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Getting the MINI Low-down

New Wheels

We’ve been busy here at GeorgeCo during the last few weeks of Autumn, taking advantage of the warmer than expected weather to get some projects done before the cold and snow of Winter sets in. Even as we prepare to sell the GeorgeCo Blue MINI, work continues on the Red MINI. In addition to getting the FES-Auto shift light to work in the new car, we finally made some suspension modifications. Here’s a brief recap:

We picked up a set of 17 inch R90 wheels couple of months ago and they were a little worse for wear under the previous owner. Nothing structural, but better to be straightened than to worry. A quick trip to the Rim Doctor and they look great, but they also really highlighted the fact that the car rides too high in stock configuration. (You can thank taller springs from the factory due to our crappy roads in the US for that.) Keeping in mind the performance goals of this car — faster, quieter, and smoother than the Blue MINI — we set to work on the suspension.

The stock Cooper S suspension is very competent from the factory. Optimized for occasional spirited driving, it starts to show its weaknesses when you get it on the track and really push it. The front wheels have little to no camber. The 16mm rear swaybar is undersized. The result is a serious tendency to understeer and excessive tire wear on the outer edges. The taller springs increase body roll and exaggerate the understeer.

We solved the camber problem in the Blue MINI with adjustable camber plates, but they proved too harsh for daily driving and were a major source of the uncomfortable ride. We liked the performance of the Bavarian Autosport lowering springs on the Blue MINI, but the Koni shocks just added to the harshness. To build on what we learned from the Blue MINI, we started with the parts we liked (BavAuto springs, stock shocks) and built from there.

New vs stock spring

BavAuto springs lowered the car and eliminated the raked stance that comes from the factory. We installed them over stock MINI shocks. Since the rear end picks up camber with the lowering springs, we added Hotchkis adjustable control arms to reset camber to negative 1.5 degrees. (Toe is set to 1/8 inch Toe-In for the rear to provide high speed stability.) We added a 22mm adjustable Alta rear swaybar to dial-out the inherent understeer. By sitting lower on the springs we also needed to reset the swaybar back to a right angle relative to the droplink, so we added adjustable drop links, also from Alta. (While we had the wheels off, we also added brass bushings to the rear brake calipers.)

rear spring

Having finished the rear end, we switched our attention to the front where we installed Ireland Engineering fixed camber plates over the BavAuto springs on stock MINI struts. If you remove the wheel liners, you can actually install the springs and camber plates without removing the strut from the hub. Just disconnect the strut from the front sway bar, compress the springs, disconnect the strut tower plate from the car and you can remove the springs and reinstall the new camber plates. The IE fixed plates are supposed to provide 1.25 degrees of negative camber on stock springs. Unlike the adjustable camber plates where the bearing is set in a thin setting of urethane, the fixed plates are set in a rubber bushing. You end up trading adjust-ability for ride comfort. When we got the car back from the alignment, we were happy to see they provide 2.5 degrees of negative camber on the BavAuto springs. (Toe is set to zero in the front.)

Fixed Plate

The net result of all of these changes is pretty dramatic. The car has a nice stance; is tall enough to get out of the driveway and over speed bumps; and is firm but not harsh. We’re heading out to the skidpad on Saturday to dial-in the swaybar. For now, it’s set in the middle setting which proved the best setting on the Blue MINI in the past. The photo below shows the previous ride height superimposed on the new stance.

Comparison