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BA XR8 What to do with the Diff gears??

14K views 11 replies 10 participants last post by  GLENNL1977 
#1 ·
Hey everyone,

If you were to change the Diff gears in a Manual XR8 what would it be? I was thinking 3.70, because its manual
if i read correctly it comes out with 3.23, any comments??

also if i did happen to change the Diff gears how would i configure Speed dial as it would be out by a fair bit

(however, auto comes out with 3.45 so i was hoping the instruments would be easy to re-configure)

Another Question while your reading
If i was to lower the XR8, would i need a camber kit??

Thanks guys (and gals)



Note:
okay, well i should be getting my XR8 on Thrus (12-June), hopefully this dealer doesnt follow the horror stories i read on this thread
 
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#4 ·
Well when you change the diff gears, what happens, or what used to happen in all the cars i had, from VN SS, VS SS, VS Senator, FOrd Eb and EF XR8, whenever i changed the diff gears, the speedo would read arouind 120km.h and id be doing only 100km/h
 
#5 ·
you will generally need to change your speedo as the pulses per kilometer will change

whats the ford techs use thats equivelant to a the gm tech 2, im guessing that it should be achiveable maybe a dealer can do it for you

given that some of these puppies are going to the police and they regularly calibrate there speedos it cant be to hard
 
#6 ·
From what I am lead to believe, there are currently no 3.7:1 diff gears available for the new Dana diff as used in the BA XR8. The speedo is read as an average of the speed of all 4 ABS sensors in the vehicle. So if gears become available, speedo is not an issue.

Happy hunting
 
#7 ·
just get the 3.45 gear set out of the T3 and the speedo drive for a T3 all ford spare over the counter and your speedo will read spot on the car will be a lot snapperer off the line and through the gears might even be as qwick as a T3 ...hope this helps
 
#8 ·
sbutler said:
just get the 3.45 gear set out of the T3 and the speedo drive for a T3 all ford spare over the counter and your speedo will read spot on
I bags a front row seat to watch you try and fit BW 78 series gears into a dana diff! Also, T series run an electronic pulse ring speedo sender, and ABS equipped BA run no VSS unit at all.
 
#9 ·
Well, I'm ahead of you on this one.

I have a Pursuit with the 3.23 diff. I am chasing a conversion and to date the only available gears are the 3.45. This involves changing the diff gears, however you will also need to download the matching ECU program for your engine/trans combo with that diff ratio.

So, in my case I will have a manual Boss 290 with 3.45 gears. I need to download the ECU program for the GT manual.

I created a thread in the FPV area on gearing and giving speeds per 1000 rpm etc. Go have a look - I agree that 3.7 looks ideal.
 
#10 ·
Yep thats right AP you will have to download the correct program as the BA does not have a speedo sender unit, it picks up pulses from the ABS sensors and equates the speed and sends it to the instrument cluster.

Elmer Fudd
 
#11 ·
BOSSGT said:
Yep thats right AP you will have to download the correct program as the BA does not have a speedo sender unit, it picks up pulses from the ABS sensors and equates the speed and sends it to the instrument cluster.

Elmer Fudd
Umm. Not quite correct. The ABS signals will not change since the wheels turn at the same rpm. the reason for the ECU program change is to ensure the engine calibration to road speed relationship is correct. Without this matchup strange things might happen to idle speeds, stalling etc (like earlier Delco Holdens).
 
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