Which Diff Is Best 3.62:1 Or 3.92:1

[Guest phil howard]

I now have both 3.62:1 or 3.92:1 differential, however I am not sure which one to use with my Zetec engine (soon to be fitted to my Zero).

 

I live in darkest Aberdeenshire and the roads are nice and twisty and hilly which leads me towards the punchy 3.92:1 differential, however there seems to be several people who seem to prefer the 3.62:1.

 

Any thoughts?

[Guest Ian & Carole]

Phil

 

It really does depend what YOU want from YOUR car.

 

Twisty lanes and hills, trackdays with a high free reving engine then 3.9 is the way to go.

 

If like us you intend to do any touring in the car ie. Le mans, The Ring or motorway trips to and from shows etc then 80mph @ 4000 RPM.makes the 3.6 nicer on the ears, fuel and engine.

 

Not really an answer just my thoughts

[Guest phil howard]

Phil

 

It really does depend what YOU want from YOUR car.

 

Twisty lanes and hills, trackdays with a high free reving engine then 3.9 is the way to go.

 

If like us you intend to do any touring in the car ie. Le mans, The Ring or motorway trips to and from shows etc then 80mph @ 4000 RPM.makes the 3.6 nicer on the ears, fuel and engine.

 

Not really an answer just my thoughts

 

Thanks...........at least by having both I can try them both out.

 

PS see you at Newark on Saturday

[Guest Ian & Carole]

Phil

 

I will be there from mid-afternoon on Friday right through the weekend.

 

See you Saturday, make sure you come and say hello.

[Guest gordon_macnab]

I've had both on my car and found the 3.62 to be the nicer one , the 3.92 seemed to be too thrashy for my liking, it will give the better acceleration but I don't really have any problems in that department

[Bob Tucker]

I have both too. I expected to keep the 3.6 when I fitted my XE, but I found that I rarely ever used 5th.

I have a BGH gearbox with a very high 1st gear, so I changed to the 3.9.

All 5 gears are now usable.

Only drawback with a standard box & the 3.9 is that 1st becomesa lmost redundant.

HTH Bob

[Guest diyer]

It depends on your gearbox and ratio's too.

I had a 3.92 in my lightweight, paired to a mt75 gearbox and a 2.0l zetec. My experience was that 1st was a bit of a waste of time, it would accelerate away just at quick taking off in 2nd, as using 1st, not having to worry about another swift gearchange 10yards down the road.

 

Simon

[Guest old_timbo]

Also need to take into consideration the rolling diameter of your wheels and tyres. Mine worked out roughly the same as on a standard Sierra which meant with a 3.62 diff it was running repmobile gearing, IIRC about 145 mph at the (pinto) red line in 5th (standard type 9). It felt sluggish and 5th was pretty pointless. I changed to a 3.9 and it's much better, 60 mph in second and cruises well at 80 ish.

 

Tim

[Guest salty_monk]

I like the 3.92 with the Pinto but it does make 1st a little low... If you have big power in the Zetec you might be ok/better with the 3.62..

 

One other thing that made a difference for me... cycle wings. At high speed with the 3.62 the clamshell winged car I had really ran out of steam, when I went back to a 3.92 it was like a different car.

 

Dan

[Grizzly]

Just checked mine on a recent Track excursion

I have the 3.92

Revs at 3250 @ 80mph

 

Don't forget that this is std. If you go for the 3.62 your speedo will be out.

[Guest phil howard]

I have both too. I expected to keep the 3.6 when I fitted my XE, but I found that I rarely ever used 5th.

I have a BGH gearbox with a very high 1st gear, so I changed to the 3.9.

All 5 gears are now usable.

Only drawback with a standard box & the 3.9 is that 1st becomesa lmost redundant.

HTH Bob

 

3.92 diff arrived today.........................just working on a plan to convince the wife I need to invest in a BGH gearbox. Timing is everything.