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OffRoo'd FAQ


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2 replies to this topic

#1 monstaru

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Posted 19 July 2010 - 07:39 PM

HOW DO I LIFT MY NEW SUBIE?
www.sjrlift.com which is Scott in Bellingham

you can PM: http://www.ultimatesubaru.org/forum/customavatars/avatar19254_10.gif
" /> The Beast I Drive with BOSS(BillOmlinSubaruSpecialties)

or
Gloyale and
The High GUYS

or


albieone and
Smiths Specialties

I would also search for these guys and you can see what they have done.

There's cat's in Seattle that would tell ya how it goes.EZ is one of'em.....he's got a little bit of experience...... :grin:

ROB has some cool cars too...not a bad guy either


Hell, If you make it to Mt. Vernon, i bet that One Eye would build ya one too, or tell ya how to do it for free.......

Get ahold of these guys if you wish to add some needed height.I am kinda sponsored by one of them(kindof a joke, kindof not:lol:)so i cannot give opinions.

There are also several that have manufactured lifts themselves.This is much more involved obviously.Some folks have even gone as far as to add subframes and T-cases, but we'll save that for another time.....

Lets talk about lifts. THE most common lifts for EA cars are 2" (
http://www.ultimatesubaru.org/forum/...290#post850290 ) and 4".The two inch lift is most common on EA82 vehicles.(There are free diagrams floating around that i will try to link here in the coming weeks.)This is a relatively cheap way to gain height on an EA82 vehicle.Also very effective.
I have wheeled with some of these type of vehicles and they do well.
I have seen some 30" tires under one of these rigs.The fenders were trimmed moderately, and it was stuffed in there.......but it performed well.

The 4" lifts are common on the EA81 series vehicles.These are good rigs.With some other modifications you can accomplish more than you think you can if you learn how to drive.........i have stuffed 235/75/15's under a 4 inch lifted brat,McBrat stuffed some 30's, but trimmed and pounded pretty hard.....He actually had issues with his door alignment before he was done!:lol:Then he moved on..... :slobber:

There are 6-8" lifts floating around for EA81's, and 4" and 6" lifts for EA71"s , I've seen 4" and 6" lifts for EA82's.There are 4" and 6" kits for EJ's as well.....



Basically, if you want to build one yourself, there are some that will help you here, and some that won't.It is fairly intensive at first,but it is do-able!It takes some basic tools to accomplish , and little math.Unfortunately there are no released CAD drawings of these lifts.Really though , if you are tackling it you can PROBABLY figure it out for your self,If you are a kid trying to do a cheap lift, get some help......If you are a basic shade tree you can probably get away with it......It is just work,time,and time, and thinking , and time , and work......etc, you get the drift.

Diluded's build:

http://www.ultimatesubaru.org/forum/...ad.php?t=26281

SUBARUBRAT's build

http://subarubrat.com/liftday.htm

http://www.subarubrat.com/liftday2.htm

(this is kinda the "flagship" BIG lift , you will probably not get an answer if you email or Pm , As he has not posted here for years.)But ,we have all of the answers here somewhere anyway.People have done what what you see there several times now.

Here is a basic writeup by Mudrat (a banned member,i only say this to keep you from tryin to find him....cause you won't!)

Why 8 inches....???

Are you planning to put a T-case in as well.....???

If so I would Do 10" instead.....Cost of steel is going to be almost the same

Here is a rough list of steel you will need/use to do this project...

14pcs. of 1/4" x 2" x (8" or 10") x 2 inches long

aprox 20 feet of 1 1/2" x 1/8" wall square tube for tieing blocks together......

10 feet of 3 x 2 x 1/8 wall Rec. tube for tieing front blocks to rear blocks...This is also what the T-case will mount off of.....

Depending on how you are going to build front strut tops, you will need

10 feet of 1/4" x 3" flat bar
3 feet of 1/4" x 8" flat bar
2 pcs 1/4" x 8"x 6" flat bar
You will also need Tubing to sleave shift and 4WD linkage,
2 pcs of 1/4 x 3 x 3 angle iron for motor Mounts,
You will be building custom tranny mounts, so there is some steel in there
You will be stuffing a T-case Most likely, there will be steel involved there as well to mount it into the sub frame structure you build to connect front blocks with rear blocks.....
Mudrat did Jarods For $1500.00 Installed.(that was like 8 yrs ago or something)...this didn't include T-case , or 5 speed tranny......
All steel above is a Rough guess-timate but it will get you Started, let you see cost involved.....
Also you have to remember fuel lines and Brake lines have to be lengthened.....





