An integral part on E46 M3 is the rear chassis "V-Brace" (BMW # 33312229899) found on all 2001-06 Convertibles and Coupe (including the CSL). This brace attaches to the outward points of the rear chassis and to the area near the rear subframe carrier.

Since some of these vehicles are now over 20 years old, we have been seeing more and more of these start to rust away.

We began studying the OEM part, curious as to why they were starting to rust away. We found that the two arms of the "V" are made from 38mm x 12mm (1.5" x 0.5") hollow square steel tubing, pressed ends and welded to a junction plate joining them with welds holding the arms at a specific angle. Since the arms are hollow, it helps keep the overall weight down, but does little to prevent corrosion since it is difficult to paint/coat a hollow tube.

A Google search turned up very little other than used ones on eBay and new ones that turned out to be in short supply from the BMW dealer (not surprising since the car is over 20 years old). Determined to make something better, we began our engineering and R&D process.

Goals of our Design;

• Modular design, since packaging and shipping something this large would probably be too expensive
• Costs would dictate material and manufacturing methods
• Lighter weight would be a secondary (or tertiary) goal, but also keeping in mind costs
• Corrosion resistant, so it would not rust from the inside out, like the OEM version

After weighing the material, manufacturing and cost options, we decided to go with a fully CNC'd ACQ 6061-T6 aluminum assembly. The concept is to machine two identical arms (one part number) and have them joined with a "junction plate". The arms would be secured to the plate with Grade 8.8 grade hardware and the entire assembly would include replacement Grade 10.9 hardware to replace the original OEM hardware (which is probably original).

Details of our Design;

• CNC'd 6061-T6 construction, secured with Grade 8.8 socket head cap screws. Included are replacement Grade 10.9 hardware to fit in the factory locations.
• About 4 lbs. fully assembled weight (vs. 6.25 lbs for OEM), about a 35% weight savings
• Anodized gray finish
• Modular design allows for one arm to be removed in case of exhaust removal requirement.

Included in the Kit

• Two (2) arms of the brace assembly (they are idential)
• One (1) junction plate
• One (1) red spacer (this goes BETWEEN the brace and the chassis!)
• Two (2) blue spacers (these goes BETWEEN the brace and the chassis!)
• Four (4), M10 socket head cap screws
• Three (3), M10 flanged hex head bolts

It is recommended that the holes used to mount the V-brace onto the car be cleaned before installation by running an M10x1.5 tap to clean each of the holes.