simon,

as carlos stated, the bumer just refers to the size of diff.

180 is 180mm.

as john said, early type rs (version 3) were 160s.

most later sti type rs and ras came with r180s, not all as there are exceptions to every thing as far as impreza specs are concerned.

all you need to knwo is you have an r180 size rear diff which is of the plated variety and is v aggressive. It is also the toughest of the standard available drivetrains when combined with the active centre diff (the dccd).

you are already equipped to be tougher than all other standard imprezas.

you can strengthen things by fitting a front quaife diff, and centre and rear modenas. But this will affect your handling and with your sideways skills you probably dont need it.


edited for the benefit of John.

[Edited by Adam M - 2/3/2003 5:33:30 PM]

 

Modena is a company who make high quality dog boxs and also diffs similar in design to quaife ATBs.

They sell diffs for the front centre and rear of imprezas.

Quaife dont currently make their diff for R180 rear diff applications, nor for centre diffs, whereas modena do.



[Edited by Adam M - 5/1/2003 11:28:41 AM]

 

Hi All

Need a definitive answer on two questions with regard to the Type R, 22B and Type RA... I'm hoping they are all the same, but if you only know of 1 for definite, just let me know which one it is your info relates to.

1) What is the torque capacity of the centre diff (when fully locked)

2) What is the actual spec of the rear diff?

Many thanks in advance

All the best

Simon

 

I'm not trying to be funny, but could you not simply ask one of your Prodrive connections? They ought to know.

 

did prodrive work on the type r, type ra and 22b road cars then?

As I understand it they only had involvement in the 22B type UK.

Thanks

Simon

 

22b is a replica of the WRC car made from a type R shell.

Prodrive built the WRC car, based on a type R I believe.

Prodrive prepared group N cars based on type R and/or RA cars.

Therefore, I think its reasonable to suggest that they might know about these things, despite not working on any publicised road car variants with the diffs in question.

Your contacts at Prodrive could, at the very least, confirm to you that they don't know anything about these units. At least thats a start.

 

my contacts at prodrive have confirmed to me that they don't know what the diffs are. I'm sure someone in the rally team would be able to find out, but the cars they build have very little of the original components in them. As I understand it, they have a seperate company that strips and delivers the shell to them (Not official, this is only as I understand it).

Certainly the people I talk to regularly do not know what diffs are in the cars mentioned.

Anyway.. do you know / know where to look for this info?

cheers

Simon

 

simon, also they worked on the P1 which for their needs required them to ditch the R180 rear diff.

To my knowledge, barrats rate the locked centre diff to over 450lbft but I dont know how much experience they have of cars with those kind of torque levels.

The quaifes can certainly handle that kind of level, but worse case scenario you could source a modena from mark aigin for the r180 or 160 rear diff housing that would handle whatever you threw at it without question.

same goes for the centre though you should be ok to most levels unless you are going monster.

Should be putting 550 through mine, so will let you know how it stands the test of time.

 

Hi Adam

Thanks for the excellent info on the centre diff. So 450 is the answer to question 1.

Remember how thick I am on this stuff though!! LOL Do we know the actual spec of the rear diff... (pretend I don't even know what it's called - because.. erm.. that's actually the case!!).

Also.. are they the same diffs on all 3 cars?

Cheers adam

Simon

 

Prodrive also sell customer spec GroupN cars, they will have the info you need on the diffs.

The 22B typeUK is identical to a normal typeR rear diff except they changed the final drive ratio. Centre diff is identical to a normal 22B or TypeR/RA.

The TypeRA has a mechanical front LSD, most Type R's dont, not sure if the 22B had a front LSD or not? There were 2 versions of front LSD used in the TypeRA as specced at the factory, the STi5 has the later of the two specs.

This info should be readily available within prodrive as they have worked and and sold these cars to privateer rally teams under groupN, where they import the cars complete then prep them. They now sell and prep TypeRA Spec C group N cars.

 

Hi Chaps

Thanks for the info john. As I said, I'm sure someone in the rally team will have access to the info, but I don't work for prodrive and this is not prodrive business that I'm discussing, so I can't really ask them to drop everything and look for it.

Was just hoping someone would know (as Adam did on the centre diff).

Don't suppose you know the specs of the rear diff do you john?

cheers

Simon

 

Apologies Simon,

I was just trying to help.

Being that you asked explicitly for definitive answers on these questions, the facts and figures I am in possesion of of could lay my hands on are not necessarily quite what you were looking for.

I was confident that Prodrive would have the definitive information you were asking for, and could help provide really definite imperical figures on the units.

I am now aware that "i have been told X" would have been accurate enough to make it "excellent info" that fits into your "definitive" answer specification. Evidently we are singing from different hymbooks on that one, hence I apologise for having wasted your time.

