 193
posted October 17, 2005 11:34 AM  
Sal,

I would like to see one of these programs with a basic metric suspension already programed in. Most racers would be very interested in something like this if they could use it without having to make a bunch of weird measurements. If you have a metric chassis with stock metric a-arms you should be able to know what the roll centers are based on those factors using a program. I think this is a market that you could easily exploit if you had it available.

SBS
Dirt Roller

Total posts: 13
posted October 17, 2005 11:38 AM  
CLBaker24,

That is a very good point.

Unfortunately... my metric chassis is no longer what you would call "stock." It is a very good idea to incorporate the stock metric (and possibly stock camaro) setup into the program.

FATBOY90
Dirt Full Roller

Total posts: 52
posted October 22, 2005 12:51 PM  
JAMMIN HAS THE RITE IDEA

    

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