Now that I have wider tires and bigger sways, I can hold a faster speed in turns. I gained 11 mph in the sweaper turn we have at the Anderson autocross site.
My problem is now oversteer in the turn. I am holding the turn and I give it a bit more gas to go faster. Then I feel the back end start to rotate. Sometimes I get oversteer even when keeping the gas constant. After some horribly long drifts at the black lake autocross, I learned not to let off the gas, but to give it a touch more. The power goes to the front wheels and it pulls me out.
What is the fastest way to drive through the sweeper? Is it better to keep the speed down and hold a constant line? Is it better to go faster and let the car slide some then fight to regain control as the turn ends?
I made a horrible mistake at the last autocross. I felt the oversteer starting, but I overreacted. I countersteered and hit the gas too hard. That flung me to the right and into the grass with all 4 wheels.
What kind of car are you driving?
Through constant radius turns the optimal way to go around them is at one steering angle. Thethe inner most part of your turn being the apex, which should require slim to no addition of steering angle, then trying to be as wide out as you can be before turning in and as wide as out as you can after winding the wheel straight on corner exit
If your sways are adjustable, and your car is un controllable with the new parts on try slackening off your rear sway bar.
Scorke
mightyS Wrote:Now that I have wider tires and bigger sways, I can hold a faster speed in turns. I gained 11 mph in the sweaper turn we have at the Anderson autocross site.
My problem is now oversteer in the turn. I am holding the turn and I give it a bit more gas to go faster. Then I feel the back end start to rotate. Sometimes I get oversteer even when keeping the gas constant. After some horribly long drifts at the black lake autocross, I learned not to let off the gas, but to give it a touch more. The power goes to the front wheels and it pulls me out.
What is the fastest way to drive through the sweaper? Is it better to keep the speed down and hold a constant line? Is it better to go faster and let the car slide some then fight to regain control as the turn ends?
I made a horrible mistake at the last autocross. I felt the oversteer starting, but I overreacted. I countersteered and hit the gas too hard. That flung me to the right and into the grass with all 4 wheels.
Go 10 mph faster than you did before
or to say that another way:
Slow Down!
Your corner entry speeds are probably too high.
Which car is yours?
He had the legacy GT. with that car you should be able to mash it and steer where you want to go. definitely should be able to handle the sweeper with a little slip angle without sending you off into the grass.
I have the Subaru Legacy GT. It is an all wheel drive car.
With stock all season tires and stock sways, I could only go around 44 mph in the turn. Any faster and I would understeer into a wider turn. The new tires are 235/40/17 up from 215 and they are Yokohama AD07 Summer tires.
The sways are set to the stiffer setting in the front and soft in the rear. The car is controllable and I did much better at the Black lake autocross.
The back end is rotating during the long sweapers as the radius of the turn decreases. I entered the turn just fine.
Loosen up the rear sway, problem solved!!!
Scorke
Either make the front sway stiffer or the rear less stiff. That should take away some oversteer. I need to invest in a stiffer front sway for my car so I don't lose the back end so often
Well he already has the front on the stiffest and the rear on the softest so I would have to say to look at the alignment and see if you can get some more rear camber or see if for some reason you have some toe out in the rear.
Oh and as far as the line I would say take it a little easier around the turn so you can get the exit correct so you are correctly set up for whatever is after the sweeper. This past autocross if you weren't set up well after the sweeper it would cost you a good amount.
Might get Perry in here to comment on that - he was throwing his WRX around like nobody's business.
ive never driven an awd car so i cant comment
I definitely wouldn't say sway bars are the solution to everything... I'm holding off on getting sway bars (despite my ridiculous body roll) for the sheer purpose of learning how my car handles in different situations as it is stock. I've kinda wondered why something that adds weight and stiffens the rear a ton, influencing the car to lose grip in the rear or front would be a big help in handling.
I had sway bars on the Accord before and I know they work well, helping maintain mid-corner stability compared to my floppy 3-wheeling mess of an economy car, but I don't think influencing a loss of grip anywhere should be considered a good thing...
