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post #11 of 15 (permalink) Old 10-22-2007, 06:14 PM
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The steering has been one of my biggest engineering challenge.
To give you the short answer - I do not know if there will be any bump steer, but based on the initial setup geometry it will most likely be very minimal, that will be eliminated through slight adjustments.
There will not be any heat treating. The stock tie rod ends (male ends) will receive a threaded tubular adapter that will thread onto the modified tie rod. Everything will be held in place with jam-nuts. That will allow for alignment adjustments.

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post #12 of 15 (permalink) Old 10-23-2007, 01:30 AM
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Gustav,I can tell from your picture that you are going to have LOTS of really viscous bump steer.
It is absolutely vital to have the center line swivel points of the rack to be in the EXACT centerline of the upper and Lower A arm inner pivot points.
What you are doing has been done dozens of times here inOZ ( R&P conversions can bought as kits for lots different cars here).
The Federal Government has published guidelines to enable steering conversions to be done safely after a lot of resaerch. This a pdf outlining the prinicples involved.
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post #13 of 15 (permalink) Old 10-24-2007, 08:03 PM
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Thank you for your input and the attached article.

This set up is not finished yet.
One of the main issues at hand is a packaging problem. As you well know, two items are not able to be in the same place at the same time. Well, the steering rack is one of those challenges. Afterall, the engine requires oil and the pan has already been shallowed as much as it can be.
The other aspect is that the tie rod and tie rod ends are not the final pieces. The actual pieces will be custom made to fit within the proper geometry.
Just remember - there are many ways to skin the cat.
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post #14 of 15 (permalink) Old 10-25-2007, 07:28 PM
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Hi,Gustav,I'm glad you took that on board,mainly because the Mercedes steering is actually very good,if not superior in feel to the general rack and pinion design. I would hate to think you built in steering faults where none existed before.

The location of the arms doesn't matter,they go up and down constantly anyway.What is important is aforementioned location of the centerline .

If you're alluding to the position the arms from the rack take while cornering,of course the go out of the centerline,that doesn't matter. you spend 99% of the time driving in a forward direction ,not rounding curves. It's when you strike a bump at 50mph and the car decides to steer off in to a tree with no input from you ,is when you realise the mercmad man knows what he's talking about.

It would be easier for you to drop the front axle as an assembly and fabricate your mounts on the floor. Either that or pickup a scrap one from the wreckers and use it as mock up.
Here,in oZ the rack is sometimes mounted ahead of the front crossmember ( as in Mitsubishi L300 van front assemblies which bolted into everything...) .This saves lots of space .
if I were you i would spend plenty of time in wrecking yards measuring Euro and jap cars for their steering racks to see what would fit easiest. i especialy look for power racks too.

Last edited by mercmad6.3; 10-25-2007 at 07:33 PM.
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post #15 of 15 (permalink) Old 10-27-2007, 02:52 AM
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Hey Gustav,
You may be able to find out a bit more about R&P conversions if you try to google for a rotary heckflosse (or finny or finnie). When I was first trying to figure out what to do, a guy called George Attia replied and sent me a link to his photo albums showing how he had put a rotary into a w110 finnie. As part of that, he did a R&P conversion. From memory he used a VW Rabbit (is that a Golf in Australia?) rack. I can't find the link anymore as that computer died, and am in a rush tonight!
See how you go. He took the whole frot end out of the car, put it on a bench, and tried various geometries, and used gauges to measure the bump steer. Seemed to be a very clued on guy. Now if he had some templates, that may be really handy.
Anyhow, have to get cracking!
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