With the kids home for the Summer, haven't had a chance to post an update the last few weekends. In no particular order.
The biggest worry with running the supercharger on the BMW S65 has been making sure we are properly cooled to prevent detonation. The biggest obstacle has been aesthetically getting a properly sized and designed radiator and intercooler to look right behind the ’33 grille. It’s finally coming together. Heads up to Active Autowerke who did an amazing job building me an intercooler and mounting it to the grille so it all lays out at the 26 degree slope of the Grille and the outlet is a straight shot down the center of 3” tubing directly into the plenum. The mounted intercooler and grille is now in transit and on in its way to C&R to do up the radiator.
In addition, adding extra cooling protection through the oil system. Just mocked up, welded in brackets and plumbed both the engine oil cooler and the supercharger oil cooler this past weekend, and finished milling a bracket for the reservoir for the supercharger since I couldn't find one commercially I liked and the one that came with it looked really too cheap to be mounted in such a prominent spot on an open firewall in a car that will run without hood, fenders and side panels. Decided to mount both coolers in the rear so the extra distance in the hose acts as additional cooler. Additionally ran mammoth 12AN lines and a NASCAR WIX filter for extra oil capacity for the motor. Put the engine oil cooler with a fan in the bottom of the trunk horizontally to draw fresh air over the rear end and I'll have a shroud made up to dump it out the other side out the back. I put the SC cooler on the passenger side just behind the rear bulkhead and just below the floor line. I'll mount the transmission cooler in the same spot on the driver's side. Need to pick up some additional fittings, much bigger rivnuts and fasteners to mount the hose length to the frame to finish it up, but here's where it was at at the end of the weekend.
I've crossed the bridge on exhaust layout and decided to shave the doors and run traditional side pipes which is what opened up the space for the SC and trans coolers. Been spending time with Active designing a custom set to work with the S65.
Of course every step forward seems to require a tweak to something I’ve done before and this time is no different. Don’t believe the clearances for fittings and lines provided online when laying out components. The 12AN oil block fittings just hit the alternator belt. Fortunately, I had an open accessory pulley in the middle off the crank, so some aluminum spacers and a move 1 1/16th forward and will be all set.
Similarly finally got the belt for the SC from NAPA on Saturday and when went to install realized the belt tensioner the pulley layout is designed around to clear the frame puts tension counterclockwise and I need tension clockwise. After some expletive moments, discovered online and had confirmed yesterday that the tensioner for the much earlier E30 N52 is virtually the same design and puts tension clockwise. Even better, my buddy who’s been helping out when he can had a spare one in his toolbox.
The Getrag 6 speed manual transmission has a much smaller footprint and bell housing then the transmissions the Factory Five transmission tunnel was built for. Nationwide Auto Parts in Central Valley NY (who have been great to work with and through whom I sourced the drivetrain) cutout the stock M3 tunnel for me at a price I couldn’t refuse so I can use it as a mold on the inside as I can go a little smaller and lay up my own out of glass. Began the process of mocking up the mold in place this weekend. It will mate up to the recently installed for mock-up firewall. Had to build a new lower driver side panel to mate with the footbox mods I’m doing in steel for the floor pedals with the master cylinders outside the footbox, but inset and under the firewall, yet accessible.
Last weekend I finally got around to start the install of the brakes and the 12.88 Wilwoods which I ordered with the kit and looked massive for the last six months in the box, just looked way too small on the HRE wheels up front. In addition, I hadn’t really done anything about the rear yet. Thanks to the ffcars forum, the Wilwoods sold same day and will find a great home and look proportionally correct on a Cobra.
In keeping with the project as more of a traditional hot rod build, decided to do my own BBK kit. Found a set of brand new, but blemished (which is great because I was going to powdercoat to match anyway!) so massively discounted, 2013 ZR1 Brembo 4 piston rear calipers, and a set of Brembo 8 piston calipers off a Lamborghini Gallardo for the front. I’m in the process of finalizing an order of 380X34 slotted iron rotors all around with the Mustang GT hats up front and the correct BMW M3 parking brake hats in the rear. Plan is to put the Bridgeport to work and mill brackets out of the harder 7075 billet.
Tons of other attention to lead time parts for the rest of the project, but that’s what I got for now. --I