Quaife for the 01E transmission?

[90quattrocoupe]

Slight digression but on a similar theme: anyone changed the front and rear diff ratios on the (R)S2 by swapping out items from other models??

Lee,
That is one of the reasons I posted this thread to start with. I also wonder if anyone had led the way.

I am going to start taking a look. I have a 91 90 10v rear diff, a 91 V8 rear diff and an UrS6 rear diff all sitting on the self. The 90 diff is basically the same as our coupes, except the flanges are smaller.

Looking at the family album a lot of the same pieces are the same. Bearings, shims, etc. The 90 and S6 use the same lock up mechanism. The V8 and S6 cases are the same except for mod to the s6 case for the lock up. The inside diff is the same for the 90 and S6. And on and on.

I am going to take apart all three on my bench, and see what will fit in the 90. Especially the torsen out of the V8 diff. I am going to check the play in and out in line with flanges to see what the factory slop is set at if any. Then I well check to see what shims were used.

I have never done a rear diff on any car before, so it will be a learning experience. I am trying to do a house remodel at the same time, so don't expect the results right away. I will take some pictures and post them as I go along.

A V8 torsen in a coupe rear diff would be cheap.

Greg.

[Lee]

Cool. Look forward to it. I am in no rush but very curious and may need it for the future. Have you got the settings to shim the diff to and appropriate measuring gear? If not you might want to look into that before you build you hybrid diffs.

[Lee]

Actually I was leaning more towards: has anyone replaced just the ring gear and pinion to change the ratios without touching the rest of the diff? Are the pinions interchangable and do all ring gears have the same install geometry (bolted interface and pinion centreline proximity).

[90quattrocoupe]

Cool. Look forward to it. I am in no rush but very curious and may need it for the future. Have you got the settings to shim the diff to and appropriate measuring gear? If not you might want to look into that before you build you hybrid diffs.

Well,
I will check my Bentley for the Coupe and see if it say what the in and out maximum is for all three flanges. Barring the book not telling me this, I will check each of the flanges on all three diffs and see if there is a norm. Unless the diffs are bad, and they don't feel that way, I should be able to get an average reading.

I will be using a dial indicator, either magnetic or bolt mounted. I use to use this method for setting the shims on my air cooled flywheel shims.

Any other suggestions or anyone already know the max play for the flanges?

Actually I was leaning more towards: has anyone replaced just the ring gear and pinion to change the ratios without touching the rest of the diff? Are the pinions interchangable and do all ring gears have the same install geometry (bolted interface and pinion centreline proximity).

When I take the diffs apart, I will compare the ring and pinions. They are all approx. 4.11s. We will see if they are transferable. Would be nice. I would have 3 extra sets.

Greg

[Lee]

Are they all 4.11:1? Nothing else used in these differentials? I WILL need taller gearing and there are many options like late 6speed S4 B5 diesel boxes as it is difficult to get the standard mechanicals to crack the 200mph barrier without it...there are quite a few here that can go into the 190's at redline but I know of none that can go higher. Being an engineer I need to assess all options before plunging for a solution. There is one reader on here that is annoyed with his low gearing on his vehicle so he is interested in different diff ratios too just to compare with replacing the whole box.

[maRS2]

True. If your application requires this function then that is appropriate to go this way. The guys who have done this, what are they setting their cars up for? Gravel, Mud or tarmac? The requirements are different for all. I have no requirement for off-throttle locking in my S2.

PS I have no desire to ever enter a scooby Forum!

Your are totaly right when you said that my choice are up to my application and the way I want to go.

I would like to keep 225 width wheel on the 4 corner of the car and not move to larger wheel in the front wich would have been an other option to get less understeer.
I think 225 on all corner with the Lsd seting way that I want to go will come to about the same result as you on dry surface but I will get better alround wether condition because here in the south of france when it rain it rain crazy and with 255 in the front I can't imagine the aquaplaning also I'm going skiing every weekend in the winter ( just 2 hour of mountain twisty road) and I get many time snow and I can't imagine the understeer of the front 255 and I think the 1.5 way back lsd will a lot of fun with lot of sideway drift.

The guys who have done this, what are they setting their cars up for?

They have 400 to 600 hp scooby set for trac on tarmac. on THe EVO it's Original set up to the VI

PS I have no desire to ever enter a scooby Forum!

You could learn a lot from them, they are also a lot of eengineer theyre.
So please stay opened mind and the best eengenire are the one able to think out of the box at least that how i see it with the one working for me

I will look if you guy's can fit the quaif that also fit the 02J trans to rear so that I can fit the KAAZ 1.5 way

Ps Lee I always enjoy reading you constructive and intresting post so nothing about you

[maRS2]

Lee

You are running front 255/35/18 and Back 235/?/18 are those exactly the same Diameter wheels?
If not are you not afraid to get your center torsen diff very quick destroy

[porkkis]

5cyl models are 4.11:1, 4 and 6 cyl models have longer ratio IIRC.

If I were you and wanted a longer ratio, I'd buy a complete B4 V6Q rear diff. BUT front is a bit different story as you have to change the pinion axle of the gearbox and that's a big job!

