C5 Corvette Steering Knuckle Spindle strength

[jb1]

76mx, I see that now.. one of my car's is using c5 control arms, that is actually the one I  was planning on using them on. After finally receiving IFG chassis plans  I see on the diablo chassis it won't get the c5 arms...  Was just trying to be of some help...

[76mx]

http://www.quickracingproducts.com/html/chassis.html
For those looking for shock mounting options for the c5 this is what I have considered ordering..

JB1, Those are $353 each for the steel ones with coil over kit and springs. Times six of them that is $2,188. The aluminum ones are $457 each for all of it, and times six of them that is $2,742. Neither of them is single adjustable, let alone double adjustable, and here I thought QA1 was ridiculous. I am a dealer for Viking, six of them double adjustable in aluminum with coil overs and your choice of spring rate $1,400.

[jb1]

http://www.quickracingproducts.com/html/chassis.html
For those looking for shock mounting options for the c5 this is what I have considered ordering..

[MufasaCAT]

That's a good idea RStaggs.
If I have to rebuild my A arms I would do this as it would save the binding problem. Cheers

[RStaggs]

I’ll put in my two cents. I noticed the issues with the front a-arms binding, on a NAERC chassis. So I pitched my upper a-arm receiver bushing 7*. It took a tremendous amount of stress off the c5 spindle, and added more a-arm movement.

[rodartneva]

Someone.was asking why the shock is mounted to the top arm and it is the way that lamborghini does this. I don't use corvette suspension I have cast spindles like own with the arms and mounts the same. I was not a fa. Of the crossover to the vette suspension and understanding is the arms aren't angles up ward in the naerc setup and the front lower arms actually have a fight angle built into them. If you set them on a flat surface you would know what I'm talking.about. If  get some free time i will upload photos of all of this as I an working on a chassis right. So in the photos you can see that I can fit a magazine under the one side. This is a new factory arm I have a couple of these and they are all the same. The mounts on the chassis also have angle built into them as do the rear. And you can see where the shock mounts on the upper front arm which is twice as heavy as the lower arm.I don't know why people use the vette stuff. For me this is correct and costs less.

[MufasaCAT]

I have two ways to do this as i can't prove the strength of the C5 spindle.
1) I can mount the shock on the bottom A arm as OEM. This can be done with a few brackets and moving the Sway bar forward about 100mm.
2) Model the C5 spindle in Solidworks and give it to a poly-tech as a engineering class project which the TAC in New Zealand will look at the results and give an answer. This shouldn't cost me much money.
I just have to see which is the best way to go.
There are 3 diablo builders in New Zealand using the NAERC chassis that I know of.
Cheers

[01Lambiero]

Touché, mon ami.  

01

[99svmonterey]

I believe others have tried using the stock C5 setup on the front but the turning radius wouldn't work. That was with factory control arms. Modifying the NAERC lower control arm to accept the shock like the C5 lower arm should work in theory. You would have to design a new bracket to fasten the upper shock bolt to of course. Moving the upper shock support down from under the front hinge beam to the area where the upper control arms bolt on may create new stress issues the chassis wasn't designed for though.
On a sidenote, NAERC (Ken Esler) was located in Saskatoon, Canada so that's technically 2 Canucks and 1 Kiwi. 

[01Lambiero]

Since you are located in New Zealand, NAERC was located in USA, Jim Dinner was located in Canada, wouldn't it solve your problem in New Zealand just to setup your suspension in the OEM Corvette arrangement as manufactured?
01

[aeauto]

I think that I am missing something too. I understand what they are saying and agree that the alloy upper arm was not meant for loading, but why is it the loaded arm? When the lower arm is loaded on the last four inches of a 16" arm, the motion ratio is 1 to 4. Mounting to the last four inches of an 8" upper arm is 1 to 2. This is way oversimplified, but you are going to need a 1,500lb spring and a two inch diameter swaybar.

Charlie,  I believe he is doing the front suspension.  I don't see why both the coilover and sway bar can't be fitted to the lower a-arm as that is the way I do mine with the Mustang II spindles and tubular a-arms.  Since there isn't an axle to get in the way there should be room in there.  Am I missing something?

[MufasaCAT]

Yes diablodoc you are right I have spoken to Jim Dinner and he hasn't had any problems. The OEM has the same setup - I agree but I'm only doing this so I can drive my car on a New Zealand road. If I can prove that the C5 spindle is strong enough I would stick to my setup as i have already finished this (I don't need the extra work).
If the C5 spindle was made of steel I wouldn't have this problem, its just because aluminum has a set life per section area.
I'm not saying that the C5 spindle is going to fail it's just I can't prove it won't.
It's getting harder and harder to build a car in New Zealand with all the rules. It's like the USA brake peddle is a fail in New Zealand as the pivot ratio is wrong so I had to make a new one to make the TAC happy, is it safer NO but I had to do it.
Another thing I had to do was to draw the whole car in Soildworks so I could supply full working drawings of ALL parts of the car - this was a big job you can imagine.

[diablodoc]

I'm a little surprised at the comments on this thread.  Mounting the front shocks to the upper A-arm was not only the standard for all NAERC cars, but they patterned their setup based on Lamborghini.  All OEM Diablos had this same setup.  The only difference is that they had a proper ball joint arrangement that was made to accept the force applied to it.  And by the way, there is plenty of room for the shock/spring in the Diablo wheel well.  Jim Dinner built both of his cars this way (using the Honda ball joint) and to my knowledge he had zero problems with either.

[MufasaCAT]

Hi guys
This is my setup same as Kens but the problem is that the bump load goes through the top of the C5 spindle which it wasn't designed for. So I have decided to mount the shock from a bracket welded to the beam where the top A arms pickup and mounted to the bottom of the A arm. This will bring it back to a standard C5 setup so there is no extra load on the top of the C5 spindle. I will have to relocate the sway bar to allow the shock room.
The problem is that aluminum has a endurance limit and will eventually fail even from small stress amplitudes. So if the top of the C5 spindle is not designed of an extra load it could fail.
A good link worth reading is https://en.m.wikipedia.org/wiki/Fatigue_limit
The Honda Accord ball joint is a Moog K9643 to help with the extra load but it's not necessary if I mount the shock to the bottom A arm.
Will be interested on your thoughts. I'm really doing all this because New Zealand TAC will not allow my car on the road unless I prove that the C5 is strong enough through a FEA test and that could cost thousands of dollars.

[76mx]

MufasaCAT, Quite a bit of research from myself along with Energy Suspension and Rancho Suspension went into the decision to mount the swaybar on the top a-arm. The end result of that research is that the swaybar does not know which a-arm it is mounted to, so long as the rating is correct for that new motion ratio, and because a swaybar can mount much farther outboard than a shock, that ratio is realistic. All of this was done for two reasons. First for your same reason, there was not enough room for both on the lower a-arm, and second to get the swaybar to clear the transaxle without complicated contortions.