[pikcachu]

Originally Posted by Zooks527

You know, for someone who's "done with this", you're being a bit verbose. However,...

You seem to be unable to understand the word "vary". In your example in post #58 above, you posit a case where the wheel on the opposite side of a wheel that is spinning is putting 3% of engine torque down to the ground, and is then putting 30% of engine torque down to the ground after application of the brakes to the spinning wheel. If 3% going to 30% doesn't count as "varying", I don't think we're using the same definition of the word.

Sure, you can't get more down to the ground than is being sent to the other half of the axle. So what? That doesn't effect the fact that the torque applied to the ground through the non-spinning wheel can be varied from the amount being applied by the spinning wheel to 10x that amount.

It's coming back to the fact that you're fixated on torque being sent to the wheel, as opposed to torque being sent to the ground. Sure, the amount sent out each half of the axle is the same. What counts is that the useable amount applied to the ground can be varied so that each side is different.



You want me to speculate? Sure. If they advertised it since the DPC system came out, it would cut into their marketing effort to shill that. Is that the case? Beats the hell out of me. Ask them.




And a pig isn't close to an eagle. Again, so what? Where did I ever imply, let alone try to make the case, that an eDiff is close to a mechanical LSD?




Perhaps you might want to dial the smug down just a bit. After all, in your post #53 above, you were clearly unaware that xDrive uses the brakes as part of its control system ("It's not the xDrive that varies the break load, xdrive has nothing to do with brakes (if you had no brakes...xdrive would work exaclty the same).."). I will confess that that particular omission did make me a bit less inclined to accept your technical analysis of the system.

After all, if one wishes to opine on how the system works, shouldn't one, you know, know how the system works?




Hell, I can't show you a red one, as I haven't seen one to date. So what? BMW says they make them in red and I believe it.

Regarding the LSD, I did give you a link to BMW USA's website, showing that it's available. I also gave you a link to a parts site that gave you the part number for it. If you don't believe two external sources, one of which is the manufacturer's website, I can't do anything about it.

Now, I'll accept that you didn't know it was possible. But all that proves is that there's a number of things that you don't know about xDrive cars.

I was about done but your stubbornness is unbelievable...

the xDrive as a power transmission cannot vary torque sent to independent wheels... if you want to believe that applying the brakes to vary torque is good enough cause the torque to the ground from one wheel to the other is different, then great...

Also all this you are saying is still not even for the regular xDrive anyway... regular xdrive doesn't do this torque vectoring thing...
And again anything you find only shows regular xDrive only changes torque front to rear.

I might have not know that the specific xdrive in some M model would apply the brake... so what?
The main purpose about the xDrive is how it distributes power not if some specific version can apply brake to fake it can't sent different amount of torque to each wheel

I'm just saying I've never seen an actual xDrive vehicle with an LSD... all you did where make assumptions about part numbers...

Do you now any actual xdrive car with LSD ?

[Turbo_435i]

My brain is all burned up now yo, i just wanna know if xdrive is faster than rwd for acceleration etx.

Yall got too many marshmallows in yo lucky charms!

[pikcachu]

Originally Posted by schybrid

My brain is all burned up now yo, i just wanna know if xdrive is faster than rwd for acceleration etx.

Yall got too many marshmallows in yo lucky charms!

AWD will be faster and more consistent off the line than RWD specially when damp

RWD will be faster if traction is not an issue ie after cars are moving cause it's lighter and the drivetrain loss of awd is slightly higher than rwd

Both cars have same power, so as long as you can put the power down with the RWD, then it will be faster

[den525]

The m235i was designed as a rwd car, rwd cars is what bmw do. M235i is the better car overall end of story!

Since OP is a redlight warrior, just get the xdrive you just wanted people to agree with you and validate your reasoning to get the xdrive version.

As 0-62 difference is minimal, not noticeable at all, some have shown rwd is actually faster, but you don't care, at the end of the day you just want to show your mates on a brochure that your car does 0-62 in xx time. Rather than getting the better car

[Zooks527]

Originally Posted by pikcachu

I was about done but your stubbornness is unbelievable...

I can only assume you're not reading the references, because ....

Originally Posted by pikcachu

the xDrive as a power transmission cannot vary torque sent to independent wheels... if you want to believe that applying the brakes to vary torque is good enough cause the torque to the ground from one wheel to the other is different, then great...

Well, those were your numbers showing the difference in side-to-side torque with and without wheel braking. Granted, your reliability is low, but since open differential AWD function is pretty well established, it's a matter of of "is", not "believe".

So, tell me, if it doesn't vary power to the ground by wheel, what earthly use is any open differential AWD system?

