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lovintheboost
12-20-2006, 11:24 AM
i posted a while back that there was a noise comeing from the rear of my car. well i took it in and i need the rear diff rebuilt anyone had yjis done or know what i should be paying? its sounding like around $800.00

onemoremile
12-20-2006, 12:25 PM
Sounds like a good time to try out the $150 V8 rear LSD.

smoothie
12-20-2006, 12:32 PM
has it been done before??

b00st
12-20-2006, 12:33 PM
i just had the rear diff seals done....cost me 400.

audispeed
12-20-2006, 12:39 PM
Sounds like a good time to try out the $150 V8 rear LSD.

what is this? i only knew of the $2k stasis option, but i guess i havent really looked into it.

lovintheboost
12-20-2006, 01:06 PM
hey onemoremile more info please
i've only heared of the big bucks one from stassis as well. if you have some specifics or any place i can start some research that would be great. its funny you probably have no idea how muchinfluence you have had on my car. back in the day you helped me with my first track day to my recent chouce to gut and cage my car and i just decided not to buy a set of crobeau forza in favor of a set of kirkeys (which i had never heared of untill you suggested it

lovintheboost
12-20-2006, 01:07 PM
i just had the rear diff seals done....cost me 400.


my rear diff isnt leaking so i think the whole thing has to be rebuilt its pretty damn loud above 35mph

audispeed
12-20-2006, 01:28 PM
hey onemoremile more info please
i've only heared of the big bucks one from stassis as well. if you have some specifics or any place i can start some research that would be great. its funny you probably have no idea how muchinfluence you have had on my car. back in the day you helped me with my first track day to my recent chouce to gut and cage my car and i just decided not to buy a set of crobeau forza in favor of a set of kirkeys (which i had never heared of untill you suggested it

beat you, lol

lovintheboost
12-20-2006, 01:32 PM
^ya really
150 bucks sound to good to be true i wonder what all is involved

Daft
12-20-2006, 01:50 PM
i just had the rear diff seals done....cost me 400.


OMG!! $400!? Was it $200 per hour? That's a ton of cash to replace two $4 seals.

I'll admit that it does require a few tools and some patience but, damn!

ShawFM
12-20-2006, 02:46 PM
has it been done before??

Give me some time, I am thinking about trying it out. I need to replace my rear seals. I was looking the LSD has actually been going for ~$250-400 at most places that I have checked.

lovintheboost
12-20-2006, 03:13 PM
where did you find them? and what additional parts do i need im looking to replace my diff in the next month so if anyone can help me with info id appreciate it

thanks

onemoremile
12-20-2006, 04:47 PM
So far it is an unsubstantiated rumor. I've read that it works and that several people have used it but have no direct information on it. I've been wanting to try it.

b00st
12-20-2006, 05:47 PM
OMG!! $400!? Was it $200 per hour? That's a ton of cash to replace two $4 seals.

I'll admit that it does require a few tools and some patience but, damn!

front and rear so maybe 200 for each...dunno but it was expensive. i was say they charge 100 bucks an hr. its a top notch shop and i would bring my ride back in a second.

smoothie
12-20-2006, 06:04 PM
no kiding that would be an awsomly cheap deviation from the stasis unit. worth a shot if your looking into a new rear end [up] if any info on this arises let us know, I'm very interested :)

lovintheboost
12-20-2006, 06:14 PM
anyone know where to source one?

ShawFM
12-23-2006, 02:22 PM
anyone know where to source one?

car-part dot com search "carrier" for 1990-1994 V8 Quattro. I bit the bullet last week and ordered it $150. I figured that if I am going to pull the seals on the rear diff, I may as well have the V8q diff here for measurements and comparison. It will be several weeks before I really do anything. I still have to install the rest of my k04 and exhaust.

Tiluleshpingen
12-23-2006, 05:54 PM
WOW.. 150 man am ready to pay 300 for the rear diff. its the whole thing?.. i guess the V8 LSD should be better then what we currenty run, considering we ahve 96 and up A4? . so you guys think this is a good idea to be doing on our cars?

onemoremile
12-23-2006, 06:36 PM
car-part dot com search "carrier" for 1990-1994 V8 Quattro. I bit the bullet last week and ordered it $150. I figured that if I am going to pull the seals on the rear diff, I may as well have the V8q diff here for measurements and comparison. It will be several weeks before I really do anything. I still have to install the rest of my k04 and exhaust.

