E90Post
 


Bimmertech
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Suspension | Brakes | Chassis > eLSD in mar 08 +



Reply
 
Thread Tools Search this Thread
      07-27-2009, 04:25 PM   #1
zsapphire7
Colonel
 
zsapphire7's Avatar
 
Drives: 08 e92 M3
Join Date: Oct 2007
Location: SF Bay Area

Posts: 2,289
iTrader: (21)

eLSD in mar 08 +

So, around march 08 production cars the 3 series were equiped with an elsd where the brakes would be applied upon the slipping rear wheel to allow for transfer of tq to the other side even with all traction control off. I have a pre March 08 production car so i do not have the elsd. I was wondering, is it possible to program our cars to have this?

I was thinking that having this would be a fine addition to the quaife. Essentially in a 0 traction condition, the brakes would come in, but the quaife would be able to transfer 4-5x that to the outside wheel.
zsapphire7 is offline   United_States
0
Reply With Quote
      07-31-2009, 01:24 PM   #2
DaFish
2008 335i E92, Almost full mods
 
Drives: 2008 335i E92, Procede V5
Join Date: Mar 2009
Location: Ontario, Canada

Posts: 1,073
iTrader: (0)

Garage List
2008 335i Coupe  [3.00]
Quote:
Originally Posted by zsapphire7 View Post
So, around march 08 production cars the 3 series were equiped with an elsd where the brakes would be applied upon the slipping rear wheel to allow for transfer of tq to the other side even with all traction control off. I have a pre March 08 production car so i do not have the elsd. I was wondering, is it possible to program our cars to have this?

I was thinking that having this would be a fine addition to the quaife. Essentially in a 0 traction condition, the brakes would come in, but the quaife would be able to transfer 4-5x that to the outside wheel.

I also have a pre-march 335i. I would also like to discuss if we just did the quaife, do we even need the elsd? I heard great things about the quaife and would love to hear from someone that has a pre-march 335i and the quaife.
DaFish is offline   Canada
0
Reply With Quote
      07-31-2009, 01:28 PM   #3
zsapphire7
Colonel
 
zsapphire7's Avatar
 
Drives: 08 e92 M3
Join Date: Oct 2007
Location: SF Bay Area

Posts: 2,289
iTrader: (21)

its not need.. The only time the quaife has issues is when it loses full traction to the inside wheel since it multiplies the tq to the outside wheel. 0 times any number is still 0 and thus will behave like an open diff, minus any preload. The elsd will kick in at that time however and any braking tq applied to the inside wheel will be multiplied to the outside. Essentially u make the elsd much more efficient instead of an open diff only transfering an equal force to the outside wheel.

My thoughts are that the elsd compliments the quaife really well...
zsapphire7 is offline   United_States
0
Reply With Quote
      07-31-2009, 05:41 PM   #4
Webz
Private First Class
 
Webz's Avatar
 
Drives: e92 M3
Join Date: Jan 2008
Location: NOVA

Posts: 157
iTrader: (3)

You might try posting this in the drivetrain section or maybe pose a similar question in the thread related to the Wavetrac peice (found here: http://www.e90post.com/forums/showthread.php?t=270788)

I would like know the answer as I have an elsd and looking at the Quaife also.
Webz is offline   United_States
0
Reply With Quote
      08-01-2009, 09:06 PM   #5
chaz58
Captain
 
chaz58's Avatar
 
Drives: 328iT
Join Date: Oct 2007
Location: Detroit Burbs

Posts: 701
iTrader: (0)

Yeah, e-diff would only make a difference if there was zero traction on one of the wheels (i.e. in the air).

My Audi basically did this. If there was zero traction at a wheel, it would brake that wheel (at speeds <20mph) so that you wouldn't be stuck even though you have AWD.

In my experience, the e-diff only makes a difference if you press the DST button (and then it makes a huge difference).

Quote:
Originally Posted by zsapphire7 View Post
its not need.. The only time the quaife has issues is when it loses full traction to the inside wheel since it multiplies the tq to the outside wheel. 0 times any number is still 0 and thus will behave like an open diff, minus any preload. The elsd will kick in at that time however and any braking tq applied to the inside wheel will be multiplied to the outside. Essentially u make the elsd much more efficient instead of an open diff only transfering an equal force to the outside wheel.

