Reducing Sway and Body Roll

Just installed MSA's on my Z today! The difference is night and day. Car corners harder but once that tail is out, it's out. Tightened up that 196Kmi suspension a hell of a lot too. My friends and I were having fun tossin the stock sways bars back and forth becacuse of the weight difference of MSA vs stock.

I have MSAs on my Z, never had a problem getting the tail in line. I have coils though.

Would it be more beneficial to go with tires (RS-3, Z2, and like tires), or to upgrade the sway bar? I feel like the stickier tires may induce more body roll which could slow me down on the autocross, I'd like to do both but that may not be an option.

I would go with big rear bar and more rear tire for better grip too out of the corners. They kind of cancel out the negatives of each other. The bigger rear bar will help the rear to rotate more, and the wider rear tire will help to counteract that and give more grip too. Still will make the car "feel" more nimble and eager to turn.

What symptoms are you experiencing? Tail out powering out, tail out under braking, or understeering everywhere? Lots of different ways to tune the handling by mix/matching parts or taking parts off.

Have you checked the rules for your class? Can you change the sways without getting reclassed? Assuming that is something you care about.

Autocross? Stickier tires will ALWAYS be faster, regardless of how much body roll you have. In my experience, the rear bar will not help body roll--it's the front bar and front spring rates that affect body roll.

The rear bar will help the car rotate, but it will also cause you to lift the inner rear wheel if you're holding enough lateral G's.

From your video a few posts up, it does not look like body roll is your problem. At least from the video, the car's roll doesn't appear to be excessive.

Remember: roll means you are gripping the surface enough to get the car to deflect. Lots of roll could either mean your suspension is soft and squishy or you are holding a shit ton of G's because of awesome grip. If you put junkyard tires on your car, you will not have any roll whatsoever while cornering, but you'll lose traction without holding any kind of cornering speed.

The classing isn't really important as it's more about me and my friends competing, but I wouldn't change class. Second it's hard to say how the car acts because when racing on the 1/4 mile circle tracks the car seemed to under steer, but then at the miller park parking lot the car was tail happy. I'm not sure if it was just the way I was driving or the race course surface, you know what I mean?

Frostvectron,

Thanks I see what you mean, what tire do you use? My one friend is putting RS-3s on his 325is and my brother is putting Z2s on his Camaro.

Course surface will definitely affect how the car will feel. I am not surprised the car feels differently between your two different venues. I run different damper settings and tire pressures for different venues as well as different ambient temperatures.

I use a lot of different tires… last year I tried: Hoosier A6, Hankook C71, Kumho XS, Direzza Z1 Star Specs, Falken 615, Toyo R1R, Hankook RS3 and maybe some others. If you're sticking with street tires, any of the 200TW autox compounds would suit you well.... each have little quirks and perks (and prices), but those are sort of nitpicky details that only matter once you start splitting hairs over time (and also depends highly on your surface and temperature). Hankook RS3, Dunlop Z2 Star Specs, Toyo R1R, BFG Rival-S, Bridgestone 71R are the big names right now. The Bridgestone 71R really made a fantastic showing at the SCCA National Tour in San Diego and is sort of touted as the magic tire. They wear extraordinarily fast compared to the others though, so if you plan to go that route I wouldn't daily on them.

Just ran the first autocross from the season, definitely need better tires, I couldn't stop killing cones. But got a real good feel for the car!