SAAC Forum

The Cars => 1966 Shelby GT350/GT350H => Topic started by: NC TRACKRAT on January 12, 2019, 08:37:02 AM

Title: Axle-Limiting Cables
Post by: NC TRACKRAT on January 12, 2019, 08:37:02 AM
Brant's recent blog for 6S933 shows that this car received axle-limiting cables.  A quick check of the Registry shows no discussion of this topic as to when it was phased out.  Any definitive information on this?
Title: Re: Axle-Limiting Cables
Post by: Brant on January 12, 2019, 11:48:36 AM
Brant's recent blog for 6S933 shows that this car received axle-limiting cables.  A quick check of the Registry shows no discussion of this topic as to when it was phased out.  Any definitive information on this?

No definitive information, but my guess is that they were phased out with the Koni shock installation.
Title: Re: Axle-Limiting Cables
Post by: Bob Gaines on January 12, 2019, 11:54:58 AM
Brant's recent blog for 6S933 shows that this car received axle-limiting cables.  A quick check of the Registry shows no discussion of this topic as to when it was phased out.  Any definitive information on this?

No definitive information, but my guess is that they were phased out with the Koni shock installation.
and or override installation .
Title: Re: Axle-Limiting Cables
Post by: Brant on January 14, 2019, 05:43:41 PM
6S933 appears to have originally been equipped with Koni shocks and under ride traction bars.

Title: Re: Axle-Limiting Cables
Post by: Bob Gaines on January 14, 2019, 06:16:10 PM
6S933 appears to have originally been equipped with Koni shocks and under ride traction bars.
The transition period saw a lot of cost cutting changes. I haven't seen any definitive correlations for each yet . Since the axel limiting (not shock)cables had no direct relationship to the Koni shocks it doesn't automatically mean one phased out with the other . It could be sporadic installation until a final determination or having to do with Shelby finish which isn't always consecutive . It has been thought in the past that it was used to limit shock travel because the shocks did not have built in shocks . People from Koni have dispelled that myth.  There is not any cautionary warning then or now in the Koni literature that care needed to be taken on limiting the travel of the shocks. Having a issue with over extending the shocks would be counter intuitive to the high performance nature of the Koni shocks on any high performance usage regardless of make and model.  The axle limiting cables were a cheap way to limit the roll of the body (shifting weight ) in the turns . It was one of the cheapest high performance driving upgrades parts and installation wise however the problems in testing and the breaking of cables my have been a deciding factor for elimination. The timing of the change might be as you guess and it might not. Hopefully we will at some point narrow it down for sure.
Title: Re: Axle-Limiting Cables
Post by: gt350hr on January 14, 2019, 07:01:47 PM
   I agree with Bob that it wasn't related specifically to the KONI shocks , It is "my opinion" that the procedure was dropped at the same time Konis were discontinued.  It is fairly well documented that the transition from over to under was not real smooth . Cars with upper and lower bars etc. and I can easily see the cables added to "some" under ride cars until that worker was directed to stop doing it. There "might" even be some cars with the drilled holes and no evidence of anything being bolted there.
   Again just my opinion.
         Randy
Title: Re: Axle-Limiting Cables
Post by: Don Johnston on January 15, 2019, 12:04:39 AM
There must be a discussion somewhere with Chuck Cantwell about the cables, maybe????
Title: Re: Axle-Limiting Cables
Post by: Bob Gaines on January 15, 2019, 12:45:54 AM
There must be a discussion somewhere with Chuck Cantwell about the cables, maybe????
Yes there is however it is conflicting. I had a first hand conversation with Chuck C prior to being on a Q+A panel with him along with Dave Mathews .When I discussed the subject with him given the conflicting evidence he agreed with my observations and then later at that same convention weekend someone at the convention dinner gives him a leading question like "the limiting cables were so the shocks don't over extend aren't they? and he agrees. The bottom line is the evidence has to speak for itself because although a great man it is a lot to expect from anyone to remember some of these details almost 55 years after the fact. It was just a job to them at the time after all. I don't think any of the past employees thought they would be expected to remember this stuff or that anyone would care.     
Title: Re: Axle-Limiting Cables
Post by: Cobrask8 on January 15, 2019, 09:08:19 AM
This type of discussion is not unique to the Shelby's, but I do agree on this thread from a documentation point of view.

I have an early FFR Cobra, and FFR used to provide limiting straps so the shocks would not be continuously over-extended to the point of failure, and come apart. Like Shelby, the replacement with better shocks made the straps not needed.

