1st Gen R53 Cooper S Most liked posts in thread: Oversteer and understeer where is the balance?

REMEMBER: You're not in full "battle attack" mode all the time on the street. Often you'll be fiddling with the stereo, looking at that attractive person walking on the sidewalk, of monotonously slogging between here and there... when all of a sudden SOMETHING HAPPENS AND YOU SWERVE. In that case, are your reflexes such that you can catch a tail-happy car, in the rain, radio blaring, and your SO on the phone telling you that you're out of paper towels at home?

Perhaps so, perhaps not. Be honest. Do NOT tell me, tell yourself, because NOBODY will be commenting on your rear swaybar settings while you're driving... unless you crash...

You see where I'm going with this?

For small-course Autocross where you want some rotation and are operating at 10/10ths concentration, set 'er up for a lil' tail, a lil' oversteer. Balance using tire pressure and perhaps rear bar settings.

For long track/FOD/HPDE: Again, where you're operating at 10/10ths concentration: Set 'er up neutral. That way you can provoke over-or under-steer using throttle and brake, and take full advantage of the car. (note: this from a guy who was invited to do high speed laps in his autocross setup during a track day, and even at 10/10ths levels of concentration I still got that back end a lil' too squirrely at speed!)

For the street, my preference is the same as ScottInBend: "A slight tendency to understeer at the limit so it is easier to catch is my preference". You want, perhaps NEED, brain-free at-the-limit handling on the street, even if you give up 5% of your cornering - because you weren't going to catch that 5% anyway because of the phone call/rain/paper towels/attractive person on the sidewalk taking AWAY from operating at 10/10ths concentration.

That, folks, is one reason why adjustable swaybars are made, and good drivers bring tools (and air) to the track.

 

Slight oversteer is the best handling setup. If you want to fine tune your setup use air pressure in the rear tires. More pressure for more oversteer.

 

+1 !!

My autox setup is 15x9 up front (225/45/15) and 15x7 rear (205/50/15). With a touch of toe out up front it is a HANDFUL at highway speeds. My 100 mile (one way) highway trip to yesterday's event was a bear, no texting/talking/sipping on starbucks for me! But hey, I got to hang out with the one and only DixonL2, so it was worth it :-D

Jason

 

close to neutral is best. I like it a little oversteery for autox, but neutral for the track. High speed and too much oversteer can be pretty dangerous. That's why car manufacturers design their cars with inherent understeer, but they overdo it.
Playing with the settings on the street: you're only really guessing and going by feel, because you're (hopefully) not driving at the limit enough to properly test it.
Best way is to use a skid pad or empty parking lot that is flat. Go around in a steady circle slowly increasing speed until the tires start to break away. Do the front or rear tires break away first? Adjust suspension accordingly.

 

Neutral

FWIW I'm running a 19mm rear bar set on full stiff. At the front I am running IE fixed camber plates with -1.8 & -1.9 camber. In the rear I'm at -1.5 camber. To me it seems like a nice setup & really does not oversteer unless I provoke it. Once provoked it is pretty easy to get it back. So I would say my car is fairly neutral.

I'm not sure how a 25mm hollow bar equates to a 19mm solid bar. I'd guess they are close to the same or maybe the 25mm is a bit stiffer, but it is really a guess on my part.

Trouble with interweb advise on handling is what is nice & comfortable for one can be panic inducing for another. There is no way of knowing the OP's skill level & that makes a huge difference.

Best bang for the buck to make your car faster is to make the driver better. Do a school or a HPDE. No replacement for seat time.

EDIT... I agree with Sneed tires & tire pressure make a difference too. An easy & free way to change your handling by varying tire pressure. There are many components to get a car handling the way you like.

 

Horse dookie lol, as long as the rear end isn't sliding all over the place and you still have good forward bite off the turns....loose is fast and wins races. Nuetral with some oversteer for me!!!

