You know when you see those slammed, negative cambered BMW 3 Series at car shows? They destroy their expensive tyres and their scraping splitters choke at the sign of a speed bump? Well these guys have destroyed the months, or sometimes years of work that the manufacturer put into their OEM suspension.
These OEM systems are not only a culmination of all of the knowledge a manufacturer has gained over its years of trading, but they’ve gone through vigorous testing for performance and stress. Have a watch of this video where BMW perform a stress test on their E39 M5.
As you can see, the stress this suspension system is being put under far exceeds what it would go through the road, but the results from this are used to further improve it before it even hits the road in the form of a prototype. The severe rubber deformation, squealing tyres and movement from the suspension will carry on for sometimes hundreds of hours so as to make sure the product is as close to perfect as possible.
So, if you’re thinking about modifying your car and changing its suspension and geometry, maybe come back here, watch the video again, and think about it very seriously.