Drive-by-wire for dual carbs/throttle bodies???, would you run them?? |
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Drive-by-wire for dual carbs/throttle bodies???, would you run them?? |
Mueller |
Feb 28 2006, 03:42 PM
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#1
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914 Freak! Group: Members Posts: 17,150 Joined: 4-January 03 From: Antioch, CA Member No.: 87 Region Association: None |
A lot of newer cars do not have the traditional cable that goes from the gas pedal to the throttle body...instead the pedal has a potentiometer*, this in wired to the ECU which tells the throttle body how much to open, just because you have your foot buried to the floor, the throttle body might only be open 50% since the ECU is dictating what is going on.
Now a drive-by-wire throttle body could be wired directly to the pot. on the gas pedal to be 1:1 at all times......with a setup like this on dual carbs or individual throttle bodies, no need to worry about thermal expansion of motor and how that effects the linkage. * (similar to a variable resitor which varies the voltage output depending on foot placement) |
stock93 |
Feb 28 2006, 09:35 PM
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#2
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Member Group: Members Posts: 333 Joined: 12-May 03 From: Huntsville, AL Member No.: 684 Region Association: South East States |
BMW uses Dual linear hall sensors in the pedal assembly. One is from .5V to 4.5V the other one is .5V to 2.0V. This differing voltage is used for plausibility. Also if the wires happen to get shorted together the different voltage readings will let it know there is a problem. They use Dual potentiometers on the throttle body. One is from .5V to 4.5V and the other is 4.5V to .5V inverse of the first one. BMW uses these on more than just there V12 now. Most of the new bmws use thottle by wire. They dont seem to have any problems with it. It makes stability control really easy by limiting the thottle opening.
John |
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