Fordmods Logo

3.45s to 4.11s? 

 

Page 1 of 1 [ 7 posts ] 

 
 Post subject: 3.45s to 4.11s?
Posted: Fri Feb 20, 2009 11:54 pm 
Smokin em up
Offline

Age: 33

Posts: 256

Joined: 27th Jan 2008

Ride: WS Ford Fiesta CL manual

Location: Melbourne
VIC, Australia

I'll possibly be buying either an XHII XR6 or EL XR6 manual Falcon in a few months, my first upgrade planned is diff gears, I'm thinking of changing out the stock 3.45s out for 4.11s when i get the car. How much of an improvement will it make?

What will i be revving at in 5th at 110km/h? 90% of my driving will be highway.
Top
 Profile  
 
 
 Post subject: Re: 3.45s to 4.11s?
Posted: Sat Feb 21, 2009 12:38 pm 
Getting Side Ways
Offline
User avatar

Age: 35

Posts: 540

Joined: 9th Aug 2007

Ride: FG Ute, ED XR8 Sprint, GPZ900R

Location: Leopold, Geelong
VIC, Australia

I personally wouldn't put 4.11's in a manual, you wouldn't even use first. 3.73's are probably better suited for a manual

 

_________________

The Past: EF Fairmont, EL Fairmont 5.0, HR Special, NF Fairlane 5.0, GSX 250-F, BA II XR8, VS3 Ute, VS2 L67 Calais

The Present: FG Egas Ute, ED XR8 Sprint, GPZ 900R

Top
 Profile  
 
 
 Post subject: Re: 3.45s to 4.11s?
Posted: Sat Feb 21, 2009 3:14 pm 
Getting Side Ways
Offline
User avatar

Age: 35

Posts: 1448

Joined: 17th Apr 2008

Gallery: 3 images

Ride: VY Commodore Wagon Accli

Location: Bannockburn
VIC, Australia

Personally I would stick with the 3.45's, as if you jump right up, not only will you ever use first gear in the manual, it's not suited for it either, your speedo will be way off, and highway driving, well, I would say that the revs would be in the 3000's or there abouts.

 

_________________

Pre AU Adapters for sale

Successful Trades with: John_XR6 (John_LS1), Private9, Schmee, Manari, Kyle_Bardell, Greenhorn (Boostedfalcon.net), FTG AUTO SALVAGE, EVL098, Gogetta, EFIII, Krytox, Blue, Smik-EL, TP351.

Top
 Profile  
 
 
 Post subject: Re: 3.45s to 4.11s?
Posted: Sat Feb 21, 2009 3:25 pm 
Smokin em up
Offline

Age: 33

Posts: 256

Joined: 27th Jan 2008

Ride: WS Ford Fiesta CL manual

Location: Melbourne
VIC, Australia

Would the 4.11s make first useless? Or would it go up to 20km/h or so? Or do I just take off from second gear? I'd be after a faster 0-100 time, I hear diff gears help with that. But I think spinning at about 3000 RPM would be a bit much for highway driving.

Speedo could be corrected with that kit from Jaycar I suppose, so that isn't really an issue.

But if i did change diff gears, 3.73s would be the most ideal? Would that be much of a step up from 3.45s?
Top
 Profile  
 
 
 Post subject: Re: 3.45s to 4.11s?
Posted: Sun Feb 22, 2009 11:50 am 
Parts Gopher
Offline

Posts: 86

Joined: 20th Apr 2008

Location: perth
WA, Australia

hey mate iv just put 3.89's in my el xr6. they are a great ratio the car feels awesome!
1st gear is still very usefull, still get to around 50k's with it, and really really fast!

i bought the jaycar kit and it works very well, sitting on 110 im reving at about 2700. the car doesnt seem to mind it at all, still cruises nicely

 

_________________

El xr6
14.268 @ 96.77mph--- motorplex 4/3/08

549 crow cam
chiptorque chip
pacemakers
hiflo cat
cai w/ k&n panel filter
3.89:1 diff gears

Top
 Profile  
 
 
 Post subject: Re: 3.45s to 4.11s?
Posted: Sun Feb 22, 2009 11:56 am 
Getting Side Ways
Offline

Posts: 6113

Joined: 8th May 2007

i had 3.73's behind an EA manual box and 1st gear was a bit of a pig around town, but went like a cut snake. In the end the super short ratios were enough to make me sick of driving a manual.

but with the later model T5's having a longer 1st and taller 5th, i reckon 3.73's would be ok and would not go any higher in my opinion.
Top
 Profile  
 
 
 Post subject: Re: 3.45s to 4.11s?
Posted: Thu Mar 19, 2009 9:42 pm 
Oompa Loompa
Offline
User avatar

Age: 35

Posts: 35

Joined: 9th Mar 2005

Ride: AUIII XR8 ute

Location: melbourne
VIC, Australia

easy way to convert diff change in RPM is: take the current RPM@ 100kmh divide by the current diff ratio, then times it by the ratio you want

Mine is 2050Rpm @100kmh with 3.45
it would be 2198rpm @100kmh with 3.7's
Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 1  [ 7 posts ] 

Who is online

Users browsing this forum: No registered users and 135 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 Fri Nov 15, 2024 4:56 pm All times are UTC + 11 hours

 

 

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