I think that tells it all!

 

Thank you for the detail. That was the information I was looking for.

Regards,
Randy

 

I'm interested in this idea that you can adjust both ride height and spring rate on some coilovers.

Ride height adjustment should be easy. Changing shock stiffness (compression, or rebound, or both) would be easy on shocks designed that way.

But adjusting spring stiffness is something I can't figure out. Certainly, you might be able to order different stiffnesses when the system is produced. But once it's on the car, I don't understand how the spring stiffness can be changed.

Looking for an education here...

 

I have always wondered why this is never done by suspension manufacturers with published results. My guess is you may get some great results with only a couple of well chosen pieces.

 

For base and Z51 cars, sway bars and tires should be the first things done to the car.

Sway bars is a heck of a good way to pick up handling performance without going through the entire suspension.

Remember also, tires make a HUGE difference on the cars, and are also the only four points which the car touches the pavement so this will effect things more than a lot think.

 

From wikipedia:

Advantages
Less unsprung weight. Coil springs contribute to unsprung weight; the less there is, the more quickly the wheel can respond at a given spring rate.

Less weight. The C4 Corvette's composite front leaf weighed 1/3 as much as the pair of conventional coil springs it would replace. Volvo reported that the single composite leaf spring used in the rear suspension of the 960 Wagon had the same mass as just one of the two springs it replaced.[8]

Weight is positioned lower. Coil springs and the associated chassis hard mounts raise the center of mass of the car.

Superior wear characteristics. The Corvette's composite leaf springs last longer than coils, though in a car as light as the Corvette, the difference is not especially significant. No composite Corvette leaf has ever been replaced due to fatigue failure, though steel leafs from 1963 to 1983 have been. As of 1980, the composite spring was an option on the C3.

As used on the Corvette, ride height can be adjusted by changing the length of the end links connecting the leaf to the suspension arms. This allows small changes in ride height with minimal effects on the spring rate.

Also as used on the C4 front suspension, C5, and C6 Corvettes, the leaf spring acts as an anti-roll bar, allowing for smaller and lighter bars than if the car were equipped with coil springs. As implemented on the C3 and C4 rear suspensions with a rigid central mount, the anti-roll effect does not occur.

Packaging. As used on the C5 and later Corvettes the use of OEM coil over damper springs would have forced the chassis engineers to either vertically raise the shock towers or move them inward. In the rear this would have reduced trunk space. In the front this would have interfered with engine packaging. The use of the leaf spring allowed the spring to be placed out of the way under the chassis and while keeping the diameter of the shock absorber assembly to that of just the damper rather than damper and spring.[9]

Disadvantages
Packaging can be problematic; the leaf must span from one side of the car to the other. This can limit applications where the drivetrain, or another part, is in the way.

Materials expense. Steel coils are commodity items; a single composite leaf spring costs more than two of them.

Design complexity. Composite monoleafs allow for considerable variety in shape, thickness, and materials. They are inherently more expensive to design, particularly in performance applications.

Cost of modification. As a result of specialized design and packaging, changing spring rates often requires a custom unit. Coil springs in various sizes and rates are available inexpensively.

Susceptibility to damage. Engine fluids and exhaust modifications like cat-back removal might weaken or destroy composite springs over time. The leaf spring is more susceptible to heat related damage than conventional steel springs.

Perception. Due to its association with spring-located solid axles, the leaf spring has a stigma unrelated to the spring itself.

 

unless you use the lg or pfadt setups youre probably going to add weight with the coilovers

leaf springs work well and generally weigh less. you have less options for spring rates, but if you check out the spring rates on the various factory units and some of the aftermarket ones, you should be able to find a spring combo you like

lg bilstein and pfadt featherlight coilovers are the best pre-pieced kits Ive seen out there.


you could also go with custom bilsteins, sachs, or motons with whatever spring rates you can imagine, but the cost will be up there...

good luck! by owning a corvette you are in a good position in terms of having a lot of options for parts.

 

cant change spring rate unless you have PROGRESSIVE RATE SPRING installed

 

What Alternatives do we have if we just want to stiffen the suspension to avoid bottoming out the suspension on a slammed c6?

 

You can change spring rates on any coil over, but like with anything it requires a spring change itself.

You can change spring rates on the factory leafs as well by picking a different model spring. With a coil over package generally there are far more options on spring choices as most companies are going to use a 'standard' build spring so you can generally pick down as low as a 50 lb change in rates. But again you have to physically change the spring to do so.

 

Thanks!