rear suspension bounce

[Mike M.]

I have a 64 4 spd small block roadster. It's a driver and I'd like to find out why there is so much bounce in the rear suspension while driving city streets. I have replaced the rear shocks, and replaced the previous fiberglass mono spring (don't know the lb. of the mono spring but a mechanic who drove it thought it might be incorrect) with a new 330 lb. spring. It feels the same as before. Is this normal? thanks

[John H.]

Re: rear suspension bounce

Mike -

The fiberglass monosprings have no interleaf friction to help damp their movement, and require shocks specifically valved for higher rebound rates to reduce/eliminate the "bouncy-bouncy" syndrome. Vette Brakes & Products has several types of shocks specifically valved for this application.

[Mike M.]

Re: rear suspension bounce

Thanks John, I'll check them out...and try to forget the money I just burned on a new mono spring.

[Duke W.]

Re: rear suspension bounce

Not only does a composite monoleaf spring have less inherent damping that the OE multileaf steel spring, but the spring you selected is about DOUBLE the OE rate. It's even stiffer than the 305 lb/in F-40 spring.

Higher spring rates require more rebound damping.

Your spring rate and shock rate is totally mismatched.

Duke