Having a standard 3.62 rear diff in my escort, what would be better to go for?

a 3.62 sized quaife diff or a 3.9?

what pro's or con's would i experience by changing to a 3.9?

Cheers in advance

 

3.62 ratio is a put in and forget option, acceleration / topspeed will remain the same.

3.9 ratio will require you change the front diff / CWP to 3.9 OR use step off gears+chain in your gearbox, either option will stop the centre diff from burning out because of the different ratios from front to back. Acceleration should be faster (or slower due to wheelspin ) but top speed will decrease.

 

I'm going to be changing to a 3.9 rear, far better for track use. Its never going to hit 205mph on a track so I might as well drop the ratios and use the gears better

Apparently it gives the gearbox a far easier time, although I'm not clever enough to understand why

 

That'll be the same as me then!!!!

so if i changed my rear diff to a 3.9 what sort of top speed reduction would i see, im not greatly worried about top speed but want to gradually head more towards track days etc next year!

Also what would a front diff cost to match? and if i didnt change the front diff would i really cause major problems?

Ta

 

imagine filling your rucksack up with bricks (or mars bars) then trying run up a near vertical run of stairs.............. then do the same with more stairs and less of an angle, easier on yer legs eh?

 

With 8x18" wheels running 225/40 tyres, std gearbox, and a revlimit of 7600 rpm your theoretical top speed is 188.78mph running a std ratio.

Same setup running 3.9 ratios is 175.23

Yes you will damage the centre diff. As i said before, you have 2 options, either replace the CWP in the front diff to 3.9 OR get a step off gear+chain to go in the gearbox, either option means the centre diff will work.

 

std 3.9 front diffs are apparently very weak... better to use step off gears

 

Cheers Wes, i did get what you meant, just wasnt sure to what extent it would damage things or if id be ok temporarily running with a larger rear diff!

But i get the impression i shouldnt go that route until i get the front sorted out aswell.

Any ideas where i can get a CWP for the front diff in 3.9 or the step off gears and what costs?

Could bernie be a man to spk to here?
or could you help martin?

Cheers

 

MARTOOOOON! What the hell are you doing on here during the day!?!?!?!?!

 

day off building wardrobes

 

techincal stuff then

i fookin hate flat packs

 

I have no idea how much it would cost for the step off gear / chain, but there was a post about it a few months ago:

https://passionford.com/forum/viewto...712&highlight=

You really need to do it all at once or not at all though

 

LOL, Cheers Dave, i doubt it'll make that kind of difference but ill take the head start and get the tea's in for you