Vorshlag BMW E46 M3 CSL - V8 Downforce Monster Track Car ("Chainsaw Massacre")

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You might notice that we have this bundle of 3 hoses all stacked up with zip ties, above. That was for mock-up, but for real track use we needed proper "line separators". We couldn't find triple stack units but these dual hose brackets from Vibrant worked well, and with some threaded holes in the frame (nutserts) it made for a nice mount as well. We used a lot of these on the left side of the engine bay as well as for runs from under the radiator, going from one oil cooler to the other.



This is the remote oil filter mount and thermostatic oil cooler bypass along with one of the two oil coolers. There's hoses and hoses and hoses... That's enough about oil lines for this time. I will show why we had to change the vent line and move the breather in a future post.

EXHAUST SYSTEM FABRICATION



Last time we had just wrapped up the custom 1-7/8" primary long tubes. I was hoping these could be a pre-production test for a move on our normal E46 Ls swap headers (which are 1-3/4" at the time of this writing) but these were built to fit this dry sump equipped car only, so they aren't going to production any time soon in this size.



From the header collector 3" V-band clamps were added to a dual 3" stainless exhaust. The dual pipes fit inside the ample tunnel of this BMW, per our original LS swap design.



There's even room for an "X" style merge, which Ryan built from scratch. We did not install catalytic convertors for the initial testing and dyno tune, but if this ever became eligible for a "street car" competition series (Optima) we left room for them. Now that Optima has an "Outlaw" class, that is better suited to this car. For now it is all tucked up under the car nicely with good ground clearance.



The twin 3" exhaust was run back to the left side of the differential unit, then off to some Magnaflow 3" mufflers tucked up high at the rear. We had already competed the spare tire well surgery in anticipation of a rear diffuser, which allowed the mufflers to tuck up and mount higher in the trunk area than would normally be possible.



Probably overkill, but Ryan made sealed ends to back-purge the exhaust system with Argon for final TIG welding. This leaves a smoother finish on the inside of the welds.



I will show more of the exhaust outlets when we show the diffuser construction. With the diffuser the car sounds eerily quiet on track, but its a bit noisy right behind the car. Not too loud, but you can tell it makes some power.


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AEROCATCH REAR TRUNK CLOSURES

This trunk was a full weight steel unit, but the wing uprights pass some load through the trunk so we need the strength - for now. If we ever upgrade to a carbon fiber trunk we will need to strengthen the trunk.



During the wing upright install the trunk lock was covered up, but we had no plans of keeping the stock latch or lock. Instead it was time to add the Aerocatch latches to the trunk.



I have shown detailed installs of these for hoods before but never for a trunk. The latches go in place on the outer skin but the pin mounting was a bit different on the trunk install.



Ryan built this custom structure from some thicker sheet metal and welded it to the inner trunk flange, which has some strength. The weather strip seal was still functional when completed.



Brad shot this "ghost" image, with the trunk up and down, showing the Aerocatch latch install in the trunk as well as the pin and pin mount underneath. The correct alignment of the pin as well as the rigid pin mounts make these super smooth actuating latches, and they have been used 100s of times since these were first built in February of 2018.


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CHASSIS WIRING & MOTEC ECU INSTALL

Like the brake line system below, we bit off a lot of work when we decided to re-wire this entire car. Every wire, every module, every light bulb got re-wired. We started with a Painless Wiring "Pro Touring" chassis harness, pared it back to the systems we needed, then integrated the Motec engine harness that G-SPEED built.



I cannot emphasize enough how much work a total re-wire job is. Sure, we lopped off probably 30 pounds of the 50 pound chassis harness we pulled out, but it took 200 hours+ to get there. Ryan had to make all new wiring diagrams for the entire car, a whole binder full of them. Mount every relay and fuse box, ground busses, soldering terminations with motorsports Deutch connectors and pins on everything. Vibration mounts, harness sleeving, bulkhead connections, and on and on.



The electric assist steering system was another system of wiring - this has a 100 amp fuse to power it. EPAS draws some serious amps when you have to turn 335mm Hoosiers up front.



There were a more rounds of Deutch connector and pin orders, lots of hours spent stripping and pinning wires, and switch panels for a dozen switches, push buttons, and dials.



During the final weeks that the chassis wiring was going on, the guys at G-SPEED had the engine harness nearly done. I was out at MSR-Cresson for a race on the weekend and stopped by their shop to snap some pics. The costs involved for a Motec ECU and harness are also not for the faint of heart - but a Motec M150 has a lot of data inputs and programming potential. We're still exploring the limits of that.



A month after my shop visit the packages from G-SPEED arrived with the harness, M150 ECU, and other goodies.



