When do the rear wheels get power

[boxkita]

This thread has given me more motivation to do an STI swap for better diffs all around.

 

As you have posted about doing this before (search is a powerful tool), here's a few threads to get you back up to speed:

http://legacygt.com/forums/showthread.php/6mt-quaife-atb-center-differential-interesti-174143.html?t=174143&highlight=QUAIFE

 

http://legacygt.com/forums/showpost.php?p=4296987&postcount=765

 

http://legacygt.com/forums/showthread.php/so-just-picked-up-one-these-subaru-front-lsd-99463.html?t=99463&highlight=QUAIFE

 

IDK if the quaife group buy could be revived, however, I've always thought that would be a nice upgrade to go along with my other "if I won the lotto" upgrades.

[Beanboy]

Ha!

 

Subaru doesn't have a rally race division anymore and hasn't for years. I bet the tranny's they have are pretty tricked out. LSD mech front/rear and locking center diff. They then sell us all on an 'amazing awd system straight from their rally cars' which is disappointingly not true.

 

In the US they do: http://www.subaru.com/enthusiasts/rally/cars/rallyamerica.html. Stock STI center diff that's remapped along with Cusco f/r diffs which I believe you can buy.

 

With that said, which company has sold anything remotely close to their race-prepped vehicles from their ads in their street cars?

 

The most recent debacle with the Ford Raptor comes to mind. A supremely capable factory truck, but folks were treating it like a Baja racer and bending frames.

 

Anyway, there's plenty of things you could say was wrong with Subaru's AWD system, but for all the stock systems disadvantages, you have plenty of advantages as well. Lightweight, always on so there's far less unsettling of the chassis when slip does occur, equal length driveshafts all around, fully mechanical, etc..

[wpmarky]

Thanks for the refresh, got them all bookmarked eh?

 

I still wanna do a track day with you some time, I'm eyeing Sears Point 11/23... only $199 with TrackMasters Racing if you're interested.

[boxkita]

Thanks for the refresh, got them all bookmarked eh?

 

I still wanna do a track day with you some time, I'm eyeing Sears Point 11/23... only $199 with TrackMasters Racing if you're interested.

 

You & Max both. All my track days are in 2014. And no wagon. It's a miata or nothing. We'll see, I'd like to come down from Seattle and run on a track or two in California. Maybe Thunderhill.

[wpmarky]

oh you moved to seattle? bummer i thought you were still in sac

[wpmarky]

i wanna do one of the pnw courses

[boxkita]

actually I was always in Seattle. My folks live part-time in LA, so I come down for a visit.

 

If you want to do a course, I'll meet you at the airport to lead you & your rental car to the track :-).

 

Max has offered to find me a car if I come down. So I might have to take him up on that this Jan/Feb

[rob-2]

You & Max both. All my track days are in 2014. And no wagon. It's a miata or nothing. We'll see, I'd like to come down from Seattle and run on a track or two in California. Maybe Thunderhill.

 

I like thunderhill. If you go I'll pop over the mountain and join you in my S

[JMLegacy]

Ironic, I experienced similar problem today. There is an offroad i travel sometimes that has a hill. I got stuck on the hill with the front left wheel being the only one spinning.

 

I knew i have open diff in the front so i know that was the reason. But still, like most others i've been sold on AWD meaning all wheel getting power and no slips. Wrong!

[idiot4hire]

That's it I am getting a sti now

[iNVAR]

Very long, but good to watch. Have a few Subarus in there.

 

[ame=http://www.youtube.com/watch?v=tpp5tW71qYI]AWD sistems wars (testing) on rollers - YouTube[/ame]

 

The important thing that you have to remember is that you are limited greatly by the amount of traction you have. Look at about 33 minutes into the video, where they have a Subie up. You have to remember that at engine speeds <2K, you are producing very little torque. Take that torque, divide it amongst all your wheels, and the bottom line is that the wheel or two that you have that DOES have traction simply isn't getting enough torque at those low speeds.

 

Sometimes, you can try revving it to higher speeds to your torque peak and that can pull you out. A lot of people baby their throttle when they're stuck. That helps, if you're trying to regain traction because of tire slippage. But we have AWD. That's not always what you want to do. Sometimes you just need to produce enough torque. Note how the guy finally gets out at around 33:45. I believe he revs the engine up a bit and drops/slips the clutch quickly to give it the kick it needs to get out.

 

He does it again (gets out) at 34:40, but note he's revving the engine up this time.

 

Then at 35 minutes in, I believe (I don't speak Russian I think it is?) he asks for a redo for all 3 wheels because he thinks he figured out what I said above and it'll work.

