rack and pinion question regarding bumpsteer

[abadsvt]

I want to use the c5 front and rear suspension for my project but the track width is a couple inches too wide. So I was thinking that if I kept all the points the same for the suspension and just narrowed the X coordinate (width of car side to side) and got a custom rack and pinion. If the points for the rack and pinion were not changed except by narrowing the body of the rack leaving tie rod on rack and tie rod on spindle points the same in relation to the control arms as factory. Would that create any issues like additional bumpsteer. Thanks for you help ahead of time.

Josh

[abadsvt]

Anyone? I can't imagine it affecting anything but I'm still learning. If I need to reword question I can if I didn't make much sense. Thanks

[Ron Sutton]

I want to use the c5 front and rear suspension for my project but the track width is a couple inches too wide. So I was thinking that if I kept all the points the same for the suspension and just narrowed the X coordinate (width of car side to side) and got a custom rack and pinion. If the points for the rack and pinion were not changed except by narrowing the body of the rack leaving tie rod on rack and tie rod on spindle points the same in relation to the control arms as factory. Would that create any issues like additional bumpsteer. Thanks for you help ahead of time.

Josh

Hi Josh,

I think why no one answered was, when you say ask, "Would that create any issues like additional bumpsteer?" ... with no dimensions on rack, tires sizes, ride height of chassis, etc ... the situation is pretty cloudy. Each of those variables you're not mentioning affects bump steer.

Bump steer is one of those key geometry things that needs to be worked out. If you want it to be correct, you'll need to invest the time & energy to work it out. The three common options are to
1. Get all the measurements, buy the software & play around until you get a happy combination ... then order & mount your rack.
2. Get all the measurements, hire someone to work it out for you & provide a happy combination ... then order & mount your rack.
3. Pay a knowledgeable race shop to do it for you.

[Rod]

I agree with Ron...there's no easy answer.. everyone wants to hear, mount the rack at X and Y and it will work. Fact is with many early cars a rack will always have bumpsteer, in a first gen camaro the rack has to be mounted so damn high to get rid of bumpsteer you couldn't use an oil pan.....that's what I discovered building my own car and moving the rack till bump was minimized before I installed the engine (the crank would have been in the way also) but hey I'm no expert maybe someone has finally made a kit that works

[abadsvt]

Thanks guys. I really want to build my own suspension and want to make sure I fully understand everything prior to starting. Ill play with suspension analyzer to see if I can get a hang of everything.

[astroracer]

If you design your own suspension you can start with a Corvette rack and build off that. Suspension Analyzer has the Corvette suspension points canned in the program. Just be aware of tierod and upper and lower control arm to rim clearances.
That is where these "design" programs will get you into trouble. With no way to check actual clearances you won't know what they are until you actually build the parts and put them together. This is where a 3D CAD program can save you a lot of time and money. While I was designing the suspension for BadAst I was able to run the suspension and all of it's components through jounce, rebound and left and right steer to check all of the clearances. When it came time to build the parts I was 99% certain everything would work and the components practically fell together at mock-up time.
As the guys above said, there are a lot of variables to take into consideration when it comes to doing this work. It is not as easy as most people think and moving "one Point" only and inch two will upset the continuity...
Mark

[Rod]

As the guys above said, there are a lot of variables to take into consideration when it comes to doing this work. It is not as easy as most people think and moving "one Point" only and inch two will upset the continuity...
Mark

VERY TRUE!!! I can change my own camaro from a neutral handling car to a car that pushes and turns like crap just by lowering the rear ride height on my car 1/4 inch (.250 thousands) its really that simple. HAPPY to CRAPPY is determined by hundreds of factors ride height, suspension points, spring rates to control pitch and yaw and so on