Help tighten back-end

[vtracer20]

Hey guys, the other day me and my buddy were tooling around with our cars and we decided to see who's faster and i won but i ended up going like 100+ around a corner and my back end wanted to kick out. Kinda was scary trying to correct it, my ? is what should i do to make things more stable at higher speeds? The car feels floaty at 100+ and everything just seems hard to control the steering gets very stiff. Any suggestions?

 

[mavisky]

Maybe that's because the corner you went around was designed for people traveling a maximum of 65mph if not lower.

What suspension work have you done to your car if any? What tires are you running?

 

[BigRand]

Sway bars on a stock set-up seem to work really well (RM Sway bars apparently), Although its been said that they tune to give either a neutral stance or slight oversteer, so you should really be careful if your not an experienced driver. Good learning tool as well.


Don't forget those strut bars to stiffen the chassie up, and a lower tie bar.

I know what you mean about feeling unstable at high speeds, I took a corner that was meant for 45mph, at 90mph, tires slipped on a little bit of water, and I wasn't sure if I was going to make. Needless to say, be vary careful. I'm trying to save the money to get to racing school for a weekend, but its a lot of cash.

 

[jtmcinder]

This reminds me of an issue that often causes road-racers and autocrossers to get into nasty arguments about how to set up a car.

Almost all front-heavy cars become more loose (i.e., tend towards more oversteer) as speeds increase. There are a bunch of theories as to why, but the empirical fact remains. This is important to recognize if and when you start driving faster in a car that you think that you know very well. You might be used to it understeering, for example, so you might have acquired the habit of remaining lightly on the brakes at turn-in (which is called "trail-braking"). But if all of your experience is at low to moderate speeds, this habit might only be appropriate for those speeds. Goring farther, if your car is like mine, which understeers a little at low speeds and is terrifyingly loose at high speeds, then even lifting off the gas in a high-speed corner leads to a spin. If I go so far as to trail-brake above 45 mph, then the tail is gone before I can say "boy, that was stupid."

Why does this cause arguments between road-racers and autocrossers? Autocrossing is done at low to moderate speeds. Road-racing is done at high-speeds. The correct set-up for one is often not the correct set-up for the other. Failing to recognize this -- just like failing to take the differentials into account when discussing spring rates -- will cause useless arguments in which both sides are correct, but for different situations.

- Jtoby