pontifex4

This is a good discussion, and thanks to Mahler for bringing it up.

Is there a definitive answer on whether the failure is exacerbated by a significantly lowered car?

951and944S

Charlie, in part yes....but isn't it always more complicated...?

From center, the ball joint has a limited amount of travel so if you move your "center" (lowering of car), you lessen the amount of designed travel which could cause the pin to bind.

On race cars, you get way less actual suspension movement because of the stiffer springs.

It is recommended that your arms be level with the road surface when lowered and sitting static on the ground.

Mahler - it's not an issue of people being un/mis informed....these cars have been being raced without interruption for a very long time and this problem is well known and thoroughly discussed.
The only reason I even posted on it is, I think, at least in our case, that the way we tow the car and the stress we introduce by doing so seemed to be a logical explanation due to the way our failures occurred and I had only just recently put 2 and 2 together.

Travis - I have used them all, I definitely was not singling out any product you sell....as a matter of fact, all of ours that failed were from other sources. That said, I think I will move back towards you as a source because of the offer you stated in your last post.

Van, cool info. I was looking at some spindles before I saw your post to see if taking meat out there by boring would just move the weakness to the spindle.
I am encouraged by the post bore pic you posted so thanks for saving me the trouble.
Just wondering if the increased pin diameter would further limit the pivot range or are they tapered down low near the joint to the same diameter as the original and other replacements.
If so, that strength would be similar at that part of the pin but like I said earlier, ours fail at the upper part where the 19mm would be an improvement.

Thanks everybody....even you West....
We'll have that a-arm that Hamza borrowed back to you at NOLA...!

JC elected Eon to do the chalk talk.

T

Mahler9th

As for lowering, I am not an advocate of advising people to only lower so far or thus and such et cetera. The ride height, rake, suspension settings, wheel rates... what is best for all of that stuff depends...

Sure lowering makes a difference, but I am not sure anyone knows anything definitive.

"Mahler - it's not an issue of people being un/mis informed....these cars have been being raced without interruption for a very long time and this problem is well known and thoroughly discussed. "

Yes I know, I started in a 944 at Lime Rock in 1987, and was pretty continuously involved from then until I sold my 951 in 2002.

Well, perhaps I should be more direct. One of my concerns is that the range of folks getting into "performance use" (AX, DE, racing) is different now. The cars are so cheap and the demographics may have changed in the last decade or so. Heck, I am sure there are quite a few in Lemons and Crap Can, etc. running these cars. Plus we have the "wonderfully accurate and thorough" internet to share and proliferate information.

I had an experience with a young enthusiast at Partsheaven on Saturday. Younger than 25 I beileve. 944S that he has driven on track maybe a half dozen or more times. He has a 968 M030 bar on front and some type of custom or semi-custom adjustable rear bar on back. Screwed full tight. Stock springs and t-bars and stock ride height. Yes, stock ride height (which blows my mind a bit).

He has plans for many mods for safety and performance. He has never done a PCA event. Not a member. Gets most of his perspective from the internet I reckon. An impressive and nice young man. But do you think he knows that Kelly Moss and other teams raced the 4-valve cars back in the day, including Rich Moskalik's very trick, somewhat factory supported NA 968? Does he have access to the Pano or Up Fixen' der Porsche where Bruce Anderson describes how to properly set the rear ride height of a 944? I remember when I read that... I immediately went out and dropped my car down then had it aligned. Transformed the handling...

Anyway, this young man had never heard of this potential alu arm/ball joint issue, and likely was not on a path to find out. As I started to fill him in, my two friends working the counter at Partsheaven just smiled. I have known those guys for 20+ years, and they are around my age. So of course they know about these kinds of issues.... even as non-racers.

The way these young folks get information and perspective these days is different. I used in person conversations and my telephone.

If I raced a 944 in Lemons I would want to know about this and at least make informed decisions.

951and944S

10-4 Mahler, point taken.

That's what is so good about PCA, and to the same extent, the modern age and the internet.

