"It's best to have CVs parallel to tie rods..."

[boy&hisdogs]

I just read this here... is this true? I've always heard flat is best, and my non-engineer brain says that makes more sense than what these guys are saying.

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[Hipster]

Not really sure what you or they are talking about here. You posted a few lines out of context of the rest of the article.

With the wheels straight and centered the outer tie rod and the cv's shafts and the control arms are going to swing in similar arc unless you have the wheels cut to one side or the other then the relationships will change somewhat or if you've done some goofy suspension mods.

From a performance standpoint the control arms , steering linkage etc parallel to the ground is the most neutral position with the least amount of bumpsteer but normally you're not trying to achieve race car handling on a 4x4

They're mainly referencing extreme ball joint and cv angles which can be detrimental. Full lock, full compression, or full drop, and hammering the go pedal is a bad recipie.

 

[454cid]

I notice that's a GMT-800 with the weak tie-rods. I've heard that the sled pulling guys will get wheel oscillations under load. It could be that the components not being lined up is what's driving the oscillations, but that's a very specific situation. I have nothing to back this up, it's just a guess.

 

[Erik the Awful]

Your CV joints and tie rod ends should stay relatively parallel to the control arms and should be the same length as the control arms. The control arms describe the arc that your spindle will follow. If the arc of the tie rod doesn't match, you'll get bumpsteer. If your CV is fixed-length and the arc doesn't match, the CV will bind with suspension travel.

[storytime] Several years ago we were racing an MR2 at Eagles Canyon in Decatur, TX. We were getting crazy bumpsteer on the front straightaway. We started jacking the car to inspect, and Ross noticed the front wheels turn in as the car was jacked. There's a kit for MR2s to flip the tie rod mounting points on the spindle to correct the bumpsteer that they naturally have, but if you lowered the car (we did) it made the bumpsteer worse. The tie rod was the correct length, but changing the mounting point wrecked the handling.

Since the spindles were permanently modified, we swapped them out for another set Pat had in his parts stash. The new spindles still had the dust shields, and Pat didn't want to disassemble them to remove the dust shields, so we left them on. They trapped heat, and three hours into the race we set the brakes on fire. I then grabbed a hammer and chisel and removed the dust shields in about thirty seconds. Fun stuff!