OZ951

I have been searching around but haven't been able to find if anyone is making delrin control arm bushings for stock 951 aluminium control arms. Does anyone know if the delrin bushings are available ? I have had stock rubber and Weltmeister red PU bushings in there but they have started to wear with only 11 track days on them.

Larry Herman

Forget them. If you are going to track the car, buy Fabcar or Charlie arms. The ball joints are not strong enough for the track. Our original ball joints got loose, and then we tried rebuilding them, and they got loose again twice, and then the ball joint spindle broke! Fortunately inspection found the problem the first two times. The third time the ball spindle broke at 100 mph, but luckily the wheel went straight back and lodged itself in the fender. Fortunately my son was able to get the car stopped straight. It could have been very bad.

jc22

Search the 951 board. I believe Adrial made some prototypes and there were some references to others more easily available.

Bill L Seifert

Larry,

That depends on where you race. In SCCA they are specifically not allowed. Of course that is just for SCCA ITS. (Where I will run with a 944S) If you are running in ITE with a 944 Turbo, you can run the Charlie or FabCar arms, because ITE is kind of a run-what-you-brung class. Of course all other sanctioning bodies allow them PCA, NASA.

To OZ951, I don't think anyone makes a Delrin bushing. A guy in Canada named Marcus, has a pretting good arm, but I have lost his Phone Number, maybe someone else can help.

Bill Seifert

1987 944S Race Car under const

Larry Herman

LOL! That's comical Bill, because PCA has deemed them so unsafe, that you cannot run the stock aluminum arms anymore, even on a bone stock car.

Mike Buck

That is not true. The rules state you may change the control arms for approved aftermarket parts, but it is not mandatory and/or needed.

Wayne,
If you are interested in Delrin for the control arm bushings try PM'ing "Chris Prack". He hasn't posted in a while, but earlier this year I believe we discussed this. He told me he could make some for me.

Larry Herman

True, it does say that, but I was under the impression that the scrutineers weren't allowing 951s to run with stock A arms. Anyway, with my experience, and from others as well, I will never take a stock A armed 951 out on the track again.

Doug Donsbach

I've never had a scrutineer even look under the car, let alone ask what kind of control arms I was using, but I still wouldn't track a 944 with the alloy arms.

Bill L Seifert

Doug
I wish I could make that choice, but mine is either run alum, or not run, or cheat. That's life.

Bill

1987 944S Race Car under const.

OZ951

Thanks for the responses.

JC22 I have looked through the 951 board for some meaningful comment and had previously contacted Ahmet since he had in fact made a prototype but I had no response from him. Hence the post here.

Mike thanks for the tip on Chris Prack, I'll see if I can locate him.

Larry, I hear you with respect to the stock control arms, I'm not yet in a position to swap them out hence they get a good inspection every time (hence my finding the wear that developed on the new-ish poly bushings) My 951 is not yet a fully fledged track car and so is not as low as i'd like to have it, I believe that once properly lowered the suspension geometery becomes poor and causes additional strain on the A arms and that combined with track stresses ultimately leads to failure.

Bill thanks for the Canadian A Arm tip, I'll see what I can find.

I was talking to a friend who races stock cars here and he has offered to machine some bushes out of nylon. I'm not sure where nylon fits in, in comparison to poly urethane and Delrin, any comment ?

Cheers,
Wayne

Rich Sandor

I'm told nylon wears easier.

Markus knows his 944 control arms well. He re-did my arms last year. I'd recommend him.

There are a pair of 86 951 charlie arms for sale on the 944/951 boards.

With the advent of the DIY kits for 944 aluminium a-arms, you can even install 19mm ballpins (like in the fabcar arms) instead of the stock 17mm ones. You must modify the strut a bit tho to fit it. I think it's the same as the 944 turbo cup ballpin.

Anyways, there are lots of options.

The one drawback about the fabcar/charlie arms, is whomever designed them had a major brainfart and forgot to impletment the rubber boots for the balljoints, to protect them against road grime. Thus, they are unsuitable for road use. (Or so I've read about them... )

/me shrug

Geo

Larry, as a member of the SCCA Improved Touring Advisory Committee (which considered Bill's request for alternate control arms) I feel I need to respond to this. I'm not responding to be defensive, but due to the fact I think there is a poor understanding of how each group works (one group looking at the other).

PCA racing is a one marque, relatively limited scope group. PCA has, as would be expected, many true experts in all of the various configurations of all the cars. It's a relatively simple task to allow (or even require) various modifications from stock. The scrutineers will either know and understand what what changed and why or they will have someone close at hand who does.

The SCCA in contrast has a very broad scope. Improved Touring alone has well over 300 classification lines (cars or groups of cars). There are no experts on all of the various classifications at each race nor even within the rules makers (Club Racing Board and the ITAC which serves the CRB). IT is a very limited modification category. Making allowances for one car sets a precedent that leads to all sorts of anomolies and is diving down a slippery slope.

I understand fully Bill's (or anybody's) desire to have alternate control arms. From a narrow perspective it makes sense. From the big picture it doesn't. Too easy to get out of control. The BMW guys want to install braces in the chassis from the M3. The VW Golf guys want to use alternate wheel bearings. And the list goes on. The bottom line in this category (IT) is the cars get limited modifications. There are other categories with more open rules that could accomodate this.

Again, this is not to be defensive in the least. I try when various issues come up to get the ITAC to understand the perspective of those who race PCA and BMWCCA. I don't race with those groups, but understand how and why they have a more narrow view of the racing world where many in SCCA don't understand. They are good groups that serve very different purposes.

One last thing, there has been a feeling that the SCCA is afraid of Porsches and classify them poorly. Well, I'm not sure that the SCCA is afraid of Porsches, but the classifications are improving. The 924 has been moved down a class for next year as have the 914s. The 944s are still outclassed (although not by that much) but I'm still lobbying for some relief. We'll see. With the classification of the 944S at a much more favorable power to weight ratio, the poor P/W (as classified) of the 944 is at least getting noticed.

Geo

Wayne, I've been thinking about this one. I'd be kind of surprised if you found Delrin front control arm bushings.

One of the issues with using them is your control arm would have be be perfectly lined up front to back. IOW the trailing pivot would have to be in the exact same axis as the leading pivot. Anything else and your suspension will bind. Rubber bushings will deflect when the suspension binds and so with urethane. You don't notice the bind because they deflect.

Take a hard substance like Delrin and I don't think it will deflect.

The solution for you would be spherical bearings. Not cheap however.

OZ951

I have had a look at Markus's web site and he has emailed me some information regarding his control arms. I think I will make that the next upgrade for reliability / peace of mind as well as any handling improvement.

Thanks Geo for the thoughts regarding binding. I did contact Racers Edge regarding spherical bearings for the front of the control arm (only), I didn't ask about binding as it was prior to your comment, however they also did not mention any issues with using a spherical bearing at the front with a rubber castor block in the rear (Incidentally I use 968 castor blocks which have less potential movement).

macnewma

OZ-

I have some delrin front bushings on a set of 86 control arms. They aren't installed in my car, and I recently purchased some Charley arms so they won't get installed.

The bushings were fab'd by lister in NC named Ahmet. I bought them second hand with the used control arms. Here is a link: https://rennlist.com/forums/showthre...+front+control

The arms are for sale with the bushings or I could push the bushings out and sell them separately. In my opinion, you would be better off getting some reinforced arms from Marcus or a set of Charley arms since you track the car. But if you are interested, let me know.

Max