45 replies to this topic

[dattoman]

I must apologize to Retro

They joined the forum and posted up a big reply but I accidentally pushed delete rather than approve and now I can't seem to get the post back

 

They apologized for the incorrect catalogue listing and invited people to discuss it with them 

If they want to reply again I promise to push the right button and approve the post.

[76lxhatch]

Words to me (as the end user) are cheap, and final proof is always in the fit-up and drive. Sounds like Retro might have done things the right way, which I hope gives Torana owners another no grief option. However we need end user feedback before singing the praises.

I disagree with this a bit, to me its just maths. If the numbers are right (measure twice, cut once) then it will work.

Having corrected the initial catalogue info (which was what concerned us, being so far out) and provided real numbers rather than just "it works" statements, its looking like a feasible option. The measurements provided in the email response are good (620mm width, original outer tie rod position). All they need to do is add a measurement as to how close to the original rack mounting position it fits, if that stacks up then I would buy one (if I were in the market).

I never meant to make any un-informed statements about the quality and fitment of the product, all I was stating is the measurements needed to make it work, so that others can make practical decisions.

[A9X]

Words to me (as the end user) are cheap, and final proof is always in the fit-up and drive. Sounds like Retro might have done things the right way, which I hope gives Torana owners another no grief option. However we need end user feedback before singing the praises.

 

The majority of businesses I have found might say they can deliver but imo 90% fail terribly regardless of the initial hype.

 

I agree. 

 

Between the big brake advertiser, the supplier of replacement parts and every shonky guy in between, this torana community can point the finger at dozens of people standing on their soapboxes screaming 'buy my new part, perfect fitment, can't tell the difference, 100% guarantee "

 

but where is the list of successful suppliers?

 

Maybe we need a Forum endorsed thread, members access only 

[BIG KEV]

Top idea ....I would love to see what others have done and what really works .....and shame the ones that don't

[355LX]

 

Looks like in the pic with the tape measure its approximately 610mm between balls centres. 

[Toranamat69]

It is mounted way too far forward and will have shit ackerman angles.

[76lxhatch]

Is that the kit in question? Unfortunately the width measurement alone is a little meaningless with the rack mounted significantly lower than standard. Can't see whether the outer tie rods have been lowered to match, presumably if you wish to purchase one you'd get access to the bump steer curve measurements to double-check everything.

Shame about the Ackermann angle but I guess something has to give if you don't want to cut the cross member and still have maximum clearance.

[axistr]

Wow that input shaft uni is at quite a big angle, as you turn the steering wheel it will give you the slow and speeding up effect due to the excessive angle. Mack trucks in various models have angles simular to this and they have this problem. It feels terrible trying to go through roundabouts.  

 

If I start stating any problems about other systems it appears that my comments are only bias, but all I am doing is trying to do here is help other Torana owners in making an informed decision.  But when I seen the photos I couldn't help but feel that the only benefit in this one is lighter steering and that's it. As mentioned by Matt and 76lxhatch with the rack mounted so far forward and low I can not see how you would ever achieve good steering angles. Even if the inner ball joint centres are close to original they still need to intersect with the upper & lower inner control arm centres.    

[ls2lxhatch]

This picture by 76lxhatch from this thread illustrates axistr's point.

 

 

[ls2lxhatch]

The input shaft probably looks worse than it is because the input shaft is not connected to a column.

 

I also noticed that they have cut a bit off the drivers side engine mount to clear the uni on the rack. The top part of the engine mount bracket with the big hole that the factory rack goes through. The drivers side engine mount usually looks like the passenger side engine mount.

 

 

 

I don't see a problem with trimming the engine mount brackets other than it is no longer original and can't be done with the engine in place.

 

I have trimmed both brackets on my k-frame so I can remove the factory rack without the need to remove the rag coupler from the rack.

 

 

Edited by ls2lxhatch, 13 March 2014 - 11:26 AM.

[axistr]

The photos below are with the Torana suspension at ride height - 1"  around 95% of Torries we see are lowered from standard height, so when I set up the rack kits I tried to keep the rack up so at ride height the tie rod bars would be close to level at the -1" height. Also of concern was that no mater what the inner rack ball joint centres are they must intersect with the line between the top and bottom inner control arm mount pivots in the straight ahead position. The rack being either too high or too low will effect the steering geometry considerably.  Most if any engineers would not pass power steering conversions with cutting of engine mounts without some type of reinforcement.

 

Yes your right Andy on closer inspection I noticed the vice grips holding up the steering shaft giving it an increased look angle. I wonder how they are going to connect the square steering shaft to the small round Torana steering shaft.

 

 

Attached Files

•  rack.jpg   189.88K   9 downloads
•  rack2.jpg   178.4K   9 downloads
•  rack3.jpg   199.17K   7 downloads

[ls2lxhatch]

 I wonder how they are going to connect the square steering shaft to the small round Torana steering shaft.

