Project S2000, Stiffening the Chassis
By Khiem Dinh
Khiem Dinh is an engineer for Honeywell Turbo Technologies at the time of this writing. All statements and opinions expressed by Khiem Dinh are solely those of Khiem Dinh and not reflective of Honeywell Turbo Technologies.
As with anything, a strong foundation is the key to success. For a good handling car, that means a super rigid chassis. The S2000 is blessed with a very stiff chassis from the factory, but when you chop the top off of any car it will be less stiff compared to a car with a roof. The S2000 doesn’t have the bad cowl shake that is the tell-tale sign of a not-so-stiff convertible chassis, but there are a few creaks from the soft top roof as the chassis flexes.
A flexing chassis is a detriment to handling because it does not allow the suspension to work properly. Firstly, chassis flex alters the suspension geometry. Secondly, the chassis acts like a big spring without a damper, meaning we have no control over it. On a stock suspension setup with relatively soft springs, the chassis flex is not as noticeable as the stock springs are soft enough to absorb most of the road input energy. Since we’ve just basically doubled the stock spring rates, more force will be transmitted to the chassis increasing the displacement that it twists and flexes. This means greater alteration of the suspension geometry and more uncontrolled chassis flex action.
|The Whiteline front subframe brace mounts where the stock engine mount stiffener and gussets attach.|
To combat those forces, we’re going to fortify our chassis with some additional bracing. Honda did a pretty good job from the factory with some chassis bracing, but there’s always room for improvement on a street car. One of the most common braces is the 2-point shock tower brace. With no brace, the tops of the shock towers are free to flex inwards and outwards relative to each other. We’re using a Whiteline brace between the shock towers which ties them together. By doing so, we’ve just eliminated that degree of freedom helping to keep our suspension geometry optimum.
|Whiteline front strut tower brace.|
|Whiteline front strut tower brace in place.|