Awesome. If the rumors are true about this diff fitting then a whole lot of folks are going to follow in your footsteps.

ShawFM
12-23-2006, 07:55 PM
And if they are false.... I lost $150 [:(]

Awesome. If the rumors are true about this diff fitting then a whole lot of folks are going to follow in your footsteps.

lovintheboost
12-24-2006, 11:10 AM
did you get the whole diff for 150? whats additional parts do you think will be needed

ShawFM
12-24-2006, 12:51 PM
I don't know yet. I just ordered it on Wednesday. I should have it sometime next week. Still haven't picked up a new digi cam so no photos of what I will get just a description.

did you get the whole diff for 150? whats additional parts do you think will be needed

ShawFM
12-27-2006, 01:42 PM
I got the whole rear diff and housing for the $150. Just arrived today. Quick assesment of physical size: won't fit the A4, crack the housing open and pull the TorSen diff out, a thing of beauty, the V8q housing has a bit of fluff to it. the TorSen is small enough to possibly fit into the A4 diff housing. This is where it will require dismantling the one on the car to say yes or no. Now the weather comes into play, I am in Chicago and it can get cold. So, it may be a while before I work on it. But it is in excellent condition.


did you get the whole diff for 150? whats additional parts do you think will be needed

ShawFM
12-27-2006, 06:41 PM
A short E#TA search right seal is the same, right tapered roller bearing is the same, left side is not. The flange shaft (the part that bolts to the axle) is different the V8 is a 108mm flange the A4 is a 100mm flange. Have not checked to see if the splines are the same.

ShawFM
12-28-2006, 03:34 AM
I found the Quaife technical drawings online, I can do a comparison on the V8 differential with the drawing for the differential from Quaife that does fit into the A4 This makes things a lot easier. It includes everything we need to know dimensionally, including the number of splines on the shaft.

lovintheboost
12-28-2006, 09:53 AM
i will be taking notes keep the updates coming man

LateraLex
12-28-2006, 11:04 AM
Very interested in how this turns out

ShawFM
12-28-2006, 01:02 PM
Me too, I hope I don't end up biting the $150. But the left side bearing looks like it might be the sticking point, the V8 is I.D. 45.2mm x O.D 77.8mm the A4 is I.D. 41mm x O.D. 68mm I will need to either locate a bearing or price machine work to for this to work. Also take note of what other car the quaife is used in...
D3/A is the problemhttp://www.quaife.co.uk/shop_files/QDF4Q30998.jpg


Very interested in how this turns out

onemoremile
12-28-2006, 01:11 PM
http://www.quaifeamerica.com/differentials/diff_apps.htm

Quaife lists the 40.309.170 as fitting the following:
Audi Rear: A4 Quattro (B5), incl S4
Audi Front: Coupe GT, 4000 Quattro, Quattro Coupe (016/093 trans)
Porsche 944 1986 on including turbo (add'l parts may be required)

The additional parts note for the 944 is as follows:
nstallation Note for 944 Application:
Models with both transmission oil cooler AND open (non-LSD) differential will require the bolt-on type pump drive gear from a limited slip vehicle.
Parts required:
016.115.165 gear
999.119.011.00 screw (4 req)



I had heard of some folks running the 944 rear LSD so this is promising.

onemoremile
12-28-2006, 01:14 PM
http://forums.audiworld.com/a4/msgs/2435131.phtml


-the 944 diff fits in our rearend?
-Yes, with some very minor machine work... (Audii-Dudii)
In fact, the LSDs that Stasis originally sold were made by Guard Transmission for the 944. I don't know if they spec'd them any differently, though, and I understand they are now selling units either made by them or made to their specs.

FYI, ZF is the OEM source for the LSDs installed in many european cars. Although the side gears usually have different splines and cannot be easily interchanged, economies of scale dictated that most of the other internal parts be shared among the various diffs ZF produced for several different manufacturers.



For instance, I'm using the thrust plates from an E12 BMW LSD in my setup since they have steeper ramp angles (45/45) than Porsche used (30/30, as shown in the photo above) -- this causes it to lock-up less under load (25% v. 40%), something that's beneficial for a car that understeers -- and stiffer Belleville washers to increase the preload on the clutch discs, which is all that keeps the inside rear wheel from spinning when it's in the air, turning AWD into ZWD.

