Upper A- Arm mounts

[joedoozer]

Against my better judgement I am going to post this question :).

I want to mount my RF Upper A-Arm with sliders instead of bungs. Because the Upper is a following A-Arm and not the load carrying one. What type of slider can I use?

Option 1: Round tube verts with aluminum ballast clamps.
Option 2: Round tube verts with steel ballast clamps.
Option 3: Square tube verts with aluminum ballast clamps.
Option 4: Square tube verts with steel ballast clamps.

I wonder if square tube verts would be necessary for lateral stability.

[Matt49]

There's a lot more load on the uppers than you might think. Yes the lower is supporting the spring but the wheel is out on a lever and the upper ball joint is experiencing an inward force when the car is sitting on the ground. During cornering on the race track that force is amplified many times over.
And under braking, the upper ball joint sees a lot of force pushing it forward because the entire spindle is trying to rotate as the caliper grabs the rotor.

[joedoozer]

I know that. I know I have seen cars running sliders. I am looking for some info/experience people have with them. What works, what doesn't. What breaks what twists?

[MasterSbilt_Racer]

I would use square or rectangle. I have had or worked on several cars with them.

[MasterSbilt_Racer]

That said, Lazer does use round mounts. Go to their website and look at a setup guide.

[tbaileyjr]

ive seen different companies use both and work i woud use a round tube that was braced real well and if you plan on running alot downward slope on ur upper control arm probaly have an extra set of clamps bellow it resting agaist it form more support against sliding.

[joedoozer]

Thanks for the help Masters. Once you mentioned Lazer I changed my Google searches haha. This is exactly what I am looking to do. It almost looks like they are twisting the sliders to set caster too.

http://www.racingjunk.com/Late-Models/2520769/2011-Laser-Dirt-Late-Model-Chassis.html?imageIndex=7&showSuperSize=true

[Matt49]

It would be neat if you could figure out a way that it was notched so that when you tightened it down, it wouldn't want to slide. This would also be a good way to make sure your settings are reproduce-able so you don't have to measure every time you make an adjustment here.
Just our of curiosity, what are you looking to achieve? Roll center adjustment? Camber gain?

[dualdj1]

See? It didn't turn out that bad :P

It's a repair, just wants everything back where it was geometry wise, but with frame not being exactly the same as before, need adjustment.

The nice thing about going this route, is that it's then flexible to try changing geometry down the road if you'd like.


As far as "locking" the clamps in place, with everything tight they shouldn't move, but you could always use a bolt with a point on the end, through the bracket into center of the tube to lock it down better.

[joedoozer]

Yeah, I went nose first into a concrete wall at about 100 mph. I had to cut the RF frame off from the motor plate forward.

I have all my measurements from before the crash, including front roll center. I want some flexibility it in so I don't have a "aaaww crap it's off", when I get it all tacked up. This way I can get my verts in and then just position my sliders so it lines up. I don't have to try and drill and weld up bungs, to find out they are off a little, or not quite square.

[joedoozer]

It would be neat if you could figure out a way that it was notched so that when you tightened it down, it wouldn't want to slide. This would also be a good way to make sure your settings are reproduce-able so you don't have to measure every time you make an adjustment here.
Just our of curiosity, what are you looking to achieve? Roll center adjustment? Camber gain?

I have 2 piece lowers so I will continue setting my caster that way. I won't twist the sliders to set caster. I suppose I could use a center punch and make a dimple every 1/2", those could be reference points.

[Egoracing]

We used to use the steel ones on an asphalt car. We cut a 1/2 inch out of the back of teh calmp between where the bolt went thru and the tube it would mount on. We welded a 1/2 X1/2 square bar to the rear of the upright tube. The clamp would go around the tube and over the square tube and when clamped will not allow it to twist, well.... That is will not twist unless you hit the wall at the 5/8 mile asphalt USA speedway going into turn 3 with a hung throttle. It twisted.

[zeroracing]

I ran them on my first Swartz, rectangle tubing, aluminum clamps, you can make changes easy and in a pinch can adjust anti dive with them. The car came with them and they worked good. I checked them every race, never a loose problem.

[hpmaster]

I have used round 1 1/4" Lazer A frame clamps and rectangle GRT type clamps. Last year my car was hit real hard on the left front breaking the spindle, upper A frame, bending both ball joints and the shock shaft. The round Lazer clamp twisted but did not bend or break anything on the chassis. In 3 years of running them I did not ever have them come loose unless I wanted them to.
This year my car is a new chassis and the guy who built it used the GRT rectangle ones. To be honest I sorta wish I would of told him to use the round Lazer ones on this chassis but I just didn't think about it when he was building it. I have only raced the car 4 nights and have not tested them like the old car yet, thank God.

JoeDozer, if you need help in doing it I have pictures how I welded the round tubes in for the Lazer sliders, PM me and I will send them out to you.