STI R180 rear diff on an 04WRX?

[UP2MTNS]

I've heard a few times that the R180 rear diff is the one to have for racing....

Do I also need to swap rear STI axles and hubs? Or does this just bolt in? TIA

[I Like It Sideways]

I thought the R180 needed the STi parts as well... Transmission, halfshafts, hubs.

I could be wrong though.

[BlackParis]

Isn't the R180 out of the Turbo legacy?

I know thats just a Limited slip unit, that can be had for cheap.... and everything should bolt right up...

I know the STi diff needs all the STi parts to work...

[L and E Fab.com]

First you need to put in in a box. Then tape the box up and ship it to my shop.

Pairs, you are thinking of a limited slip from the turbo loyals. the turbo legacy rear diff is nothing special.

Up2Mtns
All you need is the rear diff, axels, and STI hubs.

But you want the STI hubs they have stronger wheel bearings then the WRX stock hubs.

[UP2MTNS]

First you need to put in in a box. Then tape the box up and ship it to my shop.

Pairs, you are thinking of a limited slip from the turbo loyals. the turbo legacy rear diff is nothing special.

Up2Mtns
All you need is the rear diff, axels, and STI hubs.

But you want the STI hubs they have stronger wheel bearings then the WRX stock hubs.

axles....check (that's easy)
STI hubs, ok........but will my wrx brakes will fit on those?

thx Erik.

[L and E Fab.com]

wrx brakes will fit on those?

Yes. I have seen STI's running the rear 2 pot calipers and they fit on the GC's, and GD's

But do you really need the R180?

I am running 300 wheel horsepower on a r160 with a clutch type limited slip. with a 34mm turbo restrictor you will not be making alot more then that.

On gravel you have a lot less force applied to your diffs because the inside tire can spin on the gravel.

I would spend the money on the stuff to make it to your first rally event first. Replace it if you break it.

(Cage, Seats, Fire suits, HANS device, fire extinguisher system, tires)

In the words of Pat Richard spend your money on tires and entry fee, seat time is more valuable then car parts any day.

[lorenkb]

I am running 300 wheel horsepower on a r160 with a clutch type limited slip. with a 34mm turbo restrictor you will not be making alot more then that.

Which clutch type limited slip are you using for the r160?

[UP2MTNS]

Yes. I have seen STI's running the rear 2 pot calipers and they fit on the GC's, and GD's

But do you really need the R180?

I am running 300 wheel horsepower on a r160 with a clutch type limited slip. with a 34mm turbo restrictor you will not be making alot more then that.

On gravel you have a lot less force applied to your diffs because the inside tire can spin on the gravel.

I would spend the money on the stuff to make it to your first rally event first. Replace it if you break it.

(Cage, Seats, Fire suits, HANS device, fire extinguisher system, tires)

In the words of Pat Richard spend your money on tires and entry fee, seat time is more valuable then car parts any day.

I agree, this is just a good deal so I thought I'd jump on it......instead of potentially breaking something down the line, then *needing* it and having to pay retail. I hate paying retail.

Unfortunately, its going to be awhile before I spend any $$$ on entry fees.

[L and E Fab.com]

Which clutch type limited slip are you using for the r160?

I am using the L.S.D. out of the Turbo Loyals I have to have the end gears machined to work with the WRX half shafts.

I wish I was running the Cusco 1.5 RS L.S.D. I think it would work better but the stock subaru one has worked very well and has 4 seasons of racing on it now.

[L and E Fab.com]

I agree, this is just a good deal so I thought I'd jump on it......instead of potentially breaking something down the line, then *needing* it and having to pay retail. I hate paying retail.

What is the rear limited slip in the STI R180?

If it is torsen don't waist your money.

http://members.aol.com/solomiata/Torsen-T1.jpg

When a wheel is lifted off the ground on a torsen it will spin the wheel in the air.

In rally you are lifting wheels off the ground all the time.

Up2mtns if you already bought the r180 that is fine, but I would be really surprised if you break the r160 on dirt. The better upgrade would be to go to the STI hubs. and keep the wrx axles and r160 diff.

But you NEED a clutch type L.S.D. in the back of you car you need a very positive diff.

Colin McRae always ran a spool in the back of his imprezas, talk about a positive rear end.

