Flat spot

[broncoupe]

My car is 210 E88 135i with DCT gearbox
Flat spot maybe the wrong term
Basically if you accelerate hard from rest all is reasonable good , if you are cruising at 60mph go full throttle with kick down or manually select 3rd gear fully open throttle the engine makes noise but isn't pulling and revving like a train
The other thing i have noticed is the car accelerates better with half throttle I think its full throttle that is the issue
in normal driving you dont notice any issue
There are no fault codes stored
Plugs are 1000 miles old all filters changed also

 

[wheela]

My car is 210 E88 135i with DCT gearbox
Flat spot maybe the wrong term
Basically if you accelerate hard from rest all is reasonable good , if you are cruising at 60mph go full throttle with kick down or manually select 3rd gear fully open throttle the engine makes noise but isn't pulling and revving like a train
The other thing i have noticed is the car accelerates better with half throttle I think its full throttle that is the issue
in normal driving you dont notice any issue
There are no fault codes stored
Plugs are 1000 miles old all filters changed also

Sounds like DSC/traction control intervening, do you drive with traction control on? Do you have any logs of it happening?

I used to have that problem, and it was traction control/DSC intervening. I started driving with traction control off and that solved it. Not sure why it would think it needed to intervene when I don't have enough power to break traction, but that's what I was encountering.

 

[carabuser]

Get a log of the issue. Make sure to include timing, fuel mode, torque limiter, boost, target boost and throttle pos.

My theory would be that you are exceeding the target clutch torque and the timing will be very low as a result. Or wheela's suggestion that traction control is kicking in, and you will see a value of 1 in the torque limit channel.

 

[broncoupe]

Get a log of the issue. Make sure to include timing, fuel mode, torque limiter, boost, target boost and throttle pos.

My theory would be that you are exceeding the target clutch torque and the timing will be very low as a result. Or wheela's suggestion that traction control is kicking in, and you will see a value of 1 in the torque limit channel.

Sorry to be an idiot where do i get a log I do have MHD software will that produce a log or what do i need to buy some software

 

[carabuser]

Sorry to be an idiot where do i get a log I do have MHD software will that produce a log or what do i need to buy some software

Yes, if you have an MHD logging license then you can select the parameters that I mentioned above and upload the CSV file it produces on these forums.

If you don't have the MHD logging license then I can give you access to an app that will provide the same logging for free as I think MHD charges quite a bit for it.