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**DansSlk** · 06-01-2007

There was another thread on this somewhere but instead of messing about trying to find it here's how it works -

0% pedal travel - Idle RPM
100% pedal travel - Kickdown

MB make the first few % of travel "sloppy" to allow for around town driving, backing into spaces and so on the way they do this is by instructing the ECU that the first lets say 10% of pedal travel requires the throttle valve be actuated slower than the other 90% so you can more finely control the car at slow speeds.

So if you give the pedal 50% travel then you are moving past this slow zone before getting into the faster take up section this gives the feeling of a dead pedal because you can jab your foot about as much as you like in the slow zone and the car just wont jump up and go until you get into the 90% of faster take up travel.

The sprintbooster works by sitting on the electrical lines and monitoring pedal travel it knows how much of the travel is slow and where the faster take up kicks in so as soon as you apply even 1% throttle it uses the 12V feed to up the voltage returning to the ECU so it thinks your at 10% throttle and goes into the fast take up mode.

This gives the faster acceleration feeling because the car starts to move faster and with less travel of the pedal once the pedal reaches 10% travel the device shuts off and the feed is sent directly to the ECU as normal so to get kickdown you still need to floor the throttle, its not actually messing with the system so 90% of travel equals 100% throttle it just cuts out the first 10% and holds it at the lowest setting it can until the pedal reaches the fast take up zone.

So basically it does not matter where your foot is during that first 10% with the booster connected it can be at 1% or 9% your at 10% throttle until the pedal moves to 11% and then your back in control.

The disadvantage being that you lose the more relaxed throttle and this can make slow speed maneuvers more difficult.

I hope this explains it OK

06-01-2007	#2 (permalink)
DansSlk Super Moderator Join Date: Jun 2006 Location: Wales Vehicle: 05 55 (Brabus 6.1 S) Posts: 6,954 Country: Thanks: 116 Thanked 299 Times in 207 Posts	There was another thread on this somewhere but instead of messing about trying to find it here's how it works - 0% pedal travel - Idle RPM 100% pedal travel - Kickdown MB make the first few % of travel "sloppy" to allow for around town driving, backing into spaces and so on the way they do this is by instructing the ECU that the first lets say 10% of pedal travel requires the throttle valve be actuated slower than the other 90% so you can more finely control the car at slow speeds. So if you give the pedal 50% travel then you are moving past this slow zone before getting into the faster take up section this gives the feeling of a dead pedal because you can jab your foot about as much as you like in the slow zone and the car just wont jump up and go until you get into the 90% of faster take up travel. The sprintbooster works by sitting on the electrical lines and monitoring pedal travel it knows how much of the travel is slow and where the faster take up kicks in so as soon as you apply even 1% throttle it uses the 12V feed to up the voltage returning to the ECU so it thinks your at 10% throttle and goes into the fast take up mode. This gives the faster acceleration feeling because the car starts to move faster and with less travel of the pedal once the pedal reaches 10% travel the device shuts off and the feed is sent directly to the ECU as normal so to get kickdown you still need to floor the throttle, its not actually messing with the system so 90% of travel equals 100% throttle it just cuts out the first 10% and holds it at the lowest setting it can until the pedal reaches the fast take up zone. So basically it does not matter where your foot is during that first 10% with the booster connected it can be at 1% or 9% your at 10% throttle until the pedal moves to 11% and then your back in control. The disadvantage being that you lose the more relaxed throttle and this can make slow speed maneuvers more difficult. I hope this explains it OK __________________ One thing you will learn with German cars - If it's simple it ain't happening.