[Drpoomanchu]

I have been using sport + primarily for the last few months and enjoy it. On straight line acceleration at WOT in 2nd and 3rd gears (Manual) the car pushes shifts weight side to side and feels like it loses power or power settles out and will not increase through the powerband to redline. I dont believe im riding the clutch enough to cause slippage. It feels like the car is cutting and moving power around to keep the rear wheels in traction. Am i correct in my assumption ? Is this partially due to it not having an LSD..? I just feel like the car could accelerate harder and cleaner in some situations. BTW my car is 6spd FBO minus IC and 19" 255 MPSS in the rear with Dinan springs running JB4 stage 2 Map 2 4gal E85 to 93

[M2WOO35]

I have an automatic with the MP LSD and similar mods (JB4, DP, Intake, +E85). I usually just put it in to sport not (+) but I do feel the same feeling you describe with the rear shifting side to side (especially more with E85 )

I've read that putting it in to sport+ activates DTC 'dynamic traction control'. In this mode traction control is still active but it allows more tire spin before intervening. Maybe try using sport instead of (+) and see how that goes.

To my understanding, with a standard differential the wheels would receive equal power at all times right? only with an LSD will it redistribute power to different wheels depending upon traction conditions.

Would love to hear more on this, hoping others can also chime in on this..

Check this link out too from another member:

http://www.2addicts.com/forums/showp...9&postcount=22

Originally Posted by Drpoomanchu

I have been using sport + primarily for the last few months and enjoy it. On straight line acceleration at WOT in 2nd and 3rd gears (Manual) the car pushes shifts weight side to side and feels like it loses power or power settles out and will not increase through the powerband to redline. I dont believe im riding the clutch enough to cause slippage. It feels like the car is cutting and moving power around to keep the rear wheels in traction. Am i correct in my assumption ? Is this partially due to it not having an LSD..? I just feel like the car could accelerate harder and cleaner in some situations. BTW my car is 6spd FBO minus IC and 19" 255 MPSS in the rear with Dinan springs running JB4 stage 2 Map 2 4gal E85 to 93

[Bee Pee]

Originally Posted by M2WOO35

To my understanding, with a standard differential the wheels would receive equal power at all times right? only with an LSD will it redistribute power to different wheels depending upon traction conditions.

Would love to hear more on this, hoping others can also chime in on this..

Your understanding is correct with std open diff. The cars TC brain tries to emulate an eLSD by applying brakes individually to check a spinning wheel and also cutting the power.

An LSD prevents one side from spinning by locking (so axle becomes solid momentarily) and the power is then shared to both wheels without needing to cut back on the engines power.

With yr assorted mods, my last comment above is the key differentiator for LSD as more of your modified power can be used for longer......

[Smallm]

I have the LSD and mine does the same thing with any button combination, it's constantly fighting the traction controls. I'm trying to find a way to make it go away when I don't want it.

[Beartato]

I believe that sensation is the car trying not to kill you. You're welcome.

Try running that scenario again with DTC off and enjoy your rear-end rotating to the front, as it seems your application of power is overwhelming your actual traction therefore activating your DTC system.

[M2WOO35]

Originally Posted by Beartato

I believe that sensation is the car trying not to kill you. You're welcome.

Try running that scenario again with DTC off and enjoy your rear-end rotating to the front, as it seems your application of power is overwhelming your actual traction therefore activating your DTC system.

[XutvJet]

I car attest to the fact that the electronic LSD (eLSD) does NOT operate in any mode but DSC OFF. In Sport+, it behaves very much like an open diff with lots of single tire spin being reeled back in dramatically by the brakes. What you get in Sport+ is some tail wagging but the way the system brings things back in line is very abrupt. In DSC OFF, the eLSD does a pretty dang good job at emulating a limited slip differential and oversteer, straightline spin, etc. is very progressive and natural feeling. It's not perfect, but it's far better than what I gave it credit for when I first bought the car.

IMO, driving in DSC OFF is by far the best mode in terms of power. None of the nannies are on to save you or dial back power. It's like good ole days. The motor, the chassis, and the dynamics feel unleashed. In the other driving modes including Sport+, it is very apparent to me how much the DME and nannies work to keep you safe (while reducing power). DSC OFF is my preferred mode. My second mode of choice is DTC OFF if I want soft suspension/steering, but still some ability to spin the tires a bit (though the differential behaves like a true open diff). It's also my preferred mode in inclement weather.

[Drpoomanchu]

Originally Posted by Beartato

I believe that sensation is the car trying not to kill you. You're welcome.

Try running that scenario again with DTC off and enjoy your rear-end rotating to the front, as it seems your application of power is overwhelming your actual traction therefore activating your DTC system.

This explains nothing... have tried with DTC off and did not enjoy the rear end rotating to the front because it never happened. Please respond next time with some sort of intelligence otherwise troll elsewhere.

[Drpoomanchu]

Thanks to the others that responded with useful info, I appreciate it. From your responses sounds like the LSD would do little to mitigate the loss of traction. I guess i will just need to use boost by gear or learn to feather the throttle a little better through 3rd gear. Thnx again..!

[Bee Pee]

Originally Posted by Drpoomanchu

From your responses sounds like the LSD would do little to mitigate the loss of traction.

I think you have mis-intepreted my response. You are running more add-ons than I am and so likely to be pushing more power and torque to yr rear axle than mine.

Quaife LSD helps me a lot with traction on both road [uneven surfaces and or wet road conditions which effect grip] and trackdays [applying more power sooner out of corners].

[amw896]

Originally Posted by Smallm

I have the LSD and mine does the same thing with any button combination, it's constantly fighting the traction controls. I'm trying to find a way to make it go away when I don't want it.

hold down the DSC off button for 5sec will take care of that for you. I pulled a sweet drift on an on ramp the other day.

[amw896]

Originally Posted by Drpoomanchu

Thanks to the others that responded with useful info, I appreciate it. From your responses sounds like the LSD would do little to mitigate the loss of traction. I guess i will just need to use boost by gear or learn to feather the throttle a little better through 3rd gear. Thnx again..!

yea, I get the same sensation in mine, only in sport +. I have no mods but I do have the m performance lsd and I thought it was because of that. It does make sense that it's the rear brakes now that I think of it because my CBS is showing I'm going to need new rear brakes waaaay sooner than fronts and I thought it was odd.

[kdog26372]

Originally Posted by amw896

It does make sense that it's the rear brakes now that I think of it because my CBS is showing I'm going to need new rear brakes waaaay sooner than fronts and I thought it was odd.

On my old X3 the brakes were biased more to the rear to prevent the front end diving upon hard deceleration. I don't know if this is the case with the M235i, but rears also wore out sooner than front on X3 and the cause wasn't the traction control, but how the system was designed towards back brake bias.