Steering rack query GTD

Simon · 07-10-07, 03:45 AM

I think it's well documented on this site that the GTD chassis benefits from having the steering rack raised a tad to reduce the effects of bumpsteer.
My query is, the rack is then brought much closer to the "X" brace in the front bulkhead (see pic) would it be better/possible/advisable to have packer made that instead of being flat, was wedge shaped, giving a few degrees of tilt to the steering rack and so bring the steering joint back to somewhere near its original position in relation to the stiffeners?
If wedges were used it would still keep the centreline of the rack in the same position, but may move it rearward by a mm or two.
Can anyone see any problems? we are talking about only a VERY slight tilt rearward here, I would guess no more than say five degrees?
Any advice much appreciated.
Simon

Simon · 07-10-07, 03:47 AM

oops, forgot the pics

Malcolm · 07-10-07, 08:15 AM

The problem bolt will be the passenger side rear bolt (on a UK car). The rest are as accessible as before. My only concern with a wedge plate system is that you will need to have a matching wedge under the existing platform so that the nut sits properly. You do not want the nut or the bolt head at an angle to the bracketry. You may also find the steering column shafts do not reach if you start to tilt the rack. Can be overcome but is it worth it for what you are trying to achieve.

My rack is raised by 3/8th inch. The ideal for standard GTD suspension setups was calculated as 7/16th inch. However when I had standard suspension components this 3/8 was fine. You will not get a perfect bump steer solution though as the rack is too long but this trick does help noticeably.

One other thing to do when installing these risers is to make them so that the sideways support is tighter than the standard chassis makes it. If the rack bolts are not properly tight you can possibly see your steering wheel not centering as previously and this can be due to a rack moving in its mounts. Not good.