C6 Suspension and Drivetrain under a 1969 Camaro under construction @ Ironworks.

[ironworks]

Then what kind of Analysis are you talking? Stress analysis or suspension analysis? The stress analysis can be done through Solidworks. The suspension analysis we have been working with some engineers and just some smart guys I know. I have had some Hot Rod front suspension spec from some guys alot smarter then me and we have been running with those numbers. But we are now working to improve things even further then that.

Here is an email from some things we are looking into on the C5 suspension.

So I just got done running a few simulations with the C5 Corvette Hardpoints that you emailed to me. The only other thing that would be nice is if I had more accurate Anti Roll Bar hardpoints. Something I found over the past year is that in keeping those motion ratios linear, you can drastically improve the handling of the vehicle.


Some quick notes I have on the C5 chassis:


For Longitudinal Case (3 degrees pitch braking, 3" travel, then 3 degrees acceleration, 2" travel)


Camber looks very good in this situation, appears to be the main focus of this car.
Toe needs serious help - 1.3 degrees toe out in front under breaking (should toe in), rear stays within .7 degrees which isn't bad.
Track change isn't bad, the track increases on the side that's being loaded- good for stability.
Wheel/Shock Motion ratios look not too bad, but something that can be improved with rockers- also, can make them with a rising spring rate to help the car become stiffer as its loaded - all dependent on the springs though.
Roll Center height looks okay except for full breaking, it does go below ground. Having a Higher RCH would help this and can be done a number of ways, I'd be curious to see what happens in a C5 with you mash on the brakes all the way then cut the wheel...
Pitch center looks really good- migrates less than 13", less than 15% the wheelbase, it is pretty high though- probably to make the car more responsive under braking and accel without sacrificing ride characteristics...


Now for the Lateral Case - Go into a ~ 1.5 G turn (4 degree roll) and simultaneously turning the steering wheel 60 degrees.


Camber looks okay in the front - due to the similar amount of KPI and Castor, not much camber gain on the outside (.3 deg) so the can be improved a lot, just by adding a little bit of castor, but it all depends on what the tire wants, It may not be that camber sensitive in that case we shouldn't even look at camber.
Rear camber looks bad, depending on what the tire wants - outside wheel goes way positive (3 degrees) and inside goes way negative (-4 degrees) This is probably why I see a lot of people setting these cars up with so much negative camber in the rear. This can definitely be improved and make a huge difference on track.
Toe change is fairly mild- rear moves to create oversteering moment, front is pro ackerman with about 2 degrees difference - seems pretty good. Starts at about 103% and moves to 133% which makes sense if this car is running on radials.
Track change in rear is near nothing and okay in the front- could stand to go a bit wider under compression.
Roll center heights stay damn near the same in roll, and migration is 2 inches inside on the front and 2.4" inside in the rear (less than 4% the track width). This seems to be the large focus of the suspension design as this is what looks the best.


Overall I can see where these cars get their good handling characteristics, but there is a ton of things that can be done to improve it, from a kinematics perspective. I'm curious to see how this differs from the C6 setup and if they made any geometry changes for the ZR-1.


Let me know what you think.



Bobby Alley
Chief Engineer
Sooner Racing Team


So like I said, I may not be that smart but I know some guys who are. Someday we will be able to track test some of these projects and show beyond the drawing board the functionality that they work better then we can probably drive.

At the end of the day the best mod you can do to your suspension is put slicks on. All this time looking for the unicorn of suspension geometry perfection changes with every car. Plus is anybody on this site going to beat on their car enough to justify all the effort we put into geometry. Probably not, but it sure is fun.

Rodger