Coilovers would definitely help, but as someone said above, the sidewalls are pretty soft on the RS3s. Keep in mind that you need some body roll. Too little body roll will cause less grip because you're not taking advantage of weight transfer. For now, you could stiffen the sway bars and see if it helps much. If it doesn't make much change, then the tires are being overpowered by the cars power and weight, causing the sidewalls the flex.

Make sure you do some research on spring rates before diving right in. Stiffer is not always better. Every car/owner is going to be different, though.

 

Just out of morbid curiosity: what the heck are you talking about?

 

Also the sidewalls on the RS3 are pretty soft compared to what? I've read of plenty of people having fantastic results with these tires, the tires aren't my problem.

Just driving down the street quickly wiggling the wheel back and fourth you can feel the car moving. This week I will play around with the stiffer settings, and from what I'm read this should be the solution to my issue.

 

wat? Stiffer sway bars would decrease body roll and kinda contradicts your entire opening there....

so... it's not the size, it's how you use it, right?



I think he means it will cause rotation (oversteer) if too stiff in the rear.... as for the front, you'll chew up more tire on the opposing turn tire and add more understeer.

 

That's a charitable reading. My guess is that he has cause and effect all mixed up. He has noted that cars that don't exhibit any body roll have less grip (e.g., a go-kart) and has inferred that it's the lack of body-roll that is causing the decrease in grip. Technically, the relationship between body-roll and grip is spurious; there's a correlation, but not because of any cause/effect relationship between them. Rather, a car with too much total roll stiffness will exhibit very little body-roll and not have as much grip as a car with less total roll stiffness. That's where the observed correlation between a lack of body-roll and a lack of grip comes from. It does not come from the lack of body-roll causing the lack of grip. (If anything, less body roll is almost always better for grip, especially when the car has a terrible bump-camber curve, as do Evos.) Instead, both of these observable things come from total roll stiffness.

If my guess is correct, then it's a typical error by humans. (My day job is studying this sort of thing, as well as teaching logic.) We see correlations and infer causation all the time. At one time, I suspected that turbochargers caused people to lose their ability to spell. I mean, seriously. Have you seen the posts on the forums for DSMs?

 

Less roll is good as long as you have tires that can handle it. I'm not sure what he is talking about, either.

Find me any type of race car that has body roll, now of those were on street tires they more than likely would be sliding all around, but since they're running a extremely grippy tire, they can take full advantage of the suspension.

 

Mechanical grip comes from maximizing tires. To little weight transfer can reduce grip. I think that is what he is referring to instead of body roll per se. For example, when it rains, one of the first things you do is loosen the roll bars so you have more weight transfer because you have less overall available grip from the tires. If you have ever driven a car set up for dry in the wet, it has almost no grip on wet tires. In the end, for a racing car, balance is more important than overall grip anyway (within certain limits).

 

Body roll can be controlled with spring rates and sways. Since you have sways then stiffer springs may be necessary. If you need crispness and nimbleness then proper negative front camber and toe settings go a long way in this department. You are correct that good coilovers with adjustable plates are the ticket to address all the above.

You can also tighten up the response airing up the tires to about 38 to 40 PSI.

I've done all the above and the good news is my car does drive like a go-kart. The bad news is my car drives like a go-kart...

 

Higher quality coilovers with 8k/10k or 10k/12k spring rates and proper shock valving will really help response and counter body roll as well. Having -2.5* front and -2.0* rear camber is probably the sweet spot. The Hankook R-S3 tires do have slightly softer sidewalls than most but in the 285/35-18 size they are incredible grip on a Evo X. You can go overkill on the swaybars and if the front is too stiff relative to the rear and your shocks are not up to the task to control the springs plus the swaybars in the turns, you will get some awfull bump steer.

In general stiffer lowering springs on the stock shocks are just a lose lose proposition if you want a good handling car with minimal body roll.

 

I keep seeing this concept on a variety of boards ... that weight transfer is good ... but it's nonsense. In general, it isn't true because you lose more grip from the inside tires than you gain at the outside tires (because the normal-force to grip curve is sub-linear [i.e., bent downwards]). Maximum total grip comes from even weight distribution.

Again, you can have too much roll stiffness for your tires and lose grip. You can also have too much camber and need to roll the car a bit to maximize (outside tire) grip. But weight transfer is always bad.

 

If all weight transfer is bad then please reconcile how too much roll stiffness would ever be bad. Why does high roll stiffness result in less grip on low grip surfaces? Finally, what do you think gives the tire grip and in what direction does it generate the most grip?

 

you need body roll. If you close it out completely the car will be under-steer even more or become unpredictable etc. No amount of adjustments will help on that, in the Evo case.
These are not formula cars.

you need to learn and use the body roll for your advantage.

ROb

ps one common thing , braking too late and upset the car balance. Number one explanation: blame the body roll ...

 

Even in formula cars you need weight transfer. Even karts depend on weight transfer to turn.

 

I cannot help you.

 

Agreed. You need body roll, which is the same as saying you don't want too much roll stiffness.

But please note (and this is to others, not Rob) that saying that you need body roll or saying that too much roll stiffness is bad is not, by any means, the same as saying that weight transfer is good.

It almost seems like some people have cause and effect exactly backwards.