 

Then 37 minutes in, he's got the "diagonal" stuck thing going.

[iNVAR]

They actually put a lot of subies up there. Pretty good video to watch if you guys have time. Tons of cars get stuck. They really put them through the wringer.

[rob-2]

Very long, but good to watch. Have a few Subarus in there.

 

 

The important thing that you have to remember is that you are limited greatly by the amount of traction you have. Look at about 33 minutes into the video, where they have a Subie up. You have to remember that at engine speeds <2K, you are producing very little torque. Take that torque, divide it amongst all your wheels, and the bottom line is that the wheel or two that you have that DOES have traction simply isn't getting enough torque at those low speeds.

 

Sometimes, you can try revving it to higher speeds to your torque peak and that can pull you out. A lot of people baby their throttle when they're stuck. That helps, if you're trying to regain traction because of tire slippage. But we have AWD. That's not always what you want to do. Sometimes you just need to produce enough torque. Note how the guy finally gets out at around 33:45. I believe he revs the engine up a bit and drops/slips the clutch quickly to give it the kick it needs to get out.

 

He does it again (gets out) at 34:40, but note he's revving the engine up this time.

 

Then at 35 minutes in, I believe (I don't speak Russian I think it is?) he asks for a redo for all 3 wheels because he thinks he figured out what I said above and it'll work.

 

Then 37 minutes in, he's got the "diagonal" stuck thing going.

 

Interesting video.

 

I've hit '80 mph' wot stuck with one wheel up front bleeding it all out.

 

I really do think Subaru and the like have seriously over sold their AWD platforms and I think the general public thinks because they rarely get stuck that it proves the AWD system works. Fact is I've rarely got stuck in a FWD car in the winter too.

 

All the base AWD systems are hindered by one tire lifts and traction isn't the factor. It's because there is nothing in the system that forces the power to the other wheels.

 

If you look at the more sophisticated systems from Honda, Toyota, Land Rover etc. They often use a computer system to monitor the ABS sensors and apply a brake to the slipping wheel. This puts the power through the other wheels. The best systems can move the car forward on one wheel alone.

 

For a company like Subaru to base their cars on their H4 and AWD system they've really done little in 20 years to improve their systems. As you can tell by now I've had it with their marketing machine. The motor and AWD system really fall short.

 

A Toyota Land Cruiser from 11 years ago would eat anything Subaru is making in a traction test. Need a sedan, the TL SH-AWD will power the car on as little as one wheel. Where it's old or new AWD system's there are platforms out there that actually work.

 

The Subi system it's basically a FWD system in low traction.

[rob-2]

They actually put a lot of subies up there. Pretty good video to watch if you guys have time. Tons of cars get stuck. They really put them through the wringer.

 

They get stuck because they're very basic AWD systems. No logic or mechanical stuff to properly transfer power.

 

Sadly the cost is really low to provide a basic brake fix via the ABS system.

[iNVAR]

Dude, come on, you made a thread about this 2 years ago, with very detailed explanations by other members.

 

http://legacygt.com/forums/showthread.php/05-legacy-gt-stuck-dry-conditions-168788p2.html

 

I am wondering if I had applied the brakes gently if that would have helped? Thoughts?

 

Could this have simulated tire contact?

 

no, this only works if you have a torsen/helical active torque biasing diff. with those, the wheel with traction is given a biased tq amount compared to the wheel that is about to slip. the amount that is biased is based on the amount of traction the slipping wheel has. using the brake to simulate traction on a free wheel in the air will bias tq to the other wheel and move the car.

 

with these kinds of diffs, VDC works better since it will brake the spinning wheel and activate the diff to transfer power. this is why VDC in the 6mt sti makes the most sense. the STI has ATB diffs front and rear.

 

It seems like every month or so you come up with another gripe about our cars and how Subaru sucks and some other car is superior in some way or form. I still remember your thread complaining about our cars and how they "fall on their faces."

http://legacygt.com/forums/showthread.php/falling-its-face-197514.html

 

Subaru hasn't done nothing or "very little" in 20 years. Like every car company, they have to constantly develop and research, although I do have to admit they really do market the crap out of the "symmetrical AWD" thing. The real benefit of the symmetrical AWD isn't for getting your car out of stuck situations.... it's for maintaining stability when your car is actually already moving and you're applying throttle.

 

Also, it hasn't been until recently in the past decade that car manufacturers have really been jumping on the AWD train when Subaru's been doing it for a long time. Subaru actually has MANY different implementations of AWD. YOUR car (and mine) is EIGHT YEARS old already.