All in all it is relatively simple to lift your car, whether or not you buy one or build ...is up to you.
Ok. So that basically covers the ea series stuffs.
On to the EJ stuffs.........(mostly dealing with Legacies from 1989-1994)(some Outback ideas as well)
There are a couple of different ways to go about this one.Once again it depends on what you wish to be doing with your car.with a little more power under the hood than the EA series cars, some have said that it alleviates the aching pain of wanting a second transfer case(don't worry , i'll get to that)......


Suspension lifts for EJ series cars? ie: Legacy, Impreza, OBS, Outback, Forester



Impreza, OBS:

You can use Outback or Forester springs and struts and strut tops. These will each give about the same amount of lift. I used the KYB GR2 Outback struts and stock Outback springs (96) on my 96 OBS and gained roughly 4 inches in the rear, and 3 in the front. The car sits with a little bit of rake in the rear. It rides nice and firm. The KYB Outback struts have about an inch and a half more travel than the stock OBS struts.
Here's a couple comparison shots. 96 Legacy OutBack struts and springs added to 96 OBS.
The tires on the green one are 225-55-17 (about 27.5)

*****************

Outback and Forester:

You can buy lift springs from companies such as Scorpion and Custom spring makers in your town. These will give you roughly 2-3 inches of lift. Down travel may be compromised a little.



The angle of the CVs and the DOJs is not increased enough to cause worry about ware and tear.

http://www.ultimatesubaru.org/forum/...ad.php?t=49116

http://www.ultimatesubaru.org/forum/...ht=legacy+lift
http://www.ultimatesubaru.org/forum/...ad.php?t=49336
http://www.ultimatesubaru.org/forum/...ght=outback_97
http://www.ultimatesubaru.org/forum/...ht=legacy+lift
http://www.ultimatesubaru.org/forum/...ghlight=legacy
http://www.ultimatesubaru.org/forum/...ghlight=legacy

Those are just a few.As you can see there is a ton of info, in crosslinks etc.

m


There are a ton of threads to start looking at , so GO AHEAD!


This thread most Definitely is still under construction. I am by no means a master of information, so i will be working on it for a while.
cheers , Monstaru


Edited by baccaruda, 18 May 2013 - 08:20 PM.
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#2 monstaru

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Posted 19 July 2010 - 07:40 PM

WHAT SIZE TIRES CAN I RUN WITHOUT ANY LIFT? Here's a link to a thread about that. http://www.ultimatesubaru.org/forum/...d.php?t=111056

I know folks that have run 29 inchers with no lift, and cut the livin hell out of the fenders.Do you want to do that?And i know guys running 31's with 8" of lift........
WHEELS FOR BIGGER TIRES
Your car is 4x140 bolt pattern.The wheels that will fit are HERE

Remember that most 6 lug wheels are also able to be modified for the job ....
A goo thread about it
http://www.ultimatesubaru.org/forum/...d.php?t=111897
Or your stock hubs can be modified to accept 6 lug .....HERE is where you will find the best write up i could find for hub modification.......(35/64ths bit for the hubs I used the same on the rims I did as well, then a 3/4" countersink for the "lugnut seats" on the rim........

i found this and thought it would go good in the sticky for offroad.it is a listing of specific vehicle's equipped with 6 lug rims we can use.it is only missing a couple...........
6 x 5 1/2" Make Model Years of Production Chevrolet All thru 1948 Chevrolet & GMC Pickup and Van thru 1970 Chevrolet & GMC K-10, K-1500, 4WD Blazer, And Jimmy 1971-86 Chevrolet Luv Pickup 1972-83 Datsun All Pickups 1967-86 Dodge D-50, Ram 50 Pickup 1979-87 Ford Courier Pickup 1977-84 Mazda Pickup 1972-84 Nissan/Datsun Pickup, Pathfinder 1967-89 Toyota SR5, 4-Runner, Land Crusier, 4WD Hilux 1969-85(some to 1989)

TIRES
This is a slippery slope.The good thing about it,is that you can get smaller LT tires that are BIG on our cars.I know of an ea82 wagon with 33" tires on it.I also know of a completely stock height EA81 wagon with some big 14's on it.....

Basically it comes down to cost,how much do you want to spend?
I'd go to craigslist in your local area, there are always folks upgrading there current tires.

When you think about offroad, or mud tires , you have to consider the noise levels, wear and tear on your car, etc.....
I never cared about the noise, but it can increase significantly with knobbier tires.

