Making front upright safer

[Casey]

Hello all,

I have researched previous threads in regard to the upright issues with the early CAV. I was glad to talk with Ian in Canada who makes some fantastic uprights for our cars.

The problem seems to be that the ball joint will lock out before the suspension travel is gone, most especially with bigger tires. This then puts undue tension on the bolts that mount the aluminum block to the aluminum upright. Many of us know what happens next and know it can be catostrophic.

This has me especially worried in that my car sees triple digits reguraly and while around courners with horrible consequences if your car failed.

While I would love to buy the fantastic new uprights, I can't afford them at this moment.

Has anyone thought of machining new blocks that connect the ball joint to the upright, but that put the ball joint at a favorable angle? I havn't yet looked at my car in detail to see if this is feasable, but I have to believe that this might be a cheaper option so we are safe.

In the future, I am still VERY keen to buy Ian's steel uprights, as I am convinced they would be VERY safe and make our cars handle the way they should. As a race driver, I feel my CAV has some odd handling characteristics that are built in with the geometry. I'm eager to see this go away and think those uprights would be the ticket.

 

[Casey]

After looking carefully at the pictures of our uprights, I do not think my idea of new mounting blocks on the uprights is possible. There is not enough room to work with to make it work.

It seems we must either deal with bolt issues or change uprights. Unless there was a ball joint that was the same size that would have more deflection.

Sorry to open back up this can of worms, but I didn't see anyone talking about it from this angle.

 

[chuck smith]

apparently the problem is the bolts can pull through the aluminum blocks. There are washers to help prevent this, but I was thinking of making it a through bolt, with washers on both sides with a nut on the inboard side. It is tight in that area however.

 

[Frank Catt]

Casey / Chuck, take advice and change the uprights, dont even think of continuing at speed on the early units.

 

[David Briggs]

I will second Franks recomendation, Ians uprights are far less expensive than losing the car.
The handling will be more predictable and your confidence level will improve dramatically.
IHMO, Dave

 

[Cliff Beer]

apparently the problem is the bolts can pull through the aluminum blocks. There are washers to help prevent this, but I was thinking of making it a through bolt, with washers on both sides with a nut on the inboard side. It is tight in that area however.

Chuck, I think you nailed it right on the head. Perhaps it's only an interim measure until time and money can be arranged for the upgraded uprights, however, utilizing a through bolt will go a long way to improving things. This is, in fact, exactly the change I made on my car after the upright bolts failed on my CAV mono. It appears as if the failure was caused not so much by suspension movement exceeding the ball joint's range of motion but rather the block bolts simply loosening and unwinding to the point that the bolt is not simply bearing a sheer pressure but rather a bending motion. My upright bolts were 8.8s instead of 12.9s (half the problem) and the blue thread lock that was used at the factory eventually let go. My fix was to use longer 12.9 bolts (with the special washers as well) that go all the way through the ball joint block and then are secured with a nylock nut (and blue thread lock too). I have check them a couple times since and they haven't moved despite some vigorous driving.

Hope that helps.

 

[Casey]

Does anyone have a part number and source where I can get 12.9 grade bolts until I get new uprights?

These original uprights amaze me, to have a car like the CAV with a timebomb in rediculous. Thank god I got on this forum or I would have never known. I would probably have ended up upside down in some trees.

Casey

 

[Casey]

Are the stock rear uprights failure prone and dangerous too?

What else is a timebomb on our cars?

 

[Ron Earp]

Check McMaster-Carr for bolts.

There was a CAV car that I saw pictures of over a year ago that had an accident at Road America I think. If I recall correctly a front upright failed at speed and it tore the car up but the driver was okay and the car repaired.

The situation is by no means simply isolated to CAV. I know that some GTD uprights have failed as well, however, the early CAVs and GTDs shared common DNA and it very well might be the same exact issue under a different name, I'm not sure.

If you find another good source for some high grade bolts let me know as I'm shopping some too for another race car project.

R

 

[Pat Buckley]

Does anyone know when the change was made by CAV to an upright that is better?

 

[Pat]

Ron,

Try:

1877WeRbolts.com - Standard and custom bolts, nuts, washers, machined parts & blueprint fasteners in stainless steel, English and Metric Chicago Industrial Fasteners 1877WeRbolts.com


I have found them to be a pretty good high end hardware source. CAV also had a kit to replace the wrong upright hardware pieces and that is what I used on my car. But that would have been in the pre-Autofutura era and I don't know if it is still available. (Roy Sales may still have some). The new post-100 CAV upright apparently won't retrofit.

