Quote:
Originally Posted by clivem2
Given that the tubes are very flexible and easy to compress the clips BMW use are the wrong type, they ought to use figure of 8 clips, threading the tubes through them. I had no sharp bends but there was some compression. I've bent the clips to release some of the pressure. I feel there is more of a power rush now - not wanting to discuss lag.....but this almost feels more like a lag as when then power comes in now there seems to be more of it. It's chucking it down with rain, my next plan will have to wait. I'll go for a drive with the tubes totally free of the clips. I'm not thinking this fully fixes anything, it's just another variable. More of an interesting tweak.
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So it seems I was not experiencing a placebo effect. My car is almost back to normal without the compression by the clips. It took the DME a while to adapt, too.
I wondered what if BMW was correct in stating that they changed wastegate response but the driver should not get aware of that? I doubt that they did not test the change before releasing it.
With DME software < v29.2, there is no change in wastegate when you accelerate, because it is almost closed even at 1000 RPM. There is no fast change of wastegate position, so restrictions in the tubes can have no effect.
With the changes of v29.2, the wastegates are open at 1000 RPM and should get closed quickly when you accelerate. If there are any restrictions in the tubes, the response to the input impulse will be delayed. Tube restriction could be one of the "triggering conditions" that make some cars behave worse than others. Among those conditions, there could also be stiff wastegate actuators.
Also, I think that BMW has seen that some cars (e.g. mine) have deviations in wastegate response time due to these conditions and will now release a software where the wastegates are more closed at low RPM than they are now.
I'm not saying everything is fine yet, but this might explain why some people say they have no Lag - maybe their cars do not have any conditions that slow down the wastegate response.