XJS Rack & Pinion

Terry1 · #1 (**permalink**) 01-27-2011, 08:39 PM

I have a 90 XJS front suspension assembly that I intend to narrow 4+ inches to get to a 55 inch tread width (The XJS is apparently 59.08 inches). I've tried doing searches on this site to see what others are using for a rack & pinion once they narrow the XJ suspension but haven't found an answer. I've seen a few that appear to have simply threaded the tie rods up a little further and clipped off a couple of inches from each end. ...seems as if that would cause a bump steer problem, right??? So what is everyone using?

Thanks for your help.
TWM

mickmate · #2 (**permalink**) 01-27-2011, 08:58 PM

If you narrow the suspension arms you'll probably want to replace them with tubular. If the tie rods are shortened the same amount and all other pivot points, rack height etc remain the same you should be good. The only problem with shortening the arms and leaving inner pivot points will be more limited suspension travel and maybe an increase in camber change. If you move inner mounting locations you'll need a shorter rack to keep tie rod inner joints lined up with upper and lower pivot points. Do some reading here
http://www.mustangandfords.com/techa.../photo_05.html
Take all your measurements and draw them out in CAD or on squared paper. You'll see how it all works before cutting into anything.

Terry1 · #3 (**permalink**) 01-28-2011, 07:08 AM

Mickmate,
Thanks for your input - I hadn't seen the website you mention in your post. That will be helpful. My plan at the moment is to replicate the pick up points for the stock XJS A arms but on a 4" narrower scratch built subframe. My thought is that it would be easier to align once this is all completed. ....will have coil overs in place of the Jag coils and shocks. All of which leaves me looking for narrower rack & pinion - I think. Regardless, the link to the web site will keep me learning - and playing.
TWM

strictlypersonl · #4 (**permalink**) 01-29-2011, 05:41 AM

Flaming River offers some Mustang-based racks that are shorter than the standard 24.6" (inner pivot-to-pivot).

http://flamingriver.com/index.php/mi...?search=fr1502

mickmate · #5 (**permalink**) 01-29-2011, 09:38 AM

That's what FFR does for pin drive width they just change a-arm lengths. Also done on different race car arms although you see as much variation there with ball joint angle as you do in length due to ride height differences. Flaming River as Bob points out are good for publishing their available inner pivot point lengths.

Three Peaks · #6 (**permalink**) 01-29-2011, 09:47 AM

Flaming River also makes a Cobra Rack as per the originals. That is what I have in my Cobra and it is identical (as far as I can tell) to the originals.

Depending on what you use for front uprights, you may need to use different tie rod ends. I am using Mustang II front spindles and the Mustang Tie rod ends I had weren't the right length to work. After some research, I found that Flaming river makes 3 different lengths of tie rod ends for their rack. I'm sure I don't have the optimal front geometry with this set up, but I'll run it for awhile to see how it works out.

Of course, next year when I install the original style suspension front and back, I'll need to go through this again with the tie rod ends but that is just part of the fun of this hobby.

Bob

Dominik · #7 (**permalink**) 02-11-2011, 05:52 AM

I just don't like the idea of chasing the thread a bit further. You weaken it right where you cut it.

Mark IV · #8 (**permalink**) 02-11-2011, 10:58 AM

Quote:

Originally Posted by Three Peaks

Flaming River also makes a Cobra Rack as per the originals. That is what I have in my Cobra and it is identical (as far as I can tell) to the originals.

Original "Cobra" rack is MGB and they are available from a couple of reproduction sources. Many are made in Argentina!

mickmate · #9 (**permalink**) 02-11-2011, 03:47 PM

Original Cobra rack is Cam Gears, the MGB will work if you shorten the input shaft. I have them available shortened and overhauled ready to install. The Flaming River unit is the FR1512 which is the same dimensions as the MG's with the shortened shaft. They make nice hardware.

Mark IV · #10 (**permalink**) 02-11-2011, 04:24 PM

Quote:

Originally Posted by mickmate

Original Cobra rack is Cam Gears, the MGB will work if you shorten the input shaft. I have them available shortened and overhauled ready to install. The Flaming River unit is the FR1512 which is the same dimensions as the MG's with the shortened shaft. They make nice hardware.

Nick is right but my understanding is Cam Gears was the vendor to MG