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Centered Unisteer?

Discussion in 'The Hokey Ass Message Board' started by bonechop, Mar 23, 2013.

  1. bonechop
    Joined: Apr 19, 2009
    Posts: 29

    bonechop
    Member
    from NW Indiana

    I have seen varying opinions on the varieties of steering setups from BMW boxes, '32 vs. '34 ford boxes, vega and the Unisteer setups. But I recently found a Unisteer setup that mounts to the front crossmember via the leaf spring studs instead of the vega mounts. Has anyone tried this? Or think this would work better than the vega mount style?

    http://www.rjays.com/Maval/uni-28-34center-steer-01.htm
     
  2. never tried one, never knew it existed until now

    my first thought is how will will you hook it up to your column? i would think the engine/oil pan/ balancer would get in the way

    my second thought is how will it work? frame mounted racks never seem to work . this has been discussed here many times

    i think i would stick with the tried and true Vega box and let someone else go first on that one

    or maybe i'm all wrong
     
  3. mustang6147
    Joined: Feb 26, 2010
    Posts: 1,847

    mustang6147
    Member
    from Kent, Ohio

    Unisteer is a great product. If they make it, its gotta work and be good.

    While the Co itself, has been in the stock rack rebuild business for many many years, its entrance into the after market, and hot rod market was a result of disgruntled engineers at FLaming River.....

    I have been in the shop many many times. They have lifts with all kinds of hot rods from all years, being fitted with Racks.....

    I cant say enough good about Dave.....He is a car guy!
     
  4. with that short of a rack i don't think you will get a lot of toe change as the axle moves , but you will get some
     

  5. supervert
    Joined: Mar 8, 2009
    Posts: 433

    supervert
    Member

    Bad geometry. To me it don't look like a good choice.
     
  6. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member

    OKAY, lets explain this one more time. If this is a double sided rack that attaches to both spindles, this is a very bad idea because... As the frame and the axle move independantly of each other, the tie rods on the rack move up and down in an arc. At the top of the suspensions travel, and at the bottom of the suspensions travel, the tie rod ends attached to the spindle are closer together than they are at the suspensions mid point, or neutral. In other words, as you go down the road your toe in or out out (if your weird that way) is constantly changing. This is a bad idea at best, and even if you consider minmal suspension movement (And really why would you?) as a mask for bad design to "get away with it" why in hell would do it to simply fight physics?

    Rack and pinion seems to be viewed as a "better" steering system, when in all reality it's simply a "different" steering system better suited to independent front ends.
     
  7. bonechop
    Joined: Apr 19, 2009
    Posts: 29

    bonechop
    Member
    from NW Indiana

    I like the clean look of it, but the center mount one seems questionable especially since i am going to run a flathead. Hoses, pulleys grinding on a steering shaft doesn't make me want to go that way. I was just curious to see opinions off how 2 wheels twisting on a rack would pan out......
     
  8. Blue One
    Joined: Feb 6, 2010
    Posts: 11,459

    Blue One
    ALLIANCE MEMBER
    from Alberta

    Lets place the rack hookup right where the front of the engine will sit. Just a big 700 pound chunk of iron and a radiator and a bunch of other stuff between it and the steering column.

    Seems like a great idea to me :rolleyes:
     
  9. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member


    If it's the physical weight of the wheels being turned that your concerened about, that is sort of a moot point and really wouldn't be a problem, it's the piss poor geometery that would limit the cars use and prevent rack wear in the long run.

    Just to be sure you understand what I wrote earlier, set up with a double sided rack mounted solid to a sprung frame and turning a suspended beam axle, when you jump up and down on the frame and actuate the suspension you can actually see the tires change their toe in to toe out.... I guess you could refer to it as double bump steer if you wish...
     
  10. Here's a "Sweet" center rack on a 32 RPU.
    This car drives like a slot car, no bump steer ! And when I say DRIVE
    I mean drive.
    Made the trip from OK to LARS 2 years ago, almost fell asleep @ the whell it drive so smoooooooth
     

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  11. mustangdug
    Joined: Nov 29, 2007
    Posts: 102

    mustangdug
    Member

    I have the one sided uni-steer on my 29 coupe, works awesome, is cheaper and you wont have as many clearance issues as with that setup. Looks like too much work to make work, also bump steer will play into that setup
     
  12. mustangdug
    Joined: Nov 29, 2007
    Posts: 102

    mustangdug
    Member

    Now that looks good!
     
  13. Like I said ZERO BUMPSTEER !!!!!!!!!!!!!!!!!!!!
     
  14. Bad Daddy
    Joined: Nov 13, 2010
    Posts: 829

    Bad Daddy
    Member

    Those a cool and all, but how do you connect a center rack to your steering column?
     
  15. Jpriebe66
    Joined: Jul 12, 2011
    Posts: 141

    Jpriebe66
    Member

    DA34guy, am I losing my mind, is it an illusion from the photo or is that rack mounted directly to the tube axle? If so then that would solve the geometry changes induced toe changes. A new issue is created as the suspension articulates how do you handle the geometry changed in the steering shaft? You must have some kind of slider arrangement...


    Posted from the TJJ App for iPhone & iPad
     
  16. big vic
    Joined: Jan 3, 2010
    Posts: 400

    big vic
    Member
    from cary il

    Id like to see how the steering shaft gets from the firewall to the rack please
     
  17. gimpyshotrods
    Joined: May 20, 2009
    Posts: 23,263

    gimpyshotrods
    ALLIANCE MEMBER

    Da34guy, what you have IS NOT what the original poster is describing. You have zero bumpsteer because your rack is mounted to the tube. It moves as a whole unit.

