[magicbmw]

I'm pretty sure all this 335d sedan has is just the basic level DTC system. Which is a total let down, I have owned Camaro's (HOT STREET RODS) & 1 KICKASS 72 MACH I that had 800 HP 351C (built ALL in our living room) so NOT NEW TO POWER, Just now getting N2 BMW modifing.

Have pretty good baseline, having to LEARN BMW's line of products etc, & the dealers around here don't want to give ANY insight less your SPENDING $$$$$, then just PU$$YA$$ things ya'll reference.

& not looking to do any unresponsible teenager moves on roadway, just wanting to learn about some well built vehicles as car enthusiacists.

Love the info

[MFactory]

Applying brakes does not "transfer" anything; it simply reduces the torque to the wheels (again, with an open diff, left torque = right torque. Reduce left torque = right torque is reduced identically) READ: Left & Right torque are the SAME

Yes, LSD's work on friction, but the difference is, left torque is NOT equal to right torque, as the LSD can limit torque from the spinning wheel and increase torque to the traction wheel. This is impossible to do with an Open Diff, electronically controlled or not, and that's what I've been trying to explain to you. READ: Left & Right torque are independent

Again, SAME is not equal to INDEPENDENT, unless you want to discuss Quantum Theory with me.

And to add to my post and quote hassmachine, the benefit of being able to having independent torque between the left/right wheels is increased traction & stability during acceleration or braking above and beyond what electronic braking pseudo marketing thingymajig you want to call it

[Ozzie335i]

Originally Posted by Dozhdbog

So, to conclude:

Open diff sucks.

You finally got to the point Dozhdbog. If you are FBO, you are wasting power, as the brake in the spinning wheel is actuating, versus transferring usable power to the wheel with traction. Some people have said that eDiff, or whatever you want to refer it as, was created to compromise non M cars, so that the perceived value is greater. Having gone from an eDiff myself to an LSD, in my non tracked car, there may be some merit to that discussion.

[justpete]

Originally Posted by MFactory

Applying brakes does not "transfer" anything; it simply reduces the torque to the wheels (again, with an open diff, left torque = right torque. Reduce left torque = right torque is reduced identically) READ: Left & Right torque are the SAME

Yes, LSD's work on friction, but the difference is, left torque is NOT equal to right torque, as the LSD can limit torque from the spinning wheel and increase torque to the traction wheel. This is impossible to do with an Open Diff, electronically controlled or not, and that's what I've been trying to explain to you. READ: Left & Right torque are independent

Again, SAME is not equal to INDEPENDENT, unless you want to discuss Quantum Theory with me.

And to add to my post and quote hassmachine, the benefit of being able to having independent torque between the left/right wheels is increased traction & stability during acceleration or braking above and beyond what electronic braking pseudo marketing thingymajig you want to call it

You do realize braking the wheel spinning faster steers torque back to the slower spinning unbraked wheel cuz that's how an open diff works, right?

There's no preload so no static lock and this makes the biggest difference between an electronic automatic diff and a mechanical automatic diff. For example I believe a Quaife acts as an open diff and only steers torque when there's an imbalance. Or not, whatever...

[MFactory]

All braking the wheel does is reduce the torque to the spinning wheel, and with an open diff, the traction wheel torque must equal the spinning wheel torque.

What you are referring to is the classic unloaded condition (i.e one wheel in the air). When the wheel is in the air and is spinning freely, there is zero torque to that wheel, thus the traction wheel ALSO has zero torque thus, your car loses momentum.

However, when you apply brake (i.e load), the open diff will function again i.e you regain momentum. However, applying brake will only load the wheel so much, and again, the traction wheel will ONLY have the same amount of torque as the spinning wheel.

This is why having a Plate LSD is of more advantage than an open diff or a Helical LSD. However, the "brake to simulate load" principal still applies, so whereas with an open diff both wheels will have limited torque, with a Helical LSD, far more torque can be transferred to the wheel with traction (unlike with an Open Diff)

And this is why Helical LSD + Traction Control = Best of both worlds, as they work hand-in-hand, without the NVH of a Plate LSD (and the reason why a certain patented wavy thingymagic is just Marketing)

Hope that explains it?

[PhaseP]

Originally Posted by MFactory

Example:

Max Torque - 100lbs

If left wheel is spinning and brake is applied, say left wheel is equal to 20lbs. If you have an open diff, the right wheel MUST ALSO equal 20lbs. You have lost 80lbs in torque/momentum

With an LSD, if left wheel is spinning and brake is applied and has 20lbs, the right wheel can have upto (depending on setup/type of LSD) 80lbs in torque momentum i.e You do not lose momentum

The brake to the left wheel applied can be more than 100lbs torque, than it will force the other wheel with traction to move at 100lbs torque.

The brake application to the wheel that lost traction basically simulates traction on that wheel, not from friction between tire and road but from the friction from pads.

Looking at the picture of an open diff below, say wheel on left tire on left axle was lifted off ground. That axle has no torque since no friction on it, and hence the right axle has no torque with tire on the ground. The left wheel spins widely, right wheel stays.

