During the winter months we did not sit still and a lot of adjustments were made to the R-Box BMW M3 E30. Below the photos we give a comprehensive overview.
To be able to make even better onboard videos, we mounted an extra camera in the front bumper. The annoying whistling that we struggled with in the past has largely disappeared by placing an LCL filter in the power line of the intercom. Unfortunately, the problem is not yet completely solved, but here only an intercom powered by a battery can offer solace. We don’t want any extra battery stress on board and so we accept this interim solution. The proof that we sometimes dare to make compromises.
A TPMS, or Tire Pressure Measurement System, was installed to better monitor the tyre pressure of the R-Box BMW M3 E30. Super convenient!
We said goodbye to the very conservative Pagid RS4-2 brake pads. We stick with the brand, but at the front we choose the RST1 compound, and at the back we place the RST3.
We discovered in our previous races that the alternator at low revs could not provide enough power. We therefore chose a pottier version of this Denso alternator. The 240A version delivers a sloppy 178A at rest. The regulator is custom-made and has a slightly higher setpoint of 15V. Our lithium iron phosphate (LiFePO4) battery is much happier with that than with the usual 13.8V.
The alternator not only got a hefty growth shoot in current, its weight also increased significantly to 6.9 kg. The original BMW bracket is not really made for this, so we have come up with a completely new design for this. Nick, our mechanics guy, let himself go completely and developed a pretty complex thing. This bracket is capable of hanging 10 elephants and is equipped with cushioning material to eliminate any kind of vibration. We chose the stiffest polyurethane bushings of 95 shore.
Because the original BMW Motorsport crankshaft pulley only has 4 ribs and that is the limit for a 240A alternator, we choose to place a new belt every rally.
Gas slide control
The weak connection point on the gas slide, to which the rod of the throttle actuator is attached, was replaced by its own design in ALU7075. Not only the choice of material has made it stronger, but also the physical dimensions have changed in such a way that there is more “meat” on it. We are now convinced that it is indestructible.
We have made a number of new aluminum radiators with improved fan supports. In addition, we also thought better about the replaceability, which is now super fast. The eye also wants something natural and that is why we have had the R-Box logo lasered in.
The water pipes often had whimsical shapes. We had used a lot of standard bends and that caused us to have way too many connections. In itself, that is not such a big problem, but every connection is of course a potential chance of leaks. All tubes were scanned in 3D, converted into drawings and the new ones were custom-made. Nowhere is there still a connection to be seen.
The full exhaust has been replaced by the latest version of M.A.T.S. We had the header re-coated, this time not a colored ceramic coating, but the white version that can tolerate much higher temperatures.
The suspension has undergone a complete makeover. New damping characteristics, new springs and modified suspension travel. The rear stabilizer bar was also renewed and all around we placed new drop links.
The air supply was completely revised so that much more cold air is now being sucked in.
The electromechanical battery switch ended up in the dustbin. It caused us too many problems in the past and that is why we decided to switch to an “electronic” version. The alternator is now directly connected to the battery via a 50 mm² cable and no longer runs along the battery switch.
An additional control signal has been added that, at a press of the emergency stop, will inexorably switch off the ECU, regardless of whether the alternator still provides sufficient power.
In the past we sometimes lost CAN messages at the start-up of the car. In specific cases, the horn and reversing lights no longer worked as a result. A reset usually solved this problem, but now we have found the cause. We updated our software and that now ensures that we can always sound the horn and drive backwards!
The Electical Power Assisted Steering, or power steering, has had a software update that allows us to control it over a wider range.
In time, the Revolution rims on the R-Box BMW will disappear and be replaced by Evocorse “San Remo Corse” rims. We will do this in steps and the first 12 were already put in the running. The look of the R-Box BMW M3 E30 will change regularly, but we stayed true to the gold color!