FWD cars and understeer

[pranesh76]

I've been going to autocross sessions and I have a FWD car. I am a beginner at autocrossing and have a question for those who have more experience than me. Other than making modifications to the car, there has to be a way to change understeer to oversteer. Not permanently, but during understeer. I remember reading about it somewhere..said something about braking during oversteer or letting off the throttle? Does anyone know how to induce that and also if anyone could tell me the principle behind it..

would love to have more control during those awfully irritating loss of control understeers!! :oops:

[graywolf624]

said something about braking during oversteer or letting off the throttle? Does anyone know how to induce that and also if anyone could tell me the principle behind it..

would love to have more control during those awfully irritating loss of control understeers!!

All thatll do is make your rear lose control as well. You need to modify the roll bars on the car for roll stiffness. Lifting up off will cause over steer in a fwd car sometimes.. so will hand braking.. the issue is your not getting any net improvement.. Just perhaps having more fun.

[pranesh76]

The problem I'm having is going sidewards! Its firstly annoying cause its not progressive and because of me watching the world go by sideways, i have missed cones. So should I be completely lifting off at the first sign of understeer?

[AlienDB7]

Try to reduce steering angle first, that should give the tires more grip. If that still doesn't help, slow down progressively... smoothness is the only way to go fast while being in control.

[TT]

The problem I'm having is going sidewards! Its firstly annoying cause its not progressive and because of me watching the world go by sideways, i have missed cones. So should I be completely lifting off at the first sign of understeer?

Hehe, of course if you want to do long and controlled slides, there is nothing you can do to your car that will really help :D
With a good setup probably you will make the tail easy to snap out of line and put the car in oversteer mode (lift off), but it won't last long.. could be smooth of course, but once the tail is kicked out, you have to way to control it since the steer is on the front wheel as long as the traction

[Vansquish]

Ok...well, first of all, what kind of FWD vehicle are you driving? That will play something of a role in how much you can do to adjust the handling. The next thing to figure out is how much understeer you're talking about...if you're plowing straight through turns and into the cones, you're going far too fast for the course. Autocrossing is all about finesse, and that is one of the more difficult things to master. Ideally, you won't really run into any oversteer/understeer problems on a perfect lap, and the few moments of sliding will be to your advantage. The best way to induce oversteer in a FWD car is merely to let off the throttle...but this will only work if you have a reasonably large amount of space and are moving reasonably fast...barring that, the handbrake is an excellent way of bringing the tail of the car around quickly...however, you'll end up flat--spotting your tires if you do it too often, and that causes a whole new set of problems. You can also brake once you are already turning into a corner, but the likelihood is that that will merely slow you down rather than killing understeer and inducing oversteer (the autocross circuits I've been on are rather tight and twisty and max speed is only 40 mph or so, if that). Again, it really depends on the car, the course and I suppose, even the tires of the car you're driving...I drive a Mazda 6 V6 if that's anything of a point of reference.

[exhausted mules]

what i allways do is just play with the brake.

if you understeer while coming into the corner as your letting off the brakes, then theres not much you can do other then set your camber and focus on your spring and damping rates.

if you understeer while on the gas past the apex then like the others said... take it easy. its all about finess. play with the traction your fronts are giving you and dont push past.

lower your front pressures slightly and keep a small amount of brake pressure up untill the apex. keep the weight on the fronts and lighten the rears. of course..... this is coming from experience with a very light car in the rain.

[graywolf624]

if you understeer while coming into the corner as your letting off the brakes, then theres not much you can do other then set your camber and focus on your spring and damping rates.

That is only slightly true. The best way to adjust understeer to oversteer Ive always found to be roll stiffness adjustment.(adjust the sway bars roll stiffness. ).


I guess since this is turning into driving advice I might as well give some. So here we go.

Foot off the gas when entering the corner. If you need to, brake before entering the corner or slightly upon entry(trail braking). You dont want to slide at all, not over steer or understeer, you want to be smooth. All inputs should be smooth, that means smooth hand movements, no sharp brake or gas. Your pathway should be a parabola with the smoothest least turn possible throughout. And for crying out loud, slow it down a bit.

lower your front pressures slightly and keep a small amount of brake pressure up untill the apex.

