R3VLimited Forums

Go Back   R3VLimited Forums > E30 Technical Forums > Engine & Drivetrain > Transmission & Driveline

View Poll Results: What is your ideal differential ratio?
2.79 2 3.28%
2.93 7 11.48%
3.23 9 14.75%
3.46 12 19.67%
3.73 18 29.51%
3.91 5 8.20%
4.10 5 8.20%
4.27 1 1.64%
4.45 2 3.28%
Voters: 61. You may not vote on this poll

Reply
 
Thread Tools
Old 06-17-2017, 10:04 AM   #16
M-technik-3
I waste 90% of my day here and all I got was this stupid title
 
Join Date: Oct 2003
Location: Global: Massachusetts
Posts: 18,762
Send a message via Yahoo to M-technik-3
Too many variables, powerplant, forced induction, oversized wheels? where you live ie flat land and sea level vs 5K feet in Denver.
M-technik-3 is offline   Reply With Quote
Old 06-17-2017, 10:19 AM   #17
Klug
Mod Crazy
 
Klug's Avatar
 
Join Date: Sep 2011
Location: Pennsylvania
Posts: 777
For the s52, I enjoy my 3.64 LSD from a e23 and e36 LSD carrier. 3rd and 4th gear are a ton of fun, 5th can get you to 100mph at 4.2k RPM- wish isn't too bad...

For the m20, the 3.73LSD is ideally the way to go.
__________________
555Garage - Kingston, PA

'13 BMW e70 X5 35d
'95 BMW e34 525i
'92 BMW e30 325i S52 Vert (Quade the Vert)
'89 BMW e30 325i Coupe (The DIRTY30)
'81 VW MK1 Rabbit Caddy Diesel
'80 Motobecane Mobylette 50v (74cc)
'79 Motobecane Mobylette 50v
'78 Garelli Gran Sport
'76 Honda CB550K Cafe/Brat
'67 Pontiac LeMans
'24 Model T Depot Hack

Klug is offline   Reply With Quote
Old 06-17-2017, 10:40 AM   #18
Rusty.Piranha
E30 Addict
 
Rusty.Piranha's Avatar
 
Join Date: Mar 2017
Location: CA
Posts: 415
Do you think a 3.46 LSD is good on a stock m20?
Rusty.Piranha is offline   Reply With Quote
Old 06-17-2017, 11:02 AM   #19
varg
E30 Fanatic
 
varg's Avatar
 
Join Date: May 2014
Location: Palm Beach County, FL
Posts: 1,313
On the highway maybe, but it'll be slow as hell to accelerate. Needs moar torque.
__________________
@turbovarg
'91 318is, M20B25, T3/T04E 60 trim (14psi), megasquirt, coilovers, Z3 rack, cold AC
[project thread]

Just say no to screamer pipes.
varg is offline   Reply With Quote
Old 06-18-2017, 01:56 AM   #20
flyboyx
R3V OG
 
flyboyx's Avatar
 
Join Date: Sep 2008
Location: Houston, tx
Posts: 7,020
Quote:
Originally Posted by Rusty.Piranha View Post
Do you think a 3.46 LSD is good on a stock m20?
its a good balance between economy and "performance". if i had one, i would have installed it in my mtech that is sitting in denver instead of the 2.93.

you won't win many races with the 4.10 anyway so i think this is a good choice if you are going to daily the car.
__________________

Gigitty Gigitty!!!!

88 cabrio becoming alpina b6 3.5s transplanted s62
92 Mtech 2 cabrio alpinweiss 770 code
88 325ix coupe manual lachsilber/cardinal
88 325ix coupe manual diamondschwartz/natur
87 e30 m3 for parts lachsilber/cardinal(serial number 7)
12 135i M sport cabrio grey/black
flyboyx is offline   Reply With Quote
Old 06-18-2017, 01:44 PM   #21
Bimmerguy91
E30 Modder
 
Join Date: Jul 2012
Location: Huntsville, AL
Posts: 950
Quote:
Originally Posted by BlackSpeed66 View Post
Running the 3.15 Torsen in mine w/ the s52 and ZF trans. It's great around town, but to my surprise, still a bit 'much' on the highway. A 2.93 would probably suit it better. But - since I want to keep the Torsen, I think a 6 speed will be coming in the future. Still has the 1:1 5th gear and I have the option for the overdrive in 6th if I'm doing highway cruising.
I'll trade you a 2.93 LSD
Bimmerguy91 is offline   Reply With Quote
Old 06-19-2017, 08:31 AM   #22
djjerme
R3V Elite
 
djjerme's Avatar
 
Join Date: Sep 2010
Location: Portland, OR
Posts: 4,156
Quote:
Originally Posted by M-technik-3 View Post
Too many variables, powerplant, forced induction, oversized wheels? where you live ie flat land and sea level vs 5K feet in Denver.

This.
__________________
1984 Alpina B6 2.8/1 #35
1985 PRO3 #50
1991 325i Touring (the next adventure)
2004 X3 2.5 - "Bento"
2011 Audi A3 - wife's other German car
djjerme is offline   Reply With Quote
Old 06-19-2017, 07:14 PM   #23
estoguy
E30 Enthusiast
 
Join Date: May 2013
Location: Ontario, Canada
Posts: 1,069
All I have experience with is my open 2.93. For all the driving I do, it's great. After 275K km, I'm still averaging 7.8L/100 km (just over 30MPG US).
__________________
Estoguy
1986 BMW 325, Alpenweiss ~ "Elsa"

Need a photographer, come visit my site: http://estoguy.wix.com/unique-perspectives
estoguy is offline   Reply With Quote
Old 06-20-2017, 08:37 AM   #24
e30strokr
Member
 
Join Date: Oct 2011
Location: Bay Area
Posts: 66
Quote:
Originally Posted by varg View Post
On the highway maybe, but it'll be slow as hell to accelerate. Needs moar torque.


I'm good with the 292... however I'm bias since its my daily and I do 120 Highway miles every day acceleration is good but it I have a 2.7i which might make a difference in acceleration compare to the 2.5....


once I get my audi figured out I can make this a full weekend car.. which will make me change the Diff to a better acceleration ratio...
e30strokr is offline   Reply With Quote
Old 07-02-2017, 10:55 PM   #25
hot carl
Noobie
 
Join Date: Jul 2015
Location: povertyville
Posts: 24
had what i thought was a 2.89 open diff, it must've been 2.79 or whatever in my 'e'.
swapped in a 3.73 lsd and i swear it's the best upgrade i've done. also swapped in a 2.5l. that was good, too. lolz
car is a track rat/sunday driver.
hot carl is offline   Reply With Quote
Old 07-03-2017, 07:03 PM   #26
TobyB
No R3VLimiter
 
TobyB's Avatar
 
Join Date: Oct 2011
Location: Carnation WA usa
Posts: 3,773
Quote:
you won't win many races with the 4.10 anyway
sadly, this seems to be true...

t
__________________
Quote:
now, sometimes I just mess with people. It's more entertaining that way. george graves
TobyB is offline   Reply With Quote
Old 07-04-2017, 09:11 AM   #27
The Dark Side of Will
R3VLimited
 
Join Date: Jun 2010
Location: VA
Posts: 2,181
I have a 2.35 gearset which will go into my iX with S62 and GS6-53BZ
The Dark Side of Will is offline   Reply With Quote
Old 07-04-2017, 09:53 AM   #28
JimmyP
Advanced Member
 
Join Date: Dec 2007
Location: Northeast PA
Posts: 131
Diffs are too application dependent to have a perfect diff ratio even for one car depending on use.

My 318 Commuter car I put a 2.79 in, it gets 32 MPG @ 85 MPH on he highway, I don't care how it accelerates.

My Club racer with a GForce road race T5 seems to like a 4.10 for most tracks but I have 3.73, 4.27 and 4.45 to swap out to optimize when needed.

My previous CR 265 trans was happier with a 3.73 as the starting point.

My Street M3 has a stock 4.10 which for street use is about perfect, but if I was going to do track days with it I'd swap in a 4.45

My S14 powered Cabrio which essentially has an E30 M3 underneath it has a 3.91 in it which drops the highway cruise RPM a little bit over the 4.10 that would normally be there.
Acceleration is off my street car pace, but its a bit better highway cruiser.

My Gruppe A car has had everything from a 4.45 to a 3.73 in it to optimize gearing for track.

Its all dependent on the car and the use for the car,,,, and in the case of track cars the track of the day.
__________________
Jimmy P.
87 E30 M3 Prodrive British Touring Car
88 E30 M3 Zinnoberot - Garage Queen
88 E30 M3 Lachsilber - SCCA SPU #98
92 M Technic Cabrio - S14 Powered!
98 318Ti Morea Green

Last edited by JimmyP; 07-04-2017 at 09:59 AM.
JimmyP is offline   Reply With Quote
Old 07-04-2017, 04:19 PM   #29
jlevie
R3V OG
 
Join Date: Nov 2006
Location: Huntsville, AL
Posts: 13,534
Well said JimmyP!
__________________
The car makes it possible, but the driver makes it happen.
Jim Levie, Huntsville, AL
jlevie is offline   Reply With Quote
Old 07-14-2017, 04:47 AM   #30
jeffnhiscars
R3V Elite
 
jeffnhiscars's Avatar
 
Join Date: Jun 2011
Location: Officially Tampa
Posts: 4,868
Quote:
Originally Posted by Rusty.Piranha View Post
Do you think a 3.46 LSD is good on a stock m20?
We replaced the 2.93 with a 3.46 Torsen in the ETA and it almost feels "normal"

Highly recommended swap.
__________________
SEAT SHOCK SALE !!
http://www.r3vlimited.com/board/showthread.php?t=412838

Seat, Deck Lid & Cabrio Hinge Shocks available for immediate shipping
http://www.r3vlimited.com/board/showthread.php?t=409456

Alice the Time Capsule
http://www.r3vlimited.com/board/showthread.php?t=360504
87 Zinno Cabrio barn find 98k and still smells like a barn. Build thread http://www.r3vlimited.com/board/show...20#post3455220
jeffnhiscars is offline   Reply With Quote
Reply

Thread Tools

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 -7. The time now is 01:21 AM.


Powered by vBulletin® Version 3.8.10
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2004 - 2020 R3VLimited LLC