I haven't yet done a back-to-comparison (but eventually intend to, which is why I bought a second 944 LSD and A4 rear diff) but theory suggests this is a better setup for our front-heavy AWD cars and the results so far have been encouraging.

onemoremile
12-28-2006, 01:30 PM
Another great post with a link to info on the Porsche rear diffs:
http://forums.audiworld.com/a4/threads/858640.phtml#2482450

Another on the rear diffs:
http://forums.audiworld.com/canada/threads/7771.phtml#50500

Link to pic of a disassembled Torsen:
http://pictureposter.audiworld.com/69143/torsen-disassembled.jpg
^^ You'll probably have to cut and paste it into the browser to get around the AW photo sharing issues.

onemoremile
12-28-2006, 01:31 PM
More info on the ramps and whatnot:

I bought mine on eBay for around $400 but had to rebuild it...
Posted by: Audii-Dudii on 2006-10-17 10:46:58
Account #: 69143

and in the process, I swapped the Porsche's OEM thrust plates with 30/30 ramps for the thrust plates with 45/45 ramps out of an old E12 BMW 530i LSD I had lying around. I'm told the thrust plates from an Alfa Montreal have 30/45 ramps, which is probably the best combo, and they're even supposed to fit the Porsche diff housing as well, but I've never come across a used Montreal diff for sale so I can't confirm or deny this.

I acquired another BMW 530i LSD and an A4 rear diff housing late last year and had the 45/45 ramps remachined to 30/45 but I don't have any experience with this setup yet. I did drive the car briefly with the OEM Porsche thrust plates and thought this setup made the car push too much at corner entrance.

ShawFM
12-28-2006, 01:50 PM
I remember that, I just forgot about it. I recall searching for a reasonably priced 944 LSD and could never find one. Now in search of a new / cheaper[:D] holy grail
[QUOTE=onemoremile;1320160]http://forums.audiworld.com/a4/msgs/2435131.phtml
-the 944 diff fits in our rearend?
-Yes, with some very minor machine work... (Audii-Dudii)QUOTE]

lovintheboost
12-28-2006, 03:11 PM
what is the diff code for a 97 1.8t quattro? "daj" or "dak"?

ShawFM
12-28-2006, 03:43 PM
Both are good codes for a '97 you need to check the differential or the build sticker for which specific diff you have. but it seems the DAK shows up on a lot of auto;s when looking on car-part dot com

what is the diff code for a 97 1.8t quattro? "daj" or "dak"?

lovintheboost
12-28-2006, 04:25 PM
looked on the diff no code. where is the build sticker?

nevermind found it "daj" if anyone was curious

vitaliko
01-13-2007, 07:21 PM
im looking to switch rear diff out on my a4 in the near future keep this up

ShawFM
01-13-2007, 08:28 PM
The V8 torsen WILL need to be machined. One diameter D3/A from the drawing posted is 45.2mm on the V8 needs to be machined down to 41mm. I haven't been able to check overall width when the flange shafts installed. I want to do that before I spend any more money on machining this. This will have to wait a couple months, as it is now a little cold in Chicago. But the 944 LSD is still an option for you if you can find one and don't mind a clutch pack rear diff.
I know I would like to get this working too, and in a hurry. When the EDL turns off at about 35-40 mph if it is wet out and I am in boost the rear tires now break free way too easily.

im looking to switch rear diff out on my a4 in the near future keep this up

vitaliko
01-14-2007, 07:35 PM
btw how da fuck do you get rid for the EDL??

onemoremile
01-14-2007, 08:33 PM
EDL has nothing to do with the differential. It senses speed variations through wheel speed sensors and uses the brakes to slow down the spinning wheel. If you have a real limited slip diff then the EDL should activate less.

vitaliko
01-14-2007, 08:41 PM
i know what edl is. and edl is a joke if you ever driven on track in the rain. i might be getting rid of abs soon, would doing that also take out edl as it uses the same speed sensors?

audiluver
01-15-2007, 04:37 AM
not only does it use the same speed sensors, how else do you think the brakes will apply to that specific wheel on its own. Without the abs pump, edl doesn't exist.

