Steel angles bending

jpr

Well-Known Member
Hey gang,

After ~1500 miles and about 3 autocrosses, I noticed one of the steel angles on the bottom of the passenger side steering knuckle was maybe 15 degrees bent from where it should be (as pictured). The bottom of the driver side was maybe 1/3 as bad, but still visibly bent. The tops were fine.

Not sure why this is happening, but figured I would warn everyone and see if maybe there is a workaround for this. Anyone seen this before? And if so any fixes? I searched the forum and haven't seen posts on the topic - and I sure don't drive as hard as some here - so curious what's different about my case...

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jpr

Well-Known Member
BUT - I'm not sure that it's a question of traction. This bend angle would happen to the inside tire in a turn, where the outside tire bears the vast majority of the torque here. I think if I was over-cornering it would bend toward the outside of the turn, no? Maybe I'm not picturing the forces correctly.
 

Briann1177

Goblin Guru
I'm not sure anybody has bent those things. That's one of the things that I didn't even know you could bend. :) It looks like the force came from the side. The front end is so light that I don't think it could have come from the up/down direction like if you hit a huge pot hole or something like that.

Not implying anything here, but I could see that happening if you one was doing donuts and slammed the tire into a curb or took a sledge hammer and smacked the crap out of the bottom of the wheel. Since you probably didn't do either one of those, my vote is it's probably a traction issue.

What tire sizes are you running up front again?
 

Ross

Goblin Guru
BUT - I'm not sure that it's a question of traction. This bend angle would happen to the inside tire in a turn, where the outside tire bears the vast majority of the torque here. I think if I was over-cornering it would bend toward the outside of the turn, no? Maybe I'm not picturing the forces correctly.
I agree with your assessment, it would be the unweighted inside tire... not sure what would cause this. You let your 18 year old son take it curb hopping? Your autocross course has the dirt dug out on the inside of the corners, and you like to hook the sidewall on the inside tire, and rail it around the corners? lol.
 
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jpr

Well-Known Member
I agree with your assessment, it would be the unweighted inside tire... not sure what would cause this. You let your 18 year old son take it curb hopping?
Ha, I'm not nearly old enough to have an 18 year old. The only (two) other people I've let drive it are the type to fess up to their mistakes, though.

My current working hypothesis is that my front shocks are set too tight and this is just the result of running high speed over too many bumps.

I think re-making the brackets from 1/4" stock would solve the problem. Gotta see if I can find a machine shop to do that for me.
 

Torchandregdoc

Goblin Guru
Can you weld a gusset to each side of that bracket? The cost would be just an oz. or 2 of unsprung weight. It would be nearly bullet proof then.
 

jpr

Well-Known Member
Yep, that's another option... still would need a new set of brackets made though.
 

DCMoney

Goblin Guru
I wouldn't stiffen it up, just replace with the same part. Consider it sacrificial. Better the bracket fail than the upright. Stiffing it up will just transfer those loads into something not as cheap to fix or replace when/if it happens again.
 

jpr

Well-Known Member
I wouldn't stiffen it up, just replace with the same part. Consider it sacrificial. Better the bracket fail than the upright. Stiffing it up will just transfer those loads into something not as cheap to fix or replace when/if it happens again.
That thought was admittedly in the back of my head. I am having some trouble understanding why these parts failed after so few miles, though.
 

ctuinstra

Goblin Guru
I agree hitting a large bump in the road with the compression set "high" could very well cause this. Again, I would not try to change the design as you would want that to bend before the uprights break. They are easy to replace and not dangerous if they do bend (and you realize it) as opposed to an upright breaking and your out of control.
 

JSATX

Goblin Guru
Whoa, that’s a little worrisome. I have the old billet style, seems like a better solution.
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