Z51

[KTA1000]

After looking at the C4 supension chart by Hib Halverson from the Idaho Corvette web page, I came up with a few questions.
1 What is rear wheel rate ? How does it compare to Spring rate ?

2 Why are the front springs stiffer on a 1990 FE1 than a 1986
Z51 [acording to this chart] is the chart wrong?

3 Would I notice a big difference in ride and handling between a
1986 Z51 and 1990 FE1

thanks

paul

 

[Ken]

Welcome To The Corvette Action Center KTA1000!

What is rear wheel rate ? How does it compare to Spring rate?

Wheel rate is the actual rate of the spring acting on the tire. This value is not always the same rate as the spring rate on the shock. The spring rate depends on where the spring is mounted on the suspension. Wheel rate and spring rate are measured in pounds per inch.

Spring rate is the rate of deflection versus amount of load applied. In other words, how much force is needed to bend a spring a given distance.

Why are the front springs stiffer on a 1990 FE1 than a 1986 Z51 [according to this chart] is the chart wrong?

You'll have to ask Hib.

Would I notice a big difference in ride and handling between a 1986 Z51 and 1990 FE1

Probably, but that is just a guess on my part.

 

[Skant]

Don't assume that stiffer suspension provides better handling. Whether softer or stiffer is better depends on the road you're on.

Z51, I believe, is largely designed for autocross racing where the tracks are usually very smooth. On a track which was perfectly flat and smooth (ie. not real), you wouldn't even want the suspension to move at all. Stiffer suspension means less weight transfer in the turns. So very stiff suspension is better the more like this flat and smooth ideal the track becomes.

City streets and high ways aren't usually anywhere near that smooth. As well, any track with a lot of banking and elevation changes may be better with softer suspension. Consider a car with perfectly stiff suspension that doesn't move at all... if it goes over a road surface that twists, two tires on diagonal corners will be lifted off the ground. The car will teeter on the other two tires diagonally across the car. So the closer your car is to that stiff extreme, the more it will tend to get loose and unpredictable on uneven or bumpy surfaces. It will lose weight and grip on one or two tires.

From what I've heard, the really stiff Z51 suspension can be a little too stiff to be ideal for the normal street. Though a lot of people like it anyway because stiff suspensions feel very snappy and responsive.

Much as they may call the FE1 suspension 'soft', it's still quite tight compared to a normal car.

- Skant