UCFQuattroguy
01-15-2007, 09:19 AM
from what I gather...the V8 Torsen rear is fine if you don't auto-x with a setup that's stiff enough to lift the inner-rear tire. Yes, when every thing's on the ground it's great as an LSD, but by nature of the Torsen (just like the center), once one wheel lifts, or has no resistance on it, you go into Zero-Wheel-Drive while it's up. This is why the Stasis diff is the choice if you're hardcore. As long as the Porsche unit is clutched, that'll work great if you change around the ramp angles as mentioned earlier in the thread.

onemoremile
01-15-2007, 10:57 AM
The wheel is only off the ground for a fraction of a second. Altering driving style and suspension tuning will fix that. Braking deep, spinning the car around, and shooting past the late apex will keep the tire on the ground under power. If you're headed to Topeka to fight for a national championship then you already know that a clutch pack rear diff is the correct autocross setup for you. You would also know that your Audi will get killed by cars that are naturally more capable autocrossers. Not that an A4 can't autocross but there are just a lot better platforms to start with.

Clutch pack rear diffs will keep the raised wheel from spinning. They also tend to be more abrupt and jerky. Parallel parking with one of those can be awkward at best. They can pop, clunk, lock up, and do all sorts of weird things.

ShawFM
01-15-2007, 03:25 PM
Clutch pack rear diffs will keep the raised wheel from spinning. They also tend to be more abrupt and jerky. Parallel parking with one of those can be awkward at best. They can pop, clunk, lock up, and do all sorts of weird things.
And those are the reasons for my interest to do the torsen for my street car. The clutch pack is nice, if I were racing. But I really do have to live with this car on a daily basis. The torque now is really great, but in the wet wheel spin is now a problem. I never realized that the EDL actually did work until I added more power and started spinning the rear tires in the wet when the EDL cuts out.

onemoremile
01-15-2007, 11:00 PM
The Cobra has a Quaife and a pair of 315 rear tires. It can pull into a parking lot full of nice cars and back into a space without embarrassing itself. Some cars either sound like they are going to fall apart or tear a chunk out of a tire.

lovintheboost
01-16-2007, 07:12 PM
so my rear diff was fine so now i have an extra one for sale asking 80 bucks plus shiping

lovintheboost
01-16-2007, 07:12 PM
^^120k miles on it from a 97 1.8tqm

wood_e
01-16-2007, 07:30 PM
What's the deal with the V8 LSD? I'm very interested in knowing....

onemoremile
01-17-2007, 11:03 AM
The V8 rear diff is a Torsen type and is nearly a direct drop-in replacement for the stock open diff. It needs some basic machining and costs about 150 bucks. Add 50 for the machine work and it is damn inexpensive at maybe $225 all in and running.

Stasis charges $500 for a center Torsen core and another $550 to modify one. A rear Quaife can be $800-1000 although I did see a B5 A4/S4 Quaife go on eBay for under $500 once. Stasis wants a huge amount of money for their custom rear clutch pack diff.

Alex@STaSIS
01-17-2007, 12:15 PM
There are some issues with the V8 Torsen, mainly how the output shafts engage into the differential. Also there is some machine work that must be done to fit this together. Do remember that a Torsen type differential isn't ideal for anyone who is lifting a rear wheel. Our LSD is a direct bolt-in and will easily handle a lifted inside rear wheel as you may find in auto-x situations or with running a larger rear sway bar. We run these exact same units in our race program and they perform wonderfully on the track as well as the street.

If you have any questions do let us know toll free at 888.9STASIS.

Cheers,

onemoremile
01-17-2007, 12:24 PM
No argument there. It is better and costs 8 times as much money.

UCFQuattroguy
01-17-2007, 07:59 PM
Alex...dare I ask what your coast/power lock numbers are on that diff you guys run? Info like that for just about any RWD car is very easy to find...but looking for people who've tinkered with different ratios on a quattro car is just about impossible. Also...would getting the 4:1 diff be counter productive if I will be keeping the stock rear diff for a while ($$ reasons). The car is my daily driver which gets put though it's paces every month at our local Auto-X club meetings.

onemoremile
01-17-2007, 09:08 PM
The car is my daily driver which gets put though it's paces every month at our local Auto-X club meetings.

Street Mod?

