Here ya go.

 

Mike, could you expand on this? In thinking about it, it seems that with a slightly oversteering car you would be able to stay on the throttle and countersteer through the corner, but in a slightly understeering car you would have no choice but to lift throttle some, so it seems the former would be faster (assuming a competent driver, as a lesser driver may be more intimidated by oversteer). Maybe there are other factors like more scrubbing of speed with the oversteer?

 

I've heard what Mike is saying before, but I think you're right Richard. I think the understeer car is only faster with less experienced drivers. At least for me, if I have to choose one oversteer certainly feels faster than understeer.

 

But my car slightly understeers, not that I chose for it to be that way, but it makes me wonder.

 

Let's ignore downforce, because that changes things (makes them more speed-dependent). But I think a car that understeers very slightly is fastest on a typical road course. The place where understeer slows you down is in turn-in, and that's where it can be controlled easily by trail braking. Conversely, oversteer makes trail braking very difficult. On track out, the oversteering car may have an advantage, but only if it has enough power and grip to transfer enough weight backwards to overcome the oversteer. If not, it is disadvantaged on track out as well, because you have to limit acceleration in order to prevent power oversteer.

Furthermore, if the tires can handle it, in certain circumstances you can use the understeer to scrub speed and do the equivalent of trail braking. I do that in T5b at Pacific Raceways. It is the middle of a three-turn complex, extremely late apex. If you stay on maintenance or even slightly increasing throttle and turn in, the car scrubs just a bit of speed and then turns in. You kind of understeer to the apex which leaves you pointed straight ahead on the right fog line and well-placed to turn left into T6 (which, due to being uphill, has more traction and thus does not understeer).

I think the fast car will be very near neutral, and the driver will be able (for the most part) to induce oversteer or understeer at will. But I think for most cars and drivers and tracks that the faster way to go is to be slightly on the understeer side of neutral, even though it FEELS faster to be on the oversteer side. This is based somewhat on my own experience and more on what I have read and gathered from more experienced and faster drivers.

It's clear that in the old days of skinny tires, the 4-wheel drift was the fast way around the track. But you don't see that any more in the pro ranks, and I think there is a good reason for that. Surely it is not that the pro drivers of today cannot master a technique that used to be common.

 

It seems to me that you are confusing what is faster with what is easier for most people to drive quickly. Certainly a car that understeers, even if only slightly, is much more comfortable for all but the fastest drivers and will therefore be faster for them out on the track, but that doesn't make it the fastest set up from the standpoint of the car's potential speed. All the racers I know would take an oversteering car over an understeering one, but it seems our experiences are divergent here. In my experience the phrase "loose is fast" holds true, within reason.

 

Both can be fast.

I have driven a car that had slight understeer. When I lifted, the car would rotate just enough to negotiate the corner, I would then get back on the throttle, and the car was so good that it would hook up very quickly. This type of scenario is a good scenario.

On slow speed corners, such as you would find on a tight roadcourse, I actually like a car that has slight oversteer. It will turn left and right at your command. You just have to modulate your speed, throttle position and have the reflexes to turn toward the opposite lock. Sliding a car around tight corners can actually lower your laptimes, but it only works for a short time as the tires will prematurely wear out. This works on short timed events such as a 1/2 hour timed event.

When it comes to high speed, I would rather not have any oversteer period. It isn't a matter of running low lap times, but a matter of bringing her home in one piece.

 

Not on a one mile oval it isn't

 

Wow, there is a lot of discussion here for the most simple reply to be missing.

Adjust your tire pressures. Autocross guys should know this. With a stock suspension and road tires your fronts will probably need to be inflated more than the rears.

Find some place you can drive in circles. Drive a few circles both way at the edge of your grip. Then get out and look at the scrub marks on your tires (they should be pretty obvious if you are truly at the limit). On most street tires, the tread comes an inch or so down the sidewall. The scrub marks should be about half way down that part of the tread (to maximize potential grip without rolling the tire). If it is above that point, reduce the tire pressure. If is below that point increase it.

If you can get all the scrub marks to the same point on all four tires, I can guarantee it will be balanced in a constant turn.

Suspension mods will let you increase your overall grip in most situations, but if you are just looking to balance the car, do this.

 

Well I have thought of a question regarding the tire sizing. If 235/255 makes for more oversteer due to the grip in the front being greater and 205/245 is more understeer due to the opposite of the above then let me ask this. Shouldn;t the limit of adhesion for the rear tires be the same for a specific size (say 245) regardless of the fronts? Meaning that they will break loose at the same point (if you could get past the understeer of the 205 front)?