The chassis of the MINI Cooper and Cooper S is well-designed and pretty stiff just as it comes from the factory, which is one of the reasons why your MINI felt satisfying to drive when you first drove it away from the dealer. Several reviewers have remarked that the car felt “as if it had been carved from one block of steel.”
However, as you start to drive the car harder, on track days or around the autocross cones, or just like tossing it around backroads corners, you might want to stiffen up the chassis just a bit more. This upgrade is one of the easiest in this book. It is accomplished simply by bolting a “strut brace” across the front of the car in the engine compartment, to connect the tops of the two front strut towers to one another.
The benefit of this brace is to stiffen the front of the car to reduce flex in the suspension. Where the stock MINI feels pretty stiff and strong in corners, the added strut brace makes it feel really solid so that the car turns into the corners more easily without hesitation. Of course, since the brace is visible to anyone looking in the engine compartment and is an attractive accessory, it certainly adds to the performance credibility of the car.
A stiff, well-constructed strut brace is desirable on a car that is running with low-profile, high-performance tires and especially desirable when installed in conjunction with a lowered suspension. A typical well-engineered strut brace will cost about $325, and can easily be installed by anyone with the right-sized wrenches in less than an afternoon.
Chassis stiffness becomes increasingly important as the MINI is used more often for serious autocrossing, and is an important element in suspension tuning. For this reason, many tuners also prefer to add a rear strut brace to the MINI before making other changes to the rear suspension of the car. Like the front suspension, this additional component is bolted on to the rear suspension mounts and extends across the car. A good rear strut brace can be purchased for about $200 and is easily installed.
