panamajack Posted April 3, 2006 Share Posted April 3, 2006 What would happen if you placed a 2way on the front and rear, with a cusco 35/65 center diff? Link to comment Share on other sites More sharing options...
whitetiger Posted January 4, 2008 Share Posted January 4, 2008 ^bump on this thread. Anybody here running any upgraded diffs in their car? Ive been toying with the idea of doing this myself. Link to comment Share on other sites More sharing options...
whitetiger Posted January 6, 2008 Share Posted January 6, 2008 anybody? Link to comment Share on other sites More sharing options...
typeSpeed Posted January 6, 2008 Author Share Posted January 6, 2008 Wish I could help you, I was strongly considering it myself. Till I did some more research. Unless your going to rally or track the car, it isn't the best bang for the buck. The install is an involved process, poked around on a few other boards and found this: It's pretty involved. The front diff is housed in the case along with the tranny and center diff. Front diff removal: 1. Remove the tranny fron the car. 2. Remove the transfer case 3. Split the tranny case 4. Remove the drive pinion shaft 5. Remove the main shaft 6. Remove the diff installation is the reverse of removal Good luck. Silver-Arts.com - Custom web design Link to comment Share on other sites More sharing options...
whitetiger Posted January 6, 2008 Share Posted January 6, 2008 Im autoxing the car, and i want a LSD in the front and a better rear LSD. Installation for me is not a big deal. I was hoping that people in the legacy comunity had done this and that they would give some feedback. Link to comment Share on other sites More sharing options...
typeSpeed Posted January 7, 2008 Author Share Posted January 7, 2008 Im autoxing the car, and i want a LSD in the front and a better rear LSD. Installation for me is not a big deal. I was hoping that people in the legacy comunity had done this and that they would give some feedback. I would talk to Myles or Keefe at www.racecompengineering.com; they probably haven't done it to Legacy, but probably have some experience with installing it on another model of Subaru. Also, there are a few of us that also autoX and have found tires/suspension/corner balancing/fluid modifications to be more than sufficient. Don’t forget, this change may bump you into another class/group. If you get it done, lets us know. You may be the first in the U.S. to have it done and may spark others to consider it. Either way good luck Silver-Arts.com - Custom web design Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 thanks. Ive already checked and a Diff swap is allowed in ESP. you are right about the tires/suspension and other stuff as I already doing well in my class for my region, but i looking to improve times still for Pax. Link to comment Share on other sites More sharing options...
Guest Posted January 7, 2008 Share Posted January 7, 2008 I also want front LSD. I am considering STI 6spd box that comes with one, but then controlling DCCD is a problem. SpecB 6spd is a nice box, but lacks front LSD. Actually I would also want to know how much work/cost it would take to have one installed in SpecB box. You can get STI front helical LSD for 5MT. I saw one for ~$1000 at rallispec.com There is also Quaife, that is praised (it's also helical/Torsen). From what I learened, unless you want your car to clunk, clutch type LSD should be avoided. Allegedly they are best on gravel/snow. They also are wear items. Link to comment Share on other sites More sharing options...
dbrunone Posted January 7, 2008 Share Posted January 7, 2008 I wonder if the 07 STI front diff will fit on my 07 Spec.B? I already have basically an STI rear diff... Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 no the car wont clunk with a clutch type LSD. And properly maintained, they will last a long time. I would not want a clutch type in the front diff however since its alot harder to get at if i do have to rebuild it. Thank for the info on the other stuff. the center diff in our cars is easy to access. you dont have to take the trans out to get at that. just remove the drive shaft and take unbolt the tail section of the trans. I also am interested in getting a better rear LSD, though i dont know whats involved in replacing the carrier in ours. Ive done Ford Rear ends but they are alot easier to work on because they are much larger. Do i have to worry about shimming the carrier in to the diff housing? Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 Most of the aftermarket diffs i find are listed for the 02-07 wrx 5mt. Now i know the ratios are different for the 05lgt, but that has to do witht he size of the ring and pinion gears. I want to know if the legacy ring and pinion will fit on a wrx front and rear Diff carrier. Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 The quaife units look really nice. http://www.gruppe-s.com/Subaru/subtrn/Quaife_ATB.htm having these front and rear with the cusco center tarmac 35/65 slit seems ideal for a mix of autox and DD. Link to comment Share on other sites More sharing options...