Now assume brake is applied on left axle with a friction of at least the tires can provide traction (Brakes can lock up the tires when applied full, so they can apply more torque than tire and ground can).

The torque on the left axle now is increased, and so the right axle will have to go up in torque, and will start moving instead sitting in place. If the brake applied was at least equal to engine torque, all that torque will be going to both axles. The left one will be staying in place because the brake had it locked up, and the right one will move turning the torque to thrust on tire road surface friction.

That is at least my understanding. The open diff is providing the least amount of torque equal to the both axles in all these cases. The application of brake basically causes torque to be applied, or used.

[Dozhdbog]

Originally Posted by MFactory

Applying brakes does not "transfer" anything; it simply reduces the torque to the wheels (again, with an open diff, left torque = right torque. Reduce left torque = right torque is reduced identically) READ: Left & Right torque are the SAME

Yes, LSD's work on friction, but the difference is, left torque is NOT equal to right torque, as the LSD can limit torque from the spinning wheel and increase torque to the traction wheel. This is impossible to do with an Open Diff, electronically controlled or not, and that's what I've been trying to explain to you. READ: Left & Right torque are independent

Again, SAME is not equal to INDEPENDENT, unless you want to discuss Quantum Theory with me.

And to add to my post and quote hassmachine, the benefit of being able to having independent torque between the left/right wheels is increased traction & stability during acceleration or braking

We're going over the same stuff again. Left and right torque doesn't matter as both are dealt with in the same manner -through friction either at the wheels or at the gears. It's not impossible for an e diff to do this - it is EXACTLY what it's doing. How would it magically NOT be the case? Friction applied progressively is friction applied progressively, whether via a mechanical diff or an electronic one.

Ultimately, there is no huge difference in traction availability between the mechanical and electronic differentials.

[NOITALL]

Originally Posted by Dozhdbog

No. All hope is lost at that point. Abandon the car.

Though we can clearly see you're joking on this post, you should really stop trying to mislead people. Some do come here with serious questions in an attempt to get educated.

In any case, YES would've been the answer if the poster did not get your sarcasm (and I got your sarcasm on this post, but not on the other posts. You're trying really hard and that could be misleading).

[MFactory]

That is how an open diff works, correct. 100lbs was just a number I pulled out my a$$ as an example.

[Dozhdbog]

Originally Posted by Ozzie335i

You finally got to the point Dozhdbog. If you are FBO, you are wasting power, as the brake in the spinning wheel is actuating, versus transferring usable power to the wheel with traction. Some people have said that eDiff, or whatever you want to refer it as, was created to compromise non M cars, so that the perceived value is greater. Having gone from an eDiff myself to an LSD, in my non tracked car, there may be some merit to that discussion.

Again, friction is friction, and both a mechanical diff and an electronic diff apply friction to transfer power from one wheel to the other. It's the same in that respect.

I can't believe it took me that long to finally get that point.

[NOITALL]

Originally Posted by Dozhdbog

We're going over the same stuff again. Left and right torque doesn't matter as both are dealt with in the same manner -through friction either at the wheels or at the gears. It's not impossible for an e diff to do this - it is EXACTLY what it's doing. How would it magically NOT be the case? Friction applied progressively is friction applied progressively, whether via a mechanical diff or an electronic one.

Ultimately, there is no huge difference in traction availability between the mechanical and electronic differentials.

Let me humor you: YES they work the same way to get the same traction.

But the LSD equipped car will be far faster everytime. That is extremely important if you are in a track or trying to cross a busy intersection that is covered in ice (near zero friction surface).

This is more then settled. Now on to the LSD options.

[Dozhdbog]

Originally Posted by I'm wrong

Though we can clearly see you're joking on this post, you should really stop trying to mislead people. Some do come here with serious questions in an attempt to get educated.

In any case, YES would've been the answer if the poster did not get your sarcasm (and I got your sarcasm on this post, but not on the other posts. You're trying really hard and that could be misleading).

The individual in question already knew the answer and was pleasantly trolling. You would know that had you read his prior two thousand or so posts here since 2009.

My whole reason for being in this thread is to help on this topic. I was nicely surprised when I discovered just how well the BMW e-diff in my car operated, and I had no idea it even existed for the first year I had the car. There's a ton to learn about this topic and I am by no means fully versed on the subject, but I think letting others know of its existence and present the research I've done on it is a worthwhile gesture.

[justpete]

Originally Posted by MFactory

All braking the wheel does is reduce the torque to the spinning wheel, and with an open diff, the traction wheel torque must equal the spinning wheel torque.

What you are referring to is the classic unloaded condition (i.e one wheel in the air). When the wheel is in the air and is spinning freely, there is zero torque to that wheel, thus the traction wheel ALSO has zero torque thus, your car loses momentum.

However, when you apply brake (i.e load), the open diff will function again i.e you regain momentum. However, applying brake will only load the wheel so much, and again, the traction wheel will ONLY have the same amount of torque as the spinning wheel.

