IwannaSportSedan Posted September 30, 2008 Share Posted September 30, 2008 I read almost incessantly. Sometimes to the exclusion of other activities. Link to comment Share on other sites More sharing options...
Jacks GT Posted September 30, 2008 Share Posted September 30, 2008 Well you are a very helpful fellow, it's good to have ya here Link to comment Share on other sites More sharing options...
Legacy BoB Posted September 30, 2008 Share Posted September 30, 2008 I have a coworker who is way to much into Hondas. He keeps saying how my Subaru AWD system is basic, old fashioned and out dated. This pretty much shows who while a pretty straightforward system, it is used because it works. Of course I'm sure he will have some excuse how it was setup for the honda to fail. Link to comment Share on other sites More sharing options...
Jerboa113 Posted September 30, 2008 Share Posted September 30, 2008 should you inform him his FWD system is basic, economically minded and a veritable torque steer monster? or that boxer 4cyls have a lower center of gravity? or that it makes NO sense that when you mash the gas in a FWD the first thing the damn car does is takes the weight off the drive wheels? and i'm sure there's more but w/o thinking too much.. its fairly easy to come up with a few rebuttals.. What does he propose? FWD rally? does he not understand what rally racing is all about or the fact that GENERALLY the top 2 contenders are quattro and symmetrical systems? (correct me if I'm wrong there...) "The penalty good men pay for indifference to public affairs is to be ruled by evil men." - Plato Link to comment Share on other sites More sharing options...
Jacks GT Posted September 30, 2008 Share Posted September 30, 2008 Audi no longer race Link to comment Share on other sites More sharing options...
IwannaSportSedan Posted September 30, 2008 Share Posted September 30, 2008 I have a coworker who is way to much into Hondas. He keeps saying how my Subaru AWD system is basic, old fashioned and out dated. This pretty much shows who while a pretty straightforward system, it is used because it works. Of course I'm sure he will have some excuse how it was setup for the honda to fail. Good grief, where to even start... Your co-worker has a problem. Honda's AWD isn't even as good as Subaru AWD, let alone their FWD. It may be "new" but is nothing more than overly expensive and complex, while remaining inherently less effective. Real Time AWD than SH-AWD. Old fasioned... how exactly otherwise are you supposed to transmit power from an engine to 4 wheels? We aren't seeing mass-market electric cars with four wheel-hub motors, and a generator plant under the hood. Old fashioned compared to what? If it ain't broke... Most AWD cars on the market have two differentials, and a viscous power-take-off coupling, and sometimes electronic nannies to keep such a system working like AWD, rather than FWD just dragging the rear axle along. Honda, VW, Ford, Mazda, Volvo, Saab, etc... Subaru and Audi Quattro (longitudinal systems), and ATTESSA (sp?) from Nissan/Infiniti, and maybe X-drive (BMW) or 4-matic (MB), and other ultra-rare variants of caddies, lexus, etc... (with AWD derived from RWD) are the ones with three real differentials. Subaru and Audi being the most prevalent AWD in their lines, Subaru being entirely mandatory and standard AWD, and the most highly developed systems, and the most widely available, not to mention just about the only ones available with a manually shifted transmission. If this guy thinks Honda, or anyone else has anything whatsoever on the WRX STI's DCCD-AWD, or the upcoming S4's Quattro with electro-mechanical rear LSD, and 7-speed DSG... short of AWD giants like Nissan GT-R, Porsche Carrera 4, Audi R8, or Bugatti Veyron/Lambo, he's more insane than being just a fanboi. And all other Subaru AWD systems are somewhat related to the WRX-STI's system, with slightly fewer features and different transmissions. Similarly, real Audi Quattro (not FWD-based re-branded haldex in the A3/TT) is also related to the bells-and-whistles system in the new S4. Honda... well, they have FWD. Yippee. Not like they have kept up with the NSX, or the swan-song S2000 rear-drivers. They seem much more interested in CUVs, and making Acuras ugly. Link to comment Share on other sites More sharing options...
SLegacy99 Posted September 30, 2008 Share Posted September 30, 2008 They're making Hondas ugly too with those USB port grilles they are adding. Who designs these damn grilles for them? Link to comment Share on other sites More sharing options...
