spoke with him today, he got it fixed, and is now in second place in his class

 

First off all you guys that emailed and called offering help, thank you so much. I ended up discovering that the end links for my rear sway bar used the same rod end. I also expressed extra parts from mcmaster so I would have spares.

The car got back together and made it through the pro finale, and my underdog car even managed a podium finish. I broke another link in the other adjuster this morning. I now see why. The design of these is flawed. I can fix it but not here. I will gave to just keep breaking them and replacing until I get home.

Again thanks for keeping me going out here!

 

congrats on third place man, maybe next year you can beat those pesky little civics so we can have another class being won by rx7s

 

Solo:

don't know if you read my other post. are you running stock toe links or aftermarket, and are you running stock rear lower control arm bushing or spherical (the bushing where the toe bolt goes through)?

 

Stock in both cases

 

Glad to hear you got it sorted - at least long enough to compete. And congrats on a podium finish, great to see an FC running competitively at national level

Will you post more about why you think your camber links broke (pics, etc) when you get home? I'm curious, as it does seem a few are having issues with the mmr links.

 

I broke the bolt going through my mazdatrix links, looking at the cross-section, seems like fatigue took it's toll - starting at the root of one of the threads. I imagine the failure of the MMR rod ends are similar.

 

The problem with all of these designs is that there is a bending moment due to the force of the moving control arm being off the axis of the rod end. This is because the stock camber link is very short, and to remove negative camber, you want to make the rod shorter. Every time the suspension loads and unloads it bends the rod end a little more. Furthermore, all these guys eliminated one of the degrees of freedom from the design by not allowing the upper mount (subframe side) to pivot side to side. If you look at the stock links, they are a pillow ball at both ends. This is because the arm doesn't move perfectly up and down and front to rear - it also torques side to side.

Eventually it is going to snap. The AWR and Mazdatrix adjusters have the same problem. Neither design is better.. they both suck, but I understand why they did what they did.

On my long-*** 19 hour drive back home, I came up with what I think is a solution, but I need to buy some bits and test it out first. And I have too many other things to fix on the car right now to be bothered.

 

would've got a picture of you competing except andy broke something in his tranny and I had to run back to my place to get it for him then head to work.

 

Thanks for the pic! You got the first time all season that I was in the first place grid spot

 

Solo I have a question, I have the MMR links along with the control arm spherical bearings and super now toe rods. I have not had any problems so far and I have ran a couple of autocross sessions but I also noticed what you said and figured at one point or another they will break.
If you could please post or PM me the part that you bought to replace the broken one, a part number will do so I can stock up until someone comes up with a better solution.
If you do I'll buy a pair .
Thanks
Renzo

 

John, I'll go back through all the pics I took, I know I've got a few more.

 

This is the part they use in them:

http://www.mcmaster.com/#heim-joints/=8ut7b4

Or go to mcmaster.com and search for part number 59935K84. Don't forget extra 10mm x 1.5 jam nuts.

It would be plenty strong for this application if the force vector was acting along the axis of the rod end... but because of the design of the adjusters it isn't.

Just to be perfectly clear, the AWR links are even WORSE in this regard! But they use a stronger bolt, so they don't break as quickly.

 

Bump.

Well after breaking two MMR rear camber adjusters at the Solo nationals back in September, a buddy and I teamed up and designed a set of camber adjusters that don't have the same fatal design flaw. The design we came up with retains the stock adjuster's ability to pivot side to side, doesn't put a tiny bolt in shear and adds adjustability.

I'm thinking of having a machine shop make me a few sets. Anyone have any interest? I'm going to send the design out for quoting but for a small run it would likely be about $100 a pair with no profit on my side.

 

I am interested. Check your PM.

 

I'm interested too.

 

definitely interested.

 

Interested pending a little info on design.

 

interested as well, I dont wanna break one at any event

 

Interested.

 

To respond in public to the PM's - I'm not going to post up pictures of the design until I can get them fabricated.

Knowing that the main problem with the AWR style adjusters is that they have no misalignment capability, that is what we solved with the new design.

 

Because I continue to get so many PM's on this..

The issue with the aftermarket individual camber links is that none of the designs out there account for the fact that the trailing arm does not move straight up and down where the camber link mounts. Instead, it travels in an arc, both fore-aft as well as side to side. This side to side arc is key!

Look at the stock Mazda camber link. It's a pillow ball on each end. This allows the trailing arm to arc without stressing the link.

Now look at the AWR adjusters. Their camber link doesn't have any misalignment capability. That huge bolt is constantly being bent back and forth as the suspension moves. Fortunately, it's big, so it doesn't break as often as the MMR adjusters. The MMR adjusters use a cheap and small-diameter rod end which breaks very easily.

Ideally, the solution would be to use a male and female shank rod end pair... but that would be too long.

The solution is to take the AWR style adjuster and where their sleeve mounts to the subframe and trailing arm, replace the sleeve with a pressed-in ball joint.

To finish the design I really need to drop the subframe of my FC and take some detailed measurements, but I'm working on a buddy's Ducati in the garage right now so it'll have to wait a month or so. Unless someone wants to give me a trailing arm to make some measurements...

 

Anything ever some of this? Just snapped an AWR bolt.

 

holy cow! Joe is on this board too!

 

I gave up on the car before I solved the camber link issue.

Bottom line, those individual camber links will always fail eventually. The only real solution is to have spare bolts / rod ends on hand at all times. That's what I did.