whitetiger Posted October 14, 2009 Author Share Posted October 14, 2009 you should get it with the front LSD. Link to comment Share on other sites More sharing options...
FPerron Posted October 17, 2009 Share Posted October 17, 2009 OK, things are not going well. Rallispec provided the axles and other parts, the unit got installed after a day-and-a-half of work, and I went to pick the car up this afternoon. Unfortunately, when the mechanic test drove the car, he felt a wierd vibration on acceleration and deceleration - kind of feels like driving with unevenly worn or "cupped" tires. Since it was late Saturday afternoon, there was no one to ask if this is normal. So, afraid to drive it under these circumstances for fear of destroying the entire transmission, the car sits at Manchester Subaru waiting for Monday when the head technician returns and we can contact Quaife. Helical LSDs are supposed to feel like normal open diffs, right? The vibration feels to me like a bad CV joint, but I doubt it. I fear the worst. Link to comment Share on other sites More sharing options...
whitetiger Posted October 17, 2009 Author Share Posted October 17, 2009 yeah that doesnt sound right. my front diff is seamless in its operation. Link to comment Share on other sites More sharing options...
Saul_Good Posted October 18, 2009 Share Posted October 18, 2009 Same here, feel like nothing until u start to really push it. Hope you get it all worked out. Link to comment Share on other sites More sharing options...
HAMMER DOWN Posted October 18, 2009 Share Posted October 18, 2009 Coming up on 50k on my 05 STi 6MT swap. The front LSD work in the back ground seamlessly, until your putting the power down. Mike Mileage:331487 Retired/Sold Link to comment Share on other sites More sharing options...
ppettit2005 Posted October 18, 2009 Share Posted October 18, 2009 I've definitely noticed some slippage at the front wheels in the rain... So I might want to switch to this set up too. Before I do that, what type of LSD would be most appropriate for that application? Because rather than look at improving racing times with a front diff, I'd like to get one that is a good daily driver. Also, I totally wish our cars were rear-wheel drive based all wheel drive instead of being mostly front until slip, at which point it becomes symmetrical... I just think that would improve the way the car drives at least in my point of view. Link to comment Share on other sites More sharing options...
FPerron Posted October 18, 2009 Share Posted October 18, 2009 I find it hard to believe there's anything wrong with the LSD itself. It's got to be an installation issue or a problem with one of the axles. Link to comment Share on other sites More sharing options...
SBT Posted October 18, 2009 Share Posted October 18, 2009  Also, I totally wish our cars were rear-wheel drive based all wheel drive instead of being mostly front until slip, at which point it becomes symmetrical... I just think that would improve the way the car drives at least in my point of view.  Subaru AWD are always symmetrical - which means that the front and rear axles are equal-length at each axle, a mirror-image if you will - not that the AWD is equally balanced torque-wise which is another issue. Depending on whether your LGT is 5EAT or 5MT the torque-split varies, but it's never less than 50/50 unlike the previous gen 4EATs which were 90/10 F/R until slip. If your LGT is 5EAT, you're biased 45F/55R until slip, then the VTD center diff sends the power where the grip is. If MT, then it's 50/50 F/R until slip then the LSD center diff shifts power to where the grip is. HTH. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
SBT Posted October 18, 2009 Share Posted October 18, 2009 I find it hard to believe there's anything wrong with the LSD itself. It's got to be an installation issue or a problem with one of the axles. My money is on an issue with the axles. Also possible the Q-unit was reassembled incorrectly?? - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
FPerron Posted October 18, 2009 Share Posted October 18, 2009 The LSD was disassembled to the point where it was possible to determine that the stub axles were not removable. The mechanic who did it told me that there were no springs to fly out or anything like that - just gears that were not disturbed. The cover was replaces, and the bolts were retorqued to factory specs. I also feel that there is an issue with one or both axles. When I drove the car, it really felt like something was out of round or binding - like a bad CV joint. I should know more tomorrow. Link to comment Share on other sites More sharing options...
ppettit2005 Posted October 19, 2009 Share Posted October 19, 2009 Subaru AWD are always symmetrical - which means that the front and rear axles are equal-length at each axle, a mirror-image if you will - not that the AWD is equally balanced torque-wise which is another issue. Depending on whether your LGT is 5EAT or 5MT the torque-split varies, but it's never less than 50/50 unlike the previous gen 4EATs which were 90/10 F/R until slip. If your LGT is 5EAT, you're biased 45F/55R until slip, then the VTD center diff sends the power where the grip is. If MT, then it's 50/50 F/R until slip then the LSD center diff shifts power to where the grip is. HTH. yeah, I definitely thought symmetrical meant balanced torque distribution... anyway, I can sometimes feel the front sliding around, and I've got a 2006 5eat... so what should I go with? Link to comment Share on other sites More sharing options...
