How stiff is to stiff? Or is a stiffer chassis always going to respond better? I am probibly neglected some major fundementals of suspension and chassis engenering, but for some simplesity if anyone could shed some light on our cars in particular it would be greatly appriciated.

 

It depends on the application. For drag racing you want the chassis as stiff as possible, flex is bad.

For corner carving, you want some flex in the chassis.

With that said, it's impossible to get an F-Body to be totally solid, there will always be chassis flex, even with the best SFCs on the car. Keeping it to a minimum is why we install well designed SFCs.

Steve

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Spohn Performance: F-Body Chassis/Suspension Specialists

 

speaking of which steve, when are you going to start producing your SFC? I am holding of on installing the ones i currently purchased to see what you will be building.

 

I do not agree with Steve on one point of his chassis flex comment. The less flex the better whether its road or drag racing. Of course it is impossible to rid yourself completely but this is a case of less is more. Chassis flex is somewhat unpredictable and difficult to tune out. If we were comparing lap times, you would have a much easier time setting up a more rigid car to run faster.

The only problems with being to stiff are for safety reasons. If the car is to stiff to absorb some of the crash energy, the drivers body will absorb more. I know of 6 NASCAR Modified drivers who broke their necks and died before the chassis builders started using smaller frame components that were engineered to absorb impact.

 

A solid chassis will allow tire lift on hard cornering. I'm not talking oval track, I was talking road racing. When the inside front tire is off the ground, that is not what you want, you want all 4 tires on the ground.

With that said, like I noted, you'll never get a uni-body car that extremely stiff.

I do agree that chassis flex is unpredictable and difficult to tune. I think a very well designed and installed SFC system keeps the flex consistent, and therefore tunable.

Hopefully others will join in here and provide some real world input. I know there are alot of corner carvers on here! These discussions are good, and very educational for all. I learn something every day.

Steve

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Spohn Performance: F-Body Chassis/Suspension Specialists

 

Yup, I have read in a magazine article or maybe on of my books that the "engineers" designed our cars to have flex in them and that when the flex is taken out through the use of subframe connectors/stiffer chassis parts it is supposed to be a bad thing.

HOGWASH!!

I have experienced both sides of the envelope, and the stiffer I get my car over the years with chassis improvements, the better it handles; the better it rides; the better it accelerates; the better it brakes.

I'm no engineer, just an end user, but I speak from direct experience as a "canyon carver". True road racers or auto-xer's may take issue with me, but for a street driven and canyon raced car, stiffer is where it's at!

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FORMULA 350 TK
Southern California 3rd Generation F-Body OrganizationŠ