I was driving this weekend and I noticed something which I thought was odd, I am not sure if anybody else has noticed this but I figured I would throw it out and get feedback if anybody has any. If I am cruising between 1st and 4th gear at around 4,000RPM or lower and drop the pedal to the floor. The LED bars on the tach will drop by 1 notch/bar/tac mark (or whatever you want to call it) then shoot up and accelerate as it should at WOT. The car consquently jolts just for a second. I was wondering what causes this and if it is a problem. My guess is that it has something to do with a fuel delay on a smaller engine but I could be way off. All input is greatly appreciated.

 

Nobody?

 

Do you have the DBW throttle body?

 

When you hit the throttle, the little man inside your engine whips the hamsters in the wheel. The hamster goes "Oh crap, not again", takes a breath and then starts running. Its this small hamster taking its breath you are seeing.

 

Yes, I believe 06 is the year that DBW was introduced.

 

So you are saying I should take my car on the highway more often to make sure the hamster gets better cardio and will be more ready to start running at the first whip? You think it will help if I pour some muscle milk into the engine just to make sure he is properly nourished?

 

What can open the throttle faster: a human or an electric (stepper)motor / actuator?
I honestly do not know.
In a DBW car you can floor it (the pedal) as fast as you like, the throtte will not open faster than the actuator can open it.
Maybe this is still faster than a cable throttle engine can react to changes... or maybe its not... I donno.

Respect the Hamster!
(just Google image searched that and it seems there are more people thinking the same)

That would be nice on your key ring.

 

I respect the Hamster. I thought that it could be the stepper motor too but the issue isn't a slower acceleration it is an actual drop in RPM only for a second. If the stepper motor was slower in opening the throttle the O2 levels would change slower in the exhaust stream and the fuel injectors would compensate but so the result would be slower acceleration but not a drop. As a side note the DBW really isn't noticeable, I don't feel a delay or anything when stomping the pedal. The only time I am aware time I am aware is when the traction control cuts the throttle and i depress the gas and nothing happens.