I'm trying to decide what front diff to use in my Escort, ideally it will be one from a production car that can be bought for a reasonable cost but it does need to be pretty strong too. I have considered an R33 Skyline unit with an aftermarket lsd as its quite compact but am unsure of what sort of power it can take and can't even find out what size the crown wheel is, anyone know? Obviously I need to be thinking about matching the ratio to the rear but I will think about that after!!

I'm prepared to consider any diff if any of you have any other potential candidates in mind, I'd prefer to integrate it into the sump but could remote mount it on a frame if needs be, it has to fit on the drivers side.

Any better ideas??

 

What crownwheel do you need ? I think the earlier Skylines use a high 3.x range and their drivetrains are robust.

The later R34 stuff is in the 3.5x range...much better IMO. The R34 front diff is integral to the sump.
I think I posted pics of that before where the guy was fitting one to an old Celica ?

Other option is a normal IRS rear diff, inverted. Same F/R

 

As far as I'm aware the 32/33 share the same ratio which is something like a 4.2, the R34 is in the high 3s I think. I'm using an R33 gearbox so either would do but obviously I need to think about the rear matching. I know they're integral to the sump, I have built a few but never measured the sump or cwp size. Your other option is in my mind too. I'd be interested to see how big a BMW X5 front diff is because that shares the same ratio as a Cossy!

Theres a Lambo Gayardo front diff on ebay for £1600

 

Would a delta Evo diff or lancer Evo IV or are they limited to what power they can take

 

They're both transverse applications

 

r32/r33 front diffs are dirt cheap aswell martin should get a stock one one for couple hundred quid or so.

 

Oh yes soo they are ��

 

Yeah there's a sump and front diff on ebay at the mo for £175, could Ideally do with having a good look at one first though.

 

why dont you use the 2wd rear diff internals and make a housing should be quite easy to do then you can package how you want and have ford output flanges etc and have 71\2 crown wheel

 

Is your diff the 6.5 or 7.5. Or is it running something outrageous

 

I did think about that but I reckon it would be harder than you suggest (for me anyway!)

 

just machine the parts to hold bearings etc then fab rest as its only there for mounting points and to hold oil

 

I have always wondered if the subaru 6 speed unit could be fitted as its very strong, but presume its not viable else someone would have done it by now, people are running very high power through them without issue,

 

I'm pretty sure the front diff of an R34 is 3.54 or 3.45, somewhere there. Thats what my mate bought for his standstill project. the R33 etc would just be far far too short for any useful top speed.

On that basis, it would just make sense to use the F/R diff from the same vehicle.

Subaru 6 speed would be no use as it's a transaxle design, mating front shafts to the wheels would be very difficult, Subaru engine sits quite far forwards and can do because it's short.
Audi's manage it too, although they're very long nosed cars.

 

i sold mine mate, id of lent you it for mocking up if i still had it

 

What engine is in? As I thought you sold the YB?

 

I need to know what the R33 ratio is for sure as the 5th gear in the box is tall at around .765 so presuming its 4.2 ratio at 8k that's about 190 I think.

I'm sure there's loads propped up a garage wall up and down the country so finding one won't be a problem other than getting the ratio I want.

 

YB is sold, Lexus 4 litre V8 is going in!

 

From a post on GTR, R33 4.11,and R34 3.565

Most googling seems to back that up.

Not sure about dedicated front 4.11 diffs, but some Nissan 200's will have a rear 4.11, as will some R160 diffed Subarus ( that's the small diff, so may be strong enough in a front application...or may not )
I think the 200's use the R200 diff, which is obviously bigger.

 

silly question but you going the twin turbo route martin? what power you going for?
think this calls for you to put a rebuild thread up!

 

Thanks for the info Stevie, I can buy a shorter 5th so the R34 would probably the one to go for even though its rarer to get hold of. I'm thinking of making a pattern sump so that I can have one cast rather than welded up.


It will be turbo'd for sure (no point otherwise ) by whether its single or twin will have to decided when I see what sort of space I have, powerwise it needs t0 start with an 8 or more.

 

With boost and that engine....really, having a tall 5th gear will not be a problem.

From a simplicity point of view, I'd go for a big single. Manifolds dont need to be fancy, just functional, and all you'll need is a 2" or 2.25" max link pipe from one side to the other. A Single simplifies air filters and boost plumbing too.

With 255/40x17 and the 3.27 rear I seen 200mph at about 6700rpm. With a 3.55, I'd have needed about 7400rpm to achieve it ( 0.74 5th gear ), which with my engine would never happen.

So I'd say the 3.56 would be close to ideal, depending on your tyre sizes. But with lots of power and torque, shorter gearing is of little benefit.

 

cant wait to see it back in action! are you looking to break your previous top speed record?

 

That's a secret Hahaha!

 

Yep I reckon this engine will be way less fussy about tall gearing thats for sure, my tyres are 275/35x18 on the rear so at 7500 rpm Id have 210mph

 

Go too short and you risk that top speed being way off peak power/torque, so likely you'd never be able to hit it.

IMO aim peak power for your desired target speed, gives you more chance of actually hitting it when the going gets tough. It may still carry a few hundred rpm after that anyway

But it will definitely be easier than the 2.0 simply due to the wider spread of power and torque.

If you needed a little more or less gearing, it's just a tyre change away. But safer to aim for tall gearing. More boost/power can make up the difference.

If gearing is too short, you're screwed lol.

 

bit tricky on the front to rear matching Martin, not like anyone does step off, and its tight in there with a different gear setup than the ford.

I ended up matching front and rears and leaving centre standard. though my ratios are up nearer 4.3:1

 

Im just going to say it where is the mondeo and how good would that be with a lexus v8...

 

can you not just use front and rear from the skyline? the rear ones i've seen look easy enough to fit, they look very similar to supra diffs. the front would have to be grafted on, but shouldn't be a major problem!

and 1uz... awesome choice

 

If I end up using a Skybus front diff then the rear will probably follow suit.