As far as hardware goes, for those of you that like to scavange, go to military (preferably Air Force or Naval Air Station) base property disposal yards and you can find all sorts of high grade AN and milspec hardware and fittings often for pennies on the dollar. All of the control yokes, fittings and connections for my race car are milspec and some of the aircraft parts have quite the trick look about them. Helicopters in particular are great parts sources.

As far as the CAV upright problems go, my understanding was that there was an error on some of the early cars and the upright block bolts used were not only the incorrect alloy grade but were also too short. Both issues certainly are cause enough for a problem. When I put the kit on my car, it was clear the bolts were not only higher grade but also much longer. The mixup may have been related to the very early MONO cars being farmed out for assembly.

I am not aware of that many GTD/CAV upright failures given the numbers out there so I'd be more immediately concerned about bad hardware than a flawed design. Cliff's solution certainly would add piece of mind though if you plan on banging curbs on trackday. But everyone should immediately verify the hardware is correct if they have not done so.

It would also be interesting to see if ERA, sprint car or other sports racer uprights would fit.

 

[Casey]

What a bad deal.

Anyone have thoughts or experience with the better uprights available?

Ian's in Canada look great from the photos.

What about the rears, how safe are they? Heard any failures?



Thanks for the help with hardware. I'm not sure if I'll get to drive the GT40 for quite sometime as it looks like I will be rushing to move to race in Europe. If that happens I'll have my Ferrari mechanic friend do the uprights for me while I am away. Yes, I know the irony.

But he loves Ford too and secretly wants a GT40. HaHa.

You can check out my site as the GT40 is now on there with other updates and pics about the Europe racing deal Putsch Racing

Casey

 

[Ross Nicol]

David Briggs has had a rear upright failure in his car during a track session, which is a CAV according to his profile. I read an article that had a photo of the car.A Pantera outing I believe.

Ross

 

[Ron Earp]

Here is a well known National Spec Miata racer having a upright failure at about 80-90 mph. Good outcome for the driver, car was in extremely bad shape. Quite lucky actually.

http://jimdaniels.com/JDBS/jdcrashatRA.wmv

While the crash is over fairly quickly notice how far the car travels in that time period - quite a ways. Fortunately the car didn't flip or catch on anything, else there would have been hell to pay.

Not wanting to pass judgment on uprights for any cars (and I know more than just CAVs have had failures), I just wanted to post so folks would realize it is serious business.

R

 

[David Briggs]

I did have a failure on an early CAV rear upright, but I had installed a different set of lower control arms and in so doing the bridge that transfered the load from the ears on the bottom of the upright up to the attach bolts for the calipers were not used, and that is why it failed.
The design of those lower control arms has been modified and is now ok.
I think that the early CAV rear upright is fine as long as you don't attempt to support the lower control arms by the ears alone.
Dave

 

[Chris Duncan]

If you find another good source for some high grade bolts let me know as I'm shopping some too for another race car project.

R

AN costs just a little bit more and it is the BEST

Bolts from Aircraft Spruce

both east and west locations

(standard sizes only though, no metric)

 

[Chris Duncan]

Don't be afraid of red lock-tite either, it's quite a bit stronger than the blue. I don't even use the blue anymore and have never had a problem getting the red loosened when necessary.

 

[Jean]

Hi Guys

I think it important to mention that the early CAV's had an incorrect assembly on the front upright. When I purchased the company in late 2004, I had one of the earleir uprights tested. I have the results available for those who are interested. The only failure was the ball joint at 9 tonnes!
If the upright is assembled with the correct hardware, it will not fail.
Please note that the post #100 cars, as manufactured by ourselves, do have a slighly different design and a change on the upper attachment block. see CAV GT | Resurrecting a legend

Please contact me at [email protected] if you need further information.


Jean Fourie
Managing Director

 

[Casey]

Hello Jean Fourie at CAV,

Are you saying the NEW front uprights are safe?

You mentioned that what failed on the old upright is the ball joint. That is not what I have been hearing. I hear that the ball joint doesn't have enough movement range and that puts undue stress on the mounting blocks. I hear it is the mounting bolts that break.

My car is the 17th built and this upright thing has got me frustrated. A car that you can't have confidence in is no fun.

Casey

 

[chuck smith]

I think he is saying that some of the cars had incorrect hardware supplied, and that if correct hardware is used the upright is plenty strong and safe.