UCFQuattroguy
01-18-2007, 07:05 AM
actually through a loophole created in the club last year I'm "G Prepared", even though I have "modified boost". Apparently if it's done electronically through the ECU it's cool. As far as the center diff...nothing in the rule book states you cannot modify the center diff...(prolly 'cause the only other AWD cars out there running are viscous clutch diffs that aren't toothed like our Torsens. Rear's can be changed as long as the final ratio remains the same. I've got the sneaking suspicion that a 4:1 center would turn this car into an animal for the mods I have. I'm currently running right there with stock EVO's and STi's on race tires. Even on the Victoracers I'm using last month my best time was just within the overall top 10 of the day. Within the class I'm battling with a Mini-S with LSD, Smaller Supercharger Pulley and V710's. We're pretty neck and neck as it is. When I've got more $$ to throw around I'll be getting a tire that's more suited for Auto-X.

Other mods are:
APR 100octane (Auto-X only...otherwise 93 on the street)
2.5" Test Pipe
H&R Springs
Bilstein Shocks
H-Sport Swaybars (rear in tightest end-link slot)
A8 front rotors with PBR Ceramic Pads

onemoremile
01-18-2007, 10:57 AM
Hoosier A's don't last long but they are good for an incredible time.

I'm also planning on the Stasis center diff. Does anybody know if there is anything available for the front diff?

onemoremile
01-18-2007, 11:11 AM
Stasis lists locking front and rear diffs for their racecar.

Driveline

* Audi Quattro AWD
* STaSIS high bias center Torsen
* STaSIS locking front and rear differentials
* STaSIS lightweight flywheel
* Tilton dual plate clutch



The yellow AWE Tuning S4 autocrosser has a Quaife front diff.

UCFQuattroguy
01-18-2007, 01:22 PM
A tire that I've been curious about due to cost reasons are the Avon Tech R auto-x tire. I'm hoping that the level of grip difference between the Avon and the Hoosier doesn't justify the extra coin of the Hoosier...lol

ShawFM
01-18-2007, 03:11 PM
so my rear diff was fine so now i have an extra one for sale asking 80 bucks plus shiping
PM'd you with a Q

onemoremile
01-18-2007, 10:14 PM
I found a few places listing the Quaife front diff for the S4 6MT but nothing for the B5 5MT.

Audi - Front, S4 (B5) / A6 2.7T / 4.2 6-speed (01E trans) 40.309.171

Tiluleshpingen
01-18-2007, 10:36 PM
All Right Am Confused, What's The Final Verdic.. Or We Didnt Get There Yet?

ShawFM
01-19-2007, 07:07 AM
.... Does anybody know if there is anything available for the front diff?
I know you said there is one for the 6sp S4 tranny, Looking at EK Ta there are several differerences between the A4 and S4. More differences than on the rears for the V8 and the A4/S4

onemoremile
01-19-2007, 05:51 PM
AWE says the yellow S4 is a customer car and they didn't do the diffs. I haven't found a front LSD for the A4 5MT. With the Stasis center and a rear LSD the front shouldn't be much of an issue.

vitaliko
01-19-2007, 07:20 PM
what would happen if you welded the rear diff with the stasis center diff?

UCFQuattroguy
01-19-2007, 07:30 PM
one of two things... Understeer OR Snap Oversteer. Just guessing based on how a spool diff'd car acted in a race sim I use. As for the front diff...you really shouldn't need it even with just the 4:1 center diff...as you're getting more power away from the front to begin with. Beyond that..unless you litterally HOLD an inner/rear wheel in the air AND have uber power...you shouldn't need the rear diff...especially if still on stock turbo

onemoremile
01-19-2007, 07:53 PM
a fully locked rear diff tends to push a car straight ahead. It also threatens to tear chunks out of the tires when cornering.

Mine's an Outie
01-19-2007, 08:24 PM
actually through a loophole created in the club last year I'm "G Prepared", even though I have "modified boost". Apparently if it's done electronically through the ECU it's cool. As far as the center diff...nothing in the rule book states you cannot modify the center diff...(prolly 'cause the only other AWD cars out there running are viscous clutch diffs that aren't toothed like our Torsens. Rear's can be changed as long as the final ratio remains the same. I've got the sneaking suspicion that a 4:1 center would turn this car into an animal for the mods I have. I'm currently running right there with stock EVO's and STi's on race tires. Even on the Victoracers I'm using last month my best time was just within the overall top 10 of the day. Within the class I'm battling with a Mini-S with LSD, Smaller Supercharger Pulley and V710's. We're pretty neck and neck as it is. When I've got more $$ to throw around I'll be getting a tire that's more suited for Auto-X.