(Sorry Guys I love transmissions and diffs)

[lorenkb]

I don't want to hijack up2's thread (unless he's OK with it) but by all means don't stop talking about transmissions and diffs! The so called limited slip in the WRX is a joke, so any and all alternatives are good to know. Are you still running the stock diff in the front Erik?

[JacksonRally]

Ha spool thats what I'm talking about!!

[UP2MTNS]

I don't want to hijack up2's thread (unless he's OK with it) but by all means don't stop talking about transmissions and diffs! The so called limited slip in the WRX is a joke, so any and all alternatives are good to know. Are you still running the stock diff in the front Erik?

That's totally cool....rename this 'drive train and transmission thread'


Erik...nope, haven't bought it yet. I'm not sure if its a 'torsen'. is that a brand, or a type of LSD? Its on craigslist for $500....thinking I might be able to get it for $400. I haven't seen a new LSD go for less than $900 (and that doesn't include the housing, etc).

[UP2MTNS]

Ha spool thats what I'm talking about!!

what's 'spool'?

[L and E Fab.com]

Ok Here we go...

Types of Limited Slips: Open, Viscous, Torsen, Clutch Type, Spool, Electronic.

Open: What comes stock in most cars. there is no Limited Slip properties to this type of Differential. Will always spin the wheel with the lowest amount of traction.

Viscous: What comes stock in WRX rear end, and some Subaru center diffs. It relies on the properties of a dilatant fluid - that is, one which thickens when subject to shear. will spin both wheels all the time till the fluid over heats. Racing will detroy this style of LSD. Mine did not make it though one rally. It is now melted down as bean cans.

Clutch Type: This diff uses stacks of clutches that keep both wheels spinning at the same time. works wither both wheels are on the ground or one in in the air. Best for rally IMHO. Can be noisy not required in track or auto-x use.

http://www.landefabrication.com/shop/kaazlsd.gif

Torsen: the diff transfers power to both wheels though the use of a series of gears. Works best on cars that will have both tires on the ground all the time. good for auto-x, and track use. not as loud as the clutch type.

http://members.aol.com/solomiata/Torsen-T1.jpg

Spool: It is solid, has no slip at all, noisy and hard to drive. McRae Loved them! Used mainly for four wheeling, and rock crawling competitions where strength is needed.

http://www.marlincrawler.com/images/spool_500.jpg

Electronic: what is referred to as DCCD or Driver Controlled Center Diff, comes stock in the USDM STI 6-speed gear box. also available in 5-speed Impreza STIs'. they do exsit in front and rear differential options but not leagal in any U.S. motor sport I know off. they are also illegal in WRC Group A but did not use to be.

Can be gear or clutch related

http://www.aam.com/image.php?id=229

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More info: http://www.landefabrication.com/shop/kaaz.html

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In my rally car:

Front: Kaaz 1.5:1 LSD
Center: 5-speed DCCD with re-programmable computer.
Rear: Subaru R160 Clutch Type LSD - Would like the Cusco RS 1.5:1 LSD

[409industries]

awesome information. The KAAZ diagram is sweet.

[WRXCMM]

so what kind differential(s) does the wrx have?

[L and E Fab.com]

so what kind differential(s) does the wrx have?

2002-2005 WRX

Front Open
Center Open(ish)
Rear Viscus

[martinus]

Whats the differnce between the viscous and clutch type .. I thought they where the same...

[L and E Fab.com]

Whats the differnce between the viscous and clutch type .. I thought they where the same...

Look at my earlier post. bottom of page 1.

[WRXCMM]

Whats the differnce between the viscous and clutch type .. I thought they where the same...

here's the earlier post

Ok Here we go...

Open: What comes stock in most cars. there is no Limited Slip properties to this type of Differential. Will always spin the wheel with the lowest amount of traction.

Viscous: What comes stock in WRX rear end, and some Subaru center diffs. It relies on the properties of a dilatant fluid - that is, one which thickens when subject to shear. will spin both wheels all the time till the fluid over heats. Racing will detroy this style of LSD. Mine did not make it though one rally. It is now melted down as bean cans.



now if the viscous fries after a couple if not one really race (depending on how hard you drive i would assume) what's the fix do you replace parts or do you have to replace the whole thing? and if so then what is the purpose of the differential oil that we put in there for? :confused:

[L and E Fab.com]

You replace the entire differental.

You put oil in the differentail so your car will keep moving. If it does not have oil it will sease up.

