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PostPosted: February 21, 2010, 5:34 am 
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Starting with this thread: http://www.locostusa.com/forums/viewtopic.php?f=5&t=5992&hilit=miata+bump+steer

I just found myself in a very similar situation. I'm using a circle track rack and the plan was to use Chevy tie rod ends with 5/8 tubes. Well testing the suspension and having one of the tie rods get cross threaded and buggered up I found I have a problem. The tie rod ends were limiting the suspension prior to full droop not a good thing.

Looking for a cheap and effective way of fixing bump steer and the suspension bind I bought some more circle track stuff. 5/8 hemis with bump steer studs. They have a taper on one end and allow for adjustments to bump steer.
Image

So I purchased this hoping it would fix the suspension limit issue and found that it did not. The problem is the miata steering arm is at an angle, 7 or 8 degrees. This means the hemi joint is at maximum deviation just at ride height.
Image

I found this image Image on this thread. http://www.locostusa.com/forums/viewtopic.php?f=5&t=6860&p=68488&hilit=miata+bump+steer#p68488 and it looks like blue devil just used a high misalignment hemi. Looks like a McMasters 6960T31 hemi to be exact which has 64 degrees of ball swivel versus the stand 12 +/-. Also more on the hemi joints from this thread. http://www.locostusa.com/forums/viewtopic.php?f=5&t=4894&start=0

I was playing around with making an adapter to correct the single with something like this: Image

but came across this thread:http://www.locostusa.com/forums/viewtopic.php?f=36&t=4322 Mazda powered bugeye sprite. Bugeyebug posts
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We did have to modify the miata spindles a bit more, however. Besides reaming out the upper piece to accept the larger ball joint, we had to tweak the steering arms a bit to better align with the steering rack. We basically heated up the arm and then took a large wrench and nudged it up into alignment. Let it cool down slowly and its good to go. Nice forged miata spindles let you get away with stuff like this

Image

So my question is do I A:just buy High Miss Alignment Rod ends, B: Make an adapter to correct the spindal or C: Heat and twist the spindle to make it work?

evo

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Last edited by evo626 on February 22, 2010, 3:23 pm, edited 1 time in total.

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PostPosted: February 21, 2010, 11:33 am 
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I'm not qualified to analyze some of those proposals. They all involve some pretty intensive home-brew alternations to a critical system.

What I ended up doing was to use another Mazda tie rod end (off a 323, I think) with a more conventional layout than the Miata's. I ran a taper from the top, like you did. This proved to give all the clearance needed to clear the lower A-arm. I then tweaked the rack location for bump steer.

I'm not qualified to professionally analyze my solution either. However, it is very close to a factory installation -- no adapters, no metallurgical changes, very little deviation from stock. Works for me.

I detailed my solution here: http://www.locostusa.com/forums/viewtop ... 0&start=60

-dave "FWIW" hempy

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PostPosted: February 21, 2010, 11:38 am 
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I think it's probably OK. My cortina uprights had an extension welded on them for the lower ball joint.

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PostPosted: February 21, 2010, 12:01 pm 
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C: heat and twist.

I've done it to many spindles from '30s Ford stuff, to '60s Chevy truck spindles, to Miata parts just like you're working on.


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PostPosted: February 21, 2010, 12:08 pm 
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heat and twist,, yes i have done many also.
if your in doubt , take a spare spindle an try it,, then put it in a vice an put a long pipe on the steering arm, see if you can break it or bend it.
trick is to let the part cool very slowly after you modify it.


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PostPosted: February 21, 2010, 6:12 pm 
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+3 for heat and twist. Done it many times also on 40-48 Ford spindles to drop the steering arms. Works fine on forged pieces like that spindle. Use a rosebud tip to heat until cherry red, use a big wrench to move it to the desired angle, cool slowly.

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PostPosted: February 21, 2010, 6:44 pm 
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MustangSix wrote:
+3 for heat and twist. Done it many times also on 40-48 Ford spindles to drop the steering arms. Works fine on forged pieces like that spindle. Use a rosebud tip to heat until cherry red, use a big wrench to move it to the desired angle, cool slowly.


What is the best way of cooling it? I have heard of using sand, just letting it air cool, using ash or keeping heat on it but slowly reducing temps until it gets cooler.

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PostPosted: February 21, 2010, 6:45 pm 
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Just let it air cool.

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PostPosted: February 22, 2010, 11:39 pm 
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Well that worked out super well. Once it got hot it was pretty easy to bend.
After:
Image

Before:
Image

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PostPosted: February 24, 2010, 6:36 pm 
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So why not just use the oem tie rod and make the tie rod arm to suit?.I'm sure in the end it would be lighter than that bunch of parts.


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PostPosted: February 25, 2010, 12:21 am 
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L8 apexr wrote:
So why not just use the oem tie rod and make the tie rod arm to suit?.I'm sure in the end it would be lighter than that bunch of parts.


Because I inverted the tie rod point to be on the top instead of the bottom to adjust for bump steer. The bump steer stud and hemi dont weight much more and its adjustable. See DHempy's thread for why. Plus circle track parts are very cheap and easy to find.

evo

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PostPosted: February 26, 2010, 4:04 pm 
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a bit suprised to see my picture in here, but i never did think of the heat and bend. I will have to do that next time im working on the front suspension. It will help to put everything in line also. Thanks!

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PostPosted: February 26, 2010, 4:32 pm 
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Remember, putting the steering arm inline with the ball joints removes ackerman. The rack can be moved forward or rearward from being inline with the outer tie rod ends to add ackerman or even anti-ackerman!!
Playing with Wishbone will show the possibilities.

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PostPosted: November 21, 2016, 3:06 pm 
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Anyone tried to heat and bend the steering arms using just a hand held propane torch?? Will this get me enough heat?

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PostPosted: November 21, 2016, 3:33 pm 
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Doubtful! MAPP Gas might do it, but even that is 'iffy'!

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