Your young acquaintance could have found all the knowledge he wanted to read if he had been so inclined, and likewise, when he eventually huddles around a track with 944 guys at a PCA event, he'll learn the ropes through conversing with them.

PCA today (don't know about way back in the past) requires you to have a technical inspection of the car pre-event and seasoned mechanics that are keen on these problems know what to look for. Only certain local shops that usually have a relationship with the local region make the list. Repairs noted as critical must be made before an event.

As for me, as a parent, I gifted my son a 2 day one on one high performance driving school around our local circuit for his 16th birthday so he's the same 25 years old as the guy you mentioned and has been on track for nine years already....has a local championship, several PCA and NASA track records under his belt already.

People are different, to each his own I guess.

Anyways, thanks for the reply,

T

OGRacing

I remember when you and your friend were having those problems, so I'm not completely senile. Potomac region did see a lot of the ball joint and spindle breakage. At one point it seemed like one every weekend. Add to that the ones that were found at tech to be ready to fail,but were caught and the numbers were very high. Whenever I would instruct any 944 I would check them myself just to safe. Found more than one that someone else had missed. And let us not forget the rear axle nuts coming loose.

Bill

pontifex4

I'm not far off the age of your young acquaintance. I was his age when I started this, with that same car, modifications and intent, and you're right that he wouldn't likely make his way to back issues of panorama from before he was a teenager to learn information on part longevity.

Where he will almost certainly end up, though, is Rennlist and Clark's Garage (http://www.clarks-garage.com/) when the pain of paying a mechanic gets to be too much, or he starts looking for a more credible community than the vinyl wrappers. These sites are where this information needs to be, complete with pictures and video, so this thread is off to a good start (except for its title -- might be a little too academic!)

crooster

While I was already aware of the control arm issue, my local Porsche mechanic (PCA tech center) made a point to advise me when I had my 951 certified last year. He even showed me how he checks for play and what to inspect.

Mahler9th

Thanks all for the updated perspective.

That's great crooster. I used to cruise not too far away from Cambridge when I drove back and forth to college (home in WI, college in NH). And no doubt there are some folks still living in the Toronto area that were a part of the Rothman's days. I wonder if Pfaff is still a dealer there...

Thanks for chiming in Bill, and thanks for all you do and have done for us through the years.

I am pretty sure that PCA events still have great tech inspection activities. But I am not sure that all of the stuff to look for has been handed down from generation to generation. I think the internet has done a lot to dilute the info. Or worse, make "true" stuff out of poor or wrong information based solely on some poster or another's ability to be articulate and convincing.

And so many folks might be getting into track driving these cars completely outside of PCA. They may never access PCA resources.

I started corresponding on the internet about 944 family cars back before rennlist, porschelist, porschefans and all of that. I started in Car and Driver forums before any of these more current opportunities existed. Some of the stuff I have seen... OMG in young people's terms.

I am pretty sure Clark of Clark's garage was a pretty early adopter too. I just visited that web site, and it has good information.

But I do not see a lot of connection between the basics and DE/track/racing use.

There was so much learned from pro racing and early use of these cars in DE/track and racing back in the 80's and 90's. Too bad we have no archive or database or whatever. Back in the olden days, you could pick up Pano and/or Excellence, read an article, and call folks mentioned in the article. Or visit a place like KMR and have gracious hosts like David and Jeff Stone who were getting factory support running the 2.7L 16 valve cars (Nick Ham and Jeff Purner if I recall correctly) and then a 968 for da boss.

Hopefully at minimum folks will say something if they run into others doing or planning track work with these cars. Saying something is a start. I also believe that it is everyone's best interest to leverage as much stuff learned from the past as possible.

Imagine owning a 951 with just a few mods and signing up for a PCA event down at Buttonwillow. You have never been there before so you ask for an instructor. Imagine if Jon Milledge is your instructor. Wow. 1985 Norelco Cup Firehawk champ.

Or you sign up for some other groups event, and the instructor calls your car a Porsh. Sigh.

