Quote:
Originally Posted by YarkoDrives
I'm speaking from my experience with the car.
I appreciate the skepticism.
I'm getting a CAN data logger so I can confirm some things with data.
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I know exactly what you mean with E-diff intervention, it slows you down. It is braking wheels after-all... My personal experience has been that allowing the wheels to spin freely from one another doesn't make you any faster. The car will just FEEL different at the limit (smoother acceleration when laying down power since e-diff can get get choppy when applying brakes) but an open diff will be slower overall. I am talking about running with traction control fully disabled (5 sec click).
I am confused though. If you aren't disabling DSC when you drive, how are you determining it's the e-diff function that is causing what you describe? What you seem to be describing is not e-diff intervention. You seem to be describing what happens when DSC/TC cuts in... DSC/TC will cut power to keep slip angles and wheel spin in check and causes a bit of a delay before you can get back on the gas... that's not the e-diff doing that. I posted the video that explains this.
I don't see how you could possibly want to leave DSC on because you can't control your car (spin outs) but then want to disable the e-diff? DSC/TC will intervene to prevent tire spin whereas the E-diff actually doesn't prevent wheel spin at all. As previously mentioned, the E-diff just keeps both wheels spinning at the same speed to maximize power to the ground. You can drift around the autocross course all day with the e-diff...
Yes, you are correct in that both cars use the Teves Mk60 unit (and the 3 -series). Review the E90 DSC module PDF I posted that explains everything the functions do any why... Also, I have owned both cars too, and have coded both cars extensively. CBC isn't a working function on 128i/135i's. CBC is a more robust function that only the 1M got. 128/135i has the ASC function "dynamic traction control" (single click of the traction control button). Holding down the traction control button for 5 seconds does indeed disable ALL traction control functionality on both cars. The exceptions to that are the e-diff and the aforementioned functions like brake pre-tensioning, brake disc overheating, etc...
Also, I have posted both trace files of the mk60 dsc module side by side in this thread back on page 2 (
https://docs.google.com/spreadsheets...it?usp=sharing). There is actually very little differences in the coding between a 128 and a 135i. The few parameters that do differ are some slip angle characteristic and brake characteristics settings. These are different values to address the different weight bias and brake torque of the 135i. That's all that differs. Both systems behave exactly the same because they simply are exactly the same.
Another consideration is that these cars beg for a throttle re-mapping. The stock throttle map goes from 20% to 80% load within the first 10% pedal movement (a bit of a hyperbole but you get the idea). The gas pedal works like an on/off switch from the factory. Makes the car feel peppy but difficult to modulate power at the limit... I mention this because it sounds like modulating the throttle is your main issue. Again, another thing you can't modify in street trim.