Diff ratios - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

daves8 · 12-10-2003, 21:59

What are the standard diff ratios in the sedan xr8 and gt?

Can they be changed for a different range for more acceleration?

If they are 3.23???? would a 3.45 or a 3.9 make much of a difference?

What does this affect on the car eg the speedo?

bossxr8 · 12-11-2003, 01:33

Quote:

Originally Posted by XR8BOSS

In the auto XR8 the standard diff ratio is 3.23 but you can option the 3.45,In the XR8 manual the only diff you get is the 3.23. I think all the GT`s have a 3.45 but im not sure.
They can be changed .
For example if you change from the 3.23 to a 3.45 in an Xr8 manual you will have a much quicker acceleration but a lower top speed.
Im not sure how it will affect the speedo ,but im sure who ever does it should know.I know in the older cars you just change the small cog at the end of the speedo cable that fits into the gear box.
Im going to change mine early next year hopefully to a 3.7 if possible.It will take a good second off the 1/4 mile time.

The auto XR8 has a 3.45 diff ratio standard while the manual XR8 has a 3.23. All GT's are 3.45. Changing the diff ratio to a 3.7 will not take anywhere near a second off your quarter times.

christo · 12-11-2003, 13:31

carefull now bossxr8,people dont like being told negative things
i say a new diff would put a gt into the 10 sec bracket

FANTM1 · 12-11-2003, 14:25

I believe the speedos can be re-calibrated with the software.

LunaticSVT · 12-11-2003, 19:17

Speedos will be off when you increase the gearing. Of course as Fantm1 stated you can get the speedo recalibrated with software.

Now I dont know, but it is worth a shot. Maybe Herrod can do this. Not sure since I am not over there and am not modding an Aussie car. :\

PigDog · 12-11-2003, 19:22

After putting 3.73's into my EF I used an 'electronic ratio box' under the dash to fix up the speedo signal. They're pretty good as you can alter it quickly if you change ratios again or get different sized tyres, etc. The guy who installed it set the speedo up exactly by driving around with a GPS locater.

bossxr8 · 12-12-2003, 02:35

Quote:

Originally Posted by christo

carefull now bossxr8,people dont like being told negative things
i say a new diff would put a gt into the 10 sec bracket

Thats gold

XRFPV8 · 12-12-2003, 03:06

Quote:

Originally Posted by christo

carefull now bossxr8,people dont like being told negative things
i say a new diff would put a gt into the 10 sec bracket

hi christo, negative statements and insulting people are two different things ...
10 sec bracket you are just kidding aren�t you ???

XRFPV8 · 12-12-2003, 04:31

Quote:

Originally Posted by XR8BOSS

Yeah i reckon
calling christo on cloud number nine

LOL @ XR8BOSS dont say that or it will be 9 seconds next....

GT-P · 12-14-2003, 17:49

The speed pickup is taken from the tone wheel sensors on the BA, therefore it is not required to change the speedo cog because there is not one to change.

No recalibration would be needed unless you are changing the overall O.D. of the tyre.

Hope this helps.