CMP Auto Engineering
Stage 1.5 - E46 Chassis Rail Plates
Stage 1.5 - E46 Chassis Rail Plates
Fits: All E46 Non-M, E46 M3 (Excluding Hatch)
Benefits:
-Prevents catastrophic Rear Axle Carrier Panel (RACP) failure.
-Provides a direct load path between the rear half of the RACP and chassis rails
-Prevents failure at the rear wheel arch, spring perch and beyond
-Fits beneath the factory boot trim for a hidden installation
Note: Underside reinforcement plates are still required to comprehensively reinforce the chassis.
Recommendations:
-This is considered the bare minimum in topside chassis reinforcement. For a fully comprehensive solution we offer a stage 2, topside reinforcement.
-All E46 shapes - Stage 2 - E46 Rear Weld In RACP Beam
-E46 coupes - Stage 2 - E46 Front Weld In RACP Beam
Material:
-2.5mm 250MPa yield zinc coated mild steel (zincanneal)
If you've done your research on E46 subframe mount/RACP failure you've very likely seen the horror stories where the boot floor is flapping up and down and completely separated from the chassis rails. This is simply because the hollow section the subframe bolts to does not connect to to the frame rails of the car or anything else that could be considered structural. Instead, it shrinks down to a single layer of sheet metal towards the wheel arch.
Even with underside reinforcement plates installed you aren't safe from this as you cannot correct one of the biggest design flaws from just underneath.
We've done our best to bridge the weak points with our underside plates however, for those looking to more comprehensively reinforce their E46 chassis without blowing the budget, we have designed this cheap yet effective and completely hidden solution to prevent any chance of that ever happening.
This product closes the gap (pic 3) providing a direct transfer of stress from the carrier panel to the frame rail preventing the boot floor from separating from the chassis rails permanently while simultaneously providing a noticeable increase in chassis rigidity.