Novakar Chassis

D Sports Racer, F500

Elastomer Suspension "Springs"

Here are a few comments from Jay Novak about rubber springing.

F500 has some significant rules limitations to the size of the material used for the spring. The written rule is a bit strange but simply put you cannot use a piece of elastomer that is larger than 2.00" in diameter & 1.00" thick & it has to be a 1 piece part.

You can then do anything you want to the elastomer (I no longer use the term rubber as "rubber" is not a suitable material). The net result is that modern F500 cars have LOTS of adjustability & wheel travel & the best cars handle as good as anything without wings.

Everyone now compresses the material either axially or radially depending on how they want to accomplish things. (except for the Sidewinder which stretches the rubber axially)

The majority of cars (KBS, Invader, Scorpion & others) use MCU foam & compress it axially with tapered cones pushing the material into a similarly tapered receiver inside a machined aluminum can that looks like a shock absorber. This method provides adequate wheel travel but has very limited rate linearity. Rates are controlled by rocker arm geometry.

Red Devil puts the elastomer (several types) into a can but compresses the material radially & this system provides a more linear range. Again everthing is controlled by rockers etc.

The NovaKar & Rakavon system is a bit different & much simpler than the other as we do not have a machined can or tapered parts for compression. Our system uses a very simple method of axially compressing a specially formulated elastomer between 2 steel plates. Again the rates & linearity are controlled by rocker geometry etc. I have spent years on testing & developing what I think is a good material for this application. Our system has excellent adjustability for all aspects of the springing / damping systems.

I have developed computer models of our system & have correlated the system on shock dynos.

Damping is adjustable & quite functional. While it does not have the compression / rebound differentials that you can get with hydraulic shocks it is still very functional.

Revised: December 29, 2005.

Sports Racer Network