So Ive finally started sorting the chassis and brake system and a few other odds and ends on the M5 with the immediate goal to be mechanically sorted for a road trip with a buddy to Bimmerfest East (Bimmerfest East 2012 Event Registration!
) . After the road trip I'll be taking care of the exterior and after that the car will be getting a stand alone ECU. The long term goal is to have the chassis sorted and ready for a turbo system on a rebuilt engine.
So to start I dropped both subframes and cleaned the chassis looking for any rust or areas that had damaged seam sealer, paying special attention to the side skirts, jack points, and wheel wells. Lucking no rust was found but I did have a few areas where the seam sealer and under body coating had been worn through so I ground those down to bare metal and hit with Wurth High Zinc Primer then Wurth Seam sealer.
With the subframes out I cleaned them up and ground off any surface rust and again painted it with High Zinc Primer and then with Wurth Matte Black paint. One of the things that I figured could be replaced while the front subframe was out were the engine mounts and all new hardware.
I went ahead and re-tapped the chassis holes for the front support and subframe to make sure things were able to be properly torqued.
I'm also replacing all the steering components minus the box which is still in good shape and new hardware.
With the front subframe down I replaced the oil pan gasket and sender oring along with all new hardware and torqued to spec with Loctite 246.
You can see the JB Racing aluminum flywheel in the above pic, Im debating on a couple of options for when I rebuild the engine in terms of a clutch and possibly a new flywheel. Definitely want to avoid the on/off of a lot of high power clutch setups. A small project I'm tackling to hold me over till the car is turboed is deleting the secondary air injection system. Since the S38 AC system uses the secondary air injection pump to tension the AC belt you need to use the 535i bracket and compressor lines as well as do a little strain relieving on the temperature sensor on the compressor. I need to get pics of my solution up later. Here is the new bracket and new hardware torqued and installed with Loctite.
Here are the plates I machined up to delete the secondary air injection rail and feed hose.
And installed on the headers and torqued down.
So getting back to the suspension, tearing apart all the bushings in the E34 is pretty painful but I built a few tools that made it real easy to replace all the rear subframe bushings including the dreaded rear trailing arm bushings.
Here is the rear trailing arm puller in action.
The rear trailing arm bushings and the diff support bushings are being replaced with OEM units whereas the rear subframe bushings are Powerflex. Little note I found interesting the standard E34 uses a rubber bushing with metal pin bonded in rubber whereas the M5 uses a rotary bearing setup in the rear trailing arms, one more little difference brought to you by M
. The front suspension rebuild consists of all new hardware and 850csi arms and Mooseheads in OEM BMW (Lemforder) arms. Most importantly in the overall rebuild are the Ground Control bits.
Adjustable front swaybar end links
Here are the rear units installed and torqued down, along with being fully adjustable the Ground control pieces allow me to eliminate the SLS system and all its added weight and complexity.
I also removed the lines for the SLS that run forward and replaced the mounting brackets and just for kick the mounting clamps for the fuel lines and cleaned everything a bit more. Hardware.
Fuel lines as well.
With everything dropped Im also adding a set of Stoptech stainless lines from Turner Motorsport.
I noticed I had a slight leak from the drivers side output shaft so since the rear subframe is dropped I decided to reseal the diff as well as a little side project while waiting for parts to come in.
Next on the list is replacing the gaskets and hardware for the oil return pipe for the head and coolant feed line for the head. With those addressed I'll be able to get the front subframe and suspension mounted back up along with the headers. Im also working on building a remote mount windshield washer reservoir that will live behind the passenger fender so that I have more room behind the passenger headlight assembly.