Throttle Response - Lag

[supertemp]

First up - sorry - I realise this topic has had some discussion.

Hopefully someone can set the record straight for me. I have searched for throttle lag and delay, and gone through nearly 300 threads to find a definitive answer but nothing yet, please excuse me though I realise this has been done to death.

I recently purchased an 08 E92 M3, with 70k kms on it. It's in pretty good nick and had a PPI done by BMW, who had nothing but a couple of minor issues to report.

Car is going great, however the main thing that I'd like to sort is the throttle lag I am getting. I've seen the posts about DCT lag and jerking at low revs etc, I have none of that, just a muted throttle sometimes.

The only way to describe it is you put your foot down and it will start to go sedately before exploding to catch up with your foot. This can happen from a standing start or mid corner, when you reapply the throttle at the apex of a corner, there is a definitive delay before expected power is reapplied. It can also happen warm or cold, although it seems better when warm, but still prevalent. Doesn't seem to matter if it is in D mode or manual shift, power mode on/off.

I'd really like to have a linear, predictable throttle response. It can be quite alarming trying to pull into morning traffic gaps when the throttle will not respond properly. It would be unsafe for someone who really tried to shoot for a gap and wasn't aware of this quirk.

From what I've read, this could be the software version, would you agree? Now with an older car and model, should BMW upgrade this for me or will it be expected I have to fund this? I ask that because if I have to fund it, there are alternative options to the dealership I can go to.

Thanks for reading and appreciate any tips.

[nick3753]

Sorry to ask the seemingly obvious, but you never know. What rpm are you at when your are trying to accelerate hard?

[Denk]

I came into an e92 DCT in '11. I think there was a software update by BMW on the DCT just prior. Throttle response is a beauty on this car. She's not a torque monster, the power is up high in RPM's. You just have to pick the right gear for maximum acceleration. I suspect you need a DCT software upgrade from BMW. I can see someone complaining about torque, definitely not throttle response.

[supertemp]

Originally Posted by nick3753

Sorry to ask the seemingly obvious, but you never know. What rpm are you at when your are trying to accelerate hard?

From throttle off to on, and in low rpm. So from standing start or in middle of slow corner, when you throttle back on, there is lag. Also not trying to accelerate hard, this is normal driving/commuting.

Understand the power is in higher rpm, but this is not lack of power in the low range it is definitely delay of acceleration, once it starts to accelerate it is fine.

[Patrón]

Is traction control on, this could be a culprit as well. T/c kills power

[thekurgan]

Have you tried sport mode to see if it makes any difference? What about some techron concentrate in a couple of tanks? Was there ever maintenance on the throttle actuators or the throttle pedal itself?

[supertemp]

Originally Posted by thekurgan

Have you tried sport mode to see if it makes any difference? What about some techron concentrate in a couple of tanks? Was there ever maintenance on the throttle actuators or the throttle pedal itself?

I couldn't tell you what has been done to it. There's a maintenance book but it's in Japanese.

Sport mode I thought makes a tiny bit of difference but might be wishful thinking.

This isn't a T/C thing or fuel, I am using the highest octane fuel we have here in NZ and to invoke TC I'd have to be trying to do something other than drive to the next light at 30km/h.

Can I get clarification from some other M3 pilots, that when you press the pedal, even at just commuting to work in traffic level, the response from the engine/acceleration should be immediate? I only have driven one other M3, and it was a manual, about 4 years ago, for a test drive so don't recall the subtleties of it.

[car_craft]

i have an 08 6mt e92 m3.

I take it you have a DCT? Im not to familiar with that version of the car, but what gear is it in when you experience this? Is it in auto mode or are you manually shifting. If the transmission is in a high gear (maybe 3rd or 4th, around 2000 rpm) at low speed and low rpm then there is a large load on the engine, and even with the throttle wide open wont necessarily be able to rev fast until it gets up into the power band, high enough to over come the load. in this situation it could feel like a lag because you press the pedal and the engine doesn't rev fast and the car doesn't accelerate until later. throttle response or the resulting acceleration is not only a function of throttle position but also a function of engine load and available power at that throttle position and rpm.

since your in NZ im sure your very familiar with manual transmissions so you probably fully understand the point i was trying to make above. but since your car has a DCT i think the missing piece of information is what gear the car is in and whether your controlling the shift point or the car is?

i dont think i have ever experienced "immediate" throttle response (unless the car is in nuetral). it really depends on what gear im in and what rpm the engine is at, and more importantly what the load on the engine is.

might be good to drive some others to see if your car is behaving abnormally. could try resetting the DME adaptations, updating the DME software, i have heard of some people claim improved throttle response in low rpms from updated maps.