This is why having a Plate LSD is of more advantage than an open diff or a Helical LSD. However, the "brake to simulate load" principal still applies, so whereas with an open diff both wheels will have limited torque, with a Helical LSD, far more torque can be transferred to the wheel with traction (unlike with an Open Diff)

And this is why Helical LSD + Traction Control = Best of both worlds, as they work hand-in-hand, without the NVH of a Plate LSD (and the reason why a certain patented wavy thingymagic is just Marketing)

Hope that explains it?

Yes, that's exactly what I'm referring to as it's the only condition of concern on the track it can really help with. Not interested in street use, I don't drive on the street as if on a drag strip or on a track. And it's why I use a track setup PG LSD with a cooler. I'm still looking for a way to get rid of the stupid e-diff functionality which I think is in the SRS module but not sure. Once the cage is in the SRS goes so at least then it won't be a concern. Personally I don't really see the point of an LSD that isn't a Salisbury clutch type design but that's just me.

[MFactory]

Originally Posted by Dozhdbog

We're going over the same stuff again. Left and right torque doesn't matter as both are dealt with in the same manner -through friction either at the wheels or at the gears. It's not impossible for an e diff to do this - it is EXACTLY what it's doing. How would it magically NOT be the case? Friction applied progressively is friction applied progressively, whether via a mechanical diff or an electronic one.

Ultimately, there is no huge difference in traction availability between the mechanical and electronic differentials.

Your post makes absolutely no sense whatsoever, you do realise that yeah?

If left and right torque doesn't matter, then why even bother trying to corner at speed? The difference between left and right DOES matter, as it directly corresponds to how much traction you have.

An Open Diff does not allow unequal torque between the left/right wheels, period. An LSD does, and that is where you gain momentum during high speed cornering.

[justpete]

Originally Posted by I'm wrong

Let me humor you: YES they work the same way to get the same traction.

But the LSD equipped car will be far faster everytime. That is extremely important if you are in a track or trying to cross a busy intersection that is covered in ice (near zero friction surface).

This is more then settled. Now on to the LSD options.

^This

Definitely faster without the slightest doubt, at least wrt our e-diff operation.

[MFactory]

Originally Posted by justpete

Yes, that's exactly what I'm referring to as it's the only condition of concern on the track it can really help with. Not interested in street use, I don't drive on the street as if on a drag strip or on a track. And it's why I use a track setup PG LSD with a cooler. I'm still looking for a way to get rid of the stupid e-diff functionality which I think is in the SRS module but not sure. Once the cage is in the SRS goes so at least then it won't be a concern. Personally I don't really see the point of an LSD that isn't a Salisbury clutch type design but that's just me.

Yes, for a track car, a Plate LSD is a night and day difference

[Dozhdbog]

Originally Posted by MFactory

Your post makes absolutely no sense whatsoever, you do realise that yeah?

If left and right torque doesn't matter, then why even bother trying to corner at speed? The difference between left and right DOES matter, as it directly corresponds to how much traction you have.

An Open Diff does not allow unequal torque between the left/right wheels, period. An LSD does, and that is where you gain momentum during high speed cornering.

It doesn't matter IN REGARDS TO HOW THEY OPERATE because they OPERATE IDENTICALLY regarding left and right torque. The ELECTRONIC DIFFERENTIAL merely acts AT THE WHEELS. It's not something THAT MATTERS because it's DEALT WITH IN THE SAME MANNER.

[NOITALL]

Originally Posted by Dozhdbog

It doesn't matter IN REGARDS TO HOW THEY OPERATE because they OPERATE IDENTICALLY regarding left and right torque. The ELECTRONIC DIFFERENTIAL merely acts AT THE WHEELS. It's not something THAT MATTERS because it's DEALT WITH IN THE SAME MANNER.

Lol so speed of the wheels don't matter, as long as they are at the same speed?

[justpete]

...and another drink...

[Dozhdbog]

Originally Posted by I'm wrong

Let me humor you: YES they work the same way to get the same traction.

But the LSD equipped car will be far faster everytime. That is extremely important if you are in a track or trying to cross a busy intersection that is covered in ice (near zero friction surface).

This is more then settled. Now on to the LSD options.

Thank you for humoring me.

Now let me humor you, an LSD equipped car is going to do better in autocross and give the driver more confidence. It has smoother operations at the limits, it doesn't get overwhelmed during extreme maneuvers. If you routinely operate your car at the extremes, then, as I said before, get a mechanical diff. However, crossing a busy intersection covered in ice with BMW's e-diff on and its nannies off will actually be similar to doing so with a mechanical LSD.

Now that's settled, I feel the OP can make an informed choice.

[MFactory]

Ok, be honest, am I being trolled here? lol

for what it's worth, I've been stuck at Dubai airport for the past few hours waiting for a connecting flight, so I'm bored and half asleep, hence my half a$$sed replies and untypical bad language (sorry guys! I'm not usually like this, honest )

[Dozhdbog]

Originally Posted by I'm wrong

Lol so speed of the wheels don't matter, as long as they are at the same speed?

It matters in the exact same way as the speed of the half shafts matter to a mechanical differential.