You can't change just crown OR pinion. You have to change the pair. They're sold as a pair and you should not mix used ones, but only use the original pair as mixing probably makes the diff moan/scream. Believe me.

[porkkis]

Lee

You are running front 255/35/18 and Back 235/?/18 are those exactly the same Diameter wheels?
If not are you not afraid to get your center torsen diff very quick destroy

TorSen will handle circumference difference that equals to that you have brand new tyres on the other axle and completely worn on the other. This makes the diameter about 15mm different and you can count the rest. This is the official guide.

[S2central.net]

I don't get any of these wierd handling affects you guys describe. Got 285bhp but run big tyres with larger rubber up front. I drive it like I stole it generally if I have no passengers in the car and I track it on, and over, the limit. I do no off road stuff except spank it on the country lanes which are sometimes muddy or covered in cow ****. In wet, damp or greasy conditions I get drifting...no oversteer, no understeer. Thing will change with more power, but at the moment it is extremely predictable and surefooted: I like the setup a lot. Took ChrisM out in Scotland for a spin giving it some beans around a few roundabouts with hard left, right, left under power...wasn't on the limit but I think he was surprised at the poise with 2 up.

Lee - Your car and mine have some fundamental differences.

The main reason I get this mega understeer is the crap tyres I been running so long. The new ones should be enroute soon and I really hope for an improvement.

Secondly, you seem to have greatly reduced the cars nature desire to understeer cos of your monster 255s up front. Mine pushes the nose on the limit which causes the fronts to spin and then the centre diff takes a wee while to swap torque to the rear - IF you keep your foot down. I might investigate the same trick with 245/30s when my 225/40s die at the front. Can you get a 255 onto an 8J rim ?

Thirdly - you have better poise on yours with RS2 ARBs - they are on my list. That and my wheel alignment is kakked.

Fourthly - you are undoubtably a better driver than me. A combination of old age and having a family slowed me down something shocking. You probably find it easier to keep your foot in than me when it gets lairy. Something went off in my brain and I find that I just can't throw the old girl (the car) around like I used to. I need something more progressive and easier to drive on the limit than the Torsen mindf*ck that my car exhibits. Hence my interest in a lockable centre diff which would give a lovely 50:50 torque split - which is the tried and tested configuration for 4WD cars in motorsport.

Really hoping my duff tyres, a decent alignment and the RS2 plus w/line ARBs will make me feel better for now.

If I encounter a usable gearbox or rear diff in a scrappy, I'll be happy to have you let the Quaife folk poke at it.

PS - I have the 01E gearbox manual at home which gives all the differential rebuild info (at least I think it has). I can bring it to the garage meet if you like.


Paul

[Greg_S]

Where do salisbury type LSD's fit into all of this?

http://www.houseofthud.com/differentials.htm

Greg

[Lee]

Lee

You are running front 255/35/18 and Back 235/?/18 are those exactly the same Diameter wheels?
If not are you not afraid to get your center torsen diff very quick destroy

255/35R18 Front and 235/40R18 Rear. The centre diff is fine as the tyres I have selected only differ 1% in terms of their revolutions per mile. Forget theoretical tyre calculators as they are too unreliable if you are looking at different tyre makes or sizes on different axles...static diameter and circumference mean nothing as the tyre isn't round with the weight of the car. Revolutions per mile is the key number and you can pick 10 different manufacturers and you will get 10 different values for the same sidewall-marked size. IMHO <1% difference is well within the capabilities of the torsen as this is a regime you would experience with different tyre wear front and rear. Don't worry, I have done my homework on this and understand the fundamentals of Torsen and what it can and can't do. I am not the first to do this on a torsen centre differential car.

[Lee]

Can you get a 255 onto an 8J rim ?

This was comical! 3 guys with 3 tyre levers at my local ATS place. I would never have gone to this place but I was desperate and fair play, those guys were clinical and careful. Full marks...now my fitter of choice (my local branch)!
Porsche have a habit of using slightly undersized rim for their tyres to achieve a certain handling characteristic with certain tyre brands (which they also work closely with). The tyres I use are now standard fit on 911s and several other high end marques. Minimum recommended width for the 255/35 is 8.5" but they are fine once on the 8". It is a biatch to get them on but the guys wer so careful they went on without disctressing the tyre so I am happy to spank the tyres as applied.

[Lee]

Paul - am really happy with the handling. Combination of ARBs, tyres, offsets, and damper settings/specifications. I can drive quick but generally not like a tawt otherwise I would have trashed it by now. I can get it to go from A to B very quickly if needed but I would insist on no passengers and do well for the limited BHP. I just learnt to drive fast in crap cars with no power and no handling and progressed to the S2. Every time a change a setting a re-learn the feel of the car palying around on different surfaces in different conditions and even in a slide or 'moment' you will find my heart rate does not increase one bpm...

[S2central.net]

Where do salisbury type LSD's fit into all of this?

http://www.houseofthud.com/differentials.htm

Greg

Oh thats a nice description !