C3 and VBP Smart-Struts and Rack Attack

[Joe L.]

Re: C3 and VBP Smart-Struts and Rack Attack

Tony-----

Car manufacturers do all sorts of expensive things to improve ride and handling as well as NVH (noise, vibration, and harshness). The cost difference between rubber and polyurethane on a PRODUCTION basis would probably be very small. So, I fully expect that if polyurethane would work better and cause no problems, they'd have gone to it years ago. As far as I know, even premium manufacturers like Mercedes, Lexus, and BMW use rubber bushings.

[Tony Roussos]

Re: C3 and VBP Smart-Struts and Rack Attack

Joe,
Point well taken.

Thank you.
Tony

[John H.]

Re: C3 and VBP Smart-Struts and Rack Attack

Tony -

Rubber was used then, and continues to be used today for all manner of OEM suspension bushings and cradle-to-body bushings, and their design is very scientific; by selecting the right durometer (hardness) and placing voids or ribbed voids in the right places, bushings can be made stiff in one direction and compliant in another, in order to achieve both isolation/compliance and NVH targets with one part. You can't do that with polyurethane - it's just plain hard, and has no compliance at all no matter how you design it. That's why you see it primarily on race cars, where isolation/compliance and NVH aren't important considerations - they just want solid connections.

[Tony Roussos]

Re: C3 and VBP Smart-Struts and Rack Attack

John,

Thank you for the education. (This is better than college.)
What is/are NVH?

Thank you.
Tony

[Patrick H.]

Re: C3 and VBP Smart-Struts and Rack Attack

Noise, vibration and harshness.

John has told me about the old days when the engineers used to take pride in altering bushings for each car model just to achieve the proper ride and handling characteristics. Quite a science, especially for 40 years ago.

Patrick

[Tony Roussos]

Re: C3 and VBP Smart-Struts and Rack Attack

Patrick,

How many ways can bushings be altered? I guess I need to look at a few to better understand. One type for racing and another for street driving.

Tony