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Anyone using these?.....Speed Direct aluminum A-arms.....any concerns (strengthwise)? Upgrading some things (Borgeson box), and am consider these for some weight reduction.
I would ask them the material, temper, and if they are cast or forged.
I am curious, but will not compromise safety. The stamped steel ones are quite durable, and not that heavy.
I'll be honest, that big flat area with no reinforcement against flex/bend where the ball joint is mounted scares me a bit. I guess it might be fine with the correct materials, but I don't like the look of it. Compare it with the Global West arm, that has tubing tying that area from multiple directions, or the factory arms that are pressed with deep flanges around that area. Is there bracing underneath that's not visible in the picture?
I'll be honest, that big flat area with no reinforcement against flex/bend where the ball joint is mounted scares me a bit. I guess it might be fine with the correct materials, but I don't like the look of it. Compare it with the Global West arm, that has tubing tying that area from multiple directions, or the factory arms that are pressed with deep flanges around that area. Is there bracing underneath that's not visible in the picture?
A quick Google of their website says:
"Heat treated cast. Design strength safety factor of 5X - Stress / failure analysis results in 5X required load strength."
And here is a picture of the underside from the linked Super Chevy installation article
I'll be honest, that big flat area with no reinforcement against flex/bend where the ball joint is mounted scares me a bit. I guess it might be fine with the correct materials, but I don't like the look of it. Compare it with the Global West arm, that has tubing tying that area from multiple directions, or the factory arms that are pressed with deep flanges around that area. Is there bracing underneath that's not visible in the picture?
The Global West arms are heavier. Stock arms would require phenomenal force to fail.
I would NOT use a cast piece in that position. On that I agree.
One of our Vette group is an engineer. That piece scares the hell out of him.
I'm an engineer also, though electrical, not mechanical or structural etc. But yeah, looking at it, I don't like it. That's not to say that they might not be ok - I'm not doing any modelling or anything - but I probably wouldn't run them on my car, and I'm a big fan both of extra caster and lighter weight.
There are plenty of OEM cast alloy suspension arms - done right it shouldn't be a problem. Here's the upper control arms from an rx7, but look at the difference in design.:
Last edited by Metalhead140; Apr 27, 2017 at 12:41 AM.
I see what everyone's saying about the possible weakness of the cast tab area.......I'm now leaning toward VBP's arms........similar weight savings and caster adjustment, but more strongly built tubular.....
There are plenty of OEM cast alloy suspension arms - done right it shouldn't be a problem. Here's the upper control arms from an rx7, but look at the difference in design.:
Your picture didn't work for me, but I googled to have a look. The c4 corvette upper arm looks more like the Speed Direct arm except in the very area I'm most concerned about. Around the ball joint the c4 arm maintains extra thickness and has nice tapers between the ball joint mount area and the arms. Compare that with the Speed Direct arm that has that big unbraced plate hanging out in space.
I dunno, obviously it works for some people. I feel sure it is an area of weakness, I guess it's more just a question of how likely it is to cause an issue in normal use, which I can't answer.
The c4 corvette upper arm looks more like the Speed Direct arm except in the very area I'm most concerned about. Around the ball joint the c4 arm maintains extra thickness and has nice tapers between the ball joint mount area and the arms. Compare that with the Speed Direct arm that has that big unbraced plate hanging out in space.
The upper arm has no twisting force, only push-pull.
I could understand your concern for a lower control arm, but not the upper.
The upper arm has no twisting force, only push-pull.
I could understand your concern for a lower control arm, but not the upper.
I agree with that. The lower takes the weight, and the upper is just a guide per se. But I am leery of mods that compromise strength.
I have been in an old car that hit a curb going too fast around a corner. We almost flipped. (Kids then). All it did was bend an a arm. No cracks.
$25 for a new arm, and back on the road. It absorbed all the impact, and nothing else was damaged.
Aluminum Upper Control Arms
