what diff to use

[dazza 3]

Hi I'm build a XD drag car running a 250 crossflow engine no injection or forced induction, I'm trying to decide what diff to run and what ratio. I think a 9 inch would be to big and heavy.  Would an xr6 turbo diff out of a BA or BF ute fit and XD.  

[slydog 7,873]

Are you going to use a transbrake or foot brake the car ? If no put a E series wagon diff in it and you will not brake it.Thats what I use and mine shows as good as 400hp @ the crank to run 115mph plus.Mine runs 31 spline Strange axles and a full spool with a diff hat girdle and is swinging off a tri angle 4 link but other wise I started with a the ED wagon diff and never broke it but I up graded internals when I went to a full spool. 

[dazza 3]

Foot brake at this stage with leaf spring rear I want to upgrade to disc's on the rear and I'm looking for a starting point and I can go from there. I was told an xr 6 turbo limo diff out of a ba or bf would fit. What ratio would be a good place to start. Does the ed rear end have dics and did they come out with lsd.

[gregaust 319]

I think the BA diffs are wider ??

[slydog 7,873]

Go with the ED bud...right length and yes they all have disc's. You don't want a LSD you want a spool cos a LSD WILL flog out and cause issues. From my findings anyway so mini or full spool and depending on RPM HP torque cam convertor and tyre size will determine gearing.

 

I use 4:11 gears with a 26.2" tyre and the car see's 6700-6800 over the line.   

[Thom 6,651]

All e series have disk rear, au to current falcon have a 30mm wider diff Than xa- el e series from ea series 2 ( easy to tell by the flat flange on the front of the diff ) to el have 28 spline axles and 4 pinion centers

[slydog 7,873]

Ratio would need to be 3.7 atleast id suggest.

[dazza 3]

Anyone have a good used gear set for a borg warner diff in 4.11 ?

[slydog 7,873]

eBay bred...or some diff shops but be warned you W I L L have to pay for em. People know how hard they are to find now days unfortunately

[PRO250 1,506]

I have a ED diff LSD in 4.11s blow the brakets  off it and fit leaf pads and it will work in yours

use to be on my XR before I boosted then I want back to 3.0s so it would not blow the tyres away as it came on boost

[dazza 3]

I have found an ed diff and tail shaft now can any one tell me do all c4 boxes need a 28tooth yoke to adapt the tail shaft ?

[slydog 7,873]

First things first,is yours a sedan or ute? If sedan you need a sedan tailshaft if ute you need a wagon or ute tailshaft.

 

2nd the tail shaft will fit in your C4...I use a XH ute tail shaft as it's steel which TBH is a better option over the alloy units if you are planning on racing it.

[dazza 3]

Xd sedan, the car is unregistered  as it has been fully stripped out and lightened with a 6 point cage. I have found a good ED diff out of a station wagon, now I need the tail shaft .

[NZXD 2,328]

Xd sedan, the car is unregistered  as it has been fully stripped out and lightened with a 6 point cage. I have found a good ED diff out of a station wagon, now I need the tail shaft .

 

All you need is a ed-el sedan drive shaft...until you make enough power to break it.

[dazza 3]

Going from a drum rear end to a dics rear end do I need to change the brake master cylinder or can I use the standard one ?

[gerg 10,871]

Going from a drum rear end to a dics rear end do I need to change the brake master cylinder or can I use the standard one ?

 

I did this in my wags and found out that the master has no check valve, so yes the standard one will work.

[Ants 6,370]

My wagon has been running an xd master with ed diff since it was built and has very good pedal feel.