iRoush Posted July 3, 2012 Report Share Posted July 3, 2012 (edited) CamberCamber angle is the inclination of the wheels looking from the front or rear of the car. A wheel inclined inward at the top is said to have "negative camber"; a wheel inclined outward at the top has "positive camber". The angle is measured in degrees.In a road racing environment, it is important to keep the entire tread width of a tire, which is generally wide and flat, in complete contact with the track surface as much as possible. When a tire is leaned over, part of the tread is no longer in contact with the track, drastically reducing traction. Therefore, the suspension must be designed and adjusted to keep the tire flat on the track surface during suspension movement.Understand that as a car is driven through a corner, it leans toward the outside of the turn. This causes the outside tire to lean outward; more positive camber; while the inside of the wheel tends toward more negative camber. Therefore, to keep the outside tire (as it's the one that is generating most of the cornering force) as flat on the road surface as possible, generally the suspension is adjusted to measure negative camber whean at rest or driving down a straightaway.Realistically, your goald in adjusting the camber angle is to maximize cornering grip by having the tire close to zero degrees of camber during hard cornering. This can take a fair bit of adjusting and testing to come up with the closest static setting that resuilts in the optimum dynamic camber angle.CasterCaster angle provides the self-centering effect of the steering (the tendency for the car to steer straight ahead without holding the steering wheel). It is the inclination angle of the kingpin, or upright, looking from the side. Positive caster is when the top of the kingpin/upright is inclined to the rear. Negative caster is never used.The more positive caster, the more the steering will self-center; which, generally, is a desirable effect. However, the more positive caster, the more effort it takes to turn the steering wheel against this caster. With the mustang design and power steering assist this is not a huge issue, and generally you will want to run as much caster as you possibly can, up to a point. Without a bumpsteer kit 4.5 degrees should be the maxxed that is dialed in. With a bumpsteer kit you can see up to 6.5 degrees worth of caster.ToeToe can be either "toe-in" or "toe-out". It is the angle of either the two front tires or the two rear tires (if you have IRS) looking at them from above. Toe-in is when the front of the tires are closer together than the rear; toe-out is the opposite. The front of the tires are farther apart than the rear. Toe can always be adjusted at the front and can only be adjusted at the rear on cars with an independent rear suspension.Toe Plays an important role in the car's straight-line stability, as well as it's transient handling characteristics; how quickly the car responds to the initial turn into a corner. Generally, front wheel toe-in results in an initial understeer; toe-out results in an initial oversteer. (More about oversteer and understeer later).*Note* Rear wheel toe-out must be avoided; it will cause instability and and unpredictable oversteer.BumpsteerBumpsteer should be avoided at all costs. As you lower a mustang further and further you will induce more and more bumpsteer due to the incorrect geometry of the a-arm to spindle connection. You want a virtually flat plane from k-member to a-arm to spindle. Unfortunately with just lowering springs it will ruin the geometry of the suspension and a bumpsteer kit will be necessary to bring the suspension geometry back in order. That being said, what is Bumpsteer? It is when the front or rear wheels (rear wheels are IRS only) begin to toe-in or toe-out during the vertical suspension movements caused by a bump or from body roll (sometimes called roll steer). Bumpsteer generally makes a vehicle very unstable, particularly on the rear wheels for IRS based cars.Here is a video of Bumpsteer occuring during the spring cycle. watch how the wheels turn due to compression of the suspension. Edited February 21, 2013 by iRoush Link to comment Share on other sites More sharing options...
Shifty Posted July 12, 2012 Report Share Posted July 12, 2012 Care if I chime in with some amazing links? Link to comment Share on other sites More sharing options...
iRoush Posted July 12, 2012 Author Report Share Posted July 12, 2012 Care if I chime in with some amazing links?We are trying not to link anything on this site. If you come up with something yourself feel free to post. the idea is to make this site filled with information that we have, not that others have. Link to comment Share on other sites More sharing options...
Shifty Posted July 12, 2012 Report Share Posted July 12, 2012 Ok.. not that hard to transfer it to here instead of link it Link to comment Share on other sites More sharing options...
iRoush Posted July 12, 2012 Author Report Share Posted July 12, 2012 Ok.. not that hard to transfer it to here instead of link itIf you get the approval from the original owner/writer then by all means do it. Link to comment Share on other sites More sharing options...
iRoush Posted February 21, 2013 Author Report Share Posted February 21, 2013 Bumpsteer information + video added Link to comment Share on other sites More sharing options...
F8L GT Posted February 21, 2013 Report Share Posted February 21, 2013 Very nice write up a Brett. Can't wait to finally get my cc plates to get full pos caster Link to comment Share on other sites More sharing options...
TaborRacing9 Posted February 21, 2013 Report Share Posted February 21, 2013 yesss very nice write up...i likey Link to comment Share on other sites More sharing options...
Det_Riot Posted February 21, 2013 Report Share Posted February 21, 2013 SSOOO I get bumpsteer. Kinda. But I don't get how you are properly supposed to be set up. I've heard that you want to keep the tie rod ends parallel to the control arms right? Well I'm hella slammed and I don't ever experience bumpsteer even though I feel like I should be. Link to comment Share on other sites More sharing options...
F8L GT Posted February 21, 2013 Report Share Posted February 21, 2013 You might not feel its happening but it is Link to comment Share on other sites More sharing options...
Det_Riot Posted February 21, 2013 Report Share Posted February 21, 2013 Probably has something to do with my blown out steering shaft. I'm sure I'll feel it more when I put my new cobra rack n shaft in. Link to comment Share on other sites More sharing options...
iRoush Posted February 21, 2013 Author Report Share Posted February 21, 2013 Probably has something to do with my blown out steering shaft. I'm sure I'll feel it more when I put my new cobra rack n shaft in.does your steering wheel move under suspension compression? if yes, you're experiencing bumpsteer. If no, then you're not pushing your car hard enough to experience it.You are correct about the tie rod being parallel to the a-arm. This is what your suspension should look like during the spring cycle:If you don't cycle the bumpsteer, then you may be relieving the static bumpsteer (the tie rod will be even when not moving) but during spring compression the bumpsteer will cause tie rod to no longer be even. It's a LONG and tedious correction but well worth it IMO. Link to comment Share on other sites More sharing options...
Det_Riot Posted February 21, 2013 Report Share Posted February 21, 2013 Your link didn't work, I was going to answer your question, but then I remembered that I don't think my springs move ever....seriously, they're like the hardest springs in the world Link to comment Share on other sites More sharing options...
iRoush Posted February 21, 2013 Author Report Share Posted February 21, 2013 Your link didn't work, I was going to answer your question, but then I remembered that I don't think my springs move ever....seriously, they're like the hardest springs in the worldworks here.. and yeah those springs are transferring the bumpsteer to the nut that's sitting in the driver seat Link to comment Share on other sites More sharing options...