Then that was integrated with the rest of the power supply and wiring already in the car. It looks like a nightmare here, but Ryan was meticulously going through each system, striping wires, heat shrinking ends, and testing circuits. He never released "the magic smoke", which all wiring jobs can do - once.



The sensor package from G-SPEED included things we normally do not monitor, like fuel system pressure and temps. All of the normal oil and water pressures and temps, traction control sensor integration into the ABS system, even crankcase pressure (we added the sensor later).



All of this Motec goodness talks via CAN to the AiM MXG color digital dash, which also has GPS and acclerometers for predictive lap timing and data logging.


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All of that main wiring, fuse boxes, relays, and ECU are hidden under the false floor on the passenger side - it can be removed with a few quarter turn Dzus fasteners for access, but otherwise stays out of sight.

FIRST FIRE OF ENGINE

After the Motec harness and ECU were installed, Ryan programmed most of the screens on the AiM dash. The starter was "bumped". The fuel system was tested. The dry sump oiling system was primed. Then it was time to fire it up...



Big milestone when you fire up an engine in a build this extensive for the first time! Mmm... that sounded good. G-SPEED did not give us any throttle control - they thought they had locked us out of the system entirely and it wouldn't start - but we at least got it to fire up, and made this little video for the customer.



I was hoping we could get the car ready to dyno shortly after, but there were a number of details to wrap up before the tires were ready to spin the dyno drum. Things like the rear axles - we didn't see those custom ordered units for many more weeks, and then they came in at the wrong length. We're still fighting some small issues with their construction, but I will share that joy next time.

STRUT TOWER BRACE

One thing that we wanted to add for a number of reasons was a strut tower brace. Sure, there are some E46 M3 braces out there but I doubt they would clear a reverse mounted MSD Atomic intake on an LS7.



We started with the cast aluminum ends used by BMW on the E46 M3, shown below left. Ryan made a tubular aluminum cross beam that bolts to the BMW ends.



This cross bar clears the intake with about a millimeter to spare, and has integral "cradle mounts" for the MCS remote reservoirs.



The MCS remotes for the rear shocks also mount to part of the cage cross bar on the same "cradle" mounts we use on the front - as well as on a lot of other builds we do.



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PLUMBING BRAKE LINES & ADDING BMW MK 60 ABS

Since this car came with no ABS unit we planned on adding one of our "Motorsport" ABS units and mounting it in the trunk. So all of the OEM brake hard lines were removed, along with the factory master cylinder, booster, flex lines - all of it.



This is NOT something I would recommend for the casual car builder - there is a LOT of work re-plumbing a complete brake system, replacing the pedals/master cylinder with aftermarket bits, and re-wiring for a trunk mounted ABS system. In other words: Do not do this unless you are willing to spend 100 hours chasing a small amount of weight removal/redistribution.



We ordered a BMW Mark 60 ABS unit, stand-alone wiring harness, and sensor harnesses from Racing Harness Technologies. He supplied everything we needed to add this harness to any BMW. Ryan used some new tools we bought for this project (tubing straightener + more extensive flaring kit) to make all new hard lines for the entire car, front to back.



The ABS harness came with instructions and was relatively painless, just a time consuming install. The plumbing was a lot more work...



I am a fanatic for using proper bulkhead connectors when a hard or soft line passes through sheet metal, and this trunk mounted ABS hydraulic unit meant there were lots of bulkheads. The wiring harness has a bulkhead as well.



All new lines were routed for all 4 corners of the car, some through the cabin and some under the floor. The ones in the back seat went to the OBP hand brake added in the back of the stock center console. This has its own master cylinder and connects to one rear wheel.



There are hard then soft lines at all four corners of the suspension, then two hard lines to the twin OBP master cylinders for the brakes and one line (its own system) to the OBP clutch master. We used their "bolt-in" E46 pedal box, and it is a giant steaming pile of garbage. I will talk about the dozens of hours we spent replacing all of the leaky OBP master cylinders + re-positioning the OBP pedals because they were jammed right next to each other. Hot mess, don't buy their pedal box or anything they sell with a master cylinder.

WHAT'S NEXT?

That's enough for one round. That shows the work through May 2018, right before we moved from our last shop to our current one. Ryan performed all of the work on the M3 up until this point, and for about a month or so after we moved in and got settled.



Next time I will show the final work on the twin air filter boxes, then the hood ducting and splitter install, which is around the point where Evan takes over on fab work.



Tune in next time for another "catch up" post that hopefully gets us caught up to current time. We should have another track test under our belt in this car by then, and hopefully some proper lap times.

Thanks for reading,

[CCS]

Great and awesome!!!

[Goosesdad]

Fantastic!