Underdog Posted January 7, 2008 Share Posted January 7, 2008 WT, the rear differential rebuilding procedure is in the vaca pix and it contains the p/n for all the shims required. 14 - Tansmission & Driveshafts\Differentials\Section 04 - Rear Differential (T-type) The Crimson Dynamo Link to comment Share on other sites More sharing options...
Guest Posted January 7, 2008 Share Posted January 7, 2008 Most of the aftermarket diffs i find are listed for the 02-07 wrx 5mt. Now i know the ratios are different for the 05lgt, but that has to do witht he size of the ring and pinion gears. I want to know if the legacy ring and pinion will fit on a wrx front and rear Diff carrier. I believe it will. All 5MT stuff (except early drivetrains, like pre-1998 or so) is interchangeable I read. Link to comment Share on other sites More sharing options...
Joel Gat Posted January 7, 2008 Share Posted January 7, 2008 Hello, I've done a lot of transmission work on Subarus and know the Legacy tranny pretty well. We ran all sorts of diffs, from various mechanical types to clutch types, etc. However, not having one in front of me, I might not be able to answer technical questions well, but I can give some pointers. What's the specific question? BTW, from a handling/driver perspective, like I said before in this thread, you won't find better response than by asking the drivers of one of my teams - Chris and Brian Lock, GotoRacing, will have all the answers and are 100% approachable - just email them your questions. Also, if it's installation-related questions you have, I can't recommend Mike/Tommy/the GST Motorsports crew enough. They are exceptionally good at what they do... So, post up specific questions, my subscription to this thread is up, I'll see how I can help. Joel Link to comment Share on other sites More sharing options...
Joel Gat Posted January 7, 2008 Share Posted January 7, 2008 Hello, The quaife units look really nice. http://www.gruppe-s.com/Subaru/subtrn/Quaife_ATB.htm They are quite nice and work very well. having these front and rear with the cusco center tarmac 35/65 slit seems ideal for a mix of autox and DD. Personally, I didn't like working with the cusco center since it's an open diff. If they had added some slip limiting feature to it, it would have been better, but wheelspin at one corner pretty much one-wheel-drive'd your car. We'd lift and inside front under acceleration and the revs would go free as the engine drove just the one diff in the air. This is especially true with torsen-type diffs like the quaiffes that don't limit slip well when a wheel is in the air. With clutch-types front and rear, I would guess that the cusco would work better, but clutch types front and rear mean a whole lot of understeer... Joel Link to comment Share on other sites More sharing options...
Joel Gat Posted January 7, 2008 Share Posted January 7, 2008 Hello, Most of the aftermarket diffs i find are listed for the 02-07 wrx 5mt. Now i know the ratios are different for the 05lgt, but that has to do witht he size of the ring and pinion gears. I want to know if the legacy ring and pinion will fit on a wrx front and rear Diff carrier. Wait. The pinion gear in the front is on one of the transmission shafts and changing it is a MAJOR pain. You will need to pull all the gears, synchros, etc., out of the transmission - not just pull the shafts out but press all the gears off, get new synchros, press everything together, etc. Changing transmission-side final drive ratios is such a pain, that I would rather get another transmission with the correct final drive and swap that in That said, the pumpkins are all the same (ring-gear-wise) and you can take a diff and pop the ring off, put another diff in its place, and bolt down the ring gear. Well, the WRX/Legacy ones, that is. The US STI is bigger and not compatible, though the older JDM STI parts do work. The "tricky" part is the minor details, like whether the diff has stub axles, whether it uses your axles' stub-side, which snapring design the diff is meant to take, the depth of the snapring groove, etc. Everything can be made to work, but if you're crossing platforms and years, you will have to do some research into it. And it's been a few years since I worked on a Subaru team, so my memory of exact details is a little vague... Joel Link to comment Share on other sites More sharing options...
