ph31mwl

After reading prior threads and corresponding with a forum member I have decided to put a C3 camber bracket on my 65 Vette that I am in the process of rebuilding. My question is do the basic rear (or front) alignment settings change if I do this? According to an article I have read the toe in and camber settings for 63 to 82 Corvettes are;

Rear 63-82 Corvette Daily Driver Advanced Street

Toe 1/8″ in 1/8″ in
Camber 0° neg .50° neg

Do the settings for my 65 change by installing the C3 camber bracket on my car?

Thank your for your assistance,

Mark

DansYellow66

I'm going to say - no. Seems I remember the C3 camber bracket extends lower and helps minimize camber change during cornering a little. I can't see why that would require a change in the static camber and toe in settings.

DUB

If they bracket is installed and is only changing the angle of the strut rod and the camber is set back to what it was...I do not think that it would effect the toe...thus...the only time this change will be felt is when cornering and not sitting still.

DUB

SWCDuke

Unless you're going vintage racing with wider, stickier tires than what is typically installed on road-going C2s, it's doesn't make much sense.

For one thing the OE or OE reproduction under-the-car C2 exhaust pipes will likely interfere with the C3 strut rod bracket, which is no problem for vintage racers that have side pipe racing exhaust systems. GM had to "mash" the C3 pipes more than C2 pipes in order to get acceptable clearance.

The C3 strut rod bracket reduces the roll center height, which reduces the inherent roll stiffness due to the springs, so, all other things equal, the car will understeer more. Camber and toe change will be reduced, which is good but, again, that's not going to be of any significant benefit in road driving with typical low speed-rated rock hard compound replacement tires - what I call "van tires".

The primary reason Chevrolet engineers redesigned the strut rod bracket for a lower roll center is because the wider tires planned for '68-up are less tolerant of camber change, and the C2 certainly has a reputation for sudden transition to oversteer, but C3s, especially early models before they increased the size of the base suspension front ant-roll bar from 3/4" to 13/16", also have the tendency. One way to mitigate this is to install hard urethane bushings in the front anti-roll bar links that connect the bar to the control arm. (The rubber pillow block bushings are okay.)

That's because the rubber link bushings compress due to roll, but there is no equivalent compliance in the rear, so as roll increases, roll stiffness distribution biases to the rear, which can cause the car to snap into oversteer powering out of a corner, and loss of toe-in on trailing throttle as the rear suspension uncompresses from the torque reaction can lead to trailing throttle oversteer. I have lots of experience with these dynamic responses on my SWC, so I know what to expect and how to react.

Now if you want to install Avon CR6ZZ DOT legal racing tires and use maximum performance alignment settings, maybe the C3 strut rod bracket will have some benefit.

With radial tires C2/C3 rear toe-in should be set as close to 1/32" per side as possible. For both models rear camber for normal road driving should be -0.5 deg. and up to -1.0 deg. if you like to attack twisty roads with vigor. (Front camber setting should be zero for "touring" applications, and up to -1.0 deg. for serious canyon carving.)

Duke

Bill32

Will the bracket change camber? Yes, the strut rod when detached from the bracket and still attached to the bearing hub moves in an arc. The position of the pick up point on the bracket moves straight down.

Will it change the camber noticeably ? No and won't get it out of spec.

Will it improve camber control in a corner - a little but it will take a very good driver to notice it.

Will it change toe - No. Doubt if you could even measure it.

One of the main reasons to move the pick up point in the rear is to reduce bumpsteer ( toe in change in bump, especially on corner exit).
C2's will loose toe in in bump and if they go to toe out on corner exit, snap over steer can occur. (If you are going to run 1/8th toe in, don't worry about it.)

If you don't have the equipment to measure camber and bumpsteer, it will be hard to verify if the bracket changes anything.

But, putting the bracket on won't hurt anything either so, put it on if you want.

ph31mwl

DansYellow66, DUB, SWCDuke, Bill32
Thank you for all the information you have provided.

Good point that the C3 Bracket will cause interference with the exhaust pipes. I will have to talk to Allen’s Stainless Exhaust people (I am going to have them build a chambered system to fit the long tube headers that I will be installing) to see if they can make slight modifications to lower them a little so the pipes will not hit the C3 Bracket.

I also appreciate the camber/tow in specs for different tires used and for how the car will be driven and what to expect as far as steering performance.

Thank your all again for your advice and guidance.

Mark