Quit the giggling girls... I'm not talking about priapism.

In regards to the rear sway bar, is it possible to have it too stiff?

I'm looking to do this perf. mod. with the intent and desire to "dabble" in AutoX and perhaps some road racing,( taking lessons from a professional on a closed course first naturally).

The Car is also a daily driver, used to run myself all over town, work, etc. and I'm not really interested in changing the position of the sway bar once installed. So back to the question, Is it possible to have the rear sway bar too stiff in terms of handling and daily driving?

My thoughts are to make it as stiff as possible initially, as I would think this would provide the best performance the bar is capable of, and then decrease the stiffness if any undesirable effects were noticed.

Thanks.



His, Chile red all over / Hers, EB UJ on top

 

IMHO, the simple answer is "Yes", and the complex answer is "It depends".

Simple answer: The stiffness of the rear bar will negate the tendency of the front to understeer or "push", causing the rear of the car to rotate more or oversteer. In other words, the rear of the car will try to pass the front of the car, resulting in a spin in the extreme example. This is why almost all cars, the MINI included, are delivered with the suspension tuned to an understeer condition. It's easier to keep the driver out of trouble than it is to keep him out of court.

Complex answer: An ideal autocross setup is not necessarily an ideal street setup. In fact, some auto-x cars are downright unstable on the street. But the drivers have tuned the suspensions to negotiate a tight auto-x course, usually but getting the rear of the car to rotate to their advantage. So it really depends on on how dedicated to auto-x the car will be. This is where the beauty of the adjustable bar comes in - dial in oversteer for auto-x, dial it out to drive home.

You did not specify which MINI you have (Cooper NA, or Cooper S), but it does sound like you have little or no experience with auto-x. (Please forgive me if I have made an incorrect assumption.) It is the natural tendency of novice auto-x'ers to assume that car preparation is the key element. Look at it this way -

"Drag racing is for fast cars, autocrossing is for fast drivers"

My recommendation is to try an auto-x, and verify that it's for you. (I'm sure you will, BTW!) Then auto-x your a$$ off with your car as delivered, even on the street tires. Spend the rest of this season doing that. Expect everybody else to whoop up on you. Remember, they are experienced, you are there to learn and have FUN!

When you are ready for next season, start by READING THE RULES of the sanctioning body under which you are running. If it's the SCCA, and you are running in the Stock category, a swap of the rear bar is illegal and will put you into one of the categories where (like Street Prepared, Street Touring, or Street Modified) you'll get whooped up on again!

The beginning of your second season is when you will want to buy a set of dedicated race wheel and tires (read the rules first!). The race tires will make a bigger difference than the rear sway bar, and still leave your car streetable.

Sorry for being so long winded, but the answer depends on your intent.

 

It is very easy to make the rear "to stiff" for conditions. I would not recommend starting at the stiffest setting. This may be a handful in the dry - and almost certainly will be in the wet. I have run "full race" suspension setting on my daily driver before (in the early days of SCCA IT - when you could be competitive with a daily driver). With a stiff rear, in the wet - and maybe even in the dry - you will reach a point of "dedication" when running fast into a turn where lifting out of the throttle - could bring the tail around. This is useful to rotate the car on the track, but can be very dangerous on the street where conditions are not controlled and runoff may not exist. The correction for this rotation is to get back on the throttle. If there is not room to do this because of an obstacle ahead - you are likely to spin off. This condition “loose” is exhilarating, but is not particularly safe for daily driving.

Start with the minimum setting on the street, and test the higher setting under controlled conditions at a track day or Auto-x. Get a feel for how harry the car may become before you drive it home that way. By the way – changing bar setting should be no more than a 15 minute project.

Good luck – be safe.

Wes

 

I've driven cars in the past that exhibited throttle-off oversteer that I never considered unsafe. I think some clarification is in order. You're saying driving at the limits will be unsafe on the street, or that you may spin under normal circumstances?

I agree that I wouldn't go full-stiff on a rear sway bar initially. I like the reports of neutral behavior out of the middle position on the madness swaybar.

When I autox'd my MINI (first Auto-x experience) my biggest problem was not sliding around on those seats! Maybe a driving school and one of the detachable five-point harnesses for starters? :smile:

Jeff

ps: You'll definitely have a blast. It's addictive.

 

>>My thoughts are to make it as stiff as possible initially, as I would think this would provide the best performance the bar is capable of, and then decrease the stiffness if any undesirable effects were noticed.
>>


Hmmm....I think as stiff as possible will totally change you the MINI handles on the street and until you get those closed-course lessons, I would think twice about it. I think the lightest setting would give better handling on the track and on the street and it will be easier to adjust to it. A sway bar at the max setting will totally change how your MINI reacts during cornering and if not careful, you could find yourself off the road to say the least!

I'd start with the softest position. You'll still notice it, don't worry! :smile: