Fordmods Logo

diff confusion 

 

Page 1 of 1 [ 11 posts ] 

 
 Post subject: diff confusion
Posted: Tue Mar 20, 2007 4:29 pm 
Fordmods Junkie
Offline
User avatar

Posts: 3083

Joined: 22nd Sep 2005

Gallery: 13 images

Ride: EF

Location: Melbourne
VIC, Australia

ok, when i bought my car i was told it was converted to LSD and he said it was out of an XR8, so i always assumed it was a 3.23lsd (it is an lsd im sure of that), thing is im doubting that ratio, as since i converted to manual 4 weeks ago, it now sits at 2400rpm at 110.

now i have found out my speedo is 10kph out, so speedo showing 120kph (really 110kph) rpm is showing 2400.

i have a boxcar manual, and an unknown diff, im wondering two things how to find out ratio (dosnt have tags), and what gear is needed to fix the speedo.

 

_________________

Image
latest mod: A Service
MY BUILD THREAD

Top
 Profile  
 
 
Posted: Tue Mar 20, 2007 4:42 pm 
Fordmods Addict
Offline
User avatar

Age: 31

Posts: 7958

Joined: 1st Jun 2005

Gallery: 13 images

Ride: Falcon

Power: 237 rwkw

Location: Melbourne
VIC, Australia

Pull the diff hat off and look at whats stamped on the gears.
Mark tailshaft and disc, count rotations.
Theres two options.

EA box has .78 5th too, so its always gonna be shorter then BTRs 4th, .68!

 

_________________

ED XR8 Sprint - S-Trim, V500, 249rwkw
BF MKII F6 Tornado - 237rwkw

Top
 Profile  
 
 
Posted: Tue Mar 20, 2007 4:50 pm 
Getting Side Ways
Offline
User avatar

Age: 33

Posts: 1442

Joined: 26th Apr 2006

Gallery: 6 images

Ride: 97 EL XR6

Power: 162 rwkw

Location: liverpool
NSW, Australia

ill have a stab and say you have at least 3.7 in there!
a 3.45 in a 5 speed wouldnt sit that high...

 

_________________

07 BF MKII XR6T
310rwkw @ 13psi - Tuned By CMS

Top
 Profile  
 
 
Posted: Tue Mar 20, 2007 5:27 pm 
Getting Side Ways
Offline
User avatar

Age: 33

Posts: 11791

Joined: 5th Nov 2004

Gallery: 13 images

Ride: Holden VF Calais / NL FBT

Location: SE Melb
VIC, Australia

yeah pull the backing plate off and get a paint pen
make a vertical mark on the diff flange, and one on the a*** in the same place,
Turn the tailshaft and count how many turns of teh tailshaft it takes for you to make the two white marks meet again!

 

_________________

Nicko

Top
 Profile  
 
 
Posted: Tue Mar 20, 2007 6:34 pm 
Getting Side Ways
Offline
User avatar

Age: 34

Posts: 2351

Joined: 11th Nov 2004

Gallery: 30 images

Ride: Blown XR8

Location: Melbourne
VIC, Australia

and hope you don't see a number printed on the gears that you didn't really want... :shock:
3.45's or 3.7's would probably be in there.
Top
 Profile  
 
 
Posted: Tue Mar 20, 2007 6:41 pm 
Getting Side Ways
Offline
User avatar

Age: 49

Posts: 6467

Joined: 18th Dec 2006

Ride: 93 ED sedan

Power: 161 rwkw

Location: Rockhampton
QLD, Australia

Here's a formula to work it out.

 

 

Attachments:
Speed calculator with example.jpg
Speed calculator with example.jpg [ 353.25 KiB | Viewed 17 times ]

 

_________________

http://youtu.be/jJTh9F3Vgg0

Top
 Profile  
 
 
Posted: Tue Mar 20, 2007 7:30 pm 
Stock as a Rock
Offline

Age: 32

Posts: 169

Joined: 27th Jun 2005

Gallery: 6 images

Ride: EF XR8 5spd

Location: Newcastle
NSW, Australia

My ef xr8 sits on 2300rpm at 110km/h with 3.23 and 5 speed.

 

_________________

EF XR8 5spd: 302ci /178rwkw

Top
 Profile  
 
 
Posted: Tue Mar 20, 2007 7:37 pm 
Getting Side Ways
Offline
User avatar

Age: 34

Posts: 2351

Joined: 11th Nov 2004

Gallery: 30 images

Ride: Blown XR8

Location: Melbourne
VIC, Australia

Thats pretty high for that speed.
My EL XR8 sits on 2100rpm at 110km/h in 5th with a 3.23 diff.
Top
 Profile  
 
 
Posted: Wed Mar 21, 2007 7:36 pm 
Stock as a Rock
Offline

Age: 32

Posts: 169

Joined: 27th Jun 2005

Gallery: 6 images

Ride: EF XR8 5spd

Location: Newcastle
NSW, Australia

Thats pretty high for that speed.
My EL XR8 sits on 2100rpm at 110km/h in 5th with a 3.23 diff.

Do you have 17's on your car? Don't know why there would be any difference between the two??

 

_________________

EF XR8 5spd: 302ci /178rwkw

Top
 Profile  
 
 
Posted: Wed Mar 21, 2007 8:00 pm 
Getting Side Ways
Offline
User avatar

Age: 34

Posts: 2351

Joined: 11th Nov 2004

Gallery: 30 images

Ride: Blown XR8

Location: Melbourne
VIC, Australia

Sorry that was meant to be 2,000rpm at 100km/h.
My mistake!
Top
 Profile  
 
 
Posted: Thu Mar 22, 2007 8:15 am 
Oompa Loompa
Offline
User avatar

Age: 47

Posts: 38

Joined: 27th Dec 2006

Gallery: 4 images

Location: Perth
WA, Australia

Dont worry about pulling your diff centre housing cover just mark your tail shaft and the tyre and start rotating. Always been close enough to the ratio when ive done it this way

 

_________________

XC 396 Scat stroker

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 1  [ 11 posts ] 

Who is online

Users browsing this forum: Google Adsense [Bot] and 14 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 8:59 am All times are UTC + 11 hours

 

 

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