My thoughts are that the elsd compliments the quaife really well...
__________________
_________________________________________________

chaz58 is offline  
0
Reply With Quote
      08-08-2009, 05:54 PM   #6
DJKhan85
Major
 
DJKhan85's Avatar
 
Drives: 2011 4dr 6mt Golf GTI
Join Date: Jun 2009
Location: Boston Massachusetts

Posts: 1,188
iTrader: (1)

How do you know if your car has an e-diff or not? I it listed when i run the vin? I have a february 08 build btw...
__________________
2011 VW GTI 4dr-6mt-Sunroof-Nav-Xenons
OLD:
08 335i AW/CR/Poplar 6mt-ZSP-ZPP-ZCW-iPod-iDrive-PDC-Style 230s w/FK 452-Dinan LSD
DJKhan85 is offline   Trinidad_and_tobago
0
Reply With Quote
      08-08-2009, 10:47 PM   #7
stressdoc
Moderator
 
stressdoc's Avatar
 
Drives: F80 YMB, 335 E90 ZSP+
Join Date: Jun 2005
Location: MO

Posts: 9,987
iTrader: (0)

e-diff is the most absurd mislabel ever. It is brakes and power cuts. All E9xs have this, it's termed DSC/DTC. The post 03/08 version is programmed differently. The later version is not what I want because it is more invasive and apparently does not completely turn off some braking functions; IMO the pre 08 version works fine with all stages of DSC/DTC. Quaife or other LSD is great regardless of which version you have.
stressdoc is online now   Dominica
0
Reply With Quote
      08-08-2009, 11:02 PM   #8
zsapphire7
Colonel
 
zsapphire7's Avatar
 
Drives: 08 e92 M3
Join Date: Oct 2007
Location: SF Bay Area

Posts: 2,289
iTrader: (21)

actually ediff is the best compliment for a quaife.. and does not cause throttle cut off.

one way u can test for ediff is by holding down the DSC button for 5 seconds to turn all traction control off. then find a dip or something to get one rear wheel in the air. if your car gets stuck... u don't have ediff software.
zsapphire7 is offline   United_States
0
Reply With Quote
      08-10-2009, 01:50 PM   #9
chaz58
Captain
 
chaz58's Avatar
 
Drives: 328iT
Join Date: Oct 2007
Location: Detroit Burbs

Posts: 701
iTrader: (0)

Not true, my friend.

the e-diff was added march '08, and is not at all like what the earlier cars had. Earlier cars really need a Quaif – the latter cars would only show minimal benefits from a Quaif.

have you ever driven both cars hard with the DTC turned down or off? The earlier cars have the horrid “1 wheel” spin of an open differential. The latter cars behave very similar to a viscous LSD. It is seamless and not at all invasive. In road/track/Auto-X I have not found any down side to this. I do drive with DST turned down or off a fair amount of the time.

Yeah, I would rather have a Quaife than a viscous LSD or an e-diff, but that is a pretty minor difference compared to a completely open differential.

P.S. I liked your sig picture, but I still think it needs a fill flash to highlite that good looking (!) car you have - something like this below:


Quote:
Originally Posted by stressdoc View Post
e-diff is the most absurd mislabel ever. It is brakes and power cuts. All E9xs have this, it's termed DSC/DTC. The post 03/08 version is programmed differently. The later version is not what I want because it is more invasive and apparently does not completely turn off some braking functions; IMO the pre 08 version works fine with all stages of DSC/DTC. Quaife or other LSD is great regardless of which version you have.
Attached Images
 
__________________
_________________________________________________

chaz58 is offline  
0
Reply With Quote
      08-10-2009, 01:57 PM   #10
chaz58
Captain
 
chaz58's Avatar
 
Drives: 328iT
Join Date: Oct 2007
Location: Detroit Burbs

Posts: 701
iTrader: (0)

Quote:
Originally Posted by DJKhan85 View Post
How do you know if your car has an e-diff or not? I it listed when i run the vin? I have a february 08 build btw...

Easiest way is to find some dirt/snow. Turn DTC all the way off. Accelerate in a straight line, and in a J turn. Do you leave two even streaks, or are you getting a lot of wheel spin on one wheel?

The fun way of course is to do some hard driving on a track (or somewhere safe). If you get a lot of inside wheel spin with DTC turned down or off, then you dont have the e-diff.

