Drive by wire throttle

Mike Pass

I was reading a story in a UK car magazine about using a drive by wire throttle set up. On a GT40 there is a big distance between the footwell and the engine intake system. We currently use a very long cable to connect the two with all the problems that entails, so how about a drive by wire system instead. On modern cars this is built into the car ecu but what about older cars. Some aftermarket ecus now have this function built in so all you need is a drive by wire throttle pedal. The DBW throttle pedal is basically a potentiometer that is rotated by the pedal movement. The change in resistance is sensed by a control unit which then sends signals to the stepper motor which actuates the actual throttle spindle. The systems are now very reliable and used on many cars.
So what are the advantages. Obviously no sticky cable but there is the possibility of fine tuning the throttle response. You can set the system to electronically change the system response so that the throttle opens only a small amount over the first 50% of pedal movement and then speeds up rapidly over the last 50%. This would make town driving easier. Then you could switch to sport or track mode where the throttle would open much more rapidly over the first 50% of pedal movement. This used quite a lot now so cars can have a whole series of different modes to suit different situations. This effect can achieved to a certain extent on cable systems by using a snail cam etc. but it's response is not instantly switchable.
There is a system from Lokar which has a throttle pedal and a matching single throttle body unit but this won't help us quad Weber or Holley carb users. A system has been done using the parts from a BMW M3. The M3 has a throttle actuator that moves a lever and so might be adapted to our purposes.
What we need is an aftermarket system of pedal and an actuator that rotates on command or moves a lever with a programmable controller with switchable actuation speed modes. Any ideas?

Drive by wire throttle body's came with euro 4 norms.
first off all on a regular car, with the smallest problem on the engine electrics you will only have a limp home mode, with fast idling, the throttle body closed , only through by-pas a little bit of air , and rev's going up and down only t thru ignition advance and retard

regulations also require a double command system and double control system

the Bosch system as per sample is by a 0 to 5 volt signal on command line 1 and on command line 2 of the pedal it will be 0 to 2.5 volt, and through an ecu and later to throttle body,which has the same values to read, if incoherence between given order and received order, no throttle.

the drive by wire is done for anti pollution reasons, and includes a dash pot program to avoid over fueling when changing gears.

the famous sports mode with this system is just a very small program to override the volts values , on the same Principe as the kick-down program on auto boxes with drive by wire cars,its just an extension and upgrade of this application.
Mike, if I would change from a common throttle cable - I would go hydraulic with a clutch slave and good springs.
Pretty secure system and when anything fails your throttle is closed. On the "receiving" you have all kinds of choices...

Any safety inspector is robbed of arguments - even in the 18 Million regulations EU.