Originally Posted by pikcachu

Also all this you are saying is still not even for the regular xDrive anyway... regular xdrive doesn't do this torque vectoring thing...

The braking / open differential is for regular xDrive. Seriously, dude, you're starting to look clueless. The DPC torque vectoring in the X6 uses an electronic clutch in the rear axle, and we've clearly not been discussing that.

Originally Posted by pikcachu

And again anything you find only shows regular xDrive only changes torque front to rear.

Clearly didn't look at that last video on the BMW website, did you? I gave you the link, the time in the video to watch, and clips from it.

Originally Posted by pikcachu

I might have not know that the specific xdrive in some M model would apply the brake... so what?

Seriously? You still don't understand that xDrive uses the brakes in all the models, including the front axle on versions with DPC?

The reference was for overall 3-series and 5-series. It was a BMW press document describing how standard xDrive works, and had nothing to do with any M model. Again, you clearly know little about how the systems work and aren't reading the references.

Originally Posted by pikcachu

I'm just saying I've never seen an actual xDrive vehicle with an LSD... all you did where make assumptions about part numbers...

No, I gave you the link to the BMWUSA page that would let you order one for an M235xi. That's not an "assumption about part numbers".

Originally Posted by pikcachu

Do you now any actual xdrive car with LSD ?

Assuming you're asking "know of personally", no. So what? I don't personally know of any red ones, any with Dinan stage 1, any with automatic headlights, and so on. BMWUSA says they sell them. My CA says they sell them. Either of those trumps you, considering your limited credibility on this subject at the moment.

But that provides an easy solution as well. You don't believe the BMWUSA website? Fine, call your CA and ask him.

[olaosunt]

Originally Posted by olaosunt

Hey Boss,
I compared the time slip of the all wheel drive car that just ran a 12.25@109 in the 1/4 vs. mine which ran 11.9@114. Both cars are auto.

Similar mods but I probably make more power based on trap speed but weight(from AWD) may also be a factor. I ran E35 vs. his 93.

He was on the stock tires and I was on drag radials.
His 60ft was 1.6 vs. my 1.7

330ft and 1/8 are almost identical @4.9 and 7.6.

His 1/8th trap was 88 mph vs.. my 91 mph
He picked up 21 mph vs. my 23 mph on the back half.

RWD+sticky tires>/= AWD

Only reason to get the all wheel drive is if you need it for snow . I can tell you mine sucks in the snow even with bilzzacks compared to my Audi S4

Originally Posted by schybrid

You failed to mention you were running E35 at the time of your 11.9 @ 114mph run ......

Not sure how you missed that but I mentioned it in the second paragraph-and no, there was no ninja edit.

The Mickey Thompson's are radials AND not SLICKS as some keep saying .

I doubt AWD is going to see any better 60ft than 1.6 with drag radials since the stock tires were not spinning in the first place .Thus the only advantage from AWD off the line is already cancelled by the 330ft.

Yes. I was running more boost and I already admitted I was making more power,but that is really only evident on the back half of the track....but even with the same power,the AWD is going to trap lower(hence will be slower) given its heavier weight....simple law of physics.

[Turbo_435i]

Originally Posted by olaosunt

Not sure how you missed that but I mentioned it in the second paragraph-and no, there was no ninja edit.

The Mickey Thompson's are radials AND not SLICKS as some keep saying .

I doubt AWD is going to see any better 60ft than 1.6 with drag radials since the stock tires were not spinning in the first place .Thus the only advantage from AWD off the line is already cancelled by the 330ft.

Yes. I was running more boost and I already admitted I was making more power,but that is really only evident on the back half of the track....but even with the same power,the AWD is going to trap lower(hence will be slower) given its heavier weight....simple law of physics.

AWD "IS" faster than RWD from 0-60, no matter how you slice it.

Apples to Apples, awd wins.

Also, drag radials are not meant for daily driving.

[Cyberdemon]

Originally Posted by schybrid

AWD "IS" faster than RWD from 0-60, no matter how you slice it.

Apples to Apples, awd wins.

Also, drag radials are not meant for daily driving.

Yes.

Just buy the X drive already so this flame war can die and us RWD enthusiasts can go back to our uncontrollable power slides.

Next up on the rehashed forum argument agenda:

Snow tires vs AWD? 8AT vs 6MT? EBII vs every other blue?

[335BOY]

Originally Posted by pikcachu

AWD will be faster and more consistent off the line than RWD specially when damp

RWD will be faster if traction is not an issue ie after cars are moving cause it's lighter and the drivetrain loss of awd is slightly higher than rwd

Both cars have same power, so as long as you can put the power down with the RWD, then it will be faster

But you can't so AWD is quicker....only by a couple of 10ths which doesnt really matter but it is quicker.