Its not listed in the VIN. BMW didn't tell anyone when they did this, and it took some knocking on doors to get them to fess up to this change. I guess they didn't want to steal some lime light from the new introduction of the 1 series.
__________________
_________________________________________________

chaz58 is offline  
0
Reply With Quote
      08-15-2009, 04:54 PM   #11
Twilight1
Second Lieutenant
 
Drives: Fiesta ST
Join Date: Jul 2009
Location: MI

Posts: 294
iTrader: (0)

Quote:
Originally Posted by chaz58 View Post
Easiest way is to find some dirt/snow. Turn DTC all the way off. Accelerate in a straight line, and in a J turn. Do you leave two even streaks, or are you getting a lot of wheel spin on one wheel?

The fun way of course is to do some hard driving on a track (or somewhere safe). If you get a lot of inside wheel spin with DTC turned down or off, then you dont have the e-diff.

Its not listed in the VIN. BMW didn't tell anyone when they did this, and it took some knocking on doors to get them to fess up to this change. I guess they didn't want to steal some lime light from the new introduction of the 1 series.
I turned off the DTC today and brake torqued the car and left two even streaks of rubber for about twenty feet. Definitely not like any open diff I've ever seen.
Twilight1 is offline  
0
Reply With Quote
      08-15-2009, 06:33 PM   #12
stressdoc
Moderator
 
stressdoc's Avatar
 
Drives: F80 YMB, 335 E90 ZSP+
Join Date: Jun 2005
Location: MO

Posts: 9,987
iTrader: (0)

My 2002 would leave two black strips before I put a LSD in it. So did my 2007 E90 335 before I put an LSD in it. I have driven pre- and post- 03/'08 335s. There are trivial differences with full DTC/DSC and partial DSC/DTC (quick button push). Long button push on pre- results in electronic nannies completely off. Post- keeps some braking when asymmetric wheel rotation is detected -- you can never turn DTC completely off in a post-. Get over it; there is no mechanical or electronic anti-slip mechanism in the post- differential. The final drive unit is exactly the same. "e-differential" is a minor software change in the DTC/DSC system. It steals the name of the real thing, an electronic limited slip differential that some Ferraris and Porsches have. You guys want to buy into the marketing BS, fine. Go racing with your "e-diff", especially off-road rallye racing.

Do most E9x drivers really need a LSD? Of course not. But you will find the M3 equipped with a real LSD.

To answer the Q regarding possibility of reprogramming, that is can of worms. I would guess that a new ECU might be part of the picture.
stressdoc is online now   Dominica
0
Reply With Quote
      08-15-2009, 06:50 PM   #13
Twilight1
Second Lieutenant
 
Drives: Fiesta ST
Join Date: Jul 2009
Location: MI

Posts: 294
iTrader: (0)

Quote:
Originally Posted by stressdoc View Post
My 2002 would leave two black strips before I put a LSD in it. So did my 2007 E90 335 before I put an LSD in it. I have driven pre- and post- 03/'08 335s. There are trivial differences with full DTC/DSC and partial DSC/DTC (quick button push). Long button push on pre- results in electronic nannies completely off. Post- keeps some braking when asymmetric wheel rotation is detected -- you can never turn DTC completely off in a post-. Get over it; there is no mechanical or electronic anti-slip mechanism in the post- differential. The final drive unit is exactly the same. "e-differential" is a minor software change in the DTC/DSC system. It steals the name of the real thing, an electronic limited slip differential that some Ferraris and Porsches have. You guys want to buy into the marketing BS, fine. Go racing with your "e-diff", especially off-road rallye racing.

Do most E9x drivers really need a LSD? Of course not. But you will find the M3 equipped with a real LSD.
I'm not doubting your word but both of my 2002s would only spin one wheel. I agree most E9x drivers don't need it.
Twilight1 is offline  
0
Reply With Quote
      08-15-2009, 08:44 PM   #14
Twilight1
Second Lieutenant
 
Drives: Fiesta ST
Join Date: Jul 2009
Location: MI

Posts: 294
iTrader: (0)

OK, What I believe is going on is that the brake is still being applied to the spinning wheel even with the DTC turned all the way off.
Twilight1 is offline  
0
Reply With Quote
      08-15-2009, 10:13 PM   #15
stressdoc
Moderator
 
stressdoc's Avatar
 
Drives: F80 YMB, 335 E90 ZSP+
Join Date: Jun 2005
Location: MO

Posts: 9,987
iTrader: (0)

One wheel, two wheels. Whatever.

What is awesome is a freakin' diesel burning rubber!
stressdoc is online now   Dominica
0
Reply With Quote
      08-16-2009, 08:49 AM   #16
Twilight1
Second Lieutenant
 
Drives: Fiesta ST
Join Date: Jul 2009
Location: MI

Posts: 294
iTrader: (0)

Quote:
Originally Posted by stressdoc View Post
One wheel, two wheels. Whatever.