SBT Posted October 19, 2009 Share Posted October 19, 2009 ^ Part of that is your tires, and part of it is your LGTs factory-built tendency to understeer. Upgraded tires, RSB, urethane bushes (F & R), and a performance alignment would go a long way toward minimizing the front slip. But, simple physics will always prevail - if you're starting off in such a way that the front tires are unloaded, e.g., uphill from a stop, turning left or right off-camber, on a rain-slicked street, you're going to slip, front LSD will just minimize the amount of slip. Same thing if you enter a turn too fast for road conditions and you bring power to bear, you're going to slip - front LSD or not - the LSD may actually exacerbate this condition if you're not judicious in applying steering and go pedal inputs. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
whitetiger Posted October 19, 2009 Author Share Posted October 19, 2009 I've definitely noticed some slippage at the front wheels in the rain... So I might want to switch to this set up too. Before I do that, what type of LSD would be most appropriate for that application? Because rather than look at improving racing times with a front diff, I'd like to get one that is a good daily driver. Also, I totally wish our cars were rear-wheel drive based all wheel drive instead of being mostly front until slip, at which point it becomes symmetrical... I just think that would improve the way the car drives at least in my point of view.  FYI, your 5eat is rear biased. Also, they dont make a F-LSD for the 5eat so unless you do a $$$$ MT conversion, you are SOL. Link to comment Share on other sites More sharing options...
Guest Posted October 19, 2009 Share Posted October 19, 2009 ^ Part of that is your tires, and part of it is your LGTs factory-built tendency to understeer. Upgraded tires, RSB, urethane bushes (F & R), and a performance alignment would go a long way toward minimizing the front slip. But, simple physics will always prevail - if you're starting off in such a way that the front tires are unloaded, e.g., uphill from a stop, turning left or right off-camber, on a rain-slicked street, you're going to slip, front LSD will just minimize the amount of slip. Same thing if you enter a turn too fast for road conditions and you bring power to bear, you're going to slip - front LSD or not - the LSD may actually exacerbate this condition if you're not judicious in applying steering and go pedal inputs. Actually to combat "3 wheel drive" without upgrading the front diff, the only effective method is to upgrade sway bars to increase roll stiffness. Will help keep wheels planted. However, given the weight of the car, it is not substitute for a front lsd, which is surely one of my favorite mods on the car. Totally, and I mean, totally transforms the car in corners. Link to comment Share on other sites More sharing options...
whitetiger Posted October 19, 2009 Author Share Posted October 19, 2009 ^now you of all people should know that the right way to prevent roll is to get good springs and shocks. Link to comment Share on other sites More sharing options...
Guest Posted October 19, 2009 Share Posted October 19, 2009 ^now you of all people should know that the right way to prevent roll is to get good springs and shocks.  Of course, I know. For me, it's more like mandatory mod, and I tend to forget one may not do it... sways complement it for sure. However, I would still claim stiff sways will do more for roll. Case in point I currently run Bilstein coilovers on both of my LGTs, one has upgraded sways (Swifts), the other has only JDM rear sway. The one with Swifts leans FAR FAR less than the other. Bilsteins have much stiffer springs than e.g. Pinks (6/8 kg vs. 4/6 kg of Pinks), yet they still roll a lot despite having the car pretty low. I know you're running Tein Flexes, which I also have, and these with 8/9 kg indeed make further difference in reducing roll, yet I'd not consider that sufficient and would run sways anyway to keep the wheels on the ground, particulary the inside front one. Link to comment Share on other sites More sharing options...
whitetiger Posted October 19, 2009 Author Share Posted October 19, 2009 well if you go really stiff sways and dont have stiff enough springs and struts you will be more likely to 3-wheel the car. better to have some roll and keep the wheel in the ground than to lift up 1 wheel completely. Link to comment Share on other sites More sharing options...
Guest Posted October 19, 2009 Share Posted October 19, 2009 well if you go really stiff sways and dont have stiff enough springs and struts you will be more likely to 3-wheel the car. better to have some roll and keep the wheel in the ground than to lift up 1 wheel completely. True, rear wheel lift can happen, which is not a good thing, but the discussion was about keeping the front wheels on the ground. Either way, I don't recommend sways only, and as I said the weight transfer on these cars is such, that front lsd is essential to help put power to both front wheels in corners, regardless of the other suspension mods. Link to comment Share on other sites More sharing options...
whitetiger Posted October 19, 2009 Author Share Posted October 19, 2009 ^you know I agree with that. Link to comment Share on other sites More sharing options...
Guest Posted October 19, 2009 Share Posted October 19, 2009 I do Link to comment Share on other sites More sharing options...
rao Posted October 19, 2009 Share Posted October 19, 2009 I actually consider the Legacy to be rear wheel drive. Rob   IF YOU CARE ABOUT YOUR CAR YOU SHOULD NEVER DRIVE IT Link to comment Share on other sites More sharing options...
ppettit2005 Posted October 19, 2009 Share Posted October 19, 2009 FYI, your 5eat is rear biased. Also, they dont make a F-LSD for the 5eat so unless you do a $$$$ MT conversion, you are SOL. really??? rear biased??? if so then yeah, I probably need an alignment and some different tuning done to the front suspension. Link to comment Share on other sites More sharing options...
whitetiger Posted October 19, 2009 Author Share Posted October 19, 2009 yep, the vtd center diff int he 5EAT biases to the rear. its somthing like 45%front 55% rear. Link to comment Share on other sites More sharing options...
ppettit2005 Posted October 19, 2009 Share Posted October 19, 2009 cool, I like that. Link to comment Share on other sites More sharing options...
Gator GT Posted October 20, 2009 Share Posted October 20, 2009 so, FPerron, what did you learn today? "If we are to guard against ignorance and remain free, it is the responsibility of every American to be informed." - T. Jefferson Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.