[Cyberdemon]

Originally Posted by 335BOY

[/B]

But you can't so AWD is quicker....only by a couple of 10ths which doesnt really matter but it is quicker.

And I suppose that right there is the crux of the argument.

In reality, your reaction time will probably be longer than the 0-60 delta. But in order to gain back that 10th of a second you are saddling the car with more weight.

So 100% of the time the car will be heavier which impacts everything else (braking, turning, top end, fuel economy, etc) for what, 2/10ths of a second? You'll be paying away those 200ms every time you stop at the gas pump and you have less horsepower getting to the wheels.

In reality the 235 doesn't have so much power that a sticky set of rubber, reasonable driver and LSD couldn't get it to hook up damn quick, especially in some place like Florida where the tires are going to be hot year round. Those of us in the cold north have the disadvantage of tires being cold which does not help things hooking up and AWD makes a bigger difference.

So that's the big question do you sacrifice everything else for something that has a minimal impact on the real time things take? If the OP's answer is yes, 0-60 or bust then he's made up his mind and the discussion is over.

[pikcachu]

Originally Posted by Zooks527

I can only assume you're not reading the references, because ....



Well, those were your numbers showing the difference in side-to-side torque with and without wheel braking. Granted, your reliability is low, but since open differential AWD function is pretty well established, it's a matter of of "is", not "believe".

So, tell me, if it doesn't vary power to the ground by wheel, what earthly use is any open differential AWD system?




The braking / open differential is for regular xDrive. Seriously, dude, you're starting to look clueless. The DPC torque vectoring in the X6 uses an electronic clutch in the rear axle, and we've clearly not been discussing that.




Clearly didn't look at that last video on the BMW website, did you? I gave you the link, the time in the video to watch, and clips from it.




Seriously? You still don't understand that xDrive uses the brakes in all the models, including the front axle on versions with DPC?

The reference was for overall 3-series and 5-series. It was a BMW press document describing how standard xDrive works, and had nothing to do with any M model. Again, you clearly know little about how the systems work and aren't reading the references.




No, I gave you the link to the BMWUSA page that would let you order one for an M235xi. That's not an "assumption about part numbers".




Assuming you're asking "know of personally", no. So what? I don't personally know of any red ones, any with Dinan stage 1, any with automatic headlights, and so on. BMWUSA says they sell them. My CA says they sell them. Either of those trumps you, considering your limited credibility on this subject at the moment.

But that provides an easy solution as well. You don't believe the BMWUSA website? Fine, call your CA and ask him.

Ok even DSC can apply the brakes individually, so I agree that xDrive could do it too.

Don't be silly. I'm not asking a specific red or white or whatever... I'm asking ANY XDRIVE CAR WITH LSD.
The link you posted says LSD is not available for xDrive models...
Looks like you didn't even bother to select a vehicle and try

I guess you don't know it all either...

[olaosunt]

Originally Posted by schybrid

AWD "IS" faster than RWD from 0-60, no matter how you slice it.

Apples to Apples, awd wins.

Also, drag radials are not meant for daily driving.

Says who?
These are radials with thread.They wear faster but if your car makes so much torque that may be the only tire that is going to keep you from spinning

And you realize 0-60 is different from time to 60 ft right?
The few calculators that try and use time slips to calculate 0-60 use 1/8 th time and speed.
According to the calculator my 0-60 was 3.3 seconds while the X drive was 3.5

http://www.wallaceracing.com/0-60_equation.php

See RWD wins again

[Zooks527]

Originally Posted by pikcachu

The link you posted says LSD is not available for xDrive models...
Looks like you didn't even bother to select a vehicle and try

I guess you don't know it all either...

For the love of God, you posted a link to a 4-series xDrive, showing that there's no LSD available. No kidding, the 4-series xDrive uses a different suspension and under-car driveline than the 4-series RWD. That's not the case in a 2-series.

Do the same thing in a 2 series. Select an M235xi, you know, the car we've been talking about. Surprise, there it is!

And if you go back to post #62, you'll find exactly the same image from the last time I did this.

[Turbo_435i]

Wait, maybe i get rwd. I wanna fishtail on turns.

Back in the day...... Toyota Supras ruled. RWD

Current day...... Nissan GTR's rule. AWD



Wonder why ?


Is the GTR's awd same as BMW's xdrive ?

Also, the power a stock 235 makes moght be ok with rwd, but at 400whp & 450wtrque, i would tend to think awd rules, no ?

[RPM90]

Originally Posted by nike001

The X-drive cars are still RWD biased, so you'll still get that RWD feel. BMW tuned them very well so you can still feel a little bit of rotation from the rear end when you're having some fun.

