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Fully Adjustable A-Arms

Old 01-11-2018, 11:01 AM
  #41  
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I've done that as well, and that happens to be the size of the cinch bolts here. If I made some nuts for the heim lock nuts I'd be in business. Have to see if I can track down some metric hex bar stock.
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Old 01-11-2018, 11:05 AM
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Old 01-11-2018, 11:07 AM
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Where you located Bronson?
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Old 01-11-2018, 11:35 AM
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I'm in central West Virginia, just past the banjo player.
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Old 01-11-2018, 06:22 PM
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Impressive. Thanks for sharing!
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Old 01-21-2018, 11:32 AM
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Originally Posted by Bronson M View Post

I'm more concerned with rotation in the side view plane since acceleration will rotate towards the front of the car and braking to the rear.
Isn't it the other way around?
Pad grabs disc, disc want to rotate towards the front, forces upper control arm towards the front...

Impressive work, btw.
Something I will be tackling in the future...
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Old 01-21-2018, 05:58 PM
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You know I had the same thought, but the force from the rotor would have to cancelled out from the force of the tire decelerating the car.......otherwise you'd go faster when you hit the brakes. It certainly reduces the total force on the upper arm compared to the lower though.
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Old 01-21-2018, 06:18 PM
  #48  
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Saw these rear upper arms in a different thread. Kinda cool but not as adjustable as the ones I this thread


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Old 01-21-2018, 06:35 PM
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Originally Posted by matrussell122 View Post
Saw these rear upper arms in a different thread. Kinda cool but not as adjustable as the ones I this thread


Ah, that doesnt work. Doesnt properly constrain the top of the upright, will eventually cause the lca to break. It would need the inner heim to be a single rotation only bearing and then it would just rip the tabs off the chassis instead.
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Old 01-21-2018, 06:43 PM
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Yup that's our car. Group of friends endurance race it. I'm a technician at a popular NW performance shop, and I have aligned and installed a LOT of aftermarket arms. We recently struck a deal with SPL and would run nothing but their products. Quality, ease of adjustment, and design are far above anything else I've seen, including $1400 Tarett Porsche arms.

These arms are only needed if you're lowered enough that you can't dial out enough camber. I think we're limited to a minimum of 3 degrees in the rear.

We use a $15,000 John Bean alignment machine, and I struggled with my first few alignments with the double eccentrics in the rear. I've gotten the hang of it over the last few years and it's now pretty easy to nail my desired toe and camber numbers. If you're struggling with it, you're simply not good at it yet and need more practice.

I don't see much wrong with the rear upper arms in this thread, although it seems like the outer lock nut would be difficult to get to. On an alignment rack any of those 4 lock nuts look difficult to access. With the SPL arms it's one lock bolt and a single adjustment hex.
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Old 01-21-2018, 06:46 PM
  #51  
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Ah yes, and as for any questions or concerns about the strength of these arms, I will say I have a small concern for them in terms of getting rid of the triangulation of the stock upper arm. Like I said previously, SPL always produces well designed parts, so I'm hoping there's no issue, but a rear subframe is at max a 2 hour job if the worse happens.
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Old 01-21-2018, 06:49 PM
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Originally Posted by curly View Post
Ah yes, and as for any questions or concerns about the strength of these arms, I will say I have a small concern for them in terms of getting rid of the triangulation of the stock upper arm. Like I said previously, SPL always produces well designed parts, so I'm hoping there's no issue, but a rear subframe is at max a 2 hour job if the worse happens.
As it its not going to break the rear sub frame, just the LCA. But if you need UCAs to get camber under 3* you're either so low you're not going fast so you probably wont break things or you need to tell your alignment tech to rotate both your alignment bolts 180* and try to align it again.
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Old 01-21-2018, 07:23 PM
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Yeah so I saw the spl arms and to me.... They are a bad design. Like it was mentioned they do not resist the rotation of the spindle under power and braking. Any time you allow suspension parts to wind up they will be a hot mess when traction is lost and they unwind, most of the time this manifests as axle hop which I am fighting with mid 2xx hp.

I primarily made these for ease of alignment, but removing all compliance without adding bind is also a big selling point.
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Old 01-21-2018, 11:45 PM
  #54  
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Originally Posted by Bronson M View Post
Yeah so I saw the spl arms and to me.... They are a bad design. Like it was mentioned they do not resist the rotation of the spindle under power and braking. Any time you allow suspension parts to wind up they will be a hot mess when traction is lost and they unwind, most of the time this manifests as axle hop which I am fighting with mid 2xx hp.

I primarily made these for ease of alignment, but removing all compliance without adding bind is also a big selling point.

I still want a set of your upper arms. I think paired with the v8r lower arms with heim would be a good setup
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Old 02-01-2018, 02:53 PM
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Edit- I made a dumb

Last edited by matrussell122; 02-01-2018 at 03:16 PM.
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Old 02-01-2018, 03:09 PM
  #56  
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That's pretty much exactly what I made with holes for the clevis bolts.

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Old 02-01-2018, 03:14 PM
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I know but if those end heims or what ever they are called had a flat to rest on would that keep the rotational movement from happening because it wouldnt be able to pivot around the bolt? Or am I screwed up on where the rotation is coming from


I was confused but up to speed now. A guy at work just schooled me.
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Old 02-01-2018, 03:21 PM
  #58  
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Ahh I see where you're going, so the problem is you need to be able to adjust the angle of the clevis to the bracket depending on what toe and camber settings because the angle of the arms will vary depending on both. Because the length of each arm is locked in order for the bracket to rotate the bushing would have to have compliance, I've eliminated this with a delrin bushing. In theory the entire spindle could rotate as viewed from above but because of the H lower arm this will not happen.
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Old 02-01-2018, 03:26 PM
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Yea as soon as the guy at work looked at it and started talking it made complete sense
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