How To Reinforce BMW E36 M3 Strut Towers
It's no secret that the BMW E36 chassis is an awesome platform for building a race car, but it's not without some design flaws. When BMW designed these cars, they wanted to shave weight on the chassis to help offset the additional weight of the safety equipment and modern technology that would soon be added to it during production.
One of the ways they did this was to make vehicle's sheet metal thinner throughout the chassis. Unfortunately, the front strut towers also received this weight saving treatment which, in time, can lead to cracked towers. BMW recognized the flaw and came out with a fix for it, which was a reinforcement plate sandwiched between the strut's top hat and the strut tower, effectively doubling the thickness of the metal and helping to distribute the load over a wider area.
While I was cleaning and prepping our M3's engine bay for paint, I noticed a crack in the passenger side front strut tower. Knowing that we were going to be driving this car pretty hard while rallying, we wanted to reinforce the strut towers so that this would hopefully never happen again. We towed the car over to our favorite local welder and fabricator, Adam, at Final Fabrication and Repair to have him work his magic. First, he fixed the crack by welding it back together, and then we needed to figure out how to reinforce the towers. I decided to order a set of "E36 High adjustment Reinforcement plates" from Garagistic to have welded underneath the tower.
Adam then took the factory reinforcement and modified it to fit on top of the tower.
He then welded it all together.
By using the Garagistic plate underneath and the modified BMW plate on top, we are effectively tripling the metal thickness on the top of the tower, all while staggering the welds and eliminating any stress risers. We believe that these towers are now ready for anything we can throw at them!
Because Ryan and his E36 will be facing six-foot jumps, constant abuse during rally stages requiring the utmost protection and rigidity, welding in plates makes sense. But for daily use, it's more than most people will need. For that, we recommend what's on our site, the Genuine BMW strut + shock mount reinforcement plate kit. - Editor