Jacks GT Posted September 30, 2008 Share Posted September 30, 2008 I dont think we are the right people to complain about how ugly other manufacturers grills are, , Link to comment Share on other sites More sharing options...
Garandman Posted September 30, 2008 Share Posted September 30, 2008 P//If Subaru can come up with a way to combine Variable Torque Distribution with an electronically assisted clutch LSD in both the front and rear differentials, with a constant preload on the rear, and a front diff that can be engaged or disengaged as a limited slip diff, they could solve even the one-front-tire-traction issue, without the parasitic drag and torque effects of constantly steering the front wheels with an LSD between them.//Or, they could just build the WRX STi.....the Legacy system is a tractor by comparison. Who Dares Wins スバル Link to comment Share on other sites More sharing options...
IwannaSportSedan Posted September 30, 2008 Share Posted September 30, 2008 Legacy's system isn't as feature packed, true, but I don't know if I would call it "tractor" in comparison. 5EAT-SS, and Spec B 6MT are not all that far from STI's AWD, only missing the adjustable center diff by the driver, the computer does it, with no over-ride with VDC/VTD. The Symmetric system on the 5MT is not that bad. It has static 50-50 bias, and a limited slip rear diff on the GT. A bit basic, but quite effective. I was under the impression that the normal DCCD-AWD in the WRX STI has no front Limited slip device, that the front diff is open, but I could be wrong. The WRX STI Spec C, and S204, and other variants of the STI have a torsen front and rear LSD, IIRC. That is pretty darn good. The thing is, as I mentioned, that limited slip diffs generate heat. Viscous diffs rely on heat to work, the heat thickens the viscosity of the oil/fluid in the LSD element, and strengthens a fluid coupling between the axle shafts, somewhat like a torque converter. And the front wheels, under any sort of steering angle, start to really differ in wheel speeds, right to left, even a bit moreso than rear wheels. And with a lot of steering work, the front LSD would get quite heated. Not bad in a robust race car... a bit of a different story in a hundred(s) of thousands of miles road car, in terms of bulletproof reliability. I was thinking that an electro-mechanically engaged or disengaged LSD element in the front differential, kind of like an electrically-engaged "locker" differential that trucks use off-road, but not just open or locked, rather open or limited slip. Limited slip, obviously allows some slippage and speed differential, which a tarmac-car needs. A Variable center differential, computer controlled or driver ajustable, a full-time rear limited slip, both of which are already in place, augmented by a front LSD that can be engaged by the stability program, and based on steering angle, more likely to be engaged near center, less likely to be engaged near full cornering lock, and possibly getting programmed input from the speedo signal and abs wheel-speed sensors, which can sense wheel speed differences, or one-wheel spinning. A computer program to engage and direct torque seems better to me, than the programming telling the ABS brakes to grasp any one or multiple spinning wheels to 'emulate' limited slip behavior by preventing spinning wheels from spinning. When trying to gain motive traction from a slick standing start, the drivetrain computer directing torque would be more effective than it juggling the brakes. Audi had started going down the road of Electronic Brake Force Distribution replacing it's trademark use of torsen differentials at the axles, but their new rear differential in the 09 S4 seems to have some advancements and some torque vectoring capabilities, somewhat like SH-AWD's rear differential. Audi's center differential makes the overall system even better than SH-AWD's PTO/viscous coupling to the otherwise FWD drivetrain. Would it not be amazing to see a truly state-of-the-art AWD system, with a DCCD-type computer/driver controlled center diff, with a front and rear electronically controlled, torque-vectoring LSDs, like the new Audi unit, as well, where the front diff can be "opened" sufficiently not to drag and heat-up too much under normal steering activity, but be active when it needs to be. All that hooked to the SI-drive engine management profiles, a double-clutch DSG/PDK type transmission, as well as PSS10 Bilstein electro-mechanical adjustable dampers, and variable ride height control... A nice 'manetino' switch on the steering wheel, or the center console, like the Ferrari F430 that selects programmable profiles for all the systems, engine, transmission, drivetrain, and suspension, and ABS braking profiles... It sounds like isolation from the driving experience at first, but when I think more about it, it seems like technologically assisted versatility. A car that via computer programming acting on the primary control systems, can adjust those systems on the fly. The programming and driver input can optimize them for certain tasks, rather than having a static overall compromise in ride height, damper rates, maybe spring rates (performance air springs?), engine control mappings, drivetrain traction management, ABS frequency and threshold levels, stability control program thresholds, drive-by-wire throttle curves, maybe even exhaust back-pressure (via cutouts or bypass valves), and turbo boost profiles. Race-track/performance, highway cruise, low-speed stop-and-go on broken streets, driveway approaches, snow and ice, gravel/rough roads, fuel economy optimization... all specific real-world profiles that the cars primary systems can be adjusted for, rather than compromising to try to handle all of them. When a phone is now a computer, and a computer is now an internet connected theater, why can't a car be an even more versatile performer via technology? That to me is better use of technology in cars, than nanny-state black box recorders, and onstar-GPS-phone tracking systems that don't report to the driver, or even internet and DVD entertainment systems, and ICE that weighs more than the car does, and shakes all the bolts out of the chassis with too much bass. Link to comment Share on other sites More sharing options...