 

LOL

no time waste moray. Thanks for trying!

 

i dont have the loading mate, maybe mark aigin at lateral performance has them to hand, why dont you mail him?

The rear diff isnt very strong in rally aplications and quite often the diff housings are replaced with steel items, i would expect the replacemnt supliers will know the rough loading rates of the stock kit, i doubt subaru have released that info to the general public. so your best bet is people like mark who now import the autralian unbreakable gearkits and diff units.

 

simon, never taken the rear diff apart but to help you, there are two versions r160 (160mm) or r180 (180mm).

obviously the larger diam can handle more grunt. all r180s as standard were a plate type lsd, which has much sharper lock up characteristics for gravel stages.

r160s were viscous coupled lsds apart from the sport which was an open rear diff ie geared.

The plate type diffs by their nature should be a tough construction but I have never operened one.

I know that the r180s are coupled to larger diam drive shafts as they are intended to handle greater torque.

what has brought on this question?

 

i believe the P1 uses an R160 plated diff unit.

 

John

damn fine idea on contacting the people who replace them.. I'll give that a go.

Adam

top info again... The rear diff on my type r is incredibly agressive, so I'm assuming it's the r180 type???? Are you saying that both the r160s and r180 are fitted to RAs Rs and 22Bs or that they are the 2 type of diffs installed on STi's in general but possibly only one of those types is ever fitted to Type RA's (for instance).

Hope you get what my babbling means!! LOL

cheers

Simon

 

sorry adam.. forgot to answer the "what's brought this on"...

just trying to decide whether the diffs would cope with an auto system under extreme condition.

 

Let's get one thing a little clearer, R160 and R180 are the names of the diff not the LSD's. The R180 is a bigger diff (the housing is bigger, bigger axles, etc.) but you can fit an aggresive LSD to both the R160 or R180.

Carlos H.

 

Simon, the TypeR/RA and 22B (which is basically an STi4 typeR) have the same rear diff unit, an R180 with a plated LSD. The centre diff is the electomagnetic DCCD unit. Front diff is either open or one of two types of mechanical LSD depending on year. torque split is 65R/35F.

The UK spec Impreza, including the P1 and non TypeR/RA STi's have an R160 rear diff unit. These are viscous diffs except the P1 which is plated. The centre diff on these cars is also viscous. The front diff is open. torque split is 50/50.

Carlos is correct the R160/180 refers to the diff casing/size of diff, not what type of LSD is in there.

Thats my understanding.

[Edited by johnfelstead - 1/31/2003 6:05:19 PM]

 

OK.. now we're getting somewhere...

So.. All rears are R180... are we also saying then, that within the R180 there could be lots of different options as to what kind of LSD is in them? (I really don't understand this stuff do I! )

If so.. do we know what those types are, and which one has which!!???

cheers

Simon

 

Simon, we are giving you too much info to digest. LOL

All TypeR/RA cars use the same R180 plated rear diff assemblies.

edit to say that some of the very early TypeR/RA may have been built with an R160 diff, that i am not 100% certain of.

[Edited by johnfelstead - 1/31/2003 6:14:50 PM]

 

LOL

What I was refering to was carlos' post saying that you can fit different types of diff to an R180?

If I was to go to an engineer and say will x work on an R180 diff.. will that tell him what kind of diff it is? (sorry for being thick) I assume that you would need to know what kind of diff it is also?

cheers

Simon

 

well, the R180 diff is actually a nissan diff unit used on some of the Z cars.

In the Impreza aplication The R180 diff always has a plated LSD unit, just like in your TypeR unless someone has stripped it and used an aftermarket LSD/diff cage.

 

AHA!

OK... so R180, plated LSD?

thanks john

 

Can I just tag a quick question on the bottom just to lay that cat to rest, are there markings on either of these Diffs to distinguish them, ie is R160 stamped anywhere on the unit??

 

no probs simon, i'll have a look at my diff in the morning.

 

thanks a million chaps.

JUST the info I needed.

All the best

Simon

 

That's wrong Adam, the V-Ltd is identical to non V-Ltd mechanically, except SOME of them have a higher 5th gear. The TypeRA V-Ltd does use an R180 rear diff.

 

sorry john but you are wrong too.

look at morays cr and formerly lou c's car. both were sti 3 type ra v lims, both with roof vent and neither with a dccd or an r180 rear diff.

There are no hard and fast rules about this, and I am well aware that yours and mike ts old car, as well as mellows old car were all v lims and all had r180s, just saying that of the type ras, it is the v lims most likely to have the r180 as most of these were respecced up to pre ra spec, ie re adding abs and leccy stuff.