[nissanite]

The purpose of this is not to cast blame or start any issues. I broke a pin Saturday on the right front turning in for turn 13 at Sebring. The car stopped inches from the wall, ending our weekend. With some minor front fender damage the car was towed home & added some batwing damage.

Please do not use the name of the supplier to cause a stink. The supplier of my arms is a well respected vendor of parts for our cars and was kind & helpful on the phone today but said he had never heard of a pin failure on their arms.

If this is unappropriate please excuse me

Partial Post: Please Login or Register to read the full post.

[Johannvb]

That must have gotten your hart racing!

I'm glad you managed to get ti sorted.

Partial Post: Please Login or Register to read the full post.

[94SilverCab]

Add Crespo's name to the same list...his was a result of using 17mm pins. His outcome was not as successful as yours [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img]

Jay

Partial Post: Please Login or Register to read the full post.

[RS Barn]

I have said broken pins in stock along with new replacements. Mfg can't possibly say they haven't heard of failure
I had some harness testing done but didn't pursue, just moved on to better products with 19mm pins

Partial Post: Please Login or Register to read the full post.

[MC968CS]

Can someone please clarify specifically
1. what exactly keeps breaking and is this the same on all 968's (CS, Euro etc)
2. What exactly is the best fix , ie: our options, parts summary, work required. Thanks.

Love my car, hate the idea of this failure on a high speed circuit.

Partial Post: Please Login or Register to read the full post.

[RS Barn]

OK, There are several problems and failures.
1. Stock ball joint pin breaks from fatigue or binding when ride reight set too low. When you lower front ride height too much the control arm will actually sit up from level even without weight on car. When suspension is loaded the ball joint pin binds on control arm and eventually breaks pin or control arm. Top arm
2. LR Aftermarket Arm uses longer ball joint pins to correct lowering geometry. This then puts much more stress on middle of pin. See broken pin Middle arm
3. Another aftermarket arm uses a much beefier pin at base but still 17mm where it goes into spindle. I've forced that manufacturer to make 19mm at upper point . then we machine spindles to accept Lower arm
4. Racers edge makes an arm with best of all. 19mm pin that is longer to correct geometry and pin is space age alloy-very strong. No pic available

Partial Post: Please Login or Register to read the full post.

[nissanite]

Thanks Pete! So many choices, so little money!

Partial Post: Please Login or Register to read the full post.

[nissanite]

Using the middle arm would it be smart to add a very slight chamfer to the bottom of the spindle to spread the load over more of the pin.?

Partial Post: Please Login or Register to read the full post.

[pmcrespo]

Great to read there was no contact as a result. Excellent news. You'll make the upgrades and hopefully will never have to look at a totaled car as a result. The only think that is left of my #68 race car is the hood hanging on Pete's shop wall and the Rear Bumper. [img]style_emoticons/<#EMO_DIR#>/mad.gif[/img] For sale by the way.. LOL... And all manufacturers KNOW the issue very well, and there should be liability and accountability with recourse for damages as a result of failed pins and/or arms but the reality is that this is a tight small community and it becomes difficult in more than one way. I just wish the product manufacturer would have just stepped forward with a voluntary private offer to help some going forward...

Pete is working on my new (to me) race car (breaking news soon...), which coincidentally rolled into the Barn this weekend with a broken arm as a result of contact with another vehicle on track. In this case, the arm was the one tat actually broke. Nonetheless, when it rolls out, it is DEFINITELY going to have 19mm pins on both sides with a pair of one of the top two arms on the market per his recommendation. Along with that he will likely also replace the hubs with billet racing grade units. This is especially important if you are planning to run non-DOT slicks with added grip as we may decide to do in NASA GTS3.

Good luck with your repairs!

Partial Post: Please Login or Register to read the full post.

[MC968CS]

Fantastic, thanks for a great reply Pete. I will follow it all up for my car!

Partial Post: Please Login or Register to read the full post.