 

The fact of the matter is that all AWD systems are not built the same way, and fixing it isn't a simple matter of putting a "brake fix via the ABS system". If it were really that easy, everyone and their mother would have already done it and we wouldn't be having this discussion.

 

There are compromises and design concerns related to every production AWD system out there and they are all susceptible to different low traction situations. There is no such thing as the perfect AWD system. An LSD is exactly that: limited slip, not non-existent slip. All systems have shortcomings.

 

As I said, if you want a car that can get over all terrains and climates without a problem, get something with the ability to fully lock all the differentials. Get a real off roading vehicle. You might end up with a HMMWV then.

 

Meanwhile, you're holding up an 11 year old car designed for real off roading (a Toyota Land Cruise) and comparing it to soccer-mom type SUVs and sporty grocery getter AWD sedans like the LGT and WRX? I bet if you threw on a front LSD in your car it would’ve helped. Or better yet, don’t drive your car into a ditch. ;-)

[rob-2]

Dude, come on, you made a thread about this 2 years ago, with very detailed explanations by other members.

 

http://legacygt.com/forums/showthread.php/05-legacy-gt-stuck-dry-conditions-168788p2.html

 

 

 

It seems like every month or so you come up with another gripe about our cars and how Subaru sucks and some other car is superior in some way or form. I still remember your thread complaining about our cars and how they "fall on their faces."

http://legacygt.com/forums/showthread.php/falling-its-face-197514.html

 

Subaru hasn't done nothing or "very little" in 20 years. Like every car company, they have to constantly develop and research, although I do have to admit they really do market the crap out of the "symmetrical AWD" thing. The real benefit of the symmetrical AWD isn't for getting your car out of stuck situations.... it's for maintaining stability when your car is actually already moving and you're applying throttle.

 

Also, it hasn't been until recently in the past decade that car manufacturers have really been jumping on the AWD train when Subaru's been doing it for a long time. Subaru actually has MANY different implementations of AWD. YOUR car (and mine) is EIGHT YEARS old already.

 

The fact of the matter is that all AWD systems are not built the same way, and fixing it isn't a simple matter of putting a "brake fix via the ABS system". If it were really that easy, everyone and their mother would have already done it and we wouldn't be having this discussion.

 

There are compromises and design concerns related to every production AWD system out there and they are all susceptible to different low traction situations. There is no such thing as the perfect AWD system. An LSD is exactly that: limited slip, not non-existent slip. All systems have shortcomings.

 

As I said, if you want a car that can get over all terrains and climates without a problem, get something with the ability to fully lock all the differentials. Get a real off roading vehicle. You might end up with a HMMWV then.

 

Meanwhile, you're holding up an 11 year old car designed for real off roading (a Toyota Land Cruise) and comparing it to soccer-mom type SUVs and sporty grocery getter AWD sedans like the LGT and WRX? I bet if you threw on a front LSD in your car it would’ve helped. Or better yet, don’t drive your car into a ditch. ;-)

 

It actually is that easy. It costs money to design the program for the ECU to manage the power distribution. If you have a computer controlled AWD you can move to open diffs and lock up the wheel that is spinning. ECU controlled AWD based on my understanding are cheaper then a mechanically locking center diff, but still more money then the AWD we have.

 

I guess I keep getting disappointed every few months when I run into another issue. The first time this happened I didn't bother to research it. This time I had time to study the problem in the real world and follow up with it afterwards. I recall getting suck in Tahoe on a front wheel lift in the summer, but forgot I posted it up.

 

I've never owned a car that has been so disappointing. I guess I keep kicking myself for keeping it, rebuilding the motor and fiscally forced to keep it less take an even bigger loss on the vehicle in the short term. I really do like the looks of the car and it's size though. It's not all bad just a far cry from what I'm used to engineering wise on a car. Subaru could and should do better. They have stated 55% of my power goes rewards, but it doesn't. Sometimes zero goes rewards.

 

Keep in mind I have an LSD in the rear and that doesn't help much. Around here if you don't have the AWD badge on your car you're often forced to throw on chains during snow fall in the mountains. Though based on what I know now I basically have a 2 wheel drive car.

 

I should stop harping on the car and just drive it until I ditch it.

[wpmarky]

Sounds like you need to get a truck or SUV with a locking center diff for a true off road capable vehicle, or stay off the rugged roads in a family sedan.

 

I haven't had any problems driving around tahoe in my wagon + LM22's. Coming from my old 99 Maxima, I'd much rather be sliding sideways on ice with my subi than the maxi. Much easier to recover and drive with confidence.