mikegreen

I don't have the book in front of me.. But I recall Fred Phun in "How to make your car handle" says that oversteer is the fastest way around a racetrack.

I need to validate this to a friend.. Which I agree having a *ever so slight* slide helps me out when driving and exiting corners.
Thoughts

Mike

JC in NY

For a given chassis you want all of the tires to be at their optimal slip angle under load, and this may mean that the car is yawed into the turn which gives the impression of oversteer. Otherwise the statement sounds like an over simplification.

Geo

[quote]Originally posted by mikegreen:
<strong>I don't have the book in front of me.. But I recall Fred Phun in "How to make your car handle" says that oversteer is the fastest way around a racetrack.

I need to validate this to a friend.. Which I agree having a *ever so slight* slide helps me out when driving and exiting corners.
Thoughts

Mike</strong><hr></blockquote>


You cannot generalize that much. Even on F1 teams the drivers often prefer opposite set-ups (oversteer or understeer) and often they are equally as fast.

Carrera51

I would think that slight oversteer would make the car faster. Understeer requires the driver to lift in a corner to make the car turn. Oversteer requires the driver to increase the amount of throttle to keep the car going in the proper direction.

Personally, I can't stand understeer. My 911 is set up to oversteer based on the torsion bar and sway bar sizes I have installed. Works for me.

Tony'z911

I feel that it really depends on each individual's driving style, but in general a car that has a tendency to over steer would be faster than a car that under steers. My 911 is set up to be a very neutral handling car and I often have to lift a bit to help the car turn in. I am still learning how to trail brake, but I feel that when you trail brake you are generally making the car over steer into a turn. This to me allows the car to make the turn and carry more speed through it by allowing the driver to still make the turn even at the faster speed. If the car under steered it would require the driver to lift and/or get on the brakes in order to get the car to turn and scrub off some of the speed. By maintaining the higher speed and still having the car turn, you should have a higher exit speed from the turn.
This is only my $.02 and I'm interested in reading the posts that follow in this thread.
-T

John Luetjen

Actually; "Understeer" and "Oversteer" are such gross generalizations almost to the point of not being meaningful. There are at least 3 specific situations which need to be analyzed separately: Corner entry - mid-corner and corner exit. The car's performance for each aspect of the corner (and for each corner) needs to be optimised so that the shortest possible race time results. Often a car that has a slight push works better for fast sweepers while a loose car works better for hairpins. Sometimes cars may be loose in, neutral in the middle and push slightly on the way out. Other times the reverse will work better . The optimal set-up for a certain track on a certain day may result in some corners or aspects of corners compromised so that better performance can be gained elsewhere. Furthermore a car may be set up with a chronic push initially so that as fuel is burned off and tires wear that the handling becomes "neutral" for the last portion of the race. TransAm and NASCAR teams commonly do this. Handling is such a dynamic problem that static solutions such as "understeer" or "oversteer" are meaningless.

As you mentioned, set-ups often are different for each driver. A curious phenomina which needs to be kept in mind is that set-ups which are fast often feel slow to the driver. The same applies to drivers -- often the fastest drivers appear to be slow. A classic example is Alain Prost who almost never appeared to be "on the edge" but who cranked off a lot of front row starts, fast laps, race wins and championships. Ultimately; the stop-watch or datalogger (and a pyrometer) is the only way to tell what the right set-up is.

That's one of the fun parts about racing - trying to come up with the elusive "Optimum" balance. If it was as easy as "dial in some oversteer" everyone would be a winner.

Carrera51

John:
Great post. You are right about Prost. He made it look so easy. I remember a race in 1993 that he won (can't remember which track) where he ran the entire race without a pitstop on one set of tires. This was before the FIA brought back refueling. Amazing drive.