Aftermarket front control arms

74goldtarga · 12-11-2006, 01:18 PM

I'm not getting any hits on this thread in the race/autoX so I thought I would try it here - thanks.

I have heard stories of front control arm failure on 944/951 and do not want to experience this at speed. I am looking at the Lindsey chromoly units which include caster blocks (@ $500 savings) vs Charley Arms which are billet aluminum and look perfect but are hard to get, and the racer's edge units which are steel and PCA race legal, no caster blocks. Anyone know the weight difference between these options and the strength/failure resistance differences if any? Anyone tried these and been happy/disappointed? Thanks.

Dave L · 12-11-2006, 04:16 PM

I saw you post on the other forum but dont have any info based on personal experience, But;

failure at the ball joint is a real concern,here is a little info and possible solution.

http://www.blaszakprecision.com/Control_Arms.html

I think what ever you do will be better than the stock arms.

74goldtarga · 12-12-2006, 04:04 PM

Thank you Dave L, I have seen that website. Those arms look strong but too simple - they may be properly engineered in the right places though.

JivenJim · 06:54 AM

From what I understand it's not necessarily the Arms at fault. When We lower the car alot with Adjustable height (perch) kits we alter the angle of the ball joint. That why most modded Ball Joints are longer and thicker. I think, All the Aftermarket ones account for that. 1500 for A-Arms is Crazy money. I guess if your pulling big super sticky tires you could load the lateral G's to justify buying those Aftermarket Arms. I've never heard of any of them busting unless your off track hard....

The spec944 guys like the steal over Aluminum Arms. Why.. cause they bend and give you some steering before they snap. Steal just goes bye bye.. Or at least that’s what I’ve heard.

But if you have the cash I would think any of the aftermarket arms will give you extra double beck, stout hauss. (and that's all good)

Sorry don't know the weights but check shipping weights from various sites.

ERAU944 · ERAU944's Garage

the cast aluminum arms would be more prone to crack/break than to bend, the steel would bend before it outright broke.

the stock steel arms can be strengthened by welding them on the edges, making them stiffer/stouter and less likely to bend.

Techno Duck · Techno Duck's Garage

The spec guys actually like the steel arms. They are cheap at $30 each. Ball joints are $15 and can be changed with 3 bolts. Boxed steel arms are popular, basically reinforced factory steel arms.

Most alloy arm failures seem to be ball joint related. As JivenJim explained, when you lower our cars past an inch or so, the geometry of the ball joint pin is changed and makes it easier for it to bind against the ball joint pocket. A steel ball joint pin banging against an alloy pocket over bumps eventually breaks the pocket or breaks or bends the ball joint. There are solutions around this such as longer ball joint pins. I have the geometry correcting balljoints on my '87. If your car is dropped more than an inch you need to take this into consideration. I have my car dropped 1.25 inches in the front and you can tell how the control arm does not sit level with stock balljoint pins. The longer pins even it out.

If i were building a track dedicated car.. aftermarket arms would definetley be on the list of things to do to make it bullet proof.

Im not even sure if the aftermarket balljoints available are PCA race legal. Technically as per Porsche, the alloy arms do not have a rebuildable balljoint.

JivenJim · 12-13-2006, 07:07 AM

Thanks for catching my mistake guys. I reversed what I meant. Comment edited for Steal and Aluminum.

Dave L · 12-13-2006, 12:47 PM

I guess the question is; At stock height is there a risk of failure or it is simply with lowered cars?

I ran last year in AutoX with stock A arms and figure I am fine even with sticky tires. Even if an arm were to fail we are talking about relativly low speeds. I am somewhat concerned as I venture into Solo1 and DE's next year though.

Techno Duck · Techno Duck's Garage

Even at low speeds i would not want a control arm failure. Having a tire end up in the fender is not acceptable to me. Loss of control when people are standing in the general area as i pass by them (cone gophers) at 30mph is also not acceptable.

Dave L · 12-13-2006, 03:54 PM

so are you saying that the a arms are a problem even at stock height?

I agree that having one break under any circumstance isnt going to be a possitive situation, but what is the risk.

JivenJim · 12-13-2006, 04:27 PM

I'd think low to zero risk at stock height on DE's in the Cone Zone on stock height. I lowered mine 2.5 inches and ran fine without the raised steering Balls. (lots of people do) But catch that bad bump and who knows.... Knowing more now, I'd agree with the Techno duck. Why Chance it. Drill out the three Rivets and buy the 90$ kit. I'm adding that to my list. 90$ is alot better than 1500$.

Somebody remember where to buy those?

Dave L · 12-13-2006, 04:58 PM

for $90 its makes a lot of sense. details on this kit please!

I also inspect my a arms and have my mechanic do the same and they seem fine.

74goldtarga · 07:15 PM

Thanks everyone, I am planning on converting to coilovers at all four corners not this summer but next, I will lower the height (I'm not sure just how much). If there is any chance of failure at stock height because of the design I don't want to risk it, turns 1 and 2 at Brainerd are entered at 100mph and up and there are trees not far away. My plan has been safety first, reliability second, and speed third. $1500 is a LOT of money for A-arms, but loss of control at speed without warning is about the scariest thing I can think of over 100mph. I just want to get it right (and then go really fast).

Techno Duck · Techno Duck's Garage

At stock height its anyones guess what can happen to the ball joint or control arm. I would say the more you lower the car, the more you compound the danger of ball joint failure. Besides, with the vast majority of 944's having probably close to if not more than 100k miles on them, new ball joints cant hurt.

No rivets to drill out..just one huge pain in the ass snap ring to take out. This is the snap ring from hell, possibly worse than the water pump / thermostat one.

www.rennbay.com for the rebuild kits. I have there track kit (solid bushings) with the longer ball joint pins. 10k miles and 3 or 4 auto-x's and they are holding up just fine. My car is also lowered 1.25 inches all around. If you do any type of track or auto-x...get the solid bushings. For one you will like the more solid steering feel they give and the nylon / delrin bushings did not hold up well to auto-x the first time i rebuilt them. They failed after about 5k miles and 2 auto-x's.

74goldtarga, plenty of people run there cars very hard with the aluminum control arms at stock height and even lowered and do not have problems. However i just felt its a good idea to inform people of potential problems running any lower than 1.5 inches. I for one was not really aware of it when i immediately 'slammed' my car after going to coil overs. I was dropped almost two inches before someone PM'ed me after i posted pictures of my car asking what i had done about ball joints. Sure enough i looked under the car and you can see the control arms no longer sitting parallel with the ground. I would say you can probably get away with running low and not have problems if you are running a relatively high spring rate, i would say over 350lbs.

I for one use my car as a daily driver also and have a relatively low spring rate as i am to lazy to change the torsion bars in the rear. I run 200lb springs which is defenetley not enough to compensate for the NYC pot holes and bumps i come across. Complete coil overs for the rear of my car with deleted torsion bars are hopefully coming next year. Then i will be running 350-400lb springs in the front.