318ti.org forum

Go Back   318ti.org forum > Technical, Maintenance and Modifications > Differentials

Notices

Differentials Limit Slip, gear ratio discussions.

.
» Recent Threads
Another Swapped Ti
11-19-2016 07:43 PM
Last post by ZEK
Yesterday 07:43 PM
63 Replies, 18,489 Views
WTB: Ascot Green 318ti,...
11-17-2017 03:08 PM
Last post by apexspeedtech
Yesterday 07:26 PM
1 Replies, 216 Views
HELP!! Airbag sensor
11-18-2017 08:18 PM
Last post by John Firestone
Yesterday 06:00 PM
5 Replies, 226 Views
Knocking noise when cold...
11-11-2017 03:53 PM
Last post by Yellow ti
Yesterday 10:56 AM
5 Replies, 774 Views
WTB M44 Motor
11-18-2017 09:38 PM
Last post by radicalr6
11-18-2017 09:38 PM
0 Replies, 200 Views
2018 318ti.org Calendar...
11-15-2017 04:10 PM
Last post by FunElan
11-18-2017 08:05 PM
8 Replies, 623 Views
Thermostat housing
11-17-2017 06:51 PM
Last post by rudyst514
11-17-2017 09:09 PM
2 Replies, 254 Views
SF Bay Area Spotted
06-03-2009 09:10 PM
Last post by Coyoteh
11-16-2017 06:17 AM
61 Replies, 25,995 Views
You know you a drive a...
11-12-2008 10:26 PM
Last post by 1996 328ti
11-16-2017 02:31 AM
298 Replies, 73,030 Views
new engine build. dasc +...
01-02-2016 02:28 AM
Last post by andakn
11-16-2017 01:00 AM
133 Replies, 50,971 Views
Reply Share/Bookmark
 
Thread Tools Display Modes
Old 07-24-2012, 01:26 AM   #1
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default What LSD ratio?

I have a stock M42. I bought a 2.93 LSD with half shafts for a great deal, and I know I'm going to want to change the ratio. So what ring and pinion gear set should I buy? 3.73? 3.91? 3.64? Please help me out. Haha.
Breticus is offline   Reply With Quote
Old 07-24-2012, 02:47 AM   #2
jca
Senior Member
 
jca's Avatar
 
Join Date: Dec 2010
Location: Wichita Falls, Texas
Posts: 1,363
iTrader: (1)
Default

Any of those ratios will be giving up top end speed and gas mileage for acceleration. The higher the number the more top end and mileage you give up. I would leave the 2.93 in, but that's just me. No BMW was designed with brute acceleration in mind. That's an American thing.
jca is offline   Reply With Quote
Old 07-24-2012, 04:18 AM   #3
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default

What do you think would be best if I have a 6cyl swap in mind in the future? Like s52 or 2.8? I think I'll do the 3.64 or 3.73. If I don't like the top end I'll still have the old gear set to throw in. Anybody else have input?
Breticus is offline   Reply With Quote
Old 07-24-2012, 05:25 AM   #4
slow_ti
Senior Member
 
slow_ti's Avatar
 
Join Date: Nov 2010
Location: Potomac Falls VA DMV
Posts: 1,794
iTrader: (1)
Default

I have a 3.73 in (S52 with some goodies) I love it cause it goes like hell and will do about 150 or so at redline. That's plenty fast for me in crowded northern VA.
__________________
Im guessing im the youngest member on here with a S52 power'ed Ti at 16 years old!
slow_ti is offline   Reply With Quote
Old 07-24-2012, 05:31 AM   #5
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default

Hmmmm. you think a 3.64 will still go like hell and maybe get me to 155 or 60? Hehe.
Breticus is offline   Reply With Quote
Old 07-24-2012, 05:36 AM   #6
slow_ti
Senior Member
 
slow_ti's Avatar
 
Join Date: Nov 2010
Location: Potomac Falls VA DMV
Posts: 1,794
iTrader: (1)
Default

Yea, it'll pull pretty dern hard. You'll have to get used to the high rpm's on high way but it's tolerable.
__________________
Im guessing im the youngest member on here with a S52 power'ed Ti at 16 years old!
slow_ti is offline   Reply With Quote
Old 07-24-2012, 06:03 AM   #7
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default

What do you think I should get? 3.64 or 3.73?
Breticus is offline   Reply With Quote
Old 07-24-2012, 06:30 AM   #8
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default

I think I'll go with the 3.73 because I tend to like to downshift a lot, and I'm a sucker for brutal acceleration and seeing as I don't think I'll ever have enough road for 160 I think 150 will make me plenty happy and if I ever want super top speed I still got the 2.93 THANKS GUYS!
Breticus is offline   Reply With Quote
Old 07-24-2012, 01:28 PM   #9
spidertri
Senior Member
 
spidertri's Avatar
 
Join Date: Apr 2007
Location: Elizabeth City, NC
Posts: 3,801
Vehicles
iTrader: (9)
Default

If you put the ratios into a gearing calculator, diffsonline.com has one, you'll only be able to get to ~125 with the stock 5spd and 3.73. With a 6spd you can get to 150 but those aren't cheap.
__________________
~Dave~

98 328ti Morea Grun slicktop
02 Z3 Coupe Topas Blau slicktop

Search | RealOEM
spidertri is offline   Reply With Quote
Old 07-24-2012, 01:30 PM   #10
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default

Well I'm hoping to find a 6 speed when I do my swap at some point.
Breticus is offline   Reply With Quote
Old 07-24-2012, 01:31 PM   #11
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default

Thanks though I'll fiddle around with that website some!
Breticus is offline   Reply With Quote
Old 07-24-2012, 10:59 PM   #12
Uber E30
Senior Member
 
Join Date: Aug 2010
Location: Nor Cal
Posts: 281
iTrader: (0)
Default

Ratio really depends on the tranny not the engine (assuming you have enough power to move the gears). If you tell me the tranny you are going to use I can post a speed/RPM chart up for you.
__________________

-Alex
Uber E30 is offline   Reply With Quote
Old 07-24-2012, 11:20 PM   #13
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default

Well I haven't looked much through transmissions yet.
Breticus is offline   Reply With Quote
Old 07-24-2012, 11:22 PM   #14
Uber E30
Senior Member
 
Join Date: Aug 2010
Location: Nor Cal
Posts: 281
iTrader: (0)
Default

If i were you I would hammer that out first because it might affect your diff choice.
__________________

-Alex
Uber E30 is offline   Reply With Quote
Old 07-24-2012, 11:23 PM   #15
Breticus
Senior Member
 
Join Date: Sep 2011
Location: Florida
Posts: 403
iTrader: (2)
Default

For now I'm all stock.
Breticus is offline   Reply With Quote
Reply

Bookmarks

Tags
differential , gear , lsd , m42 , ratio


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

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
WA Small-case 3.91 LSD / LSD Core FMD US and North America 0 03-23-2011 08:22 PM
i LOVE my LSD! Junk Differentials 8 03-29-2010 04:43 AM
Auto 4.44 LSD repost spykejones US and North America 4 02-15-2010 06:50 PM
Quaife LSD vs OEM 3.45 LSD 318ti_Portugal Differentials 8 10-29-2006 11:44 PM
feeler e30 3.73 lsd with halfshafts tctwnd US and North America 6 05-09-2006 09:21 PM


All times are GMT +1. The time now is 10:14 AM.


.
Powered by site supporters
vBulletin Version 3.8.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright ©1999 - 2017, 318ti.org
© vBadvanced CMPS v3.2.2
[page compression: 117.85 k/141.67 k (16.81%)]

318ti.org does not warrant or assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information or products discussed.