67King

FWIW, since I wrote this, just want to point out that I was mistaken. Apparently they all replace the ball joint with a spherical bearing. This pin designs are different, though (which is why the appearance is misleading).

odurandina

who if anyone has the technical capability to rebuild the so-called

unrebuildable, uber-expensive 968 front control arm??


they're $618.00 per unit at Pelican Parts.

clearly this is not acceptable when we're just seeking to replace the ball joints.

I don't want to use 944 control arms. I want my A-arms to stay 968 oem.

we need the answer to this dire situation, and we need it now.

Mahler9th

I haven't "studied the problem" in years, but I suspect that the late offset well-designed aftemarket products available for the other 944 family cars would bolt onto a 968.

I haven't heard of any rebuilding process or "kit" for 944 family cars with aluminum front control arms that I would trust under any circumstances for regular AX or track use, even with a completely stock suspension and street car tires.

Even for a "street only" car, I would be extremely vigilant if the suspension configuration, and settings (including ride height) deviated from stock/M030 in any way.

odurandina

thanks....

from the 944 forum:



awesome, thanks! that's a fantastic price too!!

I just talked to one of the guys about rebuilding my actual 968 A-arms, but he's gonna call me back with confirmation.

if it's not the 968 oem arms, i'll just send them my cores and use whatever they have.

Mahler9th

Just for completeness, I wouldn't trust ANY such product for a stock car used in AX/DE and/or racing, or a street car with ANY mods.

I just wouldn't. Period.

odurandina

thanks.

mods.... well, I'm running a mild-cammed, 388 c.i. LS7 with ported heads, long tubes and 3 1/2" open pipe in my 968.

I don't plan to track it, but, maybe I should go non-idiot about my ball joint choice, and stay with the Porsche A-arms.

don't know if those rebuilt arms will be solid or not.

but, we know the oem arms are.

Mahler9th

Back in the mid-90's, when I decided to "try" a rebuilder, there were two choices. Both in Texas.

If I recall correctly, one was <$200, but a business I had never heard of despite about a decade of involvement with 944 family cars. The other was a long term Porsche parts place that I had done business with before and is still active. Their price was >$200.

After speaking with some racing experts, I decided to try rebuilds and chose the more expensive option. I decided to forego the $$ for Fabcar arms, opting to wait until the car was more developed and my budget was larger.

The arms I sent them were from an '89 944 Turbo (same as '88 Turbo S). They had seen a few seasons of use in DE and AX, and only about 25k of street mileage. The car had a stiffer than stock suspension, 17 inch wheels and a 968 M030 sway bar up front. Ride height was just below M030 specs.

In my first track event days after receiving and installing them, the ball pulled out of the left side arm. This happened in the second session, starting somewhere before turn 1 at Thunderhill. The ball was completely out at the exit of turn 5. The resulting accident damaged a wheel, the left front fender, the Koni double adjustable strut, and ripped off the brake line, so I had no brakes.

I contacted the company to give them a heads up as I presumed they made a mistake in their processs-- perhaps with epoxy or ??? I wanted some compensation for the several thousands of dollars of damage and to help ensure no other Porsche folks were put at risk. Since they were a "trusted" resource, I was most concerned about the latter, and assumed they'd be stand up about the former.

Well, lawyers had to get involved. Mine was a fellow 951 driver with a nearly identical car that was in my car coaching my wife the session before the failure. I got paid and my lawyer got paid and I have never done business with the rebuilder since then. Nor have I recommended them. They are still in business and still offer rebuilt arms.

I still have the damaged arm and ball joint in my shop. Jim visited my garage and wrote an article about my engine build for a couple of issues of Excellence back in Y2k or so, and he took pictures of the failed parts, but he never published the article before he sadly passed away.

There is no evidence to suggest that my failure couldn't have happened on a spirited street drive or on my commute to work.

So even for modified street cars, I'd use a lot of vigilence when/if the need arose to deal with front ball joints.

By now there are a lot more statistics with various kits, processes and configurations. But I'd still only want to do business with an enterprise that would stand up if something happened.