Be careful with lowering your tire pressures. This will increase the contact patch and allow the tires to meet operating temperatures quicker, but it will also increase slip angles and lower spring rates.


My fwd experience is limited to a mazda 6 on the street. I have a decent amount of experience on the track in a rwd car, both autox and track.

[astonmartinandy]

I would definitely agree with the point about fitting good tyres if you really want to control the car properly when you start sliding, but is it possible to fit a more advance Limited slip-diff on the front wheels like on the Focus RS to adjust the understeer/oversteer characteristics, or is that only possible on 4WD??

[jon_s]

Anyone said anything about left foot braking??

If you are understeering into a corner, applying the brake with the left foot puts the weight onto the front wheels, more grip hey presto...VERY simplified explanation, but there is a good DVD about, extreme driving or something, that does a good job of explaining it.

[graywolf624]

If you are understeering into a corner, applying the brake with the left foot puts the weight onto the front wheels, more grip hey presto...VERY simplified explanation, but there is a good DVD about, extreme driving or something, that does a good job of explaining it.

That just cancels out the gas your already applying allowing you to slow down to the correct speed. While braking does bring weight to the front of the car, it also requires grip to brake. You shouldnt be braking in a corner unless on entry and only then when your talented enough to trail brake. Think about it... Braking brings weight over the front wheels by the gs created by decelleration. In order to do this your slowing down and using more grip in the front tires for braking. The better approach is to drive at a slower speed at a smoother angle to begin with. In that way you are better prepared for the exit of the turn.
Left foot braking is generally only used for drifting and occassionally for rally driving. It allows you to control a slide, but you dont want to be sliding on a road or autox course to begin with.

[pranesh76]

I am just learning how to control my car. I drive a VW VR6 and that has a reputation for being extremely front side biased(over the 1.8T etc).

I have stock suspension and am not too keen on changing that too much since its my daily driver. But a bit would not be a problem. How much would any kind of small modifications cost? I've heard of coilovers - thats basically changing out your shocks?

Vaquish, graywolf - I assume that the mazda is not that much of a problem? You should have seen the amount of understeer that VW's seem to have.

Also the autocross circuits I've been to get to around 60mph - they have long stretches.

Other than learning through experience, which I plan to do, what would anyone suggest me try to find the limit of the car - basically when it starts to lose grip? What should I try to look out for to find out when exactly I'm going into understeer?

[graywolf624]

Take the car to an empty parking lot and play with it. Listen for tire squeal. Try to get it to let loose. Figure out how it feels right before it begins to plow.
Then take it to that mark.
The tell tale signs that give you feedback are tire squeal, and pull on the steering wheel in the opposite direction caused by tire slip angles.

The mazda is pretty nutural. Ive actually experienced oversteer in the rain while playing a little with the car. I've also gotten understeer though too. It seems to be very well behaved up till the limit though and it isnt a sudden or tremendous plow or spin.. Both were quite controlable. I have the full sport packaged with the 17" michlin piolets, so experiences may very.

Shocks- well my camaros set ran around 700 dollars(springs seperate for 250). You can get a half way decent set for around that unless your swapping to coilovers.. in which case we are talking 1300 for a good set. Roll bar change would be relatively cheap. I'd suggest first stop is a better set of tires. From there Id suggest looking at aftermarket roll bars.. prolly 200-300 dollars depending on car aftermarket. Go from there based on the feel of the car. Each car has its own weaknesses. You have to fix them in the order of the worst ones.

[pranesh76]

Thanks everyone for the infomation.

Everso - have you looked the the 3.2DSG? that sounds like quite a good improvement - dual clutch takeup? Best of both worlds...

Greywolf - thanks - will look into a sway bar first - cheapest thing comes first!

Thanks everyone else for all the suggestions.

[Vansquish]

My 6 sounds like it is specced exactly like Graywolf's...and my experiences are relatively similar, though I have to admit I've actually managed to get some oversteer in the dry as well...it just depends on how and when one turns in and when and if the throttle or the brakes are used. As for the VR6, I've driven a couple and you're not far off in your statement that they are renowned for front-bias and heavy understeer...the best thing you could probably do is invest in some anti-roll bars or shocks or both and a set of decent tires for autocrossing...you'd be amazed at the difference a nice sticky set of tires will have.