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We will show the work on the front inlet ducting and the hoses in a later post - we have a good place for that on the 1M style front bumper cover that the customer chose.
Out back the nickel plated trailing arm got new bearings, plated hubs, and AKG spherical bearing kit in place of the RTAB bushing. I always say that the RTAB bushing needs to pivot freely in 2 axis and won't do polyurethane here - only the OEM rubber bushing + limiter OR a spherical bearing like this. Anything else is just asking for suspension bind. The spherical bushing kit needed a hair of clearancing to press into the trailing arm, and the entire setup was held in place by both a press fit + a little bearing retaining compound (above right).
The rear ducted backing plate was a little trickier. With the rear hub installed (its a bear to remove) we noted that a 2piece backing plate made more sense. So a backing plate was made that fit close to the Powerbrake 4 piston caliper and rotor. With the rear suspension assembled a 3" oval ducting inlet was added to clear the control arm. Its usually pretty difficult to route hoses to rear brakes, but again - with a car like this its worth the effort.
SUSPENSION PARTS INSTALLED
Since we ended with the brakes out back we'll start with the suspension there also. The rear control arms are all mounted in spherical bearings - a mix of OEM sealed rubber versions (where the factory included those) and aftermarket spherical bearings elsewhere. We also sourced all brand new rear suspension bolts from BMW - cheap insurance.
The reinforced and powder coated rear subframe (detailed in my last update) was installed with AKG aluminum chassis mount bushings and bolted to the reinforced mounting holes using the new BMW bolts. Then the rear suspension was bolted in with the plated aluminum upper arms and SPL Parts adjustable length, spherical bushed, lateral lower arms. The plated and spherical bushed trailing arms were also bolted in place.
That wraps up the rear suspension - well other than the shocks/springs. We went with MCS Remote Reservoir 2 way adjustable dampers on this car (RR2) along with a firm set of springs - rates which might change later due to aero and lateral loads (track testing will sort this out). Vorshlag spherical rear shock mounts were installed as well.
MCS RR2 dampers installed on this E46 M3
Up front we used the M3 version of our E46 camber/caster plates along with the RR2 front struts. We were working pretty quickly around this time and the suspension went on, ride heights were quickly set, and then wheels went on before I could get good pictures of the suspension installed. I'll make a point to get shoot these with the wheels off soon.
We haven't mounted the reservoirs yet but they have hoses long enough to keep them mounted underhood for easy access to the compression knobs. The rebound knobs are on the top of the strut, which makes them easy to access. The camber-caster plates bolt into the reinforced E46 strut towers - which may receive further reinforcement with bracing to either the chassis and/or the cage.
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For most track E46 builds we'd put in a new pair of Lemforder lower control arms, Powerflex 2-piece LCA bushings, and fresh tie rods. This isn't the typical track car - its spherical or nothing.
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