Jacks GT Posted September 30, 2008 Share Posted September 30, 2008 u asked for that VVG longest post ever! Link to comment Share on other sites More sharing options...
soopah Posted September 30, 2008 Share Posted September 30, 2008 50:50 in the Legacy GT? I thought it was more like 30:70 front to rear power distribution. Where is the reference I can see for the straight goods?! Link to comment Share on other sites More sharing options...
SLegacy99 Posted September 30, 2008 Share Posted September 30, 2008 50:50 in MT models. Link to comment Share on other sites More sharing options...
SLegacy99 Posted September 30, 2008 Share Posted September 30, 2008 I dont think we are the right people to complain about how ugly other manufacturers grills are, , I can. You don't see me in new Subaru with one of them ugly grilles. Yeeuck. Link to comment Share on other sites More sharing options...
Jacks GT Posted September 30, 2008 Share Posted September 30, 2008 I can. You don't see me in new Subaru with one of them ugly grilles. Yeeuck. Link to comment Share on other sites More sharing options...
IwannaSportSedan Posted October 1, 2008 Share Posted October 1, 2008 50:50 in the Legacy GT? I thought it was more like 30:70 front to rear power distribution. Where is the reference I can see for the straight goods?! http://www.subaru.com/misc/sos/index.jsp?from=topNav I would start at the source. Otherwise Google Subaru Symmetric AWD. Symmetric AWD is what the manual transmission 5-speed Subarus have. 50/50 torque distribution, Turbo and H6 models get viscous Limited Slip rear differentials. 6MT in the Legacy GT Spec B has Variable Torque Distribution AWD with Vehicle Dynamics Control (VTD and VDC), and a torsen helical-gear limited slip differentials. STI 6MT has a similar system with an electrical switch on the console, called Driver Controlled Center Differential, which has an Auto mode that is VTD, or manual mode to adjust the rearward torque bias. I don't instantly recall the range of torque distribution, but I believe Auto mode starts at the same static 65/35 rearward bias that the Spec B has with VDC. 5EAT Legacy, Outback, and Tribeca also have VTD and upper models of the Outback and Legacy have VDC. Some lower 2.5i models of Legacy and outback don't have rear Limited Slip Differentials. I think the automatic transmission based center differentials are set to 55% rearward bias, and varies from that point. 4EAT automatics in Imprezas and Foresters may have more of a forward torque bias, I am not as familiar with those base models. I am sure others here can chime in, and the Subaru site above probably outlines it. Link to comment Share on other sites More sharing options...
nismoz Posted October 1, 2008 Share Posted October 1, 2008 2006 5EAT has VTD? I thought only the Legacy from 07-09 has VTD except spec B. Having VTD meaning they can send torque to other wheel if certain wheel spins? Link to comment Share on other sites More sharing options...
