rack and pinion steering arm angle question

I have just installed a no limit engineering air glide front suspension on a 52 chevy, the problem is when its all the way down there is severe toe in, I adjusted the toe at a pretty low ride height and still pulls way in when down, and i have not adjusted the camber yet and i think it will be worse when i do and i know there is some toe in when all the way down but not this much.
looking at the rack it seems that it is mounted too low on crossmember, should those steering arms be at the same angle as the lower control arm, you can see at ride height that they are pointing up, im thinking of raising that rack up until the arms are parallel to the control arms.
thought i would get some opinions on here before proceeding since im not getting a call back from there tech line.
thanks.

 

Hard to see: are your tie rod ends bolted into the steering arms from the top? Or from the bottom? Mine go in from the bottom.

 

The inner joint should be in line with the upper and lower A-arm pivots, it looks like the rack is way too wide. I would want the rack up higher just so it doesn't get smashed so easily. It looks like it will be the first thing to get hit.

 

That too. The tie rod pivots should align with the lower a-arm pivots, so both articulate from the same centroid/identical arc.

 

Yes it looks too low and yes, you want the arms to be level and parallel at ride height or as close as you can get them.

 

the pivot point on the rack is about 1 1/2 wider than bottom control arm pivot, i compared that to a tci unit and is the same, and the tie rod ends do mount from the bottom,and yes the rack is hanging below the crossmember.
thanks

 

ok thanks thats what i needed to know before moving it.

 

For correct steering geometry (i.e, little or no bump steer) the R&P tie rod pivots should intersect an imaginary line drawn from the upper and lower INNER A arm pivots. In addition, the tie rods should be parallel to the lower A arm.

The height of the steering arms, and whether the outer tie rods mount from top or bottom, will determine the height that the R&P must be mounted to accomplish the latter.

But, again, the rack width is an important factor to attain correct geometry throughout the wheel travel. I think all too often these principles are ignored, especially by home many home builders, and even by vendors who sell stuff they think is "close enough"

It's probably a rare R&P unit that is "just right" for an application unrelated to it's original usage unless a front suspension has been designed for the rack's dimensions in the first place. Or, the front end is designed and a rack is specified that meets the criteria.

Ray

 

personally i wouldn't be overly concerned about toe changes at the extremes of travel as you won't be driving it like that but i'd agree the rack appears to be too low and raising it will reduce or eliminate that 1.5" difference in the pivot points. I've also had some sucess with some preplacement track rod ends made by Baer - they fearute a heim joint and are height adjustable - allowing you to drop the intersection point at the steering arm. I wouldn't suggest that as an alternative to firstly relocating the rack though, just a possible fine tune later on if necessary.

Chris

 

Ok, this picture pretty much tells the story. Yes, the rack is too wide. Moving it WAY up will help, but I doubt you will have room to go far enough. As mentioned, the inner pivot should be on the line formed by the upper and lower A arm pivots.

You can help it some by installing a "bump steer" kit. You will need to convert the outer tie rod ends to heims to use it, but it will at least level the tie rods to the lower A arms.

WHOA! BIG photo! Sorry.

 

With theses kits its a one size fits all with the rack. The question is how much do you plan to drive it that low.

 

So many wrong answers from people with little experience.

This is a Mustang II type front. The rack is too low on the crossmember.

Notice where the rack is in relation to the lower control arms on these pictures and the angle of the tie rod vs the control arms:

 

Steve's second photo above also shows the bump steer kit I mentioned.

Some crazy looking steering shaft geometry on that Cobra as well! I'm ***uming it wasn't connected in that pic???

 

"R&P tie rod pivots should intersect an imaginary line drawn from the upper and lower INNER A arm pivots. In addition, the tie rods should be parallel to the lower A arm." Hnstray got it right! just check on steering geometri you´ll see it!!

ELpolacko, your Mustang setup is ok on the rack pivots, but on the parallel angle to the lower A-arm, it looks like not ok. You gonna get some bump-steer.

 

I think Polacko said as much when he posted the pictures.

 

A bumpsteer kit is unnecessary on the OP vehicle. Nice to have on a track car or something where you have changed the geometry.

Steering column was unattached in that photo. If you look just below the middle knuckle you can see the HEIM to fasten the steering system.

That Cobra had adjustable upper, lower control arms and mounting points.

 

Really?

All three of the cars I posted pictures of are several year old builds. They drive fantastic with no bumpsteer. You are going to have to trust that I do know how to set up one of these IFS. I believe you may have learned some incorrect information through the hot rod magazines.

Want to know how to set these suspensions up properly? Pick up Ch***is Engineering by Herb Adams and see if you can get a hold of Ch***is Design by Milliken. Solid and truthful information with a sales pitch in those books.

 

Here, don't take my word for it.

http://www.longacreracing.com/articles/art.asp?ARTID=13

Please read, there is some fantastic information here on how to solve this issue.

 

ELpolacko that longacre racing article is right on

 

The correct solution, no. Just pointing out he could use the adaptors to get some angle out of the tie rods if he didn't do anything else...

 

Knowing the front end what would end up happening with the bumpsteer kit like the Cobra I posted would be Symptom 3 on the Longacre site I posted.

 

How close do these repeat the ride height.
Looks to me the caster is to far back ,should be 1 degs pos.
To me the top a arm is not on correct,its to close vert to frame.
The top and bottom a arm close to parrell.

 

This may help -

 

"close only counts in hand grenades and horseshoes"

I did open that link and printed it so I won't expose myself to a public spanking on this topic again. But that still leaves me with plenty of other opportunites.


Ray

 

very good info, thanks guys
it really ****s to pay over $ 2k for a front suspension and the have to re engineer it, not only re mounting the rack but its going to take a **** load of spacing to get the camber good, this front suspension has been **** from the start. hopefully by getting the arms up even with the control arms will solve the problem.

 

Did you weld it on and make any changes to get it lower.
The crossember Looks lower then it should,or put closer to frame,makeing to top to low.
I think if you get it alined up closeer,the tie rod will be closer to were it should be,now the top may not let you level wheel up.
I think just to top has to be raised.
Get it level lower a arm and take another pic with the ball joint O caster,o camber.
Ithink to bottom will look better.

 

Dane,has it right all others are off by some small points.

 

We trust Steve, we trust! We know . . .

Hahaha! Awesome display of humility Ray. Takes a real man to say this.

 

In the 2nd pic the upper a arm is far away.
You could have a mix of parts.
You could have a shorted upper a arm,or do you need a shorter lower a arm.
My 39 Ford has shorter a arms.
Just a guess if you can,t get wheel vertical,And 0 degs caster will lower tie rod end.

 

no, i didnt modify anything on the kit to get it lower, they make a coil over front suspension also, so instead of making 2 different lower control arms if you order a air ride kit they make you use the coil over arm with a adapter plate that places the bag off center on the arm

I sent them numerous pics, asking WTF? do i have the wrong lower control arm and they said it was the correct one. i thought i had another problem because the top control arm is not at the same angle as the bottom but that diagram that dane posted shows pretty much what i have.

when i get back on that project i will post some pics. of the adjustments made and see what you guys think.