W211 Pedal Reponse - PeachParts Mercedes-Benz Forum

shertex · #1 04-29-2017, 06:26 PM

Over on Benzworld a guy posted an interesting idea on improving pedal responsiveness.

Cheapest way to increase throttle response!! W211 E320 - Mercedes-Benz Forum

His observation is, in effect, that the initial depression of the pedal is "absorbed" by the bottom part of the pedal that moves down, introducing an unnecessary lag. And that, if you wedge something under the pedal, that lag is removed.

Thoughts?

tyl604 · #2 04-29-2017, 06:31 PM

I would trust the professional engineers that work for Mercedes.

shertex · #3 04-29-2017, 06:44 PM

Quote:

Originally Posted by tyl604

I would trust the professional engineers that work for Mercedes.

Fair point...but it begs the question as to why they designed it that way. I'm genuinely curious. FYI neither W124 nor W210 employ that same design...there is no mechanical "loss."

bsmuwk · #4 04-29-2017, 07:15 PM

it's drive by wire, all this is really doing is preloading the pedal...i can only see the APP data constantly being active rather than reaching 0-1% or whatever the car needs for idle.

I can almost guarantee the only reason the guy did that because his pedal sensor is on it's way out. they're a common failure point on 211's that causes laggy response.

MTUpower · #5 04-30-2017, 08:52 AM

Kajtek1 is back on that forum- which is one reason I don't go there.

Diseasel300 · #6 04-30-2017, 10:04 AM

Most accelerator pedals have some sort of "slop" in the beginning. It's there on purpose to guarantee that the pedal can fully return to idle.

Maybe this guy just isn't used to a drive-by-wire throttle setup? He keeps mentioning the "cable adjustment" on his Bimmer. DBW throttle's don't have cables and ALWAYS have a tiny delay in throttle response due to the ECU checking things and issuing the command to the throttle actuator. Most people never notice. I'm not one of those people, I can tell when I drive a DBW vehicle (my Honda is a DBW throttle setup). It doesn't irritate me, but you have to have a reasonable expectation of how it's going to behave.

shertex · #7 04-30-2017, 01:50 PM

Quote:

Originally Posted by Diseasel300

Most accelerator pedals have some sort of "slop" in the beginning. It's there on purpose to guarantee that the pedal can fully return to idle.

Maybe this guy just isn't used to a drive-by-wire throttle setup? He keeps mentioning the "cable adjustment" on his Bimmer. DBW throttle's don't have cables and ALWAYS have a tiny delay in throttle response due to the ECU checking things and issuing the command to the throttle actuator. Most people never notice. I'm not one of those people, I can tell when I drive a DBW vehicle (my Honda is a DBW throttle setup). It doesn't irritate me, but you have to have a reasonable expectation of how it's going to behave.

That's helpful...thanks.

I know a tune can eliminate the lag.

jay_bob · #8 04-30-2017, 02:23 PM

Quote:

Originally Posted by Diseasel300

Most accelerator pedals have some sort of "slop" in the beginning. It's there on purpose to guarantee that the pedal can fully return to idle.

Maybe this guy just isn't used to a drive-by-wire throttle setup? He keeps mentioning the "cable adjustment" on his Bimmer. DBW throttle's don't have cables and ALWAYS have a tiny delay in throttle response due to the ECU checking things and issuing the command to the throttle actuator. Most people never notice. I'm not one of those people, I can tell when I drive a DBW vehicle (my Honda is a DBW throttle setup). It doesn't irritate me, but you have to have a reasonable expectation of how it's going to behave.

The W210 does have a cable between the pedal and the actuator. This was early in the days of DBW, and they basically used the pedal and cable assembly adapted from the 124 and routed it to a rotary sensor located near the brake booster under the hood. If I recall correctly the very first DBW from MB was the 400E in the early 90s, which was a 124 chassis. So when they were designing the W210 about this time it is totally plausible that they borrowed this assembly for the W210.

I think by the time they got to the 211 they integrated the sensor in the pedal. Our W164 shares a lot of systems with the 211 and this is how the pedal is set up on the ML320.

In any case the easiest way to check the operation of your pedal is with an advanced OBDII reader or a Bluetooth OBD dongle and Torque on an Android device. Call up the display for Throttle Angle on the screen and press the pedal with the engine off.