[22b-righton]

Stick with R160 rear gear and upgrade the diff (Kaaz 1.5)if you see fit. A better center diff (20kg) is also a wise investment, but costly.

Really have seen very few stock VLSD diffs fail on stage, or the street, or at all. They are not bad at all for an oem part. It's the stock center diff that's weak sauce.

[UP2MTNS]

Stick with R160 rear gear and upgrade the diff (Kaaz 1.5)if you see fit. A better center diff (20kg) is also a wise investment, but costly.

Really have seen very few stock VLSD diffs fail on stage, or the street, or at all. They are not bad at all for an oem part. It's the stock center diff that's weak sauce.

Hey Barrett! welcome to dirtyimpreza! I'm the guy that called you a few months ago asking about Bilstein PSS9 coilovers and putting custom (softer and longer) springs on them. They worked out pretty well!

Nice to see another experienced rally guy on here!

[22b-righton]

Hey there, thought that was you..thanks for the warm welcome.

Glad that the springs worked out for you. The right spring can make all the difference.

back to that diff..Kaaz 1.5 way (in your R160) FTW.:) and the 20kg STi center diff and you're ready for the stages.

[Anakin_jackson02STI]

Im not sure how relevant this is,but www.nasioc.com (http://www.nasioc.com) actually has an excellent master swap list and a really good thread for those of us planning to swap the STI 6MT into our WRX's (mines an 02 wrx). they also have a lot of really good info on the tranny of both the wrx and the sti...and also the diff's and pretty much any other driveline question you might have...Im actually trying to source the parts I need to swapmy 02 WRX glass box POS in favor of the 04 USDM STI 6MT. oh and to L and E...any input from you here would be most helpful as you seem to know your scooby trannies and such...

[kevinG]

from what i have heard from tuners/mech/read all the diffs that subies run are from nissan... and i know that team orange runs the skyline rear ends diffs and axles... iirc it is the r200... i want to see about swapping in one of those but still keeping the awd unlike the orange cars.

from what i understand the r160 is small and weak and no matter what you swap into it (like from kaaz) it will not be stronger but it WILL act differently on different surfaces.

and once you get a stronger diff your next weakest leak will be the front diff...

[MilesFox]

so what exactly does the 95 legacy have for a center diff? i have the notion to swap one into an 87 rx full time dual range transmssion to make it a true AWD (currently has locking center diff.

[22b-righton]

from what i have heard from tuners/mech/read all the diffs that subies run are from nissan... and i know that team orange runs the skyline rear ends diffs and axles... iirc it is the r200... i want to see about swapping in one of those but still keeping the awd unlike the orange cars.

from what i understand the r160 is small and weak and no matter what you swap into it (like from kaaz) it will not be stronger but it WILL act differently on different surfaces.

and once you get a stronger diff your next weakest leak will be the front diff...

Kevin,

Just to clarify about the first diff comment (we deal with all kinds frequently).. Some Nissan and Subaru diffs can interchange (eg:R180 into a 510 Datsun), but that doesn't necessarily mean that they are all Nissan diffs. Most won't just interchange. There are variations in axle style, hubs, etc, between the generations of both brands.

If the team Orange car runs an R200, axles, hubs, etc, that's all from the the Skyline (or something else).. We saw that car at Subiefest last year, and it was crazy.. But it's important to keep in mind that car is RWD, not AWD. Also 450+ whp.. That sort of power going through a RWD R160 could break it, but with the torque split between all 4 wheels, less likely to. We have 400whp WRX street cars that run an R160 with no issues at all. Don't believe everything you read or hear on the boards..How many R160s have you seen broken or broken yourself? We've seen less than a few in over 12 years of Subaru street and performance, and usually due to lack of fluid or running different tire sizes. The R180 is very, very strong. In the Nissan Z cars, some of them make 600+ RWHP on the stock tranny and stock R180.. If guys are breaking them, that's usually in a drag situation, not rally, rally x, auto x or on a road course..Track or rally guys aren't putting the shockload on the drivetrain like in a 1/4 mile. 5k antilag launch, dump clutch, BOOM!!! something will break in that situation, usually the tranny first..A R200 is not necessary for any AWD Subaru street car. There are plenty of 600whp STIs running R180s with no issues at all. R180 gear is already pretty steep cost wise..

