Notices
W211 AMG Discuss the W211 AMG's such as the E55 and the E63
Sponsored by:
Sponsored by:

Diff ratio mod .... why not ?

 
Old 12-21-2005, 05:24 AM
  #1  
MBWorld Fanatic!
Thread Starter
 
stevebez's Avatar
 
Join Date: Jul 2005
Location: London, UK
Posts: 3,003
Thanks: 0
Thanked 2 Times in 2 Posts
No longer stock '06 E55, A3 3.2 Quattro, LRD4 HSE, R107 280SL
Diff ratio mod .... why not ?

So why is a shorter diff ratio not a cost effective option if you want better 100+ performance ?

Think the E's gearing runs out at 336km/h so the final drive could quite easily be shortened without compromising top speed and helping 100-200mph performance. Also the effect in the shorter gears is quite small so any traction issues would be only marginally worse - if any.

MKB do a 2.82:1 conversion from the stock 2.65:1

Theoretical in gear speeds are as follows with the 2 final drives...

........stock 2.65........MKB 2.82
............mph................mph
1st.......48.30...............45.43
2nd......79.25...............74.47
3rd......123.09.............115.67
4th......173.55.............163.09
5th......209.10.............196.49

So 0-100mph times should be better as well as accel above 100mph. 1/4 mile will suffer though if you expect a 118-120 trap speed.

Top end suffers too but its still 316kmh !!! (theoretical)

Rgds Steve

P.S. Sorry for the repost but I think this got lost in a prior thread where a war was on the go .... geez lighten up guys !

Last edited by stevebez; 12-21-2005 at 05:27 AM.
stevebez is offline  
Old 12-21-2005, 05:39 AM
  #2  
MBWorld Fanatic!
 
Join Date: Jun 2003
Posts: 1,179
Thanks: 0
Thanked 1 Time in 1 Post
gearing is always a good option... thats not the problem. the problem is mercedes (unlike bmw) has the gearing programed into the tranny ECU instead of a sensor in the differerential so its not nearly as easy as it is in most cars unfortunately. Afterall, differentials are the "poor man's supercharger" as they say.
Bernanke is offline  
Old 09-07-2006, 05:18 AM
  #3  
MBWorld Fanatic!
Thread Starter
 
stevebez's Avatar
 
Join Date: Jul 2005
Location: London, UK
Posts: 3,003
Thanks: 0
Thanked 2 Times in 2 Posts
No longer stock '06 E55, A3 3.2 Quattro, LRD4 HSE, R107 280SL
Hey vrus ....

here is a good comparo from the past ....

Also the 2.82 is the same ratio being used in the E63 and the SL so should be dead easy to source ... and while you change it ... may as well add a Quaife too.
stevebez is offline  
Old 09-07-2006, 10:45 AM
  #4  
Out Of Control!!
 
jangy's Avatar
 
Join Date: Sep 2004
Location: San Diego
Posts: 13,394
Thanks: 0
Thanked 2 Times in 2 Posts
2015 S212
I explored this idea with my inside man (at MBUSA) when making my mind up about getting the LSD. He strongly recommended against it, unless i planned to take on a huge challenge of playing the ESP/Active safety system modification game. His basic response was that the entire system would be very close to its tolerances and would trigger a "pull back" from the system much more easily. Case in point, all the people who have gone to larger diameter wheels (tire / rim combo) will likely see traction control kicking in MUCH sooner than those that have remained with the stock diameter. As we all know, changing the diameter is an even poorer man's way to change gearing.

Bottom line...can it be done? Yes...is it as easy as changing a part and a sensor / setting? No.
jangy is offline  
Old 09-07-2006, 10:46 AM
  #5  
Former Vendor of MBWorld
 
Join Date: Jul 2006
Location: In a box
Posts: 2,513
Thanks: 0
Thanked 0 Times in 0 Posts
W211 E55
In my opinion, the approx 10% gain in torque multiplication in the lower gears will be largely offset by the additional shift in the quarter.

Traction willing, the next 'step up' gearwise seems like a better value - more multiplication to offset the time lost on the shift.
ChicagoX is offline  
Old 09-07-2006, 10:51 AM
  #6  
Former Vendor of MBWorld
 
Join Date: Jul 2006
Location: In a box
Posts: 2,513
Thanks: 0
Thanked 0 Times in 0 Posts
W211 E55
Originally Posted by jangy View Post
...Case in point, all the people who have gone to larger diameter wheels (tire / rim combo) will likely see traction control kicking in MUCH sooner than those that have remained with the stock diameter. As we all know, changing the diameter is an even poorer man's way to change gearing.
Is this not due to a differential in rollout, interpreted by the TC system as "slip" ?

If rollout differential is kept to a minimum F-R, shouldn't the TC issue be moot?

There may be a potential issue with the Cruise Control or other speed-dependent systems as well.
ChicagoX is offline  
Old 09-07-2006, 11:04 AM
  #7  
MBWorld Fanatic!
Thread Starter
 
stevebez's Avatar
 
Join Date: Jul 2005
Location: London, UK
Posts: 3,003
Thanks: 0
Thanked 2 Times in 2 Posts
No longer stock '06 E55, A3 3.2 Quattro, LRD4 HSE, R107 280SL
BTW those MPH's above are with 6100 rpms (max HP)... not red line ....

Using 6400 its 47.66 , 78.13 , 121.36 , 171.11 , 206.16

Using 6500 its 48.41 , 79.35 , 123.25 , 173.79 , 209.38

Either of these shift points look like a danm good fit for the quarter.
stevebez is offline  
Old 09-07-2006, 11:10 AM
  #8  
Former Vendor of MBWorld
 
Join Date: Jul 2006
Location: In a box
Posts: 2,513
Thanks: 0
Thanked 0 Times in 0 Posts
W211 E55
stevebez : I was under the impression that the Mph above was at redline.
I stand corrected; those look to be great 1/4 mile numbers.
ChicagoX is offline  
Old 09-07-2006, 11:28 AM
  #9  
MBWorld Fanatic!
 
Join Date: Aug 2004
Location: NJ
Posts: 1,732
Thanks: 0
Thanked 1 Time in 1 Post
2005 E55
Originally Posted by stevebez View Post
BTW those MPH's above are with 6100 rpms (max HP)... not red line ....

Using 6400 its 47.66 , 78.13 , 121.36 , 171.11 , 206.16

Using 6500 its 48.41 , 79.35 , 123.25 , 173.79 , 209.38

Either of these shift points look like a danm good fit for the quarter.
Steve - I am not so sure. You may find that you will need an extra shift from 3rd to 4th just before the timing beam. The time you lose for the shift (including boost drop) may wind up netting you little, if any, benefit from the new rear.
enzom is offline  
Old 09-07-2006, 11:41 AM
  #10  
MBWorld Fanatic!
Thread Starter
 
stevebez's Avatar
 
Join Date: Jul 2005
Location: London, UK
Posts: 3,003
Thanks: 0
Thanked 2 Times in 2 Posts
No longer stock '06 E55, A3 3.2 Quattro, LRD4 HSE, R107 280SL
I think you should make it. Trap speed of 122/124 area is pretty solid. DerekFSU's 10.95 hit a TS of 131.23 ( ) so it may not work for K2+ cars but should be perfect for stock I would think.

If you go 19" and 285's x 30 then it climbs to 125.35 at 6500....
stevebez is offline  
 

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Diff ratio mod .... why not ?


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: