THANKS Tricknology!!!! Excellent EXCELLENT info...just like you'd expect from the oval track guys! I'm sure Bloaty57 will be all over this but I still want to thank you for myself! Very cool of you to put this up.
Trick, Thanks for the links and info........... The rack Unisteer is going to make is a shortened M2 rack that'll place right where the stock centerlink used to sit. The rack won't have to go forward or backward, position wise, and will be end steer, which I preferred anyway. I thought my only answer was a center take off rack, which would've set the inner links out a little further, but when Steve at Unisteer said we could chop a M2 rack down, that took care of several questions. I looked at several racks for oval track cars, but I didn't think they were street legal. They'd probably work as is, just off the cuff. I'm still looking at the links you sent......... 32V..........I'll take a look at the Opel also......... Thanks gents..... Bob
Uni steer makes rack conversion kits for S-10 and most Gm frames,,, I would still go with a oval racing rack http://www.unisteer.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=UNISTEER&Category_Code=NEWPROD
Trick, Yep, I know about Unisteer's new S10 system......I had been in contact with Dave at Unisteer for the last 2 yrs. I've been in contact with Steve there as well, but just emails, and he advised me earlier last year that the system was almost complete. Price is scarey at $1,100......though.....too much for my blood and even if I had it, I wouldn't spend it on the rack.....I could buy a new M2 rack and machine it myself. Problem with the Unisteer S10 system, it won't work with the setup I've got due to the radiator position that has to be installed. No choice there. Now for the stupid question.........Are the oval track racks legal for the road, and also what's the average turning radius ? ( I know....that's 2 stupid questions) I need about 6" lock to lock, and I gotta check for sure, but I almost think that the S10's are 6.25, or 6.50". Thanks Bud, Bob
YEs they are legal and they work real good and are easy to fix,,,and used ones are cheap. New ones are around $350,,, But IF you are a machinst and can shorten a MII rack thats OK too. Most stock racks are too wide,,, Measure your stock S-10 center link, inner tie rod to inner tie rod distance,,, what is it? well that is about the lenght R&P you need, or even a little shorter will work too. Installing a typical manual racing rack will be like installing a 12 to one ratio steering box on your car ( Z-28, trans ams ,Monte carlo SS had about 12 to 1 ratio boxes).... 12 to 1 will work fine on the road but will be a little tuff to steer when parking / not moveing. But hot rods are driven by tuff guys .
Well I don't know about tough..... The terms tough & old (or older) don't seem to go together, and if they did exist at one time, they usually don't stay together......kinda like a one nighter with a dumb blonde.......LOL Anyway, I checked out Woodwards site and the racks look pretty nice. Yeah, I can machine pretty well.......jack of all trades, master of none. Steve at Unisteer can make me the rack I need with the correct inner tie rod centers. That'll run about $300-$400, give or take. I'd rather buy a new unit that try to pick up a used one though. The center link's inner tie rod positions "stock" are 8 3/4" and are above, and well within the lower control arm pivot bolts. Those are 14 3/4". To be able to use an end take off rack, I can follow the wider control arm pivot points, and just have one made to fit it. With that wider span, it can be done, but with the inner link points, not so. That would have to be a center take off rack to work. Like I said before, I'm sure this will work and be geometrically correct, but now I'm a little concerned with the rack travel distance. Not a real serious concern, but one never the less. Thanks Trick.......... Bob
Reading this with great interest as I am about to plunge into mine. Not much has been said about the turning radius. Have you worked this out yet? Typical recirculating ball is a 7" "throw" side to side. As mentioned the Cavalier rack is a 6 " throw. The steering "arm" on the cavalier stut is 5 1/2 " (I think) and the typical steering arm is 7 7-1/2 inches. Obviously the turning radius will suffer, but how much? Is there a formula for this?
Not sure if iti is still needed, but RJ racecars sell a narrowed rack, http://quartermax.users21.edigita.com/details.php?prodID=112&catID=45 might help with the bumpsteer, we have used them for years with no problems.
