Compatible rear differentials.

[vr4cobra]

Ok so I have been doing a little research into a compatible rear diffs for my Galant (AYC Diff). Basically I am aiming to run some decent power about 330awkw/450awhp is my goal. I am currently waiting for parts for my brake upgrade then the next step will be to upgrade to a stronger diff before my current one gives up and further power mods continue.

So with the research I have done so far I have come up with a few diffs that are possible. I am unsure on how accurate these are but here is my findings..

EVO X Rear Diff
Details - (AYC + Factory Fitted Helical LSD) with more solid casing
Apparent modifications to fit - Larger drive shaft requires some machining internally to fit into vr4, Subframe requires slight modifications
Evo 8-9 S-AYC Diff
Details – Upgrade/stronger than standard AYC setup
Apparent Modifications to fit - The front brackets, tailshaft bolts, YAW lines all bolt in, the driveshafts slot in. Requires 10mm spacers on the rear mounts. Requires 4x4cm section cut out on the rear subframe for the YAW filler plug near the original filler hole. And there is a little 12mm allowance cast into the Evo diff casing that needs to be cut off to not foul on the VR4 subframe.
Evo RS Diff
Details – LSD mechanical plate type
Apparent Modifications to fit - RS Diff install kit for evo 5-9 with 10mm spacers for rear mounts and non-AYC axels.
ST-R or type V diff
Details – Open centre, non-AYC as Standard
Apparent Modifications to fit – Remove AYC system and directly bolt in place with non-AYC axels .
Upgrades – RS LSD cartridge bolts into diff housing
Diamontae/Magna AWD Diff
Details – LSD mechanical plate type, the same as the EVO VI RS
Apparent Modifications to fit - Requires 10mm spacers on the rear Diff mounts similar/same as installing an S-AYC Diff.
**UPDATE** I fitted a AWD Magna rear diff and Axels to my Galant 2 weeks ago now and is going great so far. Only required 10mm spacing on the rear mounts of the diff and everything else bolts up.**UPDATE**

Can anyone elaborate or correct anything I have above? Also any recommendations to what will more then likely handle my goal power level?
There is a few threads on rear Diffs but nothing all together so for ease of use I thought I would combine them all into 1

Also if anyone knows of stronger alternatives for Transfer Case etc. please add to it

 

[AKKO]

Haven't yet heard of a broken Type V , but something Evo centric seems the sensible path.

 

[unclepaulie]

go the magna

 

[it's.simon]

Is this the rear diff? What would the benefits be of a mechanical plate type over an open one?

 

[trotty]

Is this the rear diff? What would the benefits be of a mechanical plate type over an open one?

Open diffs spin 1 wheel. LSD spins both

 

[VOLK]

Yep, rear diff. With my basic knowledge I assume open will just put all power to the path of least resistance, plate will proportion drive to both depending on the centre type & lock up. One scenario I can think of is cornering, if you unload one wheel mid corner, it'll receive all the drive and spin. Ideally need to push that drive to an outside wheel (with traction) to help rotate the car.

 

[Kenneth]

The benefit of STR or Type V is that usually it isn't a big hassle to get the rear axles off the same car.

I got my first diff from a Magna/Diamante but then had to source the axles separately. That was a pain.

 

[smohekey]

I don't think you can go from AYC to Open or LSD without also changing the axles. In both cases, you need axles from a Type V or ST as the ones that come from the RS/Magna are different. I'm not 100% on this. IANAL.

 

[vr4cobra]

if they are the same length couldn't just get the axels from a magna and change the inner cup? Read somewhere the evo boys doing this when they convert to a vr4 rear diff, use there original axels with the vr4 inner cup

 

[naughtika]

from what Ive read, magna axles do work in ours, if used with the magna diff of course..

not sure if the magna axles work on teh evo RS diff

 

[smohekey]

I know that the Type V/ST axles and open diff casing work fine with an RS diff inner.

 

[mills_88]

With that power level I would be leaning away from the AYC diffs as the aluminium housings aren't very strong. Can confirm you need both new axles for swapping from an AYC diff to a Type V diff but not sure about the Magna diff.

I imagine so long as the wheels have roughly the same track (+/- a couple of mm) and the diff sits in the same place that it would work.

 

[vr4cobra]

tbh I was leaning away form AYC and more towards the magna LSD. From what I have read the magna diff is the same as an evo VI LSD just slightly different housing, but same time havnt heard of any evos changing to the magna rear diff so I am unsure what is involved or how strong they really are

 

[Tophler]

I think i'll be going an evo rs diff. Can anyone shed any light on the front diff? That will be the first one I will be changing if it is indeed possible. Has anyone done it?

 

[Dice]

Front diff can be done but the evo front helical lsd is rare. There is some info on club vr4 forums.

 

[vr4cobra]

The benefit of STR or Type V is that usually it isn't a big hassle to get the rear axles off the same car.

I got my first diff from a Magna/Diamante but then had to source the axles separately. That was a pain.

could you share a little more info on fitting the magna diff? Did it only require rear spacers and the magna rear axles?
I will be going either RS or rallyart magna front diff (both LSD) but I think my rear diff is the first weak point so want to change that first

 

[pretzil]

Can anyone tell me about the 10mm spacers for s-ayc? Is it a specific part, custom, or just some washers...?

 

[vr4cobra]

http://www.ozvr4.com/threads/evo-rear-diff.11355/#post-232306

 

[smohekey]

I think i'll be going an evo rs diff. Can anyone shed any light on the front diff? That will be the first one I will be changing if it is indeed possible. Has anyone done it?

http://www.evoparts.co.nz/ here in Christchurch usually has good luck in tracking them down (I know of about 5 people in NZ that have acquired a front helical diff through evoparts. Jeremy is a top bloke and will upgrade the bolts on them for you too.

 

[Dice]

Front LSD has a different gear ratio, is this a problem for front to rear ratio? Some Evo people change the crown wheel & pinion to retain factory gear ratio.