Specs on subframes?

[Salt Racer]

Would'nt a well tuned and set up front suspension keep a certin degree of castor and camber all throught it's travel? If so it seems you could test that on a allighnment rack...

I think the subframe manufacturers should provide the info like camber curves, etc... then its up to the consumer to tune spring rates and shock valving etc...

Static testing probably would give you a rough idea of how well the car would stick during steady-state cornering. But that's not all there's to suspension design. Stuff like RC migration characteristic is tough to determine w/o computer aid (or at least scaled drawing), and those invisible stuff has major influence on transient characteristic.

As for manufacturers publishing simple date like bumpsteer, camber curve, etc, the danger is it could become just another one of marketing hypes. With enough reading of books and info available on net these days, it's pretty easy to get rough ideas of what is ideal. You can easily publish those numbers without actually measuring anything.

It is true that no matter how well the system is engineered, you will have to fine-tune stuff on your end. Look at all the Camaros on this site - how many Camaros do you see that have exact same combination of parts? Also driver ability/preference play major role in suspension tuning. However, ALL suspension manufacturers, especially the ones specializing in specific car model(s), need to be able to provide baseline setting for their own products. If a manufacturer failed to do so, personally I'd be skeptical of their knowledge and experience.

...Now you could also put too big of tires in the front and scrub too much speed in the corners. Or too big of rear tires and have severe under steer. Seems to me there probably is a magic number most race car builders look for when making their suspensions...

This is very true. Unfortunately, because of the nature of this hobby, too many people opt for the biggest tires they can fit without taking balance into account. Try 225/335 combo on a nose heavy car and go around a track, and you'll hear overheated 225s screaming for mercy while 335s on rear are barely getting hot. You may be able to balance out handling by increasing rear roll rate, but that would not make good roll rate distribution. With extra rotating/unsprung mass and stiffer than ideal roll rate, rear end would not be able to maintain road contact as well as a more balanced combo of narrower tires & ideal roll rate. Bigger rear tire is not always better when you're very limited in front tire size.

Of course, if aesthetics is the priority as in case of street rodders and cruiser type people, Bigger is always better. 335s would make nice conversation pieces at car shows.


I've already rumbled enough about leaf springs in other threads. Fuelie Fan is correct that leaf springs on C4/C5/C6 has nothing to do with suspension kinematics. As long as their rates are linear (or close to it), they'd work just as well as metal springs. As for the typical leaf spring setup as on Camaros, it has much better kinematics than a poorly-executed link suspension.

Think of leaf setup as a carburetor, and the link setup as fuel injection. A properly calibrated carburetor would make just as much power as a good MAP injection, even though the carburetor may not be as efficient. This is like a comparison between leaf and a good 3-link - leaf setup is capable of just as much cornering traction as 3-link, but it will fall behind in some other areas. The same carburetor would outperform an alpha-N system that has not been calibrated with flying color - this analogy is like well-setup leaf vs. drag race ladder bars for cornering applications. Not all fuel injections/link suspensions are created and calibrated equally.

Leaf setup should not be overlooked if rear seats and stock floor are to be retained in the original locations.