J-car rack and pinion

Discussion in 'Classic Mustang Specific Tech' started by 71vert-pga, Jul 4, 2004.


  1. 71vert-pga

    71vert-pga New Member

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    I picked up a rack assembly at the local bone-yard from a '92 Cavalier this afternoon. Measurements are...

    Length - 33 ½ inches from end to end.
    Travel - 6 1/8 inches
    Turns - 2.9 lock to lock

    I thought the Taurus setup on Chepie was slick but I believe the travel is only about 5 ½ inches and I don’t want to give up any more turning radius than necessary. I think the original is just over 6 ½ inches so I'll still lose a little but not much. Overall, the j-car looks to be the easiest adaptation.

    I’ve read all the old threads and understand there are some concerns about the Cavalier’s strength under real “performance conditions” but this will never see anything close to that. I occasionally drive it to work (about a mile and a half round trip) and for short trips around town.

    I know it’s an old story but does anyone have any thoughts on this?
     
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  2. Ronstang

    Ronstang New Member

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    I have been there and done that about 7 years ago. The J-car rack was the one I settled on as an option back in 1996-7 or so long before I even had access to the internet or had seen any other options for a R&P in an early Mustang. I spent quite a lot of time doing R&D trying to make this rack work to my standards and I finally gave up because I was not willing to make some of the compromises necessary to get the rack to work. Good luck.
     
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  3. 71vert-pga

    71vert-pga New Member

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    Really! What sort of compromises outside of the turning radius?

    It appears that this is basically the same setup as randall and SpeedDirect. Even the TCP setup is very similar (at least it seems to be).
     
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  4. Ronstang

    Ronstang New Member

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    It is the same rack as Randall's and SpeedDirect....both of which I would not use. The travel of the centerlink in an early Mustang is a little over 7 inches if I remember correctly and you are going to lose a lot more turning radius than you think. Take more accurate measurements and make a set of temporary steering stops to mimic the travel of the rack and go drive your car and see if you can deal with it....I could not. I came up with some solutions to the travel issue but they all involve heavily machined parts and safety became something I started to question.

    I also don't like the fact that all the force of the steering goes through 2 bolts about 3 inches apart in the center, regardless of what anyone claims there is going to be some deflection there and that worries me. There is going to be issues of header fit and Randall got aroung that through machining the center section to let his block come off the opposite side of normal....compare the pics for yourself.

    Like I said, I did a lot of R&D on this rack many years ago and I would have had a setup similar to Randall's long before his was available but I am not willing to have the ind of compromises that rack requires in my vehicle. I am very picky and I will be pursuing an idea for a rack that I had at the same time that I can pull off now because I have access to a full machine shop. If I can find a rear steer rack with the right amount of travel I should have no problem getting the rack to work to my liking.
     
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  5. 71vert-pga

    71vert-pga New Member

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    I’ll measure again tomorrow. The temporary stops sound like a good idea. I’ll let you know what happens.

    If you look at SpeedDirect’s corvette application you’ll see it’s exactly the same as the mustang setup that is yet to be released. It’s the same j-car rack that I picked up earlier today.

    http://www.speeddirect.com/downloads/articles/Steeroids_Corvette_6261_eprint.pdf

    I want the car to be something my wife and I can drive safely and comfortably (actually I bought it for her). It won’t be doing any hard driving. Just some light weekend cruising for the most part. But I do want it to be solid and dependable.
     
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  6. brianj5600

    brianj5600 Active Member

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  7. 71vert-pga

    71vert-pga New Member

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    Looks like that would solve the turning radius issues. The bumpsteer is something I’ll have to evaluate down the road.
     
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  8. Ronstang

    Ronstang New Member

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    That is exactly where I got 7 years ago with the J-car rack. I looked into this product and it would have solved the turning radius issues if you use a Granada spindle. I still have other misgivings about this rack though.
     
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  9. 71vert-pga

    71vert-pga New Member

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    Stock travel = Exactly 6 1/2 inches.

    OK.

    I put it up on stands and attached a blumbob to the center-link. From lock to lock the travel on my ’71 is exactly 6 ½ inches. So the j-car rack at 6 1/8 is only 3/8 inch short of the stock movement.

    I think that’s within acceptable limits. Increase in turning radius should be very minimal, perhaps not even noticeable.

    I have stock manifolds and plan to keep it that way. I know that’s not for everyone but it looks like this setup will serve my purposes. Of course the Cavalier and Intrepid are smaller and lighter vehicles but I haven’t heard of any catastrophic failures of the rack in any stock or performance applications (original or stang/vette conversions).

    I installed Granada spindles back around January with new rotors, bearings, and calipers. Also put in a new ’71 m/c and booster and swapped out the entire pedal assembly from an original power disk car. Works fantastic (at least compared to the manual drums) and I believe r&p is the next logical step.
     
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  10. streetmod

    streetmod New Member

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    j-car rack

    I have a power rack from a cavalier under my work bench but I'm working my way from the back of the car to the front. Personally, I wouldn't be concerned about the r&p being unsafe, they come from a front wheel drive car which is very nose heavy and they were also engineered to handle the engine's v-6 torque steer. I would channel my efforts towards (1) a safe center link and mounting design and (2) proper bump steer characteristics.
     
