Help needed please . How far does the throttle pedal travel - measured in the middle of the foot pad? I'm fitting a drive-by-wire pedal position sensor to the pedal box but I need to know how far the pedal typically moves to design the necessary levers. Mine's not connected to anything so it stops when it hits the fibreglass!
Hola Pete. i believe in my car (1985 LC) there is a rubber stop and the carpet is trimmed so as not to interfere.
May I suggest that with the electrical throttle out of the car you establish the resistance over the travel to then establish necessary physical travel and arrange for a stop to avoid over pressure. I do not remenber what engine you are installing, if not 9XX, throttle travel may be different.
Just a thought as it has started to rain here, after 4 months or so dry!
Thanks Stu - I thought it must be about that - I'll see how far off the fibreglass that leaves it.
Thanks Dave - It's a supercharged 912 I'm building. The throttle pedal will control a pedal position sensor (dual potentiometer mounted on the pedal box itself) via a rod connected to the top of the throttle pedal. The pedal position sensor needs 90* of rotation which is why I need to know how far the top of the pedal moves to calculate the lever length on the pot. I have to leave the cable in place though to control the ZF gearbox - this will be some sort of progressive linkage attached to the engine in an attempt to mimic the non-linear programming of the electronic throttle (until I can work out how to control a linear servo with the ECU!).
Pete, to answer your initial request I have measured the throttle pedal travel on my 85 LC which measures 60 mm from no pedal to when the pedal stop touches the body, no carpet interference. As you probably know the pedal has an adjustable bolt and locking hut on the underside of the pedal.
I keep my throttle cable adjusted to avoid slack as done at the carb end of the cable. I have not checked whether full pedal gives full carb opening, that would mean getting my wife to sit in the car and I am concerned she might not be able to get out. Comments not welcomed!
I believe you are trying to sort out how throttle position is transmitted to the electronic setting of the ZF box.
Other than use a non-electronic box, up to1990 thereabouts, it might be difficult to know what control signal is used, volts or amps. So you need a bench power supply that can provide both and RS Components I can recommend.
A possible good source of friendly advice could be Ashcroft Transnissions who have some clever kits for getting the right gear change set-up, adjustable to get the best for the Lotus, not just a repeat of some other car setting.
You could say they know the ZF boxes inside out. Have a look at the Powershift kit. Not cheap.
Thanks Dave. It's a mechanically controlled gearbox that I have - from an Excel SA. I'll be using the pedal position sensor for the electronic throttle body only (controlled by the ECU). The mechanical linkage will remain in place for the gearbox but it needs to have a less linear action than in the Excel so that it mimics the non-linear throttle body "curve" as I press on the pedal.
Your throttle pedal movement is significantly less than Stu's - his is ~ 100mm. I think I need to dig out the carbs and assess the motion of the throttle shaft.
To check for WOT on your carbs just rest a brick on the pedal or sprag a length of wood against it.
Pete, my first check and on full pedal movement I still got an extra movement at the Carb end, at least another 20mm of pedal movement. I will now adjust the pedal limit bolt to give full throttle and let you know final result.
. How far does the throttle pedal travel - measured in the middle of the foot pad? I'm fitting a drive-by-wire pedal position sensor to the pedal box but I need to know how far the pedal typically moves to design the necessary levers. Mine's not connected to anything so it stops when it hits the fibreglass!
