Corner Weight & Cross Weight

One of the additional benefits of an adjustable suspension, besides being able to dial-in ride-height and rebound, is the ability to corner weight the car. “Corner weight” refers to the static weight at each of the four wheels.  50-50 front to rear weight distribution is ideal to maximize handling on most road cars, but a distant pipe-dream for MINI owners. “Cross-weight” compares the lateral total (Rear Left + Front Right) to the total weight. If that percentage is over 50%, that’s called “wedge” in NASCAR terms. (Reverse wedge if under 50%). Corner-weight can be changed by adding ballast if necessary to make a weight minimum, or making, adjustments to spring perches and sway-bar pre-tension in an attempt to equalize the weight at each wheel. But more importantly, what matters for handling is near 50% cross-weight in a FWD car.

Take my car as an example: I have an R53 with a rollbar, AC delete, race seats, and a gutted interior. With driver and a full tank of gas, my car weighs 2,685 pounds. 61.8% of that weight is in the front; 38.2% is in the rear. That is slightly better than stock which had a weight of 2,853 (with driver) and 62.7/37.3 weight distribution.

The first time we attempted to corner-weight my car, I only had an adjustable suspension to work with. I didn’t have adjustable drop-links on the swaybars. That resulted in a cross-weight of 52.4%. That isn’t terrible, but still helped to contribute to under-steer in left turns due to wedge. We installed Alta adjustable drop-links on both swaybars, and without adding any ballast, tried again. The results are below:

Each corner is within 5 lbs. of the target weight. Cross-weight is 50%. The car now seems very neutral in left or right corners, which for MINI means equal understeer in both directions, as opposed to excessive understeer when turning left. Result.

Read more about cross-weight at GRM. If you want someone to do the math for you, see this  corner balance calculator.