If the purpose of a rear swaybar is to dial out the inherent understeer. But you can also solve this with springs with a split rate. So which is the best solution. If you did both would it over correct and cause more issues?

 

I am also interested in the answer.

I have a Cooper (non S) with regular Sports Suspension and have an option of installing rear springs from SS+. The question is will it improve or hurt handling?

Leon

 

Springs, and then dampers, are the the heart of every suspension system. You should select spring rates - if possible - for your intended use. Then, because springs are dampened or controlled by the dampers, you should select a damper that is appropriate for the spring rates. You may opt for a system developed by a manufacturer like Bilstein's PSS9 adjustable coilovers.

The fundamental handling characterisics should be determined by spring and dampers. Sway bars should be used as a fine tuning component, not dial out all of your understeer or oversteer. This is wrong. The basic balance of the car should be determined by springs and dampers, said another way. Once you're close to where you want the car, you can use an adjustable swaybar to fine tune for street, autoX, and or track.

If you're driving a track only car, your setup will change for each track and conditions - rain or sun. If you have kept really good records of your set-ups at each track and you wish to really dial in your ride, you'll have more than once set of springs and dampers...and sway bars.

Stiffer isn't necessarily better either - with regard to springs, dampers and or sway bars. Compliance, driver comfort and very predictable handling is.

Great question, lots more to write, outta time today.

 

I probably won't be hitting the track...at least for quite a while. But I do love to shoot through the "S's" every chance I get so I'm looking for better handling. I understand that stiffer rear rates will solve understeer issues. I have read that H-Sport uses a progressive rate that is actually softer than stock in the front, and stiffer in the rear. They say this split rate solves some of the inherent understeer the MINI exhibits at the limit. If I go this route will I really need to add a swaybar to keep the car "neutral"

 

Let me start by saying that I'm in the group that prefers the stiff '02 suspension on my MCS. I don't want it softer so I went with the swaybar 1st. I use the H-Sport comp rear bar to dial out most of the understeer and have two more settings to go . If you go with some H-Sport springs, you'll have to dial out less understeer but it will still be there. I'm not sure you'll be able to balance the car just by springs.

 

You can come very close to 'your' balancing goals with springs and adjustable dampers. Achieving this goal is a matter of time and money...and sometimes custom work. So then, the swaybar is a quick and inexpensive way to achieve less understeer.

A swaybar should not begin to work until you are well into your turn, before which, the springs and dampers should determine balance. Too much oversteer can actually destroy good slalom speeds. Roll stiffness just happens to be one of the benefits of a bigger bar, but it ought to come from springs and dampers for the most part. This will creat a very predictable and linear car thru turns - no abrupt squirlyness from a big bar coming on line too fast. In addition, a big bar can posses some of the qualities of a solid rear axle - transmits inputs from one wheel to the other for example during cornering and bump loading...even in straight line driving on bumpy roads.

Keep in mind too that we are fighting physics with the Mini, no matter how good it is. The weight distribution is wrong, the center of gravity is too high, Double wishbones are better, and the wrong wheels are driven. You cannot correct these things with a swaybar or springs and dampers and expect Ferrari handling.