[MC968CS]

Pete, is this the kit from Racers Edge you refer too?

http://www.racersedge-inc.com/racersedge/r...&id=11.3.10

How do you decide what pin length to order, anyone know?

Partial Post: Please Login or Register to read the full post.

[MC968CS]

Crespo, what is the rationale behind replacing the hubs - is there a safety aspect that is the key driver, or weight, or other? Thank you.

Partial Post: Please Login or Register to read the full post.

[Dubai944]

The stock hubs are known to crack with racing loads. I have the Racers Edge billet hubs and their control arms and long pins. 18 months of racing with full slicks and no signs of any developing fatigue.

Pin length depends on how far you want to lower the car. The lower you go, the longer the pin needed the restore the geometry of the arms. I have the +1.5 inch pins which puts my control arms close to parrallel with the ground with about two inch drop. You have to lower your tie rod ends also if you want to avoid big changes in bump steer.

Partial Post: Please Login or Register to read the full post.

[pmcrespo]

Yup! Thanks...

Partial Post: Please Login or Register to read the full post.

[benspeeder]

My car is also at the Barn getting 19 mm pins and new hubs with stronger, longer studs...

Some of the parts on my car lived through Crespo's crash and I want to be sure those parts and ME don't have another pin related crash.

Partial Post: Please Login or Register to read the full post.

[flash]

be careful about going too far down in ride height - even though you are "correcting" the geometry by altering the pickup points on the front control arms, the unresolved problem is the rear suspension

the roll center for the rear, due to the nature of the design, is very high - this creates a roll axis point, just as the front suspension geometry does - while this makes for a very compliant street car suspension design, it has limits when you try to really push it - the rear will tend to continue to roll, and take the rest of the car with it

ideally the line drawn between your roll axis points is close to parallel to the ground - dropping the front requires a corresponding and proportional drop in the rear - there is a very real limit though to how far you can drop the car in the rear, without major redesign - in a perfect world we would have unequal length control arms in the back instead of the VW bug banana arms

if this is not thought out on paper, you can go through all the hoops to fix up the front end, spend a fortune on parts, and actually end up with a car that is slower in the corners, can tend to oversteer, and be more unstable during weight transitions - the more you try to fix and tune it with add-ons like stiffer springs and swaybars though, the more understeer you will end up with, often without correcting the original oversteer - you can easily end up with a car that fells like it's on marbles

beefier parts are great, and resolving failures is a good thing, but like anything, the parts can be misapplied

it is always best to draw the suspension geometry out on paper, and then see where it wants to go, and what things have what effect on the angles

Partial Post: Please Login or Register to read the full post.

[benspeeder]

Hey Flash - that's why I pay the best to setup the car [img]style_emoticons/<#EMO_DIR#>/cool.gif[/img]

Partial Post: Please Login or Register to read the full post.

[flash]

yup - pete and i have had this conversation - through a lot of work, he has also discovered where is the "point of no return" on ride height, as well as what happens when the car is "over-sprung" (which a lot of cars are)

it's all about the design and the geometry - this car is not like any other, and acts very differently than others to changes

Partial Post: Please Login or Register to read the full post.

[MC968CS]

Thanks all, new arms and 19mm pins are on the way. No point for me in building up a quick 968 club car and having this potential failure in the back of my mind. :-)

Partial Post: Please Login or Register to read the full post.

[AJG]

Could the ball joint be turned upside down with the ball swivelling in a socket on the steering knuckle. Let me quickly add I haven't seen this part to judge the efficacy of machining it to accept a housing, which could be an oblong block say, with a machined bore and alumnium bronze cups on both sides of the ball to hold it closely but allow swivel movement. This would allow a fat pin into the lower arm. This might be acceptable for LOWERED cars as it might keep the arm more level. I don't know, I can't shut my arse up sometimes. Excuse me a second. SHUT UP, SHUT UP. There that's all it took, a good telling off.

Partial Post: Please Login or Register to read the full post.