I picked up some Wal TErrains at the beginning,they did fine for a while, then i needed more.i would definitely recomend them price wise, and wear wise. as long as you are not to dirty with them they are good tires.

Then I had picked up some like 50% hankook t34's that i rocked on the brat for about a yr.I loved them,so when i built Lilly i thought i would transfer them over,drove them for like 6 months then got rid of her.On a lighter vehicle they worked well,even on low tread.you gotta figure, most of the tires we are looking at here , are for LT.So they end up lasting quite a while.don't be afraid to inspect used tires, and BUY them if they are in good repair, and whatnot...

Basically you have to ask yourself what will work for you.I am betting that most of you will be able to get away with some type of all terrain tire.If you are in the NW you might want to consider a mud terrain because of the snot we are used to around here.I have had both, and would not contest either,you just won't go as far usually in an all terrain around here, but realistically, it comes down to economics.Buy the best tire you can afford right out of the gate.Otherwise you will be wanting for more.

Cooper Discoverers are suposed to be a good dual purpose tire.
For the 15 inch rim they have the exact size and demensions of a interco super swamper SSR that i'm putting on my car. they are radials and are ok for dual purpose. these do not come in a size smaller than 30 or 31 anymore, so if you see a set used in the smaller flavor, i would get them.......


Ground Hawgs/ highliner 26"/27" tires

excellent off road grip. they have pulled m through everything. the one thing that these do have disadvantage to the swampers is no offset lug pattern or sidewall grips. but they grip onto anything. fairly soft bias ply tire. the sidewall is very thick and strong (i sheared off a six inch strip off the bead of my rim. not damaging the tire)
on road, buy a set of ear plugs!! they are fairly loud. approximately as loud as the tsl's. if you like the constant sound of a B-52 Bomber flying down the runway. these would be an excellent choice for onroad tires. i have not noticed any under or oversteer problems with them. they handle similar to car tires. but be more careful on wet road ways. due to less contact with the road than street tires.
in the snow they like to dig if you don't air them down to 6psi. being that the highliners are only 7 inches wide. which really help to cut through the mud.
Price: approx $75 for the highliner, 4wheelparts sells the ground hawgs for i believe under a hundred dollars. (Jared)

I've used the swampers (both radial and bias ply), the Kuhmos, the Coopers (both AT and SST).
My personal ratings for them would go like this:

x(MikeW)

I have been running my 29x8.5x15 Wildcats for almost 4 years Now, And Have had very good luck with them in all conditions....
I had My tires Siped when New, And have never needed to chain up with them on the BEAST......Good Mud throwers, Good Sand and Snow walkers aired down, and Ok for noise on the street...
I believe the Smallest size anyore is a 215x75x15......But don't hold me to that......
(Mudrat)

-------------------------------------------------------------------
www.walmart.com/catalog/p...iameter=14
I have run these tires for 4 years and they still work great and have plenty of tread on them. They are only $45 a piece with 45k tread warranty. (Lostwater)
---------------------------------------------------------------------
So far the Hankooks seem fine. Not many miles on them Yet tho. Very similar to the Coopers I would say.
So far the one impression that I *have* got from them is that they are VERY quiet. For an aggressive tire I expected more noise. But in fact I noticed NO increase in noise over the 175/70r13's I had on the car before. Either the tires are just really well behaved on pavement, or they are very soft or something.
I probably have 1000 miles on them now. So far I'm happy with my purchase. (General Disorder)

well it sounds like I am the only one running bridgestone duelar A/T on14" pugs?
they fit well on my car with some fender clearancing and the stiffer rear springs installed.
really quiet on road but a good bit of grip in the dirt.
soon to be tested in the snow :headbang: not to expensive or complicated to install.
(RallyRuss)

Wal-Mart Liberator All Terrains. 235/75 R15 (28.9"x8.5") set of 4. Great little tires and I'm happy. McBrat is correct though; he saw first hand how they fill up quick. They also clear out easy though if you can get some wheel spin up. I've taken them up some pretty seriouse terrain and they worked great. Wear on the highway is acceptable. They are built for a pickup truck so I'm barely working them :)
(MorganM)