 

 

The steering shaft is a standard 3/4" DD. There is an optional 3/4" DD to Torana 9/16" cotter pin universal available from Retro Racks.

 

The universal joints used by Retro racks look like they may be Borgeson universal joints. Borgeson make a Torana 9/16" cotter pin universal joint.

 

Borgeson made the Torana 9/16" cotter pin to 3/4-36 splined shaft vibration damping universal joint I have on my stock rack in the picture above.

Edited by ls2lxhatch, 13 March 2014 - 09:46 PM.

[ls2lxhatch]

The taper in the steering arm means that the standard tie rod can only enter from the top.

 

You could probably machine the steering arm to accept a stud and use a rod end.

[76lxhatch]

Just bear in mind that if you start doing that sort of thing you have to start your steering calculations all over again as it is a massive movement in terms of bump steer. If you lower the outer joint you'll need to lower the inner joint a suitable distance to match, the spacing of the inner joints will need to be narrower and the tie rod longer.

[axistr]

The inner rack and tie rod ends still need to be equal distance (height horizontally) from the lower control arm ball joint and the inner control arm mount this angle/height difference is where the bump steer issues start. 

[76lxhatch]

Sure, a new steering arm. Problem is brake clearance if they're front mounted, I think you'll find that pointing the tie rod stud downward places the actual pivot with less material above it than pointing it upward would (although at least there would be no moving parts). If you're doing it to improve clearance then the whole rack needs to be moved (and potentially shortened or changed).

[axistr]

Hi Liam it's hard to explain bump steer, some get it and some don't. I get asked this question on a regular basis and its hard to explain in writing, so I have added a few photos to help those that do not completely understand steering geometry & bump steer. 

 

In the top photo the red lines shows the centre line between the top & bottom inner control arm pivots.

The steering rack inner tie rod end ball centres need to be as close as possible inline with the red centre line when in the straight ahead position on both sides. You cant see the steering rack inner ball centres in the photo due to the rack cover boots so the second photo shows the inner rack tie rod ball centre uncovered, this should give you a clearer picture. 

 

Now try to imagine if you move the rack up or down from the original mounting position the steering rack inner ball centres need to have a longer overall distance if raised and a shorter overall distance if lowered. I have extended the red lines to show if the rack is lowered the spacing on the rack ball centres will need to be quite a bit shorter. It doesn't need much moving up or down from the original position to stuff up this correct alignment. If you lowered it buy around 2 1/2"  you would need to have the overall rack ball centres some where around 15-20 mm shorter. But this is only one part of the problem.

 

Now look at the last picture, I have put a few lines on the photo to show the relationship between the inner rack ball joint centres and the outer tie rod end ball centres. The horizontal blue lines are the lower control arm ball joint centre and the lower inner control arm bolt centre (pivot). The inner rack ball centre to the inner control arm pivot marked red in the photo needs to have the same vertical height distance as the outer tie rod ball centre to the lower control arm ball joint centre.

 

Now If you drive the car down the road and hit a bump or change direction quickly there will be no or very little change in wheel alignment geometry. Now keep in mind that the Torana wasn't perfect from factory but generally bump steer wasn't a major issue, the problem is when someone stuffs around with them and interchanges miss matched parts.

 

This is the hard one to explain in writing. As the vehicles suspension goes through its up or down travel the difference in these angles or heights will cause the alignment toe to change. The tie rod bars arc must match the arc of the outer ball joints arc from the ride height horizontal position. If the rate of change between the to angles differentiate toe change occurs. If change occurs the toe will either toe in or out by the amount of misalignment. 

 

The reason you need to use A9X steering arms when you change to HQ stubs is to correct the angle/ height difference back to same height as the inner rack & inner pivot points.

 

The perfect set up would be to have the rack inner ball centre inline with the inner pivot centre and the outer tie rod end ball centre inline with the lower ball joint centre but due to GMH design makes it extremely hard to achieve in the car. 

 

If you lower a standard length rack height by lets say 2" and the outer tie rod 3" to try and compensate I would estimate you would have in excess of 12mm per side of toe in change, so depending on how big the bump or how much suspension roll or combine them together plus the opposite sides change you could end up with 20mm change easy, its like moving the steering wheel  one1/4 of a turn and that's not what you want going through corner, it could automatically steer you a 1/4 of a turn towards on coming traffic or a tree.

 

So that's why we call it bump steer, you hit a bump and it briefly steers itself, you correct it or over correct it either way its not a good thing to have in a car.  What I have described is only part of the big picture, camber change & steering arms plays a big part also with toe in or out on turn but it the rack position and tie rod bar heights relationship as I have explained would be the major contributing factor.

 

Lenny.

 

  

 

 

 

 

Attached Files

•  bump steer 3.jpg   263.28K   14 downloads
•  bump steer 2.jpg   330.22K   12 downloads
•  bump steer pic.jpg   207.85K   10 downloads