I have RWD and I live in PA and I doubt I'll have any issues with it. My 330i ZHP was RWD too and she went along fine, so I'm assuming the 235 will too. Dat 50/50 weight distribution ftw

Near 50/50 weight distribution.
M235i:
Weight distribution, front/rear -– Automatic Transmission52.2/47.8 %
Weight distribution, front/rear – Manual Transmission51.9/48.1 %

M235Xi:
Weight distribution, front/rear -– Automatic Transmission53.5/46.5 %

228i:
Weight distribution, front/rear – Automatic transmission 50.8/49.2%
Weight distribution, front/rear – Manual transmission50.4/49.6 %

228Xi:
Weight distribution, front/rear – Automatic transmission 50.7/49.3%

[RPM90]

Originally Posted by Kristalov

Here are some thoughts:


4. I regards to tires I believe it comes standard with performance tires (non run flats) unless you order all seasons.

Hope that helps somewhat in your decision

ALL new BMW's come with run-flat tires that includes summer tires and all season tires.

[RPM90]

Originally Posted by olaosunt

Hey Boss,
I compared the time slip of the all wheel drive car that just ran a 12.25@109 in the 1/4 vs. mine which ran 11.9@114. Both cars are auto.

Similar mods but I probably make more power based on trap speed but weight(from AWD) may also be a factor. I ran E35 vs. his 93.

He was on the stock tires and I was on drag radials.
His 60ft was 1.6 vs. my 1.7

330ft and 1/8 are almost identical @4.9 and 7.6.

His 1/8th trap was 88 mph vs.. my 91 mph
He picked up 21 mph vs. my 23 mph on the back half.

RWD+sticky tires>/= AWD

Only reason to get the all wheel drive is if you need it for snow . I can tell you mine sucks in the snow even with bilzzacks compared to my Audi S4

That's not really a fair comparison.
Put those same sticky tires on the AWD and it will get out of the hole even faster than the RWD with same sticky tires.
There is no disputing that AWD puts the power to forward motion more evenly and thus quicker.

Now, at higher speed AWD has more friction and thus isn't as efficient so as speed increases AWD loses it's out of the hole advantage.

Also, certain AWD designs do add handling performance such as in Audi's and Subaru's as they are designed to perform best as AWD.
BMW's tend to be better performers in their standard RWD design, and that's the beauty of a RWD BMW.

Sliding the rear around in corners may be fun, but it's not always the fastest or most efficient way to get best of fastest time on a track.

[RPM90]

Originally Posted by mike@x-ph.com

Dont get me wrong i have nothing against AWD. My favorite car is a GTR ( AWD) but there is something about the BMW being AWD , it just does not feel like a BMW.
Test drive both and you might understand what i mean.

+10

[culinarymatt87]

Originally Posted by RPM90

ALL new BMW's come with run-flat tires that includes summer tires and all season tires.

no not all of them the m235i comes with pss non rft as standard

[RPM90]

Originally Posted by moldcad

No, they are awd for an average joe the driver to be able to convey all this power to the road (but mainly for him to be safer, and you know this too).

Ever though why F1 cars are NOT awd?

They are not AWD because of F1 rules stating how the driven wheels are to be designed.
In other forms of racing Audi and it's AWD dominate for a reason.
AWD is not just for safety when it comes to performance on the track and racing, and some AWD's translate this to non track driving as well.

I love the driving feel of RWD and that's why I choose RWD BMW's.
But I've had AWD and those are also fun in a different way.
There is a driving technique adjustment that needs to be made when performance driving an AWD compared to RWD or FWD.
They can all be fun in different ways.
Which one prefers is personal choice.

[RPM90]

Originally Posted by culinarymatt87

no not all of them the m235i comes with pss non rft as standard

Unless BMW has changed things, like adding a spare and a jack, all new US, and I believe all N.America, BMW's come with RFT's.
BMW did this years ago as a weight saving measure, they don't include spares and jacks.
Perhaps in other countries they may provide this but not in the US.
I see you are in the UK, and I believe in the Euro market there is a "mobility kit" or some such, no such thing in the US market, which is what I am referring to.
CORRECTION:
Non RFT summer tires are available as an option in the US.

I am open to being corrected on this, but I'd need to see the proof.

[German1967]

Originally Posted by RPM90

Unless BMW has changed things, like adding a spare and a jack, all new BMW's come with RFT's.
BMW did this years ago as a weight saving measure, they don't include spares and jacks.
Perhaps in other countries they may provide this but not in the US.

I am open to being corrected on this, but I'd need to see the proof.

Well, you have to uncheck the RFT option on the M235xi to get PSS, but it is free of charge to get PSS and those come with a mobility kit.