Additional RLCA bracing/welded supports

[CodyAce]

Hey guys, was curious as to if anyone had comments on my bracing ideas here (cardboard templates):






Would this be a worthwhile modification, or should I spend time elsewhere? I would assume by boxing the 3 'ends' in, it woudl gain strength, but at the same time don't' really know how much 'force' is applied through here.

[SoSideways]

That's about all I have seen people do when they have braced the RLCAs.

[Matt93SE]

That oughta work... but you could make one out of tubing and heim joints for not a whole lot more work.

[CodyAce]

That oughta work... but you could make one out of tubing and heim joints for not a whole lot more work.

'rub it in' hehe.

Fabbing up Sway bar mounting points is what would kill me (to do properly)...and that jazz..that's where that tubular ones kick ur butt.

So at least I'm not crazy with my boxing idea..figure the one already was 'pre done' that it would be best on the other ends.

[Matt93SE]

Just use some 1/2" or 3/4" square tube and run it cross-ways across the control arm and voila! sway bar mounting tab.
with the right endlinks, you could also move the holes in and out (toward or away from the wheels) to change the leverage and thus the effective wheel rate of the sway bar. just a thought.

[racepar1]

Here's what I did (copied from my build thread), I don't think that I am going to bother on my s-14 rlca's though...

This is my latest project. I took my RLCA's and braced them. I basically totally boxed them in. I just took some thin sheetmetal, tacked it on around the outside, hammered it down to meet the middle, and welded it all together. They came out pretty good IMO. They could have been better if I had taken a little more time though. I had my buddy powdercoat these gloss black as well. I weighed them and they are less then a pound heavier then a stock arm. I re-used my moog sentra ball joints. I was originally planning to make delrin bushings, but decided to use the z-32 urethane ones instead and save the time for now. The z-32 bushing material is MUCH thinner with a big spacer. With as little material as there is there to deflect I doubt delrin would be much of a difference anyways.

[Umai Kakudo]

One thing to consider -- The RLCA's are designed to bend right at the inner pivot area.

If you should happen to hit something the LCA will bend saving your wheel and other suspension/chassis bits. You lose this sacrificial link when it is strengthened.

It's hard to say if the LCA is flexing enough to actually need to be reinforced without rigging up a leverage test.

Also - If you have any bushings (Delrin excluded) in your rear suspension pivots you get more deflection in the bushing that you would ever get from the control arm making this a low gain project.

Now if you had bearings all around and huge slicks you might need to stiffen up the control arms to prevent dynamic alignment changes under load.

[BeerBringer]

Just from the feel of both the front and rear controllarm I would say neither of them needs boxing. Feels super strong to me.

You might loose more performance from the added unsprung weight then from the added stiffness...

[Bumnah]

One thing to consider -- The RLCA's are designed to bend right at the inner pivot area.

If you should happen to hit something the LCA will bend saving your wheel and other suspension/chassis bits. You lose this sacrificial link when it is strengthened.

It's hard to say if the LCA is flexing enough to actually need to be reinforced without rigging up a leverage test.

Also - If you have any bushings (Delrin excluded) in your rear suspension pivots you get more deflection in the bushing that you would ever get from the control arm making this a low gain project.

Now if you had bearings all around and huge slicks you might need to stiffen up the control arms to prevent dynamic alignment changes under load.

Yeah, does the rear LCA even flex to where reinforcement is needed?

[CodyAce]

but at the same time don't' really know how much 'force' is applied through here.

This is exactly what I was curious about - but the the comment in regard to bending before breaking (in regard to a crash) certainly peaks my curiosity and would be ebough to persaude me not to do it... but at the same time, I'm curious as to why Nissan would box one, and not the rest

[djsilver]

This is exactly what I was curious about - but the the comment in regard to bending before breaking (in regard to a crash) certainly peaks my curiosity and would be ebough to persaude me not to do it... but at the same time, I'm curious as to why Nissan would box one, and not the rest

If you look at the evolution of the Nissan design it might be informative. I believe the S13/Z32/R32 chassis' all got the first version. The S14/R33 got the second gen design with several improvements, including a stronger frame, reduced anti-squat, wider pivot joints and a little more boxing on the RLCA. Based on that, I'd say a little extra boxing on the S13 arms might be an improvement but it's the least of the issues with that generation.

Were there any more versions of this subframe prior to the 350z/G35 introduction? If not, then that would be the 3rd generation of the design. It's got the upper arm triagulated, with a trailing arm/tension rod and an un-triangulated rear lower with integral spring pocket. It's also aluminum for light weight. Just looking, it appears that it would probably have less camber gain on compression as well. It looks pretty nifty but I think it's a little too different to mount in the S13/S14 chassis. The only way to reduce camber gain on the S13/S14 subframe when lowered would be to raise the inner pivot points for both upper arms.

The improved touring road racing guys in SCCA can't swap or reinforce stuff on the chassis. The main improvement for them in either chassis is that that they go all-spherical to control unintended alignment changes due to bushing flex. Of course, doing that requires careful alignment to prevent binding.

[racepar1]

One thing to consider -- The RLCA's are designed to bend right at the inner pivot area.

If you should happen to hit something the LCA will bend saving your wheel and other suspension/chassis bits. You lose this sacrificial link when it is strengthened.

I have always found arguments similar to this to be ridiculous. If you hit something hard enough to bend your LCA your wheel and probably subframe are done anyways. I've seen it more than once. The LCA is pretty strong as it is.

It's hard to say if the LCA is flexing enough to actually need to be reinforced without rigging up a leverage test.

The only area that I would be concerned about is flex around the balljoint area. Where the arm mounts to the subframe is quite strong. I would say that some bracing is a good idea though as nissan did a little on the s-14 rlca's, and NISMO RLCA's are also braced. I wouldn't do what I did again though.

Just from the feel of both the front and rear controllarm I would say neither of them needs boxing. Feels super strong to me.

You might loose more performance from the added unsprung weight then from the added stiffness...

The front LCA's are are far from strong, those could certainly use some additional strength.

As for the additional unsprung weight, that SHOULDN'T be an issue. Nobody SHOULD be using very thick guage metal to brace their arms. All that is really necessary is a thin panel to keep tension on the stock arm structure. The LCA's are also not quite exactly unsprung weight so the additional weight would have less of an effect then if we were talking about the spindle assembly/wheels.

[CoupedUp]

I know the S15 RLCAs received some moderate bracing in comparison to the S14 RLCAs I couldn't find the picture again. It's in one of the S14 Subframe -> S13 threads that I found during research.

[CodyAce]

Went ahead and boxed them in. Welding isn't of my best work, but it'll do - Freakin tank was damn near empty and I never bothered to pay any attention to it lol!

Covered up the uglyness with krylon hehe

[Solo_S14]

Atta boy.