The Liberators rule. Pehaps not the best mud tire, but here in the desert they're awesome. They also roll very well, even at highway speed.
(Singletrack)
---------------------------------------------------------------------
As for suby rims and four 4wheeling, these are my opinions on rims. just my advice. but if you've wheeled with me you know i push my car, if it don't break under my hand then it's a worthy modification.
Pug alloy rims.
for the street they are great. look good, lighten the weight a little. now as for four wheeling them. i strongly reccomend to avoid any hard trails where the rim can come into contact with rocks or roots. these rims are a lot more fragile than the steels. on lake isabele trail i split a six inch strip off the bead of the rim. they lost all respect for 4x4ing from me. if you don't follow me and you stay on the easy to moderate side of life these are worthy rims.
Pug steel rims.
they are a little heavier. but for 4wheeling they are much more durable than the alloys. i reccomend these for any of the harder trails. do to the fact that when you wedge or bounce a rim into a rock. you can usually bend the rim enough to get off the trail and to camp. been there done that (Rooinator)

I'll add that when I've wondered what size will fit I've taken a good guess, used the miata tire size calculator some and went to a place that sells used tires with an old rim. Size them up, pick out a crappy one for $15 and try it. If you're really cheap you can probably get them even cheaper if you look for junk tires or find a scrap yard that sells tires. Or go to a tire shop and ask for old junk tires of a few different sizes..
(grossgary)

Maxxis Bighorns- Available at Les Schwab. Mud terrain type tire, unbeatable traction on and offroad. Rides smooth and quiet on the highway, and is available with studs for winter. You can get it as small as 27/8.5/R14 or as large as something like 38/14/R20 or something. I have a set of the 27's and a set of 31/10.5/R15 and I HIGHLY recommend them.
The Beast I Drive

I've been running General Grabber AT2's for almost a year now, in a 215/75R15.
The tread still looks like new, and I drive a good 50 miles round trip to work.

They have little to no road noise, excellent wet traction, good dry, and are quite affordable. Now for the off road report: I've never had a problem with traction, even running with other rigs that have MT's.
SoobieDoo

I have a set of 30X9.50X15 Maxxis Mudder Buckshots, they are by far some of the best mud tires I have ever had. I ought them in 2004 for my brat and I have still Wheel with them, I got the Radials and they ware great, I have a ton of miles on them and moved them to my most recent Wheeler. I've also Ran the Maxxis Big Horns, they are just as good. They Clean well and Bite on Just about anything..........................
one eye

Running Yokohama Geolander A/T-s 225/70 15's for year now.
22,000mi and very little wear.
On road..............
Little bit of road noise but not bad at all.
Outstanding wet pavement characteristics,best for this I've ever owned.
Sure footed and tracks nice and true.

Off road..............
Excellent on dirt and sand and smaller rocks.
So-so in mud,they do OK but will load up in the sticky stuff.
Don't know about in the snow because never see it here in Jax.

There are better (louder on road) all-terrains out there but these are great for an off roader that spends most of it's life on pavement.
(I'd like to have these for street/some dirt and another set of rims with Interco SSR's for off road only.
frogstar7055

The prettiest '86 Wagon to ever offroad. 3" BYB Lift.

Tender trimming of the front and rear fenders, as well as some sensual massage to the inner fender well.

I rocked 14" steel pugs with 28" SSR Swampers. Best tire ever for what scoobs like to do. Mud, dirt, small rocks, children, grass, pavement. Handle it all with ease. I was seriously sad to sell them off. Sold them off cause I was daily driving the car more, and hated spinning the swampers on the pavement in the wet.

Also by far, clean swampers on a clean car... Hot combo to show off. (Hottest that mere mortals can pull off anyway)

Current setup is 15" AA wheels with some crap A/T's that I traded for. Was hoping to make the car more daily drivable... especially in the wet. Well, I'd be hard pressed to pick these A/T's over swampers for rainy days. They suck equally.

I have my deal gnome out looking for some swampers that fit 15" rims. Gonna get them siped for awesome wet traction.
Subarutex

Re: Will ATV rims/tires work?
I may be able to shed some light on this topic... (Sweet82)

RIMS;
There are several rims that are close to Subaru's 4X140. Most notibly the 4X144. However there are NO ATV rims that will directly bolt to our lugs.
Things to consider are the ATV rims were designed for a #500 - #600 vehicle. A subie on a good day is 4 times that weight. :eek: Five times on a bad day fully loaded for wheelin. :eek: :eek: Rims may fail under this weight and they are not Highway rated or street legal. The Offset of an ATV rim may also get you in trouble...

