1G tubular control arms

[Ludachris]

Paul is going to trace a Mustang arm and send it to me so I can compare. The Polk arm in the photos above actually have a similar curve, so I'm not sure it won't work, though I'm not holding my breath. What are the chances?

If nothing else, the BMR design gives us something to base our design off of. If that design works for a Mustang, it should most definitely work for our cars.

 

[InfiniteGSX]

Yeah just gotta get good welds on a strong material and were golden. I'd be happy with non adjustable up front cause my stock setup is perfect for me...

I still wanna get something built up for the trailing arms.

 

[PSI2HI]

I'm reluctant to point at the weld as an actual problem, as Polk has a good rep for race car fabrication.

The wall thickness of the tube in that spot is quite thin IIRC. That coupled with no gusseting, most likely due to this being primarily a lightweight dragracing design, are more likely the true cause. I doubt anyone else will be running these outside of the drag race community, and really, we are here to talk about other options.

Typically a tube will bend not break but in most cases w/ chromoly its not the weld that fails its the overheating of the material which will cause it to become brittle and it'll break outside of the weld. Im just advising those to take precaution in dealing w/ some of these parts as it can be a huge liabilty if there's failure due to lack of experience w/ design and fabrication of these types of components.

Has anyone looked into using a sypherical bearing cupstyle ball joint? Pictured below is the bearing cup style we use in the motorcross stuff.

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[underradar92]

Has anyone looked into using a sypherical bearing cupstyle ball joint?

So far, no one wants to deviate from the stock type ball joint.

Except me...

 

[pagosa dsm]

So far, no one wants to deviate from the stock type ball joint.

Except me...

I just finished the rear end with all tubular control arms.I picked up a complete front sub frame to make a set of front control arms. I was planning on using the ball joints from top chrysler or afco # 20212 tie rod end.I am still in the planning stage.Does any body have photos of Larry Parker's front control arms?I like his design.

 

[underradar92]

I just finished the rear end with all tubular control arms.I picked up a complete front sub frame to make a set of front control arms. I was planning on using the ball joints from top chrysler or afco # 20212 tie rod end.I am still in the planning stage.Does any body have photos of Larry Parker's front control arms?I like his design.

If Larry is 3litrpwr or like that, yes I have seen those and like them too. In fact, I asked him, previous to getting my Polks, if he'd make more. Of course he said no.

 

[InfiniteGSX]

Anyone else have any more info? I wish I could join in on this but I wouldn't know where to start, I want all front and back adjustable tubular arms. And got a kick ass welder but I'm not really sure where to start.

 

[pagosa dsm]

I have made hiem joint on the rear trailing arms,adjustable rear upper control arms and adjustable rear lower control arms.I am planning a tubular front control arm.I just finish steel bushings for the front control arms.They worked out fine,no extra noise or vibration.

 

[greengoblin]

afco # 20212 tie rod end

I could not find this part. Any links or more info. What are the sizes on the ]stud dimensions.

Kevin

 

[tkelly27]

Ah! so maybe the threaded rodstock wouldn't break AT the rear bushing. But you at least have you have to take into consideration the material for the lever arm between the front and rear bushings. I see. The rear bushing may see much more load than I would have thought too.

Putting a threaded piece into bending like that will break it. It may not be a hit a pothole and die kind of thing, it's a cyclical issue. The notch (thread) in the rod adds a stress concentration factor that will dramatically reduce the cyclical life span of the piece in comparison to a non-threaded rod.

You could oversize the bolt, but then again you could also just put in a solid rod.

http://www.bmrfabrication.com/05Mustang/A-armLube.jpg

That's the better way. It still has threads, but they are not bearing the bending/shear load. Anyone serious about making these things will make them that way.

 

[greengoblin]

afco # 20212 tie rod end

I could not find this part. Any links or more info. What are the sizes on the ]stud dimensions.

Kevin

I think Maybe it was a type-o. I found Afco # 30212
Here:
AFCO: TIE ROD END - (3/4 - 16 R.H.) ES150R

Is this the one you meant pagosa dsm?

 

[99gst_racer]

Yeah, definitely a typo. Afco 20212 is a 700lb IMCA torque link.

