Chassis design

[Danny Tran]

Chassis design

Ive concluded the weight isnt the only factor to determine the better handling car, nor is it only the stiffness of the suspension.

How is it that certain chassis handle better than others of the similar weight?

Example: S2000 vs RX-8.

The weight and power numbers suggest that they should handle about the same, but with a slight advantage to the S2000 due to the fact it weight about 170 lbs less. But yet the S2000 feels so stiff and it understeers more than I want it to. THe RX-8 litterally does what I want it to.

How is that?

So it leaves me with a dilemma: I prefer the RX-8's chassis (no idea why) but i hate its rotary engine (Lets not go OT here...)

I love the screaming, high-reving F22C but I cant get the S2000 handle exactly the way I want it to.

[zenkidori]

Ive concluded the weight isnt the only factor to determine the better handling car, nor is it only the stiffness of the suspension.

This is pretty obvious.

it's not just how much weight there is, it's where it's at. There are also endless suspension tuning variations, wheel and tire considerations, etc. You could just suck at driving as well. There are a HUGE number of factors that go into making a car handle well.

As for the chassis themselves, they can weight they same but have different stiffness, strength in certain areas etc.

[zenkidori]

P.S. The rotary engine rules.

[Z Draci]

There are millions of variables to a good handling car. The most obvious factor is your own driving style and techniques. Michael Schumacher in an S2000 will always be faster than you in the RX-8. The driver himself plays the biggest role in determining whether or not a car is fast or not regardless of the car itself. (No, I'm not trying to say you're a bad driver!)

For your example, the S2000 (and all tail happy cars) tend to be tuned for understeer. You NEED to get the tail out and slide around corners to make good time with cars like this. The understeer makes it easy to carry on the slide without any danger.

There are certain criterias for a "good" chassis. I think the small individual settings play a larger role in a car's handling characteristics than the actual design of the chassis (body, suspension, wheels, etc) because a "good" chassis is universally known to have very low deflection from road forces AND also be light (be it through different designs or material). But there are disagreements when it comes to the actual handling characteristics of a car. Many people say different things. That's where the difference comes from.

In the end, it's all personal preference. That's why all cars don't handle exactly the same. Every company has its own philosophy on how a car should behave. You can tweak around with toe, camber, spring/damper rates, tire type, wheel size, LSD settings, etc. to fine tune any car to your tastes. A car from the factory was set up how THEY liked it.

[andyhui01]

I agree with Draci... people all want different things in different cars, no chassis will satisfy every single driver in the world. For example, BMW's are supposed to be known for their Handling, but I've met someone who said a E46 330Ci handled like a post van...

[sandor_]

weight is one thing.

unsprung weight is another - and unsprung will affect handling much quicker. this weight would include your wheels, tires, brakes, rotors, brake lines, etc.

while you can simply say chassis and suspension affect handling, the fact is that two identical cars (same make model and year) can have the OEM parts tuned in different ways as to make them handle MUCH different.

[M3lover]

Weight destibution (sp?) also has something to say. I would guess the RX-8 is closer to 50/50 than the S2000. I also think it has a lower centre of gravity because of the much lower rotary, but i'm not sure about that.

[Svempa]

A solution to this could be to get youself a fully adjustable chassikit for the S2000 and play with the settings so you get a car you're pleased with.