But, a big point made on the FFR forums and technical discussions, and should be taken into account here, is that if the straps are too short, and limit body roll, this will hinder controlled body motion and cause some very ugly handling. By creating a travel stop  on a solid back axle, the result will be the car picking up the inside rear tire in a very hard corner. Not what you want.

I do have straps on my race car, but they are long enough not to interfere with body motion, but will not allow the shocks to fully extend. That is how the straps should be set up.
Title: Re: Axle-Limiting Cables
Post by: texas swede on January 15, 2019, 01:12:48 PM
My friend Roland's car in Sweden, 6S923 had underrides, axle limiting cables and most likely Konis.
Same as Brant's car 6S933.
Texas Swede
Title: Re: Axle-Limiting Cables
Post by: Don Johnston on January 15, 2019, 07:16:27 PM
Was the idea to use of the cables unique to the Shelby Mustangs or something used by other racers or car builders around that time?
Title: Re: Axle-Limiting Cables
Post by: GT350Lad on January 16, 2019, 05:41:36 AM
There must be a discussion somewhere with Chuck Cantwell about the cables, maybe????

The new Chuck Cantwell with Greg K book mentions the cable use as being due to the Konis but like Bob said after 50+ years things can get a little hazy. Interesting topic, I remember looking at the cable on one side of my car (one missing) and thinking what is hell is that  ;D
Title: Re: Axle-Limiting Cables
Post by: Bob Gaines on January 16, 2019, 10:52:21 AM
So many people have repeated that urban myth I believe Chuck C.  with possible foggy memory which is no big surprise with a obscure detail like this after close to 55 years just started agreeing.  A high performance Koni shock would be expected to be fully extended at some point in race driving as in the famous 4 wheels off R model picture at Green Valley. If such a design flaw was present in the shocks there would be a warning in the Koni pamphlet to keep it from happening.There is not then or now. Koni techs also confirm there is no need.   
Title: Re: Axle-Limiting Cables
Post by: gt350hr on January 16, 2019, 11:43:08 AM
   Bob,
       I can say  proof positive that the shocks WILL top out before the cable is taught IF the is lifted vertically. YET if you use "body roll" , the cable will go taught BEFORE the shock tops out. The cable location is a bigger "arc" than the shock is on , so the "separation " is greater at the cable than at the shock in a "body roll" situation( as if it was designed that way LOL). I "found" this when testing on my car  ( very high arch drag race springs). My Konis were "topping out" and I had to add some aftermarket shock extensions to eliminate the issue. My spring's front half is so strong ( along with the over ride bars) that the body actually rises away from the tires ( the opposite of a softer "stock" spring). I found the limiter cables still had 1-1/2 inches of "travel " that was limited by the shock "topping out".  A little bit repetitive , sorry.
     Randy
Title: Re: Axle-Limiting Cables
Post by: Bob Gaines on January 16, 2019, 04:13:05 PM
   Bob,
       I can say  proof positive that the shocks WILL top out before the cable is taught IF the is lifted vertically. YET if you use "body roll" , the cable will go taught BEFORE the shock tops out. The cable location is a bigger "arc" than the shock is on , so the "separation " is greater at the cable than at the shock in a "body roll" situation( as if it was designed that way LOL). I "found" this when testing on my car  ( very high arch drag race springs). My Konis were "topping out" and I had to add some aftermarket shock extensions to eliminate the issue. My spring's front half is so strong ( along with the over ride bars) that the body actually rises away from the tires ( the opposite of a softer "stock" spring). I found the limiter cables still had 1-1/2 inches of "travel " that was limited by the shock "topping out".  A little bit repetitive , sorry.
     Randy
Thanks for the racers insight Randy .
Title: Re: Axle-Limiting Cables
Post by: GT350Lad on January 17, 2019, 03:18:51 AM
Yeah always love racing stories
Cheers
Title: Re: Axle-Limiting Cables
Post by: gt350hr on January 17, 2019, 12:33:48 PM
  It just shows they were designed for body roll not "Dukes of Hazard" shows LOL
     Randy
Title: Re: Axle-Limiting Cables
Post by: TJinSA on January 23, 2019, 06:29:32 PM
In the pre-crash forum there was a discussion of specifics of the cables-- overall length, diameter, coarseness of the elementary wire, the best, most accurate swedging tool, and locking collar.  Does anyone have a copy of that discussion or its conclusions?