Beanboy Posted October 1, 2008 Share Posted October 1, 2008 VTD I believe is an auto-only version of the electronic locker in the STI. So planetary gearset with default split of whatever it is, but goes to locked state when needed, think traditional truck 4x4 system in terms of ability. I kind of like the viscous couplings LSD for onroad vehicles. Reasonable response time with no real funky changes in handling as you might get with some systems. Fairly lightweight and maintenance-free t boot. -B http://www.standardshift.com Link to comment Share on other sites More sharing options...
IwannaSportSedan Posted October 1, 2008 Share Posted October 1, 2008 2006 5EAT has VTD? I thought only the Legacy from 07-09 has VTD except spec B. Having VTD meaning they can send torque to other wheel if certain wheel spins? I could be wrong... but I think all of the 5EAT cars have variable torque distribution, which is a feature of the center differential. The center differential can send more torque to the front or rear axles, within a certain range, from a starting point of 55% rear 45% front. It doesn't really control torque side to side, on either axle, that would be the front or rear axle differentials' jobs. Vehicle Dynamics Control (VDC, not VTD), what is commonly referred to as "stability control" which can limit throttle input, or apply individual brakes depending on chassis yaw and speed sensors, I think is what came along in 2007 and later cars. 2005-2006 Outbacks at the top of the model and option range had VDC, also. I don't think the 2006 Spec B had either VTD or VDC, since it had a 5-speed manual transmission like the 5MT GT Limited. There was no 2005 Spec B, and 2007 was the first year of the 6MT Spec B, and brings the VTD differential with it, gaining a driver's adjustment switch for DCCD in the WRX STI's 6MT. At least that is what I remember. I am sure if that is incorrect, someone will bring up the correct stats. Link to comment Share on other sites More sharing options...
fishbone Posted October 1, 2008 Share Posted October 1, 2008 IwannaSportsSedan, you're right, what I've read pretty much states the same thing, the 5EAT is 4f-55r at a "stand still" or under "normal conditions", but under hard acceleration or deceleration, slipping etc. it shifts tractions front<->back as needed. If you're stuck in muck with only one rear wheel on traction, you may get out. If you're stuck in much with one wheel in the front gripping, you're not getting out. That is, at least, on the LGTs with an open diff on the front. I commented on that video because some people were bitching the presentation was rigged. "Oh noes, I cants see teh rear wheels, what r thay doing". Link to comment Share on other sites More sharing options...
Beanboy Posted October 1, 2008 Share Posted October 1, 2008 With the diff locked, the 5EAT goes from 45:55 to 50:50, negates the gears and acts like a one piece driveshaft. It doesn't actively reduce torque to one set of wheels beyond that 5% difference when the lock occurs and negates the planetary gears. Any actual torque shifting is just based on available traction, ie front wheels off ground, nearly 0:100 if measuring torque at rear wheels. Same could be said of Haldex or truck system though. It is the inbetween times and the default, like Haldex being majority FWD until computer kicks in or an old truck system that is either on or off with no inbetween, that can be annoying. Although the trick rear diffs with two clutch packs so torque can actively be removed from one wheel and sent to another is kinda promising, just haven't seen it on a sports car yet. TL SH-AWD should be telling. -B http://www.standardshift.com Link to comment Share on other sites More sharing options...
Garandman Posted October 3, 2008 Share Posted October 3, 2008 u asked for that VVG longest post ever!Yes, Iwannasportsedan must be related to William Faulkner! In the meantime, for $18K you can buy a Suzuki SX4 with a lockable center differential.... Who Dares Wins スバル Link to comment Share on other sites More sharing options...
fishbone Posted October 3, 2008 Share Posted October 3, 2008 With the diff locked, the 5EAT goes from 45:55 to 50:50, negates the gears and acts like a one piece driveshaft. I just read some pages in the repair manual. Technically it's 44.7% and 55.3% Link to comment Share on other sites More sharing options...
FireB Posted October 3, 2008 Share Posted October 3, 2008 Very nice Hard Fact! Link to comment Share on other sites More sharing options...
Garandman Posted October 3, 2008 Share Posted October 3, 2008 You can feel it autocrossing: you can get the tail out a little and drift out nicely. Who Dares Wins スバル Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.