EA 4speed Auto Diff Change - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

vbman187 · 11-29-2002, 20:57

Just was wondering who on this board with an EA Auto 4speed has had expeirence with changing their Diff.

If so what did you change it too, and how does it feel? Happy? Price?

Does the Computer need changing when changing the diff?

I travel at speeds no faster then 100km (freeways) and normal speed for me around my house is between 50km-80km. How would 3.45 go? Im not a rev head but really would like more on take off, not big on burnouts that's for sure.

i know this is talked about alot on the board but really just trying to get a narrowed down opion from someone in a car similar to mine.

Thanks

Troutman · 12-01-2002, 18:04

I was having a similar conversation the other day, and someone expressed the opinion that a 2.92 ratio (at least with a manual EA) might give best performance down the quarter mile. Most people think that 3.45 is best because the XR6s use them, but the XR6 was a complete package including engine and exhaust work.

The computer will not need changing, but you will need to replace a part (speedo sender?) in order to get an accurate reading.

old_mate · 12-01-2002, 18:19

I have the 3.08 in mine with the 4 speed auto......it will absolutely nail a 3 speed with the 2.77 (both multipoints and in good nick)

I reckon the best diff for a EA being 4 or 5 speed would have to be the 3.23 its just kinda there as being not too tall, or too short.

Having said that, I will probably have a 3.7 or 3.9 when the turbo goes on......

vbman187 · 12-01-2002, 21:39

thanks for your opinions guys

SiX_iN_a_RoW · 12-02-2002, 14:17

Do the 3 speed Auto EA's have a different diff ratio to the EA 4 speeders? I have just converted my stuffed 4-speed to a 3 speed and its faster than any 3 speed EA I have driven

Brent79 · 12-02-2002, 17:58

Garth, R U mad??? a 3.70 diff on a turbo would be crap! Yer turbo would never get time too spool up!

Brent

old_mate · 12-03-2002, 02:10

Why you say that?

Because im going to be running a stockish bottom end and head, im not expecting any fantastic gains in torque till boost comes on (I plan for that to happen at 2500 - 3000rpm and hold thru till 5100, redline at 5500). The shorter diff ratios would allow the car to accelerate a lot better up to when it comes on boost. Im thinking the 3500 grand stall might be a bit too much, might think about 2800 instead, that way she should all hook up just as it spools up some boost.....

I know 3.7 is pretty short for a 3 speed.....but this thing will either waste everyone off the lights or just smoke em to buggery. Should be fun either way.....

imagine the rush of boost coming on if I used a 2.77, 2200 stall with boost coming on at 3500 and peaking at 5000......all 18 pounds......