suspension design

[dezerts10]

I have asked a number of questions reguarding suspension design/ spindles and all things inbetween. so here the next question

I wanna build a new front end for my truck. but i am probably goign to end up getting one of the "prefabbed" spindles like the kartek pro am one or possibly something from someone else. say my spindle is "x" inches tall will that hinder the design of the suspension? cause i can not control the height of the upright only thing i would have controll of is the upper arm mounts and hte lenghts of the arms. its it feaseable to build something that will perform with out designing hte entire suspension system? does my question make sense?

Gregg

[Scott_F]

One thing to consider is that the steering arm on your "store bought" upright is a fixed location, as is the SAI, steering axis inclination. These are both very important. You are better off with a complete suspension system, unless you can get the rest of the design that goes with the uprights you want.

[dezerts10]

yeah i thought about that "stuff" one option is to see if i can ge tthe upright with out the steering arm.

I have seen quite a few trucks and buggies useing the pro am spindle from kartek. all tube chassis stuff so im assuming they figure all the deminsions off the spindle and go from there since they can mount there stuff any which way.

if only someone built something nice and reliable for an s10.

Gregg

[CRAIG_HALL]

The kartek/proam spindles dont come with steering arms for obvious reasons.There are just a few height as well as inclination angles you can run.they do come with the upright gusseting though.

As far as your question the height shouldn't make a difference if you are making the upper arm mount as well.

[FullsizeFun]

There are 10*, 12*, and 14* KPI available and a variety of heights. also you can use 1" or 1.5" monoballs. There are many combinations available, call Kartek.

[dezerts10]

so with out designing the entire suspension how do you go about choosing which "model" to buy?

Gregg

[J.JOHNSON]

1.you Need To Know What Wheel And Tire Combo You Want To Run
2.you Need To Know The Hub You Are Going To Run
3.then You Need To Either Make A Drawing Or Bolt The Peices Together. Then Draw An Imagiary Line From The Center Of The Tire Where It Contacts The Ground Tthrough The Upper And Lower Balljoints (uniballs).
4. The Closer To Center You Stay The Better It Is For The Dirt. You Do Not Want To Go Past The Center Of The Tire (or Towards The Outside Of The Car).
5.if You Decide To Build Your Own Spindle You Can Make It Hit The Exact Center Of Your Tire Patch.
Remember That Carol Smith Has Writen Quite A Few Books On Race Car Engineering That You Can Purchase Online Or At Any Book Store. There Wil Always Be Compromises When Building A Car And There Is No Perfect Set Up.
Have Fun.

[ntsqd]

There are other books that may be more helpfull in sorting out the design. Searching this topic should turn up all of those titles.
Keep in mind that they are intended for pavement racing so particular design elements that they stress may or may not be worth stressing in a dirt application.

For instance, Camber curve is more important to a pavement car than Roll Center height. So road race front suspensions end up with the RC tyipcally at or even below ground level. This is why road racers tend to have large OD front sway bars, the CG has a lot of leverage on the RC and a lot of roll resistance is needed to combat that. From my one, small experiment with camber in the dirt I do not think that it plays as important a role as it does on pavement. Compound that with the Camber Curve 'blowing up" at the extremes of the kind of travel a typical dirt vehicle has. So compromising the RC height for the world's most perfect camber curve would be a waste of time for the dirt.