Tinman & others, As far as building, or cutting a rack to fit, the ride height of the suspension, as well as where the rack's height is located in relation to it, has an affect on where your inner ball centers need to be. If the suspension was perfectly level, the outer link point's position, in relation to the pivot bolts of the control arms themselves (up or down), would determine the position of your rack housing. Above those control arms bolts & outer links, the inner's would be wider, below them, they'd be closer together. They follow that imaginary line from the upper control arm pivot points, on through the lower ones, as has always been mentioned. If you look that the stock S10 center link, it's inner tie rod centers are somewhere around 8-9 inches center to center, but the lower control arms pivot bolts are 14 3/4 inches center to center. It doesn't follow the normal theory, or recommended way of setting up the steering system quite honestly. The center link's inner tie rod centers are actually too close (based on the normal steering recommended setups). I'm sure GM did their homework, and as far as bumpsteer is concerned, and I'm not inferring that they hadn't. It's less of a problem to have inner tie rod centers that are too close, than too far out past your control arm pivot points. With the chassis loaded, picking your horizontal (and level) point across the straight line from your two outer (wheel) links is where the rack should ride if your shooting for a straight on shot across. Most loaded suspensions should have the lower control arms "pretty close" to level, more or less. Maybe a little extended, depending. I try to get my tie rods to mimic the control arm's movement as close as possible, and keep that same geometry. No matter where the suspension goes, up or down, things "should" be good to go. I've used a clean piece of cardboard, and pencils taped to the tie rods and control arms to check their travel. With the cardboard in place, and secured, as well as the pencil securely taped, I can run the tie rod up and down to scribe a line on the cardboard. Doing the same with the control arm will give you 2 sets of lines that should be as close to parallel as possible. It doesn't matter where they are in relation to each other, as long as they're both as parallel as possible. Oh yeah, I think that Steve from Unisteer told me that their R&P travel was 6.5 inches, lock to lock. Since they fabricate their own systems, I don't know whether this can be modified or not. I'll find out though. Just my 2.........always learning.... Take care, Bob
Bob...I think your off on the imaginary line stuff. If you draw a line thru the front upper and lower control arm bushings and use that as a location for the rack inner pivots your gonna be off. Heres why. The ball joints are set up to give zero scrub at the tire patch, more or less. Not vertical. The imaginary line you propose thru the upper and lower bushings angles in the opposite direction. Movement along those two lines won't be parallel so it isn't a big controling factor in pivot placement. VERY simplified explanation but I hope you get my drift. (OK...after rereading it, it isn't so clear! Bear with me anyway...) Heres my take on it. Due to all the wonky movements and the clearance issues besides, the tierods and steering arms are mounted as low as possible and parallel to the lower control arm plane. That plane defined by the three points consisting of the two inner bushing centers and the ball joint ball center of each control arm. Having the tierods/steering arms low takes spindle angle changes, due to leaning in turns and suspension travel etc, out of the equation. To locate the inner pivot points of the rack you then draw an imaginary line thru the inner bushings of the left control arm and an imaginary line thru the inner bushings of the right control arm. On an S10 these 2 lines will converge somewhere ahead of the frame. The inner pivots of the rack or center link should be the width of those lines where they pass thru the rack position. Basicly...your rack height is determined by your steering arm height and the need for the tierod assemblies to be parallel to the plane of the lower control arm. Your inner pivot distance apart is determined by the line thru the two lower control arm bushings on either side. With the rack and steering arms so low, the upper control arm effect is minimized, so not as important as it would be if the rack and steering arms were...say at the middle of the spindle. Thats why the S10 centerlink tierod holes SEEM closer together than you would think they should be. They really aren't...GM knows what works and what doesn't. (Now if you can mount the rack closer to the control arm bushings that will give you a little more leeway in width...) Everything is a variation on this due to suspension tuning needs and types of course, but thats it ( in my opinion! Others welcome!) in VERY basic terms...for this style SLA suspension anyway! Bottom line...try to reuse the same centerlink height and then the distance between the centerlink holes as the distance between your rack inner pivots because GM certainly isn't "off" by much, if at all!
Bill, Steering geometry is always a confusing pain in the ass, but you gotta admit, it's a challenge..... When you mentioned; I meant the same thing when I said this; Actually, as I understand the basics of it all I guess, I did a pretty poor job of explaining it, and like you honorably admitted; Easier to show than explain I guess. (Forgive me it's late and easier to do quotes - ) Anyway, in relation to the upper and lower control arm imaginary lines.......(I'll try and do bettter on the explanation this time ) I think we both agree that the outer control arm height determines where the R&P has to be located "up & down" wise. And, also that the inner tie rod centers have to be on the same pivotal hinge point as the lower control arms so that all rides together smoothly. Why GM's closer center link design (closer inner tie rod centers) works, I believe, is because you can go inside of the lower control arm pivot point with the inner tie rod centers without affecting bumpsteer much (tie rods longer), but, on the other hand, if you locate those inner tie rod centers out wider than that point (tie rods shorter-wider inner centers), it greatly affects bumpsteer...... That was a tired attempt.....LOL Getting late....... Take care, Bob
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