To clarify "kickdown" is when the accelerator is pushed right down to the floor and as pointed out earlier there is a ristance point felt before you just get there. Secondly kickdown will ensure that the steptronic box selects the lowest possible gear for your speed to give max acceleration, sometime it will drop two gears etc but it all dependends on the gear and speed you are travelling at when you floor the pedal. Kickdown is therefore of little relevence when racing from a standing start as you start in first gear and the steptronic box will hold on until max revs to shift up if you are on full throttle.

Finally, I appologies to the 520d driver (god that single pipe is such a give away) who I left eating my dust this morning in a loaner E270CDI. The shame of it for both of us!

 

I think the response time of kickdown is far too slow... it usually takes 1 or 2 seconds before max acceleration

 

yes 100% agree that why I got the booster I hate delay in go handling cars

 

I tested kickdown today on the way back home from work - on a clear stretch of the A4 - OMG it pins you to your seat as the car rockets ahead .

I had a coleague from work who did not know what I am about to do he later said to me "I think I pi**ed myself"

It is unlikely I will do that again unless it is really necessary

 

yes the respose time is a little slow, but its also slow on most cars, its an auto so these things are always slow and stupid at times...

 

is it because of a safety that it has a delay

 

The delay I experienced yesterday (from the second I pressed the resistance button till the transmition dropped a cog or two) was acceptable, once the gears were droped the engine's responce was instanteneous and more than enough to get you out of an emergency situation , or to freak someone out

I don't think it is safety related, BMW knows that if you press the pedal THAT far then you need to get out & quick, so any delay would be unsafe. However, the car's computer will take a couple of split-seconds to determine your action - interpret them - send instructions to the box and the box drops the cogs.
Me think

 

One of the reasons for the delay is so that you don't suddenly drop 350Nm of Torque through the transmission on a 2 tonne vehicle. You wouldn't do it too many times before the box and/ or engine would blow. To make anything mechanical last, you must treat it gently.

On the subject of test reports, on rolling start acceleration you cannot usually lock an Auto in top gear so the testers just let it do its thing, so it changes gear. The Manual is stuck at the wrong part of its torque curve in its highest gear and is therefore stuffed. Comparing the in-gear acceleration of a manual car and an Auto like this makes the results irrelevant. You can compare Auto to Auto or Manual to Manual, but not Auto to manual.