What is awesome is a freakin' diesel burning rubber!

Totally agree! As I stated, what threw me off was even though the system was "off", it still brakes the spinning wheel.

Thanks for all the info!

Last edited by Twilight1; 08-16-2009 at 09:08 AM.
Twilight1 is offline  
0
Reply With Quote
      08-17-2009, 10:51 AM   #17
chaz58
Captain
 
chaz58's Avatar
 
Drives: 328iT
Join Date: Oct 2007
Location: Detroit Burbs

Posts: 701
iTrader: (0)

Glad it helped.

I had a awful lot of inside wheel spin on the '07 models I test drove extensively. It made me think seriously about getting another car. I decided to bite the bullet and get a quaife if it bothered me that much (thinking at the time it was $2K, it is really $4K if you have a stick (meaning you have a welded rear diff)).

Fortunately BMW fixed this problem for my needs. No inside rear wheel hanging in the air spinning like mad. To me this is huge. I've been driving mostly 330's and 328's (RWD, stick).
__________________
_________________________________________________

chaz58 is offline  
0
Reply With Quote
      08-17-2009, 11:00 AM   #18
chaz58
Captain
 
chaz58's Avatar
 
Drives: 328iT
Join Date: Oct 2007
Location: Detroit Burbs

Posts: 701
iTrader: (0)

Quote:
Originally Posted by stressdoc View Post

My 2002 would leave two black strips before I put a LSD in it.
In a turn??? That just doesn't make sense...

Quote:
Originally Posted by stressdoc View Post
You guys want to buy into the marketing BS, fine. Go racing with your "e-diff", especially off-road rallye racing.

Doc, with all due respect, I know of nothing written or in any type of marketing where BMW admits to having this in the 3 series. There is no marketing of this, none with the e90. The only exception to this is a written reply I have from BMW in my enquiries as to why the two cars drive so different.

Stressdoc, no one ever said an ediff was better than the M3 diff. None of us are racing our cars or doing rally racing. I have been doing autocross and track schools for 25+ years, and on my car the system works very similar to a viscous LSD, and not quite as good as a Torsen or Quaife.

Ether way, enjoy your car! :-)
__________________
_________________________________________________

chaz58 is offline  
0
Reply With Quote
      08-17-2009, 12:06 PM   #19
Alpina_B3_Lux
Colonel
 
Alpina_B3_Lux's Avatar
 
Drives: Audi R8 V10, BMW 330d E91 LCI
Join Date: Feb 2008
Location: Germany

Posts: 2,434
iTrader: (0)

Garage List
2009 335i  [4.39]
Quote:
Originally Posted by stressdoc View Post
e-diff is the most absurd mislabel ever. It is brakes and power cuts. All E9xs have this, it's termed DSC/DTC. The post 03/08 version is programmed differently. The later version is not what I want because it is more invasive and apparently does not completely turn off some braking functions; IMO the pre 08 version works fine with all stages of DSC/DTC. Quaife or other LSD is great regardless of which version you have.
+1

It's just horrible. Cuts power more or less consistently when driving hard in the first three gears, on a track the car feels as if it hicupped continuously. I can't imagine who would really want this if you have the choice of getting a real torsen-diff. It may not be bad for the daily granny driver, but once you start adding power to your car or driving it a bit harder, you'll find it quite annoying. That is in fact THE reason why a Quaife is no. 1 on my wishlist right now.

Alpina_B3_Lux
__________________
Audi R8 V10; sold: BMW 335i
Alpina_B3_Lux is offline   Germany
0
Reply With Quote
      08-17-2009, 12:47 PM   #20
stressdoc
Moderator
 
stressdoc's Avatar
 
Drives: F80 YMB, 335 E90 ZSP+
Join Date: Jun 2005
Location: MO

Posts: 9,987
iTrader: (0)

To balance my perspective which could be interpreted as overly negative, I think BMW has done a wonderful job with DSC/DTC. Of course the relative asymmetry of traction is improved over older models such as the 2002. That said, DSC programming can never provide the benefits of an LSD, and IMO BMW has done nothing better than slap a band-aid on this Achilles heel of the 335. Not a big problem with the 328 on dry pavement, but for the 335 to perform to its potential a LSD is critical.
stressdoc is online now   Dominica
0
Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 06:38 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST