Fordmods Logo

Diff for daily driver 

 

Page 1 of 2 [ 19 posts ] Go to page 1, 2  Next

 
 Post subject: Diff for daily driver
Posted: Mon Dec 04, 2006 3:55 pm 
Getting Side Ways
Offline

Posts: 1310

Joined: 12th Dec 2005

Location: Perth
WA, Australia

I've been looking at changing my diff for the last couple of months. With the final drive ratio of the auto being lower than that of the manual, I don't see a problem with running a 4.1:1 ratio diff in my daily driver.
What do you guys/girls think?
Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 4:00 pm 
Getting Side Ways
Offline

Age: 29

Posts: 4182

Joined: 30th May 2005

Ride: 1993 EB XR8

Location: BrisVegas
QLD, Australia

Do you do alot of highway milage? if yea then eithe 3.73:1 or 3.9:1 would be better, if not then 4.11:1 will get better launches, and use less fuel around town because you need to do less heavy accelleration

 

_________________

ILL60 - EF XR8, Sunroof, Ticky Kit, 19x8.5/19x11 TE37's, 347, AFr185's, TFS BoxRcustom converter, Hurst Quarterstick, huge billet cam.

51TER - DL LTD. Stock.

Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 4:02 pm 
Getting Side Ways
Offline

Posts: 1310

Joined: 12th Dec 2005

Location: Perth
WA, Australia

Mon-Fri is peak hour twice a day. Weekend is about 50km of highway driving (100km/h) and driving on 60-70km/h roads.

Edit:
Approximate revs @ 100km/h
3.23:1 (current) - 1800rpm
3.45:1 - 1920rpm
3.73: 1 - 2080rpm
3.9:1 - 2170rpm
4.11:1 - 2290rpm

Approximate revs @ 60km/h
3.23:1 (current) - 1080rpm
3.45:1 - 1160rpm
3.73: 1 - 1250rpm
3.9:1 - 1300rpm
4.11:1 - 1370rpm
Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 4:26 pm 
Getting Side Ways
Offline

Age: 29

Posts: 4182

Joined: 30th May 2005

Ride: 1993 EB XR8

Location: BrisVegas
QLD, Australia

the 3.45:1 revs are pretty accurate... for a manual

 

_________________

ILL60 - EF XR8, Sunroof, Ticky Kit, 19x8.5/19x11 TE37's, 347, AFr185's, TFS BoxRcustom converter, Hurst Quarterstick, huge billet cam.

51TER - DL LTD. Stock.

Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 4:29 pm 
Getting Side Ways
Offline

Posts: 1310

Joined: 12th Dec 2005

Location: Perth
WA, Australia

67RCE wrote:
the 3.45:1 revs are pretty accurate... for a manual


Those calculations are based on 205/65R15 tyres in 4th gear in my 4spd auto. Final drive is 0.68.
As a comparison 5th gear in the falcon manual is 0.72 or 0.73. Can't remember which, but it's one of those. So the manual in any gear will rev higher than the auto in 4th with the same diff/tyres.


The question is.. what revs are reasonable for daily driving?
Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 5:12 pm 
Getting Side Ways
Offline

Age: 30

Posts: 2256

Joined: 5th May 2005

Gallery: 1 images

Ride: 5 Star Boxcar

Location: blu mtns
NSW, Australia

AdamN wrote:
The question is.. what revs are reasonable for daily driving?


haha i guess thats up to you and what you think is acceptable. imagine 4.11 in my car with the 5sp?!?! stuff that, i do about 300 km on the highway a week so i think that ratio would be out of the question for me....

 

_________________

Kezz's 5sp Box Car ---> RPD enhanced with a bunch of other stuff

Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 5:23 pm 
Getting Side Ways
Offline

Posts: 1310

Joined: 12th Dec 2005

Location: Perth
WA, Australia

That's where the 6spd autos and manuals come into their own.. can put in 4.11 diff and still have low revs at 100km/h lol
Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 5:35 pm 
Getting Side Ways
Offline
User avatar

Age: 52

Posts: 4370

Joined: 5th Nov 2004

Ride: BA Fairlane Ghia

Location: Karratha
WA, Australia

Look what the factory does, cooking models are around 3:08, which would be a daily driver, 3:2.... for heavier stuff, 3:45 for sportier.
4:11 arent a daily driver ratio, if you want to conserve fuel etc, why bother, unless you want to traffic light drag.
Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 5:39 pm 
Getting Side Ways
Offline

Posts: 1310

Joined: 12th Dec 2005

Location: Perth
WA, Australia

Well with 3.7:1 gears.. it'd be 2000rpm@ 100km/h.. don't see any problem with that.
Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 5:42 pm 
Getting Side Ways
Offline

Age: 40

Posts: 2015

Joined: 9th Mar 2005

Gallery: 4 images

Ride: Territory TX AWD & AUII XLS EGAS

Location: East Kurrajong
NSW, Australia

I am looking at either 3.45 or 3.7 for daily driving and highway.

Have been told for 3.45 LSD is easier to come across ... and gives a bit of a better boost off launch with auto.

Ute has crap take-off with auto and 3.23:1 single spinner ... such a dog ogg the line with load on.

 

_________________

04 Territory TX AWD - Winter White - optioned up
06 Falcon BFII XLS ute EGAS - Winter White - EGA-54D Version 2

Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 5:43 pm 
Getting Side Ways
Offline
User avatar

Age: 52

Posts: 4370

Joined: 5th Nov 2004

Ride: BA Fairlane Ghia

Location: Karratha
WA, Australia

The revs might be only 200 odd apart, but thats extra 200 every minute, for how many years? has to be less wear surely? you want fuel economy? or extra legs down low? be fine for the city, but where i live, that would kill me, doing 140/160.
Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 5:54 pm 
Getting Side Ways
Offline

Age: 40

Posts: 2015

Joined: 9th Mar 2005

Gallery: 4 images

Ride: Territory TX AWD & AUII XLS EGAS

Location: East Kurrajong
NSW, Australia

If you are contantly on the highway/freeway ... definitely stay with the longer gearing.

I do a combination of city/metro/highway/freeway ... but do a lot of load work too.

I think 3.45 LSD is going to be the go (for me anyway) ... easy to come across ... and a lot of people seem to be happy with them on autos as well ... gotta be better than trying to take off with 3.23s under load with an auto.

 

_________________

04 Territory TX AWD - Winter White - optioned up
06 Falcon BFII XLS ute EGAS - Winter White - EGA-54D Version 2

Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 5:54 pm 
Getting Side Ways
Offline

Posts: 1310

Joined: 12th Dec 2005

Location: Perth
WA, Australia

I've done all my country trips in this car already. It's now going to be a city only car.. so rarely going to be hitting anything over 100km/h.
Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 6:02 pm 
Getting Side Ways
Offline

Age: 29

Posts: 1538

Joined: 4th May 2006

Gallery: 4 images

Ride: ef fairmont turbo

Power: 213 rwkw

Location: melbourne
VIC, Australia

with an auto will the ecu be ok with the shorter ratios???
or will you have to change to a xr6 ecu???

 

_________________

96 EF FAIRMONT
Garrett gt40turbo, iceman plenum, ported head, turbo cam, double valvesprings, 023 fuel pump, 36lb injectors 4' cat, 4' dump, 2.5 exhaust, build bottom end, hypertonic pistons rods & rods, king bearings, j3. c10 3500 stall
232rwkw@4psi

Top
 Profile  
 
 
Posted: Mon Dec 04, 2006 6:06 pm 
Getting Side Ways
Offline

Age: 40

Posts: 2015

Joined: 9th Mar 2005

Gallery: 4 images

Ride: Territory TX AWD & AUII XLS EGAS

Location: East Kurrajong
NSW, Australia

Just change the speedo gear on the auto and all should be fine ... from what I could tell.

 

_________________

04 Territory TX AWD - Winter White - optioned up
06 Falcon BFII XLS ute EGAS - Winter White - EGA-54D Version 2

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 2  [ 19 posts ]  Go to page 1, 2  Next

Who is online

Users browsing this forum: No registered users and 12 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Mon Dec 18, 2017 1:37 am All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names