Another MG rack thread

Hoghead

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570
My mind is boggling over the Spridget rack conversion threads and it would be nice to have a definitive thread on this conversion with the improvements learned over the years:

Moss sells 3 different racks - which one or does it matter since we are changing the threaded ends?

MGB arms mounted reversed R and L, upside down..............?

2 Alpine LH tie rod ends?
Mounted on top or bottom of the steering arms?

Alpine tie rod end VS heim type rod end and stud?

Lower the tie rod ends using a lowering stud and standard rod ends?
http://www.speedwaymotors.com/Adjustable-Tie-Rod-Adapter-Stud-to-Heim,3333.html

Any additional mods to correct bump steer when the car is lowered.
 

steven

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875
I was going down the midget path, however the Mazda Miata MX5 path seemed the way to go, We are almost there and will post piccies in a couple of weeks when we get back from Korea and Japan. We also have the dual brake caliper system being fitted. The pump is coming from a nissan patrol 4wd
 

mwood

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175
The Miata PS solution sure sounds interesting. Is there some form of write up on it anywhere on the internetz?

I know Tom Hall is also working on an electric PS conversion for the stock rack, which mounts underdash on the steering shaft.
 

66TigerMK1A

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1,129
I created a Mazda power rack setup back in 2009 after seeing a setup on a race car...I used a Toyota MR2 electric pump to power it and a couple years later added a vehicle speed controlled variable speed setup to it. I've sent a ton of emails over the years to 'inquiring minds' but never did a 'formal' writeup . Mal Graham put one in his car in NZ a couple years ago and I gave him some 'tech support' for that install... I have a few pics in one of my albums http://catmbr.org/VB_forum/album.php?albumid=7 Other than a few 'extra' holes here and there, nothing was done to the car that can't be 'undone' ;)

Jim Ovens in the UK has been making a 'power column' for several years and it's very 'stealthy' . He uses a Vauxhall Corsa c EPAS unit and grafts some parts of an Alpine column to it and you'd never know it was there after installation. The upper part of the column functions as a stock one with telescoping wheel and turn signal etc. Here's a couple pics of that...
 

Tiger tamer

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318
I will post up some pictures and info on what I have done. I will say now it was well worth the effort.

Mal
 

Hoghead

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570


That explains it well and also why the Spidget conversion is not the panacea to the problem.
Clearly a new column will not help, but do the other steering rack solutions solve the Ackerman problem?

I do not see the new crossmember design he discusses?

I only wish there was a more affordable crossmember available, or that I am a better welder!
 

Tiger tamer

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Messages
318
I have tried two different set ups. The first was mounting the Mazda rack to the original X beam with modified mounts, stock spindles and hemi rod ends as tie rod ends and MGB steering arms.
I needed to use hemi rod ends as they positioned the tie rod ( Tie rods being the arm that links the rack to the tie rod ends, explained as they seem to get called different things depending on where you live) centres closer to the steering arm which reduced bump steer. I could space them with washers until I was happy I had them in the correct position and then had spacers machined up. The car drove well and had no sign of bump steer.
The only thing I was not happy about was I could only get 12mm hemi rod ends and I felt they were a bit light for a Tiger. I would have been happier with 14mm.

I had been in contact with Jim when I was doing the conversion. He had the difference of using Minx spindles on his car. He took some measurements of what his set up would be using the Minx spindles and Tie rod ends and thought the set up positioned the height of the tie rods close to where I had them with the hemi rod ends and Tiger spindles.
The Minx spindles raise the mounting point of the steering arms which allow the use off using tie rod ends. Yes this is more about bump steer.

My original X member was not in the best condition and had been repaired cracked again so I picked up another from a Series V Minx and modified that for the rack. These X beams are all the same in the series Minx and super minx I was told and the SV measured up the same except it hadn't sagged.
I made a jig so I could raise and lower the rack and measure bump steer with Alpine tie rod ends and Minx spindles. Once happy I made mounts to suit.




I made up some bump steer bars to measure the toe deviation through suspension travel.

The end result is the car drives like a dream. Power steering makes around town driving a pleasure. My idea is to get the car easy for myself and wife to drive. My original rack was well worn and the extra amount of muscle needed with a midget rack would not have made my wife happy to drive it.

As for the Ackerman angle issue it helps a bit. I don't get scuffing of the tyres on full lock but that could be the turning circle has been increased a little from using the longer MGB arms. But then my way of thinking is you never try and turn a Tiger with stock steering on full lock anyway so I have lost nothing.
The Ackerman angle is only really a problem when turning on full lock anyway.


I would have put up more pics but I am a bit computer wounded at the moment. Most pics are on another computer which has packed a sad , I could post more on the weekend if needed.
 

Hoghead

Gold forum user
Messages
570
I was going down the midget path, however the Mazda Miata MX5 path seemed the way to go, We are almost there and will post piccies in a couple of weeks when we get back from Korea and Japan. We also have the dual brake caliper system being fitted. The pump is coming from a nissan patrol 4wd

Looking forward to seeing how you mounted this
 

michael-king

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CAT Member
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4,132
. We also have the dual brake caliper system being fitted. The pump is coming from a nissan patrol 4wd

Steven, do you mean dual master cylinder setup... or you are going to run 2 callipers on each disc?
 
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