TIRES;
As for the ATV tire size being smaller? that is not the case. It simply depends on what size you buy. They make them in a 28X12X12 :grin: Your stock tire will measure about 22.5".

http://www.rockymountainatv.com/Pro...tv?pid=00017587

[COLOR=Gray]What I did;
I'm running a 6ply tire for strenght because I'm over steping the recomended weight rating on the tire. I'm also running at close to 30psi and normally you'd run 3 - 5 psi.

I'm running Dirt Devil 26X12X12:brow:
My Lugs are 1 1/4" deep they make them up to 2" deep
Note; I have noticed the difference in gearing while running my 26's.

[COLOR=white]I also had custom rims made to insure that they would be able to handle the punishment I would be putting them up to and to insure that the offset would be proper.

You can run ATV tire...! It's not easy or cheap...but it sure is fun :D
Sweet82

ITP Mud-Lite XT and XTR- These are 27" ATV tires that fit 14" rims. The Mud-Lite XT are bias-ply rated at 450 lbs per tire at 7psi, the XTR are Radials and rated at 1000 lbs per tire. I have a set of the 27/12/R14 that I have run on my rig and they are UNSTOPPABLE in mud, dirt, rocks, whatever. They are an extremely aggressive mud-terrain, and are NOT DOT legal, but are perfect for off-road.
The Beast I Drive
---------------------------------------------------------------------
Tire info sites
http://www.intercotire.com/help-arti...p?article_id=7 this one is a metric tire calculator
www.bfgoodrichtires.com
www.kumhousa.com
www.coopertire.com
www.4wheelparts.com
www.intercotire.com/html/interco-tires.htm
www.tirerack.com
www.tyres1.com
www.walmart.com/catalog/p...iameter=14

cheers, brain


Edited by baccaruda, 18 May 2013 - 08:19 PM.
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#3 monstaru

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Posted 19 July 2010 - 07:41 PM

this is the beginning of an lsd FAQ.please do not respond to this post.i am stealing all kinds of info from everywhere i can find it..



