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View Full Version : Bump Steer on 68 Camaro


bwarren
03-26-2005, 05:17 PM
What is it? How do yo get it? How do you get rid of it? I found a liink to some info that Dave Pozzi has up on the topic. It made a "little" bit of sense. I also read a technical piece I found through a google search.

SO, I have a 68 first gen and over the winter I put in a complete Global West suspension (UCAs, LCAs, QA1 coilovers, etc). The front sits about 2" lower. I don't know if I had bump steer before - and got rid of it OR if I didn't have it AND GOT IT NOW!!

I also JUST read the GP for the Unisteer R&P, and "bump steer" came up again!! Do R&Ps on first gens give you bump steer OR get rid of it.

I'M SO CONFUSED! I can't be the only one with these stupid questions - can I?? I feel like I'm having a panic attack and I haven't even driven my car yet this year. SOMEBODY please help me!!

In all seriousness, thanx for ALL the GREAT info everyone contributes. You guys have have really enlightened me with the Pro Touring movement. I'm hooked!!!

jonny51
03-26-2005, 09:52 PM
Definition: The tendency of a vehicle to suddenly veer or swerve to one side when hitting a bump or dip in the road. The condition is caused by uneven toe changes that occur as a result of the steering linkage or rack not being parallel with the road surface. This causes the wheels to change toe unevenly as the suspension undergoes jounce and rebound.



Got that from another website
Also try this link http://www.modularpower.com/bumpsteer.html

Marcus SC&C
04-06-2005, 09:22 PM
Try to visualize (from the front or rear) the spindle swinging in a vertical arc as the suspension moves through it`s range of travel. Now notice that the steering arm is swinging with it,in the same arc. Now picture the tie rod,bolted on the center link but with the outter tie rod end free. Picture it swinging in an arc the same height as the spindle`s. 99 times out of 100 these two curves will not be the same due to the heights or lengths of the parts being off (most of the time both). So,when you bolt the tie rod end to the steering arm the tie rod end ends up either pushing or pulling on the steering arms,steering the car with no steering input from the driver. Virtually all production cars have some bumpsteer and many older ones have a LOT. In the case of early Camaros the tie rod lengths are off some and the outter tie rod end is "around" 1/2" too high. I say "around" because it varies with alignment (especially caster),ride height and variations in different versions of steering parts and arms used on 1st gens. 1/2" of correction gets it in the ballpark though. Remember bumpsteer is MUCH more sensitive to vertical changes than horizontal (length) ones. In some cars the ratios can be as high as 1/8"V=3"H! That`s because the length of the parts dictates the shape of the arc but the vertical effects where in the arc a component is at a given time. Get the arcs so they match exactly at ride height and they`ll deviate from each other very little in the usable range of travel. If they`re in totally different locations at ride height,you`ve got problems! Without putting a bumpsteer gauge on a given car you`re not going to know *exactly* how much things need to be moved but many factory cars are so far off you can make great strides in the right direction pretty easily and really improve the way the car drives. We sell tall stud modular tie rod ends for early Camaros that drop the pickup point and get those arcs much closer together and reduce the bumpsteer to the point it`s no longer noticable. I hope this makes a little more sense of bumpsteer rather that confusing you more. :_paranoid ;) Marcus

chicane
04-11-2005, 04:01 AM
Another offering of information (http://www.longacreracing.com/articles/art.asp?ARTID=13)