Reinforced FLCAs

[Longfellow]

Saw these on freshalloy. Any thoughts about this being effective or just something that adds useless weight? Simple enough to replicate.

Pics

[a_ahmed]

lol when I saw the thread topic I thought of these too... well... not that my opinion counts but, it does make sense imo... otherwise its just a U profiled piece of metal... I can see the center twisting under stress, but then again I dunno how much that would actually happen...

SPL's are square..

[jmauld]

I've been curious about this as well. If you're really concerned about weight, couldn't you effectively drill away a good bit of the "brace" and still get the benefit of it? I wouldn't expect that it would take a lot of metal to keep the arms from flexing.

[Longfellow]

1/8inch plate steel would work well. I'll do it over the weekend just for the hell of it. I'll drill some holes in it like you suggest as well.

[racepar1]

1/8" is way thicker than it needs to be. I plan on just using some thick sheet metal (1/16" or so) as all that needs to happen is weld in a piece of metal to hold tension on the arm and prevent it from spreading or compressing. 1/16" thick sheet metal is plenty strong enough to do that and won't add very much weight to the arms. If you are really worried about making it strong just use the 1/16" sheet metal and put plates on the ends too and fill the arm with structural foam. 1/8" plate is way overkill.

[Longfellow]

1/8" is way thicker than it needs to be. I plan on just using some thick sheet metal (1/16" or so) as all that needs to happen is weld in a piece of metal to hold tension on the arm and prevent it from spreading or compressing. 1/16" thick sheet metal is plenty strong enough to do that and won't add very much weight to the arms. If you are really worried about making it strong just use the 1/16" sheet metal and put plates on the ends too and fill the arm with structural foam. 1/8" plate is way overkill.

Good point. I was thinking 1/8 was close to 14 gauge for some reason and its no where near that thin (work sucks and I'm tired lol). I'll have to see what I have laying around the garage.

[2Fass240us]

Yeah, 1/8" is far too thick. I think, to Jason's point, you could use dimple steel like what's used in rollcages.

How many of these have ever broken? The only time I've had a problem with them was when I had to press out the old bushings and the new ones in. A split sleeve later (to temporarily reinforce it for pressing), and it was done.

Those look exactly like ones that a guy on CarolinaNissans was advertising. He was asking something like $80 plus cores plus it doesn't include new balljoints. Oh, and the welds look like poo.

[jmauld]

I was thinking the same thing about the thickness, but don't know enouigh about that to comment.

I would guess that 1/16" would be fine.

[jmauld]

These braces might also help, if you were to ever get the crack along the holes for the T/C rod.

[Longfellow]

I figured it would help some under heavy brakeing. I would think there is quite a bit of stress on the arm, cant hurt either way.

[cazman]

This has been covered many times before, maybe not here though
Doing this makes the arm more prone to break at the ball joint end and the bush end.
The only way to see proper benifit of doing this it to brace the bush amd ball joint section, where as this does not.
There are pictures of peoples arms that have broken because of this, the section they boxed is strong as, clearly, but it made the bush end weaker and I have seen them break, and saying this, when was the last time you saw a factory arm break? 9I can draw a pic)

Yes I would do it to my own car (I cant, alloy arms everywhere) I can see the benifits of this, but on the street you are just more prone to bending subframes.

And we all know how weak the rear pickup points are, i def wouldnt do this without reinforcing the subrame a bit.

[Umai Kakudo]

+1 for cazman - All the factory control arms are made to bend but not snap in half during an impact which includes the front LCA. Same goes for the TC rod boxes and the rear control arms.

Here is an example (Note - this is damage from a rear end collision which illustrates what happens to the factory arms (including the FLCA) when they take a big impact):


If you start reinforcing them and end up hitting a curb (or anther car racing wheel to wheel or whatever) more expensive or critical suspension bits will start breaking and not just bending as designed by the factory making a collision end up worse possibly.

If it is a track only car or you are willing to take the risk of damaging subframes or the unibody then go banzi and reinforce the crap out of it.

A ~16 ga. steel with dimple die cutouts would likely be the best at adding rigidity with minimal weight.

[Longfellow]

Im only talking about the front lower control arm.

All my rear upper arms are from SPL so Im not worried about breaking those. Though one of my SPL RUCA's did break recently.

[racepar1]

If you hit a curb you are an idiot and deserve to break stuff. I think he was talking about just breaking from the stress of having little to no flex in the arm and having little to no flex in the bushing either. I could see that happening. I personally don't plan on re-enforcing my FLCA's untill I get a set of spherical bearings for them. With bearings there would be no problems with breakage. Also if you are going to re-enforce the arms why not do it to the ball joint and bushing ends of it too? Half-assing stuff is just not my style personally. The arms pictured in this thread are ridiculous, no way would I do it like that.

[Longfellow]

Racepar what would you suggest on how to modify the stock arm? I just saw the picture and it got me thinking.

And if you hit a curb things are pretty much going to break. I dont plan on drifting or hitting curbs any time soon so thats not really going to worry me much.

I was thinking about drilling holes through the side of the arm and bolting in a two sleeves in place so it wont twist as much.

Kinda like what they did on this front tension brace.