2cents

 

I had a 25mm hollow sway bar with no front camber plates to help remove the understeer at lower speeds. The difficulty with the large rear bar is that it tends to create a little too much oversteer at higher speeds. So it is hard to balance the handling with just a rear bar because it really depends on the speed.

I finally added front camber plates and then found the 25 rear bar to be way too much for the street with the camber plates. I now use a 19 mm rear bar with front camber plates to get better balanced handing.

 

:wink:

Lots of good advice in this thread. Hope the OP posts back here & gives us his 2 cents.

 

I've been teaching HPDE for PCA, BMW, Corvette, Pro schools and others for 34 years. What Dixon just said is spot on. The only thing to add is that 10/10ths is relative. My 10/10ths when I first started HPDE is about 2/10ths now. I have enough seat time to catch the car when sleeping. A lot of instructors that have years of driving experience make the mistake of talking like you are some kind of weakling that should bow down in their presence or they will steal your lunch money. That kind of arrogance can lead to drivers with less experience making very expensive mistakes. The skid pad or better - a big parking lot where you can do figure-8ths and accelerate/decelerate while cornering will help you learn how your car behaves. But again - Dixon is right about the street. Even if you have lots of track/autocross experience, street driving is full of distractions. What your car will do in the dry probably won't be what it does on a wet highway when traffic is coming to a stop and someone doing 40mph less than you pulls in front of you. Learn your car, practice, practice, practice and don't set it up for extremes...

My $.02...

Pat

 

Camber plates will greatly improve front end grip AND give you much better overall tire wear which could save big bucks if you are running directional tires.

 

I'd say the combination of a rear bar, camber plates & a good alignment transformed my cars handling from good to great. Oh yes the tires do last longer.

 

Nice picture Chris. You be stylin....

Having only run RWD on rally I had more than a handful of over-steer. Most times it was great a few it was :eek6: I agree over-steer is the fast way on the loose surfaces. :biggrin5: Rally car handling is another beast entirely.

 

Do you have camber plates on the front and are you sure the car is oversteering because of the suspension or the line and the way you are taking the turn?

 

A slight tendency to understeer at the limit so it is easier to catch is my preference ( I don't autoX), but it really comes down to how you like the car to feel. If you are more comfortable with one over the other, go for it.

 

My 25mm bar on my Coupe is set on the middle hole and that puts me on the edge at times. I can only imagine what having it set to the stiffest position would feel like.

 

+1

+2


It depends on the driver--I use a 19mm H&R sport (solid) and I bounce back between the soft and stiff settings. If it had a middle setting (it only has two), that's what I'd settle on.

 

I believe a true racing driver will want some oversteer at low speeds where it can be used to improve turning but changing to a little understeer at high speeds when controlling oversteer will lose time (and underwear cleanliness).

I think all that's fine for a track, but not for the road where extent of vision may be the limiting factor on speed in a bend. So if the car is set up to oversteer, it's likely that a sharp lift-off or brake mid-corner will result in a spin - so then all limited-visibility corners have to be driven at a lower speed.

A little oversteer = macho, a little understeer = efficient

 

OP posted that they were driving "in the twistys". Not 100% sure but that sounds like having a bit of fun on some back roads (hopefully not "canyon running" like a fool). That being the case follow the mild understeer advice. You will be much happier when you have to make an unexpected manuver.

 

This is my point. What is just right for one is not for another, do a couple things, honestly assess your driving skills and then YOU decide how much is too much.

2cents

 

My priorities at an HPDE are:

1. Get my car home in one piece.
2. Get my car home in one piece.
3. Get my car home in one piece.
4. Not use up my tires in one event.

And lastly, get my car home in one piece.

That's why I'd rather go neutral, or a slight understeer bias at the limits. The car is VERY forgiving, and still VERY fast. Besides, oversteer in a front wheel drive car really isn't nearly as fun as in a rear wheel drive car. There are times when oversteer looks cool as all hell, looks fast as all hell, and in reality, is slow as all hell. Granted, too much of a generalization, as there are times when oversteer is fast, but you have to pick your spots.