I'm not intimately familiar with circle track cars or maintenance. But, I believe most of the parts on those cars to be consumable since they take so much abuse. If a control arm happens to last a full season without getting bent or broken, it might be time to replace it anyways. Street cars generally need their parts to last... well forever. Who wants to have to buy a new set of strut rods every couple of years.

People think circle track parts are great to put on street cars, but I would have to disagree. They are made to be light and cheap so Average Joe can be afford to keep racing. I also see the LCA clevis being sized and designed the way it is as an engineered failure point to prevent season ending damage to the chassis. Great for race cars, not great for street cars where you want parts to deform and hold together, instead of completely break.

 

I am not familiar with 'circle track cars'. It seems the smaller cars ride on pavement and don't weigh much. The larger cars ride on dirt and place the engine back a bunch. Plus, I am not sure how much braking forces they see in a race. Less weight, less traction, less braking means less fatigue. Plus, like posted above, racing replaces many parts and often.

The only cleavis I have seen used were in limiting straps and seat belts. However, I have limited experiance. I don't even like the giant cleavis used in a lot of solid strut rods.

 

You may want to try 15 3/4 mile laps in a 3200lb car on an oval track in the passanger seat with $100 control arms...you may struggle to tell me they don't deal with much force. Nevermind the smoldering brakes and tires so sticky you could toss them up and they would stick to the ceiling. We're talking insane forces being applied in a vicious cycle: hard corner, no load (straights) > HARD brake > Hard corner and repeat...repeat....repeat.

Most people cannot stand after a few laps of trying to hold a car around a track and that's with a neck brace 5+ point harness.

You can get many seasons out of a decent suspension setup, the difference is these cars arn't picking up lunch or going for a cruise. They are worked to the edge every min of every weekend. Take that resiliance and put it in a street car and your looking at many years of enjoyment.


I have never dealt with anywhere near the kind of force on the street as I do in 1 lap on the track. Circle track components are simple in design and fabrication but don't get that confused, they are built for one purpose, to hold up.

 

I can agree on this one. I have never had a suspension failure on the track for any reason other than contact with the wall or another car.

 

eZ how's it holding up?

 

I don't think that strength for the normal racing loads is what's in question here. Obviously they have to be strong enough, stiff enough, and sufficiently resistant to fatigue for that.

More that if you do get tagged at the wheel, or get put into the wall it's better under incidental contact and other "lighter" hits to sacrifice the $100 suspension part and maybe its bracket than to have to replace entire frame sections.

All that said, a clevis still makes me a bit uneasy when the complete loading picture isn't clear. It may not always be loaded in purely tension or compression, and where the two blades join will always be a region of stress intensification, separate from that at the usual threads in the rod that it's connected to.

I don't like the OE strut rod and its bushing arrangement much better. Cylindrical things should not be asked to accommodate rotation that's primarily not about the long axis of whatever runs through them.


FWIW, anybody with any interest in suspension modification that goes beyond installing bolt-ons and calling it done owes it to themself to do at least one NASCAR-style driving experience and take in at least one ride-along with the instructor driving. You can't know what it's like otherwise.


Norm

 

So I can't help myself. I'm thinking of ways to satisfy most concerns about the clevis. I want this to work! Anyway I wanted some coments on an idea. Be nice I'm new to the idea of suspension mods.

Norm I am getting an opportunity to ride shotgun in a race car. It's a fathers day gift. Not tell later in the summer.

The image is of a tie rod end on the LCA. Like the other end of eZ's rod on both sides. With shear support on top and bottom. There appears to be three rod end but that was to show rotational limits.

My worry is this may move the rod to much from the original location 1/2" up.
Thanks

 

Review the whole lower control arm design and tell us what prevents it from twisting. From what I see, it would seem that you could twist it by hand. It can rotate at the inner heim, ball joint and clevis. A lower control arm should never be allowed to twist at will.

The orginal mustang lower control arm is really an A arm when bolted to the strut rod. Adding the clevis makes a hinge. How is that an improvement? Think about the brakes loading and unloading a twisting force on the spindle. How is the cleavis hinge going to act over time?

The fallacy is trying to beef the area destined to break when the flaw is in the design.

I have been checking for an update on EZ's car. I would like to know how it is performing.

 

Still driving! Still hauling ***. Drove it up at CA Speedway road course hoping something would fail so I could make better. But no luck. Everything is bitchin!

 

Awesome eZ! Still planning on doing this conversion...saving up for those darn coilovers

Since this whole clevis thing came up, I've been keeping my eye on aftermarket suspensions to see what they use. I see Ron Morris uses them on the ends of his strut rods.....not saying it is correct though