03/02/2026
Part 6 - A little bit of suspension geometry analysis. Just simple 2d front view analysis, that will give us some insight about camber curves and roll center heights. Found this free software from CRD Free Racing Software
Provided by Philanthropy In Motorsports: https://philanthropyim.org/free-racing-software/
I did some quick are dirty measurements of the Vette's rear suspension at full droop, just using a tape measure, ruler and plumb bob. I measured it in the pre 2010 configuration, and I know the the lower inner points get moved down 2.25" and the upper outer go up 1" to get to the post 2010 config.
Measurements taken: Height from floor and width from center of the 2 inner points and 2 outer points, link lengths and angles, height of the center of the wheel hub, and tire diameter and track width (distance between tire centerlines at the contact patch).
Refer to the first 2 images with the mock suspension....The software is an Excel spreadsheet. As the points are entered, the suspension is at full droop (called static in this software), so changing the "Chassis Dive" cell to 2" give the values at out real Ride Height or Setup Height. I also messed around with static camber values to give approx. -2deg at RH/dynamic 2". We can see for the pre 2010 config, the dynamic RC in the green box (dynamic meaning at the dive value, not static) is at 5.5" above the ground. Compared to 0" post 2010 config (as we have been running it). Not really sure why there is lateral offset to the roll center with a symmetrical suspension and no roll....so going back to the favored pre 2010 config, we will be getting a substantially raised rear roll center. This typically frees up the rear and reduces understeer. This should allow us to run more roll stiffness in the front (front bar on stiffer setting). What is more interesting is the camber curves in dive and roll.
Refer to the last 2 images with the matrix of numbers....In the PRE config camber curve for loaded (outside) tire, travelling down the straight would be 2" dive and 0 deg roll, mid corner would be 3" dive 2 deg roll. You can see that the PRE config camber stays very consistent thru this transition, losing around 0.8 deg. But in the POST config, thru the same transition we lose 1.5deg of camber. With the PRE config, there should be a few benefits - the car should be more predictable and have more rear grip, as the camber will not be fluctuating as much. We should also be able to run less static negative camber (car setup), and still achieve the desired mid corner camber (this can be inspected at the track by taking tire temps across the tread post session, or looking at tire wear). Less static camber will also give better contact patch in the brake zones.
So starting with the PRE 2010 config for 2026 season, the bump steer will be improved as discussed in earlier posts, and we can start with less static toe in. The camber curve is improved and we can start with less static negative camber. The rear roll center will be higher, so likely start with the front bar on full stiff (its been on full soft). The cars general characteristic is understeer, so the higher rear roll center should help.