I'm not the most qualified person here, but I'd just say slow your speed down through the sweeper. maintaining a speed over 50 through there is quite incredible (I certainly can't do that), but I can see how it would influence some oversteer. If you take it a little slower and stay within the gripping range of your notably grippy tires (or at the very edge of that grip, depending on how predictable your car is when losing it), you should be able to stay much more controlled through the sweeper and put your car exactly where you want it to go a little quicker and easier.
I like Sam's description of the line for the sweeper... what I did was brake a bit before entering the sweeper, going in a mainly middle-of-the-road entry line. Turning the wheel, I end up going pretty tight and close to the row of inside cones, coming close/hitting the apex (in my mind, at least). Past there, I mash the gas and understeer myself (?advantage of FWD?) to widen my line, putting me in a great position to maintain my speed out of the sweeper and into a perfect angle to keep my car going as straight as possible and maintaining my speed up to the next slalom.
I also noticed that if I wasn't pushing so hard, braking so late, and accelerating when I didn't have grip, I'd end up with even faster lap times, despite not feeling quite as quick. With my car it was a constant struggle to resist understeering as much as possible, and it ended up working out pretty well with how quick I managed to be in a fun run (63.576).
I'm no ME major and am definitely farrrrr from being the most experienced with this matter, so I could be very wrong with lots of this, but its just how things work for me in my mind at least.
Well, I wasn't having uncontrollable oversteer that can cause you to go into a spin. I know I kept pushing the car to go a little faster as I was in the curve instead of holding a speed. That is when the rear tires gave up and the end started rotating. They made some noise, I countersteered and kept on the gas and the front end pulled through. This let me go wider at the end so I could go in a streight line past those cones after the sweeper.
I'm wondering if it is faster to keep a steady speed in the curve and keep the line or push it and let it oversteer at the end.
I could also find out by having a better driver drive my car with me as the passenger.
I wouldnt mind trying to drive it
just because i wanna drive an awd car, not because im special or anything... who knows maybe i'll find something out
If your getting a heavy all wheel drive car to throttle on oversteer on corner exit I'd say don't touch anything!!!
Scorke
When driving the twin turbo stealth through the sweeper (an AWD yacht), I nearly lost it due to some oversteer near the exit... I countersteered to correct myself, but obviously the front wheels have power to them as well. The front wheels ended up hooking the car around and if I wasn't quick enough, I probably would've ended up in the grass. That car weighs 3800lbs, its quite a tank lol. In situations with oversteer and countersteering, (in my experience) it can be far less predictable than RWD cars. They take a bit of getting used to how they'd react in situations like that.
Despite how big that car is, I had a blast driving it. It felt far more nimble than the numbers would lead anyone to believe.
And Tyler's pretty quick, I'd say give him a shot with it. :-)
First and foremost. Have you been checking your tire pressures and contact patch after every run? You may have the wrong pressure in the rear. Try deflating the rears a bit.
Like they say, a loose car is a fast car. If the rear end is stepping out a bit during fast sweepers and allowing you to rotate that beast I say thats a good thing. You can use the throttle to modulate the slide while maintaining your speed through the corner as long as you're quick and smooth with your hands. Throttle steer.
If the car is sliding out thats a different story. But IMO, if you have a good rotation with a 4wd car, leave it as Sam stated.
If its too bad just enter the corner with less speed and wait until later in the corner to put the gas down. Mid corner speed is important, but if you're losing exit speed due to slides and counter-corrections its costing you time. Drive into the corner slower, but you should be able to get on the gas sooner for a good exit.
Plus you drive a Legacy. They are big cars. You're talking about a lot of weight being transfered all over the chassis. Now that you have stiff sways, the suspension is transfering a lot of the energy to the chassis since your suspension is stiffer. So you will get slides in a car like that. I would take it to Brian, one of our autox'ers, at Toyota of Anderson and have him do a mild autox alignment on the car and see if that helps.