 

[greengoblin]

Yeah, definitely a typo. Afco 20212 is a 700lb IMCA torque link.

They are very beefy. I have one here that I was going to use on my 2g toe arm I'm building. To use it would require me to ream the hole out quit a bit. I'm now looking into using Part # ES258L. It appears that it has a smaller center pin. I should know in a few days.

Kevin

 

[Ludachris]

Putting a threaded piece into bending like that will break it. It may not be a hit a pothole and die kind of thing, it's a cyclical issue. The notch (thread) in the rod adds a stress concentration factor that will dramatically reduce the cyclical life span of the piece in comparison to a non-threaded rod.

You could oversize the bolt, but then again you could also just put in a solid rod.

http://www.bmrfabrication.com/05Mustang/A-armLube.jpg

That's the better way. It still has threads, but they are not bearing the bending/shear load. Anyone serious about making these things will make them that way.

I've spoken with BM about producing control arms for the 1st gen DSM. They've told me that they would consider doing it in the off season (any time now I'd guess) but I have no details on what pricing would be or what they'd need in terms of minimum orders. I'll check in with them again.

 

[RipperXX]

Any updates?

 

[Ludachris]

Any updates?

They haven't replied.

 

[turbo23]

Sorry I haven't responded in awhile, we've been very busy with other projects. Last we wored with these, I did some strength testing, but i have lost the info from the tests, so I will do them again in the upcoming days. when I post results I'll also talk about some of the design changes we're planning on making.

 

[1fastlaser]

Bump it up....any updates!!!!!!!!!!

 

[Ludachris]

No update on my end. Couldn't get that company to produce them... well, they never said no, but they keep putting me off. I can check with them again.

 

[Ludachris]

Just an update, I've sent emails off to a few companies to try and get control arms produced for the 1g that mimic the BMR designs found here:
BMR Fabrication Products

I'd love to have BMR produce them, as they've obviously been making them for the Mustang for a little while and have a good reputation. But if they don't respond, I'll see if I can get another shop to make them available using the same design.

I figure this design will suite the road racer, autocrosser, and drag racer alike. The drag racer version could simply use less bracing to cut down on weight. But one basic design can work, and the BMR control arm looks to be exactly what we'd need.

The ball joints we'd use could be the Chrysler versions that we've touched on in this, and other threads. That would allow us to keep the same spindle taper and use the longer studs to address roll center for the lowered cars. The drag racers could just use the stock height Chrysler replacements.

I would think that if they can be produced and priced similar to the BMR pieces, we'd get a number of interested DSMers.

We'll see what type of response I get back from these shops.

 

[underradar92]

I just noticed the slotted rear pivot design, adjustable caster! WOOT! Hope that makes it into the final product.

 

[Ludachris]

I just noticed the slotted rear pivot design, adjustable caster! WOOT! Hope that makes it into the final product.

Wouldn't that be nice? Since the only real option available right now are the RRE camber plates with a fixed position that adds caster - that's nice too, but it would be nice to have some adjustment as well. I think the control arm by BMR would be a killer design for the 1g and I'm doing all I can to get it produced by someone who has experience putting out these kinds of products.

 

[turbotalon1g]

Awesome, I for one appreciate all the work you are doing for this.

 

[Ludachris]

Might actually have some good news on this front pretty soon. Keep your fingers crossed.

 

[kawgomoo]

Not a terrible shape for an arm.

But the bushing attachment point is scary.

the welding, well thats completely unacceptable. There is just no way that guy is a skilled welder having a bad day. Maybe hes a good welder and the fit up is really just that bad? Either way total crap on the execution

I dont know. But i do know to never buy anything where the weld is wider than your allowable gap. If there is a huge gap and its just welded shut...wellll you know how it goes.

to say the weld is always stronger than the base...that too is just ignorant. Welds typically fail within the HAZ {heat affected zone} but outside the weld. Typically the crack will be right a the toe of the weld, where the weld and base join and the HAZ is obviously greatest.

the filler you use tells you how strong the weld will be. I could weld a mild stainless header to a mild steel flange use SiBr {silicone bronze} and the weld will be BY FAR the weakest of the three metals. Yet, it will be DURABLE because of its resistance to heat, vibration and work hardening.