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  11. 71vert-pga

    71vert-pga New Member

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    The j-car rack does look sturdy enough. If a new center-link is fabricated that’s the same length as the original piece, all we should need to do is mount it in the stock location and attach the existing inner tie-rods (or create a new tie-rod assembly the same length as the old ones). That would still leave all of the standard adjustments to compensate for minor changes in the placement from one model year to the next.

    That would seem to be the easiest way to do this without altering the original geometry. Bump-steer should be no more or less than the factory setup.

    Agreed?
     

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  12. chepsk8

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    Good thread!

    The J-car rack was going to be my second choice if I could not make the Taurus set-up work. I am curious about the routing of the input shaft, and the hardware used. If I ever build another Mustang, I will look at this type of steering. I want something that keeps the steering input shaft as far away from the motor as possible. As with the Taurus set-up, I was willing to sacrifice some steering circle increase, as it made the car much less "twitchy" on the highway, and a very happy high-speed cruiser.

    My thoughts!
     
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  13. 71vert-pga

    71vert-pga New Member

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    Randall's response

    I wrote to Randallsrack on Friday. This is his reply...

    "Sorry, we have no plans for 71 and up. There is just to small a market to make them for those years. Thanks for the mail. Randall"

    I don't see anyone else producing anything "specifically" for 71-73 but I know the TCP setup can be adapted with some minor changes (I've seen some of those). This really doesn’t look to be that difficult. And it’s certainly not too far a stretch from a ’70 setup which everyone makes.

    Hope SpeedDirect notices this part of the market.
     
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  14. chepsk8

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    Remember that the 71-73 used the vastly superior Saginaw Steering box, with no external ram, cylinders, or the other parts. All the assist was in the box itself. R&P is not really needed for them, hence no product development.

    Just a thought, what about adapting this box into the classics?
     
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  15. 71vert-pga

    71vert-pga New Member

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    The Saginaw box was a lot better at the time but it still needs much improvement. My everyday work car is a ’97 Taurus and I want my Mustang to have the same precise steering response and road feel that it has. I think that’s a reasonable expectation (or desire) from all of us. The Taurus GL is no sports car but it would drive circles around a stock or semi-stock classic. I'm only referring to steering and suspension, not acceleration.

    Streetgrande69 has an image of a center-link on his website that brings the tie-rods to the back of the rack without any machining such as Randall did. This would/could still use the original tie-rods.

    http://www.trinitysmustangs.com/images/duane7.jpg

    What does everyone think of this?
     
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  16. 71vert-pga

    71vert-pga New Member

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    Saginaw box

    I read somewhere that there were major clearance problems when trying to adapt the Saginaw box to '70 and earlier cars. If someone wanted to try this I believe there was a quick-steer option in the 'vette that used the same box. Some of the internals could be swapped (still requires some modification) but I don't know of anyone who has done this.

    Still think r&p is a FAR BETTER way to go for a driver.

    * Looking forward to the return of Chepie, at least in some incarnation!
     
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  17. bnickel

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    randalls rack can modify the original center link so you can use the original tie-rods, you might look into trying something like that on the 71
     
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  18. streetmod

    streetmod New Member

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    J rack

    One of the reasons I like the beretta-cavalier r&p idea is the ability to utilize a center link with the rack unit. Chepsk8 brought up the issue about motor/exhaust clearance and this approach allows the possibility of conveniently mounting the rack out of the way, "off center" with the steering link still centered in the car. I just changed the inner tie rods on my 98 taurus and the same idea could be applied to that style also. I've seen that type of unit made up (can't remember where) and the center link resembled an anti sway bar in shape, with the ends of the link attached to the threaded ends of the taurus rack. Either rack allows for proper spacing of the inner tie rod pivots which saves us from bad bump steer. I also believe that a half shaft will have to be used in either case to tie the steering shaft into the rack.
    Obviously, the exhaust and engine will have to be in place during the designing and fit-up and the car should be fully assembled with the weight on the wheels so that measurements can be made with the spindles and LCAs at their ride height.
    I just wish I had a lift in the garage!
     
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  19. 71vert-pga

    71vert-pga New Member

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    Don't know about the earlier models but I have 32 inches between the frame rails in the vicinity of the current linkage.

    The crossmember for the 71-73 models seems to be an integral part of the frame and not a bolt-in unit and I don't want to mess with it if at all possible. I may have to mount the rack farther back than originally planned and attach the tie-rods forward. If so I'll really have to work with the linkage from the rack to the steering column.

    It's a good thing I said I want to stay with stock manifolds!
     
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  20. bnickel

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    71, you might want to pm another member "jikelly" he has a big body vert and is working on a rack conversion as well, another good resource is dark horse racing, here is a link to their install of a tcp rack in their 71 race car. they did remove the crossmember but they tell you how they did it as well.

    http://www.darkhorseracing.net/rack_and_braces.htm
     
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