Other mods are:
APR 100octane (Auto-X only...otherwise 93 on the street)
2.5" Test Pipe
H&R Springs
Bilstein Shocks
H-Sport Swaybars (rear in tightest end-link slot)
A8 front rotors with PBR Ceramic Pads


Hey what events are you running at? Im gonna see how I do in SM at the CFR-west events this season. I'm not counting on much since I'm relatively inexperienced but I might see you out at an auto-x. So far I havent seen a single other B5

vitaliko
01-19-2007, 09:09 PM
i was more curious on how the 4:1 center diff would act in conjunction with welded rear diff.

onemoremile
01-19-2007, 09:33 PM
It would act like a rear wheel drive in a straight line. If you tried to turn it you would have all sort of problems. A friend had a rear wheel drive car with a full posi and it couldn't go around corners in town without tearing itself or it's tires apart. The same rules apply with quattro. If the rear is locked it will just suck ass. The only real way to turn the car is to light up the rears and slide them around.

vitaliko
01-19-2007, 09:46 PM
like mechanically lol, i understand how a welded diff works, my buddy has one on his 240

onemoremile
01-22-2007, 05:43 AM
we've always heard about how Torsens will spin "loose" wheels and this video illustrates that nicely.

http://video.google.com/videoplay?docid=9072883197544018466

ShawFM
01-22-2007, 08:12 AM
we've always heard about how Torsens will spin "loose" wheels and this video illustrates that nicely.

http://video.google.com/videoplay?docid=9072883197544018466

But what they fail to tell you is that applying the brake lightly will redistribute the power and the car should have driven off under its own power. They could have easily set (partially not full on) the handbrake to get that result with the Audi.

qtek16
01-22-2007, 09:38 AM
A tire that I've been curious about due to cost reasons are the Avon Tech R auto-x tire. I'm hoping that the level of grip difference between the Avon and the Hoosier doesn't justify the extra coin of the Hoosier...lol


I autox here in the dc area. Ive had a bunch of "auto cross" type tires on my 300zx and hands down I say Hoosiers--You can push those things to limits i did not think were possible in that car. The 710's are nice too, ran them for a bit. I hate the victoracers lol but they really are not meant for autocross.

onemoremile
01-22-2007, 01:52 PM
But what they fail to tell you is that applying the brake lightly will redistribute the power and the car should have driven off under its own power. They could have easily set (partially not full on) the handbrake to get that result with the Audi.

While that is true, it would be awfully inconvenient for an average buyer to have to remember to trick their AWD auto into using all of it's wheels. If Audi insists on using electronic band-aids to make up for the lack of real mechanical torque distribution they should have been able to tell that the rear wheels were moving and the fronts weren't. EDL should take car of that by braking the rear wheels.

I've been doing that ride the brake trick in the Grand Prix rental I'm driving. Otherwise it won't make it up the hill in front of my house.

ShawFM
01-22-2007, 02:20 PM
While that is true, it would be awfully inconvenient for an average buyer to have to remember to trick their AWD auto into using all of it's wheels. If Audi insists on using electronic band-aids to make up for the lack of real mechanical torque distribution they should have been able to tell that the rear wheels were moving and the fronts weren't. EDL should take car of that by braking the rear wheels.

I've been doing that ride the brake trick in the Grand Prix rental I'm driving. Otherwise it won't make it up the hill in front of my house.

Audi should be able to add that into the EDL why they didn't I'll never know. I was really wondering if that is a trick that they used for the BMW, did they include the EDL front to rear and side to side, or what did they use for their center differential. I haven't looked yet but I will. I needs ta know what they used.

** edit ** BMW electronically controlled clutch center diff monitoring all corners and axles. Audi should have been doing all wheel/axle monitoring & control with their EDL.

onemoremile
01-22-2007, 03:17 PM
I'm still partial to the center diff in an STI. You can set it to auto and let the car sort itself out or change the bias ratio manually. You can also lock it and go play in the snow or mud.

ShawFM
01-22-2007, 06:05 PM
I'm still partial to the center diff in an STI. You can set it to auto and let the car sort itself out or change the bias ratio manually. You can also lock it and go play in the snow or mud.

I liked the old Audi locking differentials (my old 4kq) for similar reasons. I wish the torsen had a locking option but it doesn't. You know for the rare occasion that we go rock climbing in the Audi and have only 1 wheel and the ground and need traction. That 4kq when the center and rear diffs were locked seemed unstoppable. I never got plowed in, and never had to shovel myself out either.