Guest Posted January 7, 2008 Share Posted January 7, 2008 I think the best setup is simply STI box with DCCD and Torsen diff. The only issue is wiring DCCD controller or using an aftermarket one. This might be also cheaper than doing two diffs, since you can always sell the 5mt box/diff to WRX folks and recover some $$$. Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 Hello, Wait. The pinion gear in the front is on one of the transmission shafts and changing it is a MAJOR pain. You will need to pull all the gears, synchros, etc., out of the transmission - not just pull the shafts out but press all the gears off, get new synchros, press everything together, etc. Changing transmission-side final drive ratios is such a pain, that I would rather get another transmission with the correct final drive and swap that in That said, the pumpkins are all the same (ring-gear-wise) and you can take a diff and pop the ring off, put another diff in its place, and bolt down the ring gear. Well, the WRX/Legacy ones, that is. The US STI is bigger and not compatible, though the older JDM STI parts do work. The "tricky" part is the minor details, like whether the diff has stub axles, whether it uses your axles' stub-side, which snapring design the diff is meant to take, the depth of the snapring groove, etc. Everything can be made to work, but if you're crossing platforms and years, you will have to do some research into it. And it's been a few years since I worked on a Subaru team, so my memory of exact details is a little vague... Joel Well, you would not have to remove the pinion, just swap over the ring gear. As long as thats all you ahve to do, you dont have to worry about changing drive ratios. But yes, axle compatability is another varaible in this equation. Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 I think the best setup is simply STI box with DCCD and Torsen diff. The only issue is wiring DCCD controller or using an aftermarket one. This might be also cheaper than doing two diffs, since you can always sell the 5mt box/diff to WRX folks and recover some $$$. But you have to worry about your axles fitting and getting a new drive shaft and clutch and clutch hydraulic system. I think are alit more associated costs compared to buying a couple diffs and perhaps installing 2 of them myself with out pulling the trans out. Link to comment Share on other sites More sharing options...
Joel Gat Posted January 7, 2008 Share Posted January 7, 2008 Hello, Yes, if you're keeping the same ratio, then you just move the ring gear over. For the front diff, there are no shims, just those rings on the outside of the case, so it's a very easy install and adjustment (so long as you think splitting the transmission isn't too bad). I would say that by myself, at home, putting the tranny back onto the engine takes longer than the entire rest of the front-diff swap process Joel Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 Hello, They are quite nice and work very well. Personally, I didn't like working with the cusco center since it's an open diff. If they had added some slip limiting feature to it, it would have been better, but wheelspin at one corner pretty much one-wheel-drive'd your car. We'd lift and inside front under acceleration and the revs would go free as the engine drove just the one diff in the air. This is especially true with torsen-type diffs like the quaiffes that don't limit slip well when a wheel is in the air. With clutch-types front and rear, I would guess that the cusco would work better, but clutch types front and rear mean a whole lot of understeer... Joel what if you had a clutch 1.5 or 2 way in the rear, a higher torque viscus int he center and then a helical in the front to prevent understeer? Link to comment Share on other sites More sharing options...
Guest Posted January 7, 2008 Share Posted January 7, 2008 But you have to worry about your axles fitting and getting a new drive shaft and clutch and clutch hydraulic system. I think are alit more associated costs compared to buying a couple diffs and perhaps installing 2 of them myself with out pulling the trans out. You just get STI fitment clutch, although I believe 5MT clutch works on 6spd. Hydraulics work, I think even either slave cylinder (5MT or 6MT) would work with the stock master one. Drive shaft can be ordered custom, or stock SpecB will work. Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 Hello, Yes, if you're keeping the same ratio, then you just move the ring gear over. For the front diff, there are no shims, just those rings on the outside of the case, so it's a very easy install and adjustment (so long as you think splitting the transmission isn't too bad). I would say that by myself, at home, putting the tranny back onto the engine takes longer than the entire rest of the front-diff swap process Joel I agree. I have no problem splitting the case and all. i just dont have the equipment to actually pull the trans out. I got a friend with a lift though, so it very possible. The rear setup is what im worried about. does the rear diff need to be shimmed and checked for backlash and all. Link to comment Share on other sites More sharing options...
whitetiger Posted January 7, 2008 Share Posted January 7, 2008 You just get STI fitment clutch, although I believe 5MT clutch works on 6spd. Hydraulics work, I think even either slave cylinder (5MT or 6MT) would work with the stock master one. Drive shaft can be ordered custom, or stock SpecB will work. But i already have an aftermarket clutch which i like and I like to keep the taller 1st and 2nd gears of the 5spd. Link to comment Share on other sites More sharing options...
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