A-Arm Pin Failures on track - Printable Version
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A-Arm Pin Failures on track - flash - 09-06-2008
the swaybar does its job by resisting movement - that resistance is provided by the control arm to which it is connected - bigger sway bars mean more resistance - the control arm has a limit to how much force it can withstand before it breaks - the means of connection frequently adds to that force by its own geometry limitations, as is the case with the OEM link
A-Arm Pin Failures on track - Eric_K - 09-15-2008
I would like to revise my opinion that my pin broke just because of accident damage. I found the drivers side pin was cracked on Friday and it had never hit anything. 17mm pins of extended length should be watched closely.
Unfortunately, on Sunday the drivers side did hit something but that is another story....
A-Arm Pin Failures on track - Torbjorn968 - 09-15-2008
[quote name='Eric_K' post='59820' date='Sep 15 2008, 06:57 PM']I would like to revise my opinion that my pin broke just because of accident damage. I found the drivers side pin was cracked on Friday and it had never hit anything. 17mm pins of extended length should be watched closely.
Unfortunately, on Sunday the drivers side did hit something but that is another story....[/quote]
Anyone seeing reports of problems of pins with standard lengtht? Hope the driver side is not to badly hit <img src="/forum/images/smilies/968/sad.gif" class="smilie" alt="" />
//T
A-Arm Pin Failures on track - pipalli - 09-23-2008
Sorry to hear about the accidents. Thanks for sharing your stories so we can all learn. I plan to take my 968 to WSIR next month so I inspected
my hubs, spindles & a-arms, but did not pull the ball joint apart. Is this an easy replacement? My a-arm part #'s did not match those listed by
the quote from Mr. Springer from porsche motorsports, they are 944.341.149.02 & 944.341.150.02 . Are these stock or ?
JP
A-Arm Pin Failures on track - RS Barn - 10-16-2008
I am having a 19mm pin upgrade made for Fabcar arms . The spindles will need to be machined like Charley arms required for their 19mm pin
Pete
A-Arm Pin Failures on track - Torbjorn968 - 10-18-2008
[quote name='RS Barn' post='61772' date='Oct 17 2008, 02:17 AM']I am having a 19mm pin upgrade made for Fabcar arms . The spindles will need to be machined like Charley arms required for their 19mm pin
Pete[/quote]
What do you recommend regarding A arms? It is not clear to me if it is the pin only or the arm itself which is the cuprit. If it the arm what is the best choice for a really low car?
//T
A-Arm Pin Failures on track - RS Barn - 10-19-2008
The stock control arm binds at ball joint pin if car is lowered too much. This usually results in pin failure although I've seen the ends of the arm break off.
At this point I would recommend Racers Edge control arms with their huge threaded pin. It also has an outer sleve to support the pin.
The Fabcar arms are very strong but still have a 17mm pin. They suggest their pin failures are due to stress and fatigue. I still like the idea of a larger pin and have convinced them to offer a 19mm upgrade pin.
With both of these, there is still a limit to how low the car can go for several reasons. The geometry was designed for a certain ride height and when you lower car too much the roll center is bad. I've also noticed the pinch bolt for the spindle actually contacts the control arm when fully extended and machines a nice groove in the end of control arm by ball joint. This is just calling for a new type of failure
Pete
A-Arm Pin Failures on track - Torbjorn968 - 10-19-2008
[quote name='RS Barn' post='61863' date='Oct 19 2008, 04:10 PM']The stock control arm binds at ball joint pin if car is lowered too much. This usually results in pin failure although I've seen the ends of the arm break off.
At this point I would recommend Racers Edge control arms with their huge threaded pin. It also has an outer sleve to support the pin.[/quote]
Any definition of what is too low? Racers edge is one alternative and charlie arms another if I have my Internet right. You preffer RE? Does these arms also adress roll center issues?
//T
A-Arm Pin Failures on track - Torbjorn968 - 10-20-2008
[quote name='Torbjorn968' post='61867' date='Oct 19 2008, 09:06 PM']Any definition of what is too low? Racers edge is one alternative and charlie arms another if I have my Internet right. You preffer RE? Does these arms also adress roll center issues?
//T[/quote]
Is it lowering that is the problem or maxing out on suspension travell? See pic of a relatively standard car and my car which is lower but with stiffer suspension.
A-Arm Pin Failures on track - z851@yahoo.com - 11-09-2008
Hi Crew,
I am looking at purchasing the follow arms:
I have a pair of late offset Charlie A-arms (Wrightwood Racing) for sale and some Charlie castor blocks included as well. These arms are used and there is some rubbing from the suspension on the bottom outside side but it does not affect function at all. These arms are very heavy duty and beautifully made. There is a brand new set of ball joints and the pins included are the original 19mm size.
Any thoughts??? I have not heard of the Wrightwood arms discussed in any of these posts.
Thanks,
Craig
A-Arm Pin Failures on track - z851@yahoo.com - 11-10-2008
Ironically, as I looked at the Racers Edge web site (http://racersedge-inc.com/racersedge/rehome.nsf/racer%27s_edge_project968_03.pdf) on how to build a 968 race car, they are not using after market arms and their car would appear to be rather low.