What is a Limited-Slip Differential, and what are the different types?
A differential of any type allows two output shafts to spin at different speeds (See http://auto.howstuff...ifferential.htm for more information). This is important when going around corners, as the inside and outside drive wheels are spinning at different speeds. Most differentials are of the "open" type, meaning they have no limitation on the difference in speeds between the two output shafts. Without a limited slip differential, when one drive wheel gets stuck in a ditch, it could spin 100mph while the other drive wheel stands still. By their very nature, open differentials send power to the wheel with the least grip. An LSD is a differential that prevents one rear wheel from spinning while the other just sits there, but still allows for a variation in speed between right and left wheels as the car goes through a turn. In other words, the LSD unit limits the speed difference between the two wheels, allowing torque to be applied to a wheel when the other is spinning without traction. Why would anyone want an LSD differential? They allow power to be applied through two tires instead of one, and often means you can apply the power sooner coming out of turns. It is important to remember that although we steer the front wheels of a car, the car actually rotates around the rear axle. Limiting the differential's slip limits this rotation somewhat. Drivers preferring to drive the rear end of the car (oversteer) prefer a locked or severely biased limited slip, whereas drivers that prefer to drive the front end (understeer) of the car prefer a looser differential setup. Both differential types can be fast but consider that the looser differential is gentler on tires and may be easier to drive. What are the downsides? An LSD installed into an already balanced chassis can cause a dramatic increase in understeer on dry pavement, and may even cause oversteer on wet pavement, requiring changes in swaybars, springs, and shock settings to return the car to neutral. There are several variations of LSD differentials, which are very well discussed on Gordon Glasgow's LSD tech page (http://www.gordon-gl...rg/lsdtech.html) or at http://auto.howstuff...fferential6.htm , but I will briefly list them below:
Welded Differential:
Actually, this is not an LSD, but the modification is a popular with road racers as a low-cost way to make a locked rear end. By welding together the side gears and the spider gears within the differential in several places, the rear wheels are both forced to spin at the same speed. By definition, this is no longer a differential, as the rear wheels cannot spin at different speeds. This is fine at higher speeds on the race track, but is really unsuitable for street driving, as the rear end of the car skips/hops across the pavement as you go through low-speed turns since one wheel cannot spin at a different speed from the other. It also can cause severe understeer in a 510, not to mention breaking at the worst possible moment when those welds let go.
Detroit Locker:
A popular option on the Detroit Muscle cars, this is mechanical differential that acts like an open differential until power is applied, at which point it locks up and gives power to both rear wheels simultaneously. Unfortunately, this differential either gives you complete lock-up or no lock-up at all. These are available for the Datsun/Nissan pick ups, but will not be discussed here.
Limited Slip Differentials:
These come in several varieties: Clutch-Pack (or Salisbury), like the Subaru LSD, Kaaz, Cusco, ATS, and Power Brute units, Viscous Fluid units (as used in the early Miata, 240sx, 300zx, and '91-92 Subaru Legacy turbo 4WD sedans, as well as all LSDs found in '00 and up Subaru Imprezas, WRXs, Legacies, and Forester GTs), and the Mechanical Torque-Sensing units like the Quaife and the Gleason-Torsen (the latter came in the '94 and newer Mazda Miatas and 3rd generation RX-7s, Lexus IS300s, HumVees, etc.). All of these combine the streetability of an open differential with the advantages of a locked differential, but there are differences between the three types of LSDs. A brief history of LSD technology and applications can be found here.
The Clutch-Pack ( Salisbury) LSD is what we're interested in. This is the kind of R-160 unit you can buy new from Nissan Motorsports or Subaru for $800, or used from a salvaged Subaru for under $300. These LSDs have an assortment of friction disks and shims inside, arranged so that the limited slip typically has a factory breakaway setting of 45 ft-pounds (allowing the rear wheels to turn at different speeds if they have to). See exploded diagrams of this differential from the Subaru Manual here and a close-up diagram here. The major downside is that as these clutch disk units wear, their breakaway torque setting gradually lessens, so they become more like an open differential until you rebuild them again to get the breakaway back up to 45 ft-lbs. Gordon Glasgow's web page (link URL is at the beginning of this FAQ) tells how to rebuild these units, but it is tricky, as the only way to adjust the breakaway is to use different thickness shims, reassemble the entire LSD, and then see what you've got. When Bluebirds list member Gary Savage had his LSD rebuilt, adding only one extra shim sent the breakaway up to 180 ft-lbs, which is a bit too much for everyday street use. For reference, the 2.5 Trans-Am race series BRE 510s had breakaway settings adjusted to 150 ft-lbs. Too high a breakaway pressure will cause clutch-pack LSDs to function as locked differentials, as well as creating severe understeer at corner entry as well as power-on corner exit. Anything under 100 ft-lbs should be fine for a dual-purpose street car. Pro: Cheap (used Subaru R-160), easily bolts in. Con: Hard to find, limited ratio (3.7), unless you swap R&P, clutch discs wear out, hard to adjust breakaway setting. For serious on-track duty, these setups generate HEAT, so a differential cooler may be in your future. See the section on Other Datsun 510 LSD Options for more information on the various aftermarket LSD units.
The Quaife and Gleason-Torsen (stands for TORque-SENsing) units are often regarded as the best LSD. Their locking action is via a complicated worm gear setup (read the technical paper here or go to the Torsen site), so they have no clutch plates to wear out and do not have the delay in locking up that some report with the viscous fluid LSD units. In a no-slip condition, the differential splits the torque 50:50 between the two drive wheels. When wheel slip occurs, the unit sends more torque to the axle with more grip (via the torque-multiplying characteristic of the worm gear mechanism), which in an autocross or race track situation is the outside drive wheel. By design, these LSDs separate the speed differentiation and torque distribution functions of a differential, resulting in a proactive LSD that actually prevents excessive wheelspin under acceleration. Different applications come with different torque transfer ratios (torque bias ratio, or TBR), capable of transferring torque to the non-slipping wheel at a ratio of up to 9:1. The locking action of these units occurs only under acceleration, and is instantaneous and progressive in nature. Under braking, the differential behaves like an open unit. However, there are no OEM applications that easily fit under a 510, and they are very expensive (Miata Torsen units are $1200 used, $3000 new, and I have no idea what a Lexus IS300 Torsen would list for). There are rumors of both Miata and 3rd generation RX-7 rear suspensions with LSDs being installed under 510s, but I have not seen any of these in person. Probably the easiest solution (if you can afford it) comes from Quaife. Quaife now has an LSD unit that fits in a Nissan R-180 or Subaru R-160 case that sells for $1,500 new, though they can be found at times for $900. Ted Hedman has one of these R-180 units in his 200hp Autech-powered SR20DE 510. One thing to know about the Torsen or Quaife units: they require BOTH wheels to have some traction in order to work as an LSD, as the differential "senses" the difference in torque between the two. If a drive wheel comes off the ground, it will spin just like an open differential, as zero available torque (a spinning wheel) when multiplied, is still zero. Pro: Durable unit, smooth, quick action Con: Pricey, no traction if wheel comes of the ground, cannot "tune" locking action.
Viscous LSD units are popular OEM LSD solutions, as they are relatively simple and cheap to produce. They come in many performance Subarus, Nissans, Mazdas, Toyotas, etc. The LSD unit consists of stacks of thin plates with holes or slots, all suspended in a special silicone fluid. They have no clutches to wear out, and locking characteristics can theoretically be changed by varying fluid viscosity. Generally, however, these units are non-serviceable, and require no special maintenance. As the differential spins, the plates shear the fluid up to a point, after which the fluid provides some resistance to shear, allowing 15-25% torque transfer to the other wheel. The downside is that these units don't act like a limited slip until one wheel actually starts slipping (i.e., they don't prevent slippage), which means the VLSD action often kicks in after you've already exited the corner. Compared to the proactive nature of the Torsen LSDs, the VLSDs are reactive units. They do not prevent slippage, they merely sense differences in rotation, not torque. They also don't allow for very much torque transfer, compared to mechanical or clutch-pack LSDs. They do still work well for starting from a dead stop in slippery conditions. It is important to note that VLSDs locking characteristics occur both during acceleration AND braking, as it can't tell the difference between the two, but merely reacts to the rotational speed differences between the two drive wheels. Another problem with VLSDs is the limited availability of applications that easily fit 510s. Subaru USA lists the '91-'92 Legacy 4WD Turbo 4 dr sport sedans as having an R-160 viscous 3.9 LSD option. All OEM Subaru LSDs since 1991 are viscous R-160 units (Note: No U.S. Subarus between 1995 and 1999 came with LSDs). These LSDs have their half-shaft axle stubs held in with internal C-ring retainer clips, not bolts as described below. See Adobe Acrobat pdf pages from the Subaru Repair Manual with diagrams of these LSDs here. The viscous LSD can be fitted under a 510 with major half-shaft modifications, as the 510 rear track is about 50" and the Subaru rear track is about 56" wide. The modifications would include either a way to use the 510 bolt-in axles stubs with the circlip LSD diff (how?), or shorten the stock Subaru half-shafts and somehow make an adapter so it bolts to the 510 wheel hubs, or choose to make custom half-shafts from scratch -- you choose. I have never seen one of these conversions in the flesh, but when I do, I'll report on it here. Pro: Readily available from newer Subarus (R-160), Nissans (R-200), smooth action, no special maintenance needed.

