What does a ARCA do?
An Adjustable Rear Control Arm (ARCA) determines the rear wheels' camber settings. This is important on vehicles that are lowered or frequent the track. Whereas the factory arms are adjustable, they have limited range because of the eccentric cam bolt design. While lightweight in design, the design of the factory arms cannot withstand the continual pounding of track and street driving forever.
What about the factory arms?
Another undesirable (and overlooked) issue with the factory control arms inner mounting bushing itself. If a factory arm were to be replaced (because of damage or otherwise), it is important that the bushings are equally preloaded. Because Rogue Engineering's ARCAs arms do not use this style of rubber bushings, there is no chance of unequal bushing preload. This means that the suspension is allowed to move equally, freely, quietly, without any binding.
By design, the factory "cam" hardware to allow for camber adjustment has limited range of motion, allowing for only 1.0º. This is to allow the left and right side camber to be equal, more than to allow for additional adjustment for a performance benefit. With the Rogue Engineering ARCA greater range of adjustment, that extra bit of handling is available.
When a BMW is lowered, it can cause additional and unwanted negative camber (which leads to premature and uneven tire wear) which the factory rear control arms do not have the ability to dial out. Additionally, factory rear control arms are frequently damaged when an E36/E46 is towed by unknowing tow truck operators, who easily find the factory arms a convenient (but incorrect) location to secure the vehicle.
Our Design Details
We have modified our ARCAs over the years to continually improve their performance and function. Our latest changes allow for a simpler, stronger part at the same time, allowing for easier adjustments when required. However, when considering the design details of our arm, we specifically identified a few issues with other available arms:
- Adjustment points must be easily accessible. When companies design their arm with simplicity at stake, they tend to put the adjustment points on the ends of the arm. While the one near the clevis is easily accessible, an adjustment point near the subframe is not. Typically, the adjustment nut is so far into the subframe you cannot clearly access it to tighten or loosen it adequately.
A common, low-end aftermarket control arm
- Having replaceable parts is a must. Not all parts will last forever, and when they require replacement, easily sourced parts is key. This is the reason we use a rod end that is 5/8"-18 (LH) on our ARCA. In case it requires replacement, one can be sourced quickly around the country (outside the US may take longer).
- Mild steel parts do not hold up in NJ. In our region of the US, our road are salted during the winters. This wrecks havoc on steel parts. Using parts such as aluminum and stainless steel help against these corrosive elements. When appropriate, we balance the use of anodized aluminum and stainless steel in the design and construction of our parts. It's more costly, but we want our parts to last.
Kit includes two (2) complete arm assemblies. Professional installation recommended as an alignment is necessary to dial in the exact amount of negative camber.Features and Benefits
- Lighter than stock, factory rear control arm, with more adjustment range. (Factory arm is 1242g each, RE arm is 1065g each)
- Two piece design allows for easier adjustments (no adjustments required near the subframe, only near the wheel!)
- CNC'd 6061-T6 aluminum "arm" and "fork" clevis end is corrosion resistant, lightweight, yet incredibly stron
- One piece, CNC'd hardened 4140 chromoly turnbuckle
- Precision, rod end with grease fitting allows for easy maintenance.
- Made in the USA
- Sold as a PAIR
Fits the following vehicles:
- All E36 including M3 (not Z3 or 318ti)
- All E46 including M3 and xi
- All E85 MZ4 Coupe/Roadster