MK60 Standalone ABS Installation
All Race Harness Technologies (RHT) MK60 products have moved to RHTmotorsport.com. For more information and to purchase MK60 products please contact Doug at info@RHTmotorsport.com
INSTALLATION GUIDELINES
The MK60 can be fitted in a wide variety of cars both BMW and otherwise. Depending on your application, some wiring and plumbing is required but with the use of a standalone ABS wiring harness the installation can be streamlined. The key items required for installation are:
- Wheel speed sensors (one per wheel)
- Pressure sensors (measuring master cylinder outlet pressures for the front and rear outlets)
- Yaw/Acceleration sensor
- Signal to the ABS system that the brake pedal is pressed (this is typically accomplished using whatever controls the brake lights)
- 12v power
- Ground
INSTALLATION LOCATION
When you order a custom harness we will ask you to provide lengths to each wheel speed sensor from your MK60 ABS unit along with an indication of what sensor you’ll be using. The pressure sensor runs will be 36”, power and ground will be 36”, and the yaw sensor will be 72”.
Engine Compartment or Interior
The MK60 uses on-board pumps and does not require a pre-charge pump to boost master cylinder line pressures. As a result the MK60 is very flexible with regards to installation location. It's not uncommon to see these units installed on the passenger side floor or even in the trunk of a race car. This can be advantageous to make room in the engine bay for engine swaps or to simplify wiring or plumbing.
SENSORS
Pressure sensor inputs as used by the MK60 to determine pedal input levels and driver intent. They are installed such as to monitor the master cylinder front and rear outlet pressure. They are not required for ABS regulation but provide performance advantages especially in cases when the suspension is being loaded or unloaded under braking.
DSC / Yaw Sensor
The DSC sensor (commonly, but incorrectly called the yaw sensor) is a combination of lateral acceleration and yaw/axial acceleration sensor. Similar to the pressure sensors, this sensor is not required for the ABS to function. However, it is strongly recommended especially in racing applications. Cars not equipped with the DSC sensor are more likely to experience Ice Mode where the wheels lock and ABS regulation stops. This is caused by the ABS computer not being able to distinguish what the chassis is doing (rotating vs going straight) without the input from the DSC sensor. What is "Ice Mode"? Ice mode is part of the ABS software that tries to interpret when the car is on ice and allows the system to lock the wheels which is the best way to stop in a no-traction situation. The ABS sometimes interprets wheel speed conditions during trail braking as the car being in a no-traction situation when it is not provided with DSC sensor data.
WIRING
The standalone harness has minimal additional wiring required but there are some items that have to be provided by the chassis.
Power: The MK60 requires 3 power inputs. Two (2) 20 Amp inputs for the pump which should be constant when the ignition is on and one (1) 5 Amp input for the module which can be constant with ignition or switched to allow for turning the ABS system on and off. We offer a power harness accessory to aid in installation: MK60 Power Supply Sub Harness
Ground: One ring terminal must be grounded to chassis ground.
Brake Light Switch: The MK60 requires an input when the brake pedal is depressed. The wire that senses this needs to see a chassis ground when pedal is NOT pressed (Normally Closed) and open circuit when the pedal IS pressed. This can be accomplished a variety of ways. The most basic way is to use the brake light voltage to drive a Double Pole Double Throw (DPDT) relay. BMW offers a relay referred to commonly as the "Salmon Relay" (for it's color) that is perfect for this application.
Malfunction Indicator Lamp: The MK60 has a dedicated Malfunction Indicator Lamp (MIL) wire. This light only illuminates when an ABS failure occurs which in standalone mode is limited to wheel speed sensor failures. The MIL light will not provide indication of DSC or pressure sensor failures since those only degrade (but don't disable) ABS regulation.