Where Does Subaru Fit in?
Subaru is also partially owned by Fuji Heavy Industries, and through miraculous good fortune for us 510 owners, decided to use the R-160 differentials as the rear differential in many of their all-wheel-drive cars starting in about 1985. Cars which use the R-160 include the BRAT, Loyale, GL, RX, XT, Impreza, WRX, Legacy, and Outback. Most of these R-160 differentials are NOT limited-slip, but as they come in 3.70, 3.90, 4.11, and 4.44 ratios, they are an attractive replacement unit for a tired 510 differential, and can often be purchased for less than $50. Note that LSDs were NOT available in any 1995-1999 U.S. Subarus. Installation of an Subaru open differential would be the same as the LSD instructions that follow below.
How do I find a Subaru LSD?
The hard part about finding these LSD units is that almost any Subaru could be ordered with one, yet very few actually were. I'd guess that less than 5% of the cars came with LSD units, judging by what I've seen in yards. Perhaps those of you in mountainous/snowy climes might see more LSDs than those of us in flat/hot areas. What this means that there is no "one" Subaru that for sure has an LSD unit of a given ratio. Most likely clutch-pack LSD candidates are the '85-89 EA82 platform 4WD turbo cars, often with the 4AT (4 spd Auto) tranny. Rumors have it that all Turbo 4WD RX coupes and Turbo 4WD GL-10s came std. with LSDs. High-buck XT-6s, XT Turbos, and possibly even Brats may also have them. Anyway, the LSDs you'll find will be 3.70 ratio. This is fine for a street 510, and will actually make freeway driving less buzzy, as your engine revs will be lower at any given speed (compared to the stock 510 3.90 ratio), but it may hurt your 0-60 acceleration times. For an auto-x or road-racing car, you'd probably be happier with a 3.90 or 4.11. I've heard rumors of 3.90 and 4.11 clutch-pack Subaru LSDs, but never actually found one myself, nor seen one. As an aside, most manual transmission Legacys have 4.11 R-160s that are non-LSD (Auto tranny cars have 4.44 ratios), giving you a 4.11 ring & pinion you can drop the 3.70 LSD clutch unit into (using the special LSD bolt set described below). I did just this by purchasing a used Subaru 3.70 LSD unit and a used legacy 4.11 open R-160 differential and creating a 4.11 LSD unit from the parts. I paid a rear-end shop $120 to drill the six 10mm holes out to 11mm so the LSD unit's bolts could be used, and to set up the newly assembled unit with the correct tolerances. Gary Savage did put a Subaru LSD carrier from a 3.70 ratio differential into his 510 using the 510 differential case, the NISMO LSD bolt set and the Nissan 4.11 ring & pinion to get the 4.11 LSD he wanted. '00 and newer Subaru Foresters and Legacys are available with 4.44 R-160s (open or viscous LSD), with rumors pointing to the finned rear cover being a clue to the identity of the LSD differentials. 2002-2003 WRXs are available with 3.54 Rear Viscous LSD.
Used Subaru R-160 LSDs go for between $100-$300 at the yards (when they have them), though I've heard of smart shoppers getting them from U-Pull-It yards for as little as $30. The good news is that most of these rear differentials are barely broken in, so they shouldn't need rebuilding. A major problem is that most yard folks don't know much about them, and don't know how to tell an LSD from an non-LSD unit. Furthermore, I've heard from several yards that there are different universal listing code numbers for an open and a locked Subaru R-160 differential, but that there is just a single code for all 3.90 ratio Subaru differentials, making it impossible for them to search via teletype for 3.90 LSDs. Many people I know have been sold LSDs that actually weren't, so make sure it's an actual LSD before you pay for it or at least know what the return policy is before you leave the yard. For these reasons, I prefer to buy from a local salvage yard and let them deal with getting the LSD from a far-away locale.
However, Subaru made it easier for us to tell what kind of differential is installed in their cars by just looking under them. Almost all of the older Subaru differentials (both LSD and Non-LSD) have a gold or silver foil sticker on the outside of the rear case cover stating the Subaru differential part number, the ratio of the differential (i.e. 3.70, 3.90, 4.11) and whether or not it is an LSD (if it is, it will have "LSD" in 1/2 inch-tall block letters on the left side of the foil sticker, as you can see in the picture below). The above ratios are the ones I've seen on Subarus in yards around the country. Sometimes the gold foil gets really grimy, but you can gently scrape it with a screwdriver to pull off a clear covering from it (like a helmet visor tear-off) to get a better view. The foil sticker makes it really nice and easy to see the differential ratios from under the car without counting ring and pinion teeth or driveshaft/rear wheel revolutions (see picture below). Later subaru differentials, by the way, do not have the gold foil stickers on them.

