Quote:
Originally Posted by feuer
E-diff will slow the car down. Absolutely. Not only around the track. When DSC is on the e-diff is on and it will over power the engine, it will cut throttle and the engine will bog. When DTC is on by short press on the button the e-diff is on doing the same as above but is less severe and less abrupt intereference. It will not completely cut throttle but it will cause it to basically flactuate mostly depending how the wheel is gaining traction on the surface. When DSC and DTC are off by long press hold on the button the above intereference no longer happens. Like I said I can spin one wheel endlessly given no traction. Some people say e-diff is on non stop and can't be turned off by the long press hold on the button. I think if that is true then when DSC and DTC are off the brake forse the e-diff is applying is significantly reduced so that it can bog the engine and won't cut throttle. Regarding LSD allowing faster track time I don't know what to say since I'm on open diff and 2-3sec behind cars that have LSD, more power, lighter weight, and etc. so if I pick up 5-6 buy installing a LSD I will be the fastest, heaviest and least powerful car in my group. Now I don't think I'm that good of a driver lol. So probably drivers that gain that much time by going to LSD weren't really comfortable pushing the car in the corners and I know why as I find myself saving the car from a spin out often....
|
My understanding from researching the E90 traction controls and Ediff is with the long push (5 second) Ediff is now the only electronic nanny still present (well ABS is still on too). That’s the only condition where you can make valid Ediff comparisons because it isolates the Ediff and removes all the traction controls. Ediff doesn’t have settings or variables, it’s always on 100% in our cars it’s the other nannies you can turn on and off with the DTC button.
I have had my traction control cut power many times when I haven’t pressed the DTC button, or even when I have done the short push it still cuts power. A lot of power actually even with the short push. I think when talking about the Ediff we can only speak about the 5 second push (nannies off) because the other 2 settings stability control is what is cutting the power, and it’s not doing it with the brakes only it’s also cutting the throttle so the engine definitely bogs and the car slows. The traction control has much more authority with regards to what it can do to slow the car. (In your example above with DSC and DTC still on it’s not Ediff slowing the car, that’s those separate safety systems of traction controls.)
With the 5 second push I’ve never encountered a condition where the engine cut power or bogged. And I have spun completely out with the rear end power sliding all around behind me due to me using too much throttle input. My first hand experience is telling me the ediff will not slow the car, and that it can actually only make it faster than an open diff.
Since Ediff cannot cut engine power like the other nannies and can only force a wheel with traction to accelerate, this equals more forward movement of the car.
I don’t see how slowing a tire with no traction, which isn’t contributing to forward movement, accelerating a tire with traction, and not cutting engine power can “slow the car”. It makes no sense!
What I just described is exactly the same way a LSD that reduced Pete’s track time by 6 seconds does. The LSD is better than Ediff but they are working towards the same goals and the end result is the same just Ediff isn’t as effective as LSD. But the ediff car cannot be slowed by the ediff it still has to be faster then a open diff car. Ediff is not “slowing the car”.
I propose a hypothetical example to show my train of thinking...
Let’s that in Pete’s example his car had an open diff the lap time might have been 100 seconds. He had Ediff added his lap time is now 96 seconds. Now he adds LSD his lap time is 90 seconds. The Ediff is serving a function and not slowing him down! It’s just not as good as a LSD but no ones saying it is.