As far as the front diff being "weak", again, how many have you seen fail? They don't give the positive response (quicker, grippier turn in), but they don't typically fail either. The best thing about putting stronger diffs (F, R and center) is if you break an axle or something to that effect.. If you have open diffs and break an axle, you don't move (we've done that). If you have LSDs or a stronger locking diff (STi, DCCD, Kaaz) than you can usually limp it back to service or finish your stage out. We've run all type of diffs in many of our builds, and most street, auto x, or rally x, guys won't benefit enough to warrant the extra cost of a front LSD ($1k+ labor). If you take your car offroading (lifted Brats, GLs, OBs, etc on 29s), drive in deep snow, or stage rally it, you will notice the difference. The majority of the club PGT stage rally cars (WRX, Leggies, DSMs, GTXs) don't run front LSDs. It's not until you get to the national level that the tenths of second, or couple of seconds of difference gets you on the podium or into the contingency money..Then that mod pays. For rally cross, get a better set of tires. Better bang for the buck..

If a person was going to upgrade diffs, in order of cost effectiveness, this would be a good plan:

1. Better center LSD. In an early Impreza or Leggy T, 12kg STi. Newer RS or WRX 20kg STi or Kaaz. (+-1k) That's for guys with rear LSD (WRX, RS)..Otherwise rear LSD first, even a stocker.

2. Better rear LSD. Kaaz 1.5 way or JDM WRX or STi. They made some trick rear diffs in JDM land..(+-1k)

3. Front LSD. Again, going with an STi or Kaaz (+-1k). This mod will make your car less fun on the street, better in the muck. But they are spendy, and the trans needs to come out and and get rebuilt. It's a good mod to do when you are building your tranny (Stock gears, RA, PPGs, etc.). Add the cost of the diff to your other parts and labor.. Ouch! Don't buy a cheap diff, you'll be sorry and have to pay twice on labor when it breaks..:cry:

Not trying to flame, just share our experiences with everyone..

To feel the difference for yourself drive a WRX or RS on a rally x course, than an STi with the diff locked..Even with street skins, considerable difference pulling through the cones, and getting grip. :)

If any of you have other questions about diffs, or want to get something ordered up, we'd be glad to help..

[22b-righton]

so what exactly does the 95 legacy have for a center diff? i have the notion to swap one into an 87 rx full time dual range transmssion to make it a true AWD (currently has locking center diff.

4kg center diff. The RX trans can be swapped in, but you need an adaptor plate and some XT6 clutch bits..Those trannys are some of the best for the $ you can get.

[UP2MTNS]

awesome post, Barrett. thx.

[kevinG]

22b-righton,

good post... i didnt mean the r160 was "WEAK"... what i meant was if you put enough power thru it to break it you will also be putting enough power to break anything else that you can swap into that diff's body... that came from kaaz when i emailed them asking how much stronger their diff was...

[BrianL]

Do any of you guys use a torque biasing differential? Like a Quaife.

[not12listen]

heh. i'm curious if anyone uses a torsen type lsd as well...

i am looking to upgrade my oem rear open diff. i'd prefer to get a torsen type, as i wont be rallyx'ing this RS (that job is saved for another 'spare' impreza).

so yeah...

[I Like It Sideways]

Not12Listen - as a cheap(er) alternative you could swap in an '00-'01 RS for the viscous LSD

Edit: Just read your thread about going torsen.

[not12listen]

i've looked for a 00-01 vLSD for a while... they're very tough to come by. :/

most people want $500 for them. so, if i can find a torsen LSD for $900 or $1000, i'd rather buy the torsen as it'll do a better job, and be more effective than a vLSD...

[Allwheelsdriven.net]

I've got a 4:11 VLSD (and the rest of the running gear) coming out of a '00 RS swap in the next couple of weeks.. You can have it for $250 + shipping.

Have you driven both types of LSDs on the same course and noticed a difference, or is your opinion based on what you've read/heard? There is a reason why most of the diffs aren't Torsen..Only a few auto companies use that style, and by most accounts , they don't work as well as others.