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Foil Sticker off Rear Case of Subaru R-160 LSD Differential (Left),
Image of same sticker from Subaru Manual (Right)
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Sure Ways to Tell if it's a Clutch-Pack LSD:


  • Check the sticker! It should have the letters LSD on it (see pictures above).
  • Rotate one of the half-shafts (both half-shafts rotate the same way if it is LSD. If one rotates backwards and one forwards it isn't)!
  • Drain the fluid from the differential and peek inside through the fill or drain hole with a flashlight. The clutch-pack LSD unit looks different from the open unit. You could also stick a finger inside the fill or drain hole and feel the difference between the two. The clutch pack is pretty obvious. The internals of some Subaru viscous LSD units will look the same as an open unit, as the viscous plates are hidden behind the ring gear.
What if you find a 3.70 Subaru LSD, but want a 3.90 or 4.11 ratio? I have heard that the 3.70 Subaru units will fit inside the 510 R-160 cases, and that the 510 ring & pinions will fit inside the Subaru R-160 cases. I have not seen nor done this myself, so I cannot offer specifics, nor guarantee that this is the case. I am sure that Subaru LSD units will interchange inside all of the Subaru R-160 cases, using various Subaru R-160 ring & pinion ratios. I purchased a used Subaru 3.70 LSD unit and a used legacy 4.11 open R-160 differential and created a 4.11 LSD unit from the parts. I paid a rear-end shop $120 to drill the six 10mm holes out to 11mm so the Subaru LSD unit's bolts could be used, and to set up the newly assembled unit with the correct tolerances. You MUST use either the Nissan Motorsports LSD 10mm x 1.25 ring gear bolt set (Part # 99996-D3100, bolts cost $8 each and you'll need 8 of them), or just BE SURE to use the bolts that came with the LSD unit, not the ones from the open differential whenever you do this or your LSD innards will chew themselves to pieces.






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