    Apples to doughnuts.

    What the original poster is talking about mounts a center steer rack, on the frame, to the u-bolts that retain the leaf spring to the crossmember. This setup WILL have bumpsteer, no doubt about it. Whether or not that is tolerable will be up to total suspension travel, and driver comfort, but it WILL be there.

    The laws of physics are not negotiable.
     
  18. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member


    BUT, that's not what the original poster was talking about. That rack is mounted to the axle, which techinically would be the only "right way" to do this. Then finding a slip joint that woud work without wearing and binding and the extra unsprung weight become your problems.

    What the o/p was talking about was a rack mounted on a frame comtroling a sprung beam axle. Sorry, but you just can't get around physics on this deal. It will change toe as it cycles though it's suspension movement. I would never say you couldn't drive a car like that, but it wouldn't be pleasant trying to keep it going in one dirrection, so why would you do it?
     
  19. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member

    I guess I'm being a bit snarky because this is the third time this week this question has been posed on the board, and the third time I have have given an answer.

    Yes, the Unisteer single sided rack has the same basic geometry as a typical Vega box, but it is flat ugly in an engine compartment, and costs exactly what a Vega box costs brand new.

    A rack DOESN'T improve steering in any way, it's just a different means of producing the same movement. They are currently used in new cars because they are easier (read cheaper) to make function reasonably correctly with current MacPherson strut suspensions than a traditional worm and sector/articulated tie rod box. Correctly matched and mounted to an independent front suspension, they work great.

    My only contact with the Unisteer Product was a customer that brought me a very nicely finished, fresh Model "A" Ford because it "wandered all over the place". The rack was worn so severly that I could rattle the output from the housing by a good 3/16", and this with less than 20,000 miles on the car! I suggested bolting a Vega box to the framerail and making a drag link anf the customer protested that HE had insisted on the Unisteer system "'Cause everybody knows rack and pinion is better...". He is to this day 5 or 6 years later still enjoying his simple Vega box and good steering!
     
  20. Jpriebe66
    Joined: Jul 12, 2011
    Posts: 141

    Jpriebe66
    Member

    I would like to see a pic of A34guys steering shaft, how do you solve the shaft length variations as the suspension travels?


    Posted from the TJJ App for iPhone & iPad
     
  21. WTF

    Sorry to be a stick in the mud, but my experience with Unisteer products has not been positive. Disgruntled FR grunts, maybe. But since they left my FR products improved!

    [​IMG]

    The item in question, crap...

    The reasons have already been stated.
     
  22. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 12,602

    Johnny Gee
    Member
    from Downey, Ca

    Well put, some's up everything we've said thru out the thread.

    Not my cup of tea as far as period correct. But that is well thought out I an effort to rid out bump steer. As needed louvers said, all that's need is a good slip joint. Got any pic's of that?
     
  23. bonechop
    Joined: Apr 19, 2009
    Posts: 29

    bonechop
    Member
    from NW Indiana

    It just comes across to me as a product they tried to re-invent, poorly. why would I want to mount it in the middle with 4 ft long steering shaft and multiple clearance issues, if I could simply use a vega mount? And i could see bump steer being a more notable issue on this design!!

    OK, guess i will look for a '34 ford box.......
     
  24. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member

    Better yet, look for an F-1 or Maybe F-100...
     
  25. Hackerbilt
    Joined: Aug 13, 2001
    Posts: 6,254

    Hackerbilt
    Member

    [​IMG]

    Looks like the rack is maxed out but the tires are hardly turned!
    Is that just the pic angle or what?!?!
     
  26. trollst
    Joined: Jan 27, 2012
    Posts: 2,108

    trollst
    Member

    I love this stuff, entertaining as hell.
     
  27. bonechop
    Joined: Apr 19, 2009
    Posts: 29

    bonechop
    Member
    from NW Indiana

    Yea the F-1 boxes that are going for $400-600 on eBay? Pass!!
     
  28. need louvers ?
    Joined: Nov 20, 2008
    Posts: 12,903

    need louvers ?
    Member

    Not sure why you would go to ebay for one. I find them around all the time and I've paid no more than 100.00 for one. Check the classified here too.

    Thing is, by the time the F-1 was around they had the recirculting ball steering box down pat. They started using them in '37 or so, and the stuff before was just worm and sector... It sucks! An F-100 also works pretty well if you are building a '34, it's a bit bigger and even easier to find than the F-1 boxes.
     
  29. coupeman36
    Joined: Oct 18, 2005
    Posts: 220

    coupeman36
    Member

    I agree 100% with Elpolako!!
     
  30. Sorry to drag up an old one but found it in a search to see what could be done about the Unisteer that came on my 32 when I bought it. No real complaints except turning radius to the right is really big. Suspect there is some sort of centering that needs to take place to split the difference.

    An antidote regarding racks mounted on straight axles. Have a friend with a really trick chassis on his Dearborn Deuce that has a rack mounted on the axle. Although there is not a lot of axle movement there is some and there was enough the the steering shaft to the rack dropped out one day while he was doing 55 mph. He was fortunate to be in the left lane and there were Jersey barriers in the center that the car slid along so minimal damage. He replaced the connection with something used by sprint cars and hasn't had any problems since.
     

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