What are you going to do with the car? read 22B-righton's post (my other screen name)..:)

Barrett-
www.allwheelsdriven.net (http://www.allwheelsdriven.net)

[not12listen]

i have no experience with LSDs. this is purely based upon everything i've read.

i've only played in the dirt a few times in my RS (again, this impreza will not be taking on rallyx duties - that is saved for my next impreza), but nothing harsh or car breaking at all.

my plans are for some pretty heavy autox usage and the occasional track day.

i was going to create a new thread with the 'full' (so far) plans for my build-up of my daily driver RS... heh. it might shed some light as per what my driving is like and what i intend for this RS. :)

btw - i'd be very interested in your vLSD... :)

[not12listen]

I've got a 4:11 VLSD (and the rest of the running gear) coming out of a '00 RS swap in the next couple of weeks.. You can have it for $250 + shipping.

Barrett-
www.allwheelsdriven.net (http://www.allwheelsdriven.net)

would this be the entire rear end with housing, or just the diff with ring gear?

any idea what shipping might cost? :)

[RA Limited]

My version 6 STi RA comes with a "Suretrack" up front.... is this a Torsen or Helical type? I ask, because the one time i gymkhana'd, the front diff felt comepletely useless. On high-speed touge runs, i often spin my inside tire (dry pavement, fast corners in 2nd-3rd gear)... This is mainly times that i'm transferring a lot of weight off the inside tire.
Could it be messed up, and therefore not working properly?


Also, i have been trying to understand how teh Cusco Tarmac Gear works. They say it is not an LSD- so how does it work? I don't understand the mechanics behind something that constantly applies the 35/65 split.

[snicker]

so I just destroyed my 3rd gear. Figure it's time to install some ra gears. I like the five speed. might as well install an lsd up front while it's a part right. Has any one heard of a dual cone first gear syncro ( supposedly to help smooth 2nd to 1st shifts)? I'm pretty sure I'll be running a cusco rs 1 way or a kaaz 1 way. Any suggestions?

[Allwheelsdriven.net]

The RA gears are a little stronger (and shorter) than the stock, but not a huge strength upgrade. Good for about 300whp. How much whp are you putting down, and do youplan on going over 300?

The '06-07 WRX gears are the same strength and size, but a bit less $. You can get the dual cone syncros with either. The 1 way diff is a good idea, both work well, but we use more Kaaz diffs in our builds.

We'd be glad to help you source everything you need for you tranny build.

FYI, for the $ you'll be spending on you 5mt build, you're not_that_far from a 6 speed..:)

Hope this helps.

Barrett-
www.allwheelsdriven.net

[RA Limited]

ok, reviving an old thread.

I'm working on the finishing touches of stockpiling parts for my 02 WRX that i have yet to drive (it's back home in TX).

I have a Cusco Tarmac Gear that will be in for daily driving, and am on the lookout for front/rear LSD's. This car won't be hardcore rally, it'll be my wife's daily lol.
From what i've read on NASIOC, GC8 R160 LSD's have a different spline count or something, so they won't work in a bugeye.
I am working on figuring out what i would need to do in order to swap R180 in- get R180 diff/pumpkin in 3.54 ratio, axles to work with R160 hubs (i have that worked out), and that is that right? Does the 5mt driveshaft bolt up to the R180?
I should be able to get all that for ~$600 or less... i think?
Would that be tremendously better than getting a KAAZ/Cusco R160 and just running with that?
I'll be running stock power, but lots of abuse lol. I'm not easy on my cars. And keep in mind the 35:65 tarmac gear.

edit: a GC8 diff like this would be awesome, if it will work for me:
http://www.upgarage.com/upgarage/stock/1/2/1006110008287/110

[snicker]

I'm running a GC RVLSD w/ 4.11 gear coupled with an older JDM 5 speed Leggy spec-b tranny, in my '02 wrx. It feels awesome! perfectly useable. I am planning on attaching a JDM STi RA DCCD to it. Maybe Barret can give me some pointers on this. As far as I can tell the housings match up good and the pinions/output match up good. Any thoughts or has anyone done this yet?

[RA Limited]

so you have a GC8 rear LSD and it works. Man i hope that will work for me, means SUPER easy for me to get a proper R160 LSD!

[snicker]

Yeah, my GC VLSD works great, I just pulled the whole housing and it bolted in place to my wrx driveshaft and rear axles. I was a low mileage one and I traded some guy my 140k mi wrx one for it. He knew how many miles were on it, He just wanted it for the pinion gear. I wanted the 4.11 so it worked out.

[Jard]

I have a 3.9 R160 VLSD from an older GC I'm trying to sell!