This thread completely lacks any information of substance or usefulness.

Also, the Subaru = only AWD is only for the North American market. In other markets, they do FWD platforms as well (barring the BRZ).

I have somewhat of a grasp about how the Evo AWD with ACD system works. Now let's find someone who has a good grasp of the Subaru system and compare notes. I think you will find that differentials are situational where one system works better than another. So, I could devise a test that will significantly favor one system while severly handicapping another.

Considering the aftermarket availability of different differential systems (Quaife, Wavetrace, OS Giiken, Cusco, etc.) that will go into our stock housings, I think this argument is pointless.

 

You could run the drive shaft up the A pillar, above the headliner, down the C pillar and through the trunk. What's the difference, the rear wheels still have drive? Supposedly the Subie's engine has a lower center of gravity. I'm not sure I even believe that. Open the hood of my WRX and there is engine stuff, manifold and intercooler right up to the top of the engine compartment. So, what it comes down to is which company wants to put more money into fancy differentials and suspension.

 

This is probably the only post in this thread worth reading. Barney's makes a relatively good point as well.

First, the way you're implying that the Evo's AWD system is FWD based is incorrect. You're saying that the base car for the Evo is FWD, so the Evos AWD system must be FWD based, which would be like saying since the Audi TT is based on a VW Golf, it must be a hatchback.

1. The Evo's AWD system is not, nor has it ever been FWD based, or FWD biased at all. It is a 50/50 AWD system.

2. The STi and all Subaru AWD systems in current production use something called "Symmetrical AWD". Symmetrical AWD is different in the actual, physical structure and geometry of the system. The simplest way to explain it would be to think of the center diff in the center, the front diff at the front, and the rear at the rear. The wheels at all 4 corners (sound like every other AWD car on the planet yet?). The DIFFERENCE is essentially that all of the pieces that connect all of these parts are the same length/size (I'm being VERY broad here) which enables an equal amount of power to be shifted in any direction without having to be compensated with a computer.

ie. The right rear wheel receiving 100% of the power from the motor would put down the same amount of power as any other 1 wheel in any given scenario. This is one of the reasons that you see all of those cool videos on YouTube of Scooby's being able to accelerate forward when only 1 wheel has grip.

3. The reason for the understeer in the Evo, or any car really has nothing to do (directly) with the way the AWD system is functioning. AWD can of course assist with quelling understeer, but when you have a high horsepower car, and you're trying to accelerate out of a turn, the weight shifts backwards which unweights the front wheels, and as such... you understeer.


So... to recap. The tl;dr version.

1. The Evo is 50/50. Always has been. It is NOT a FWD system in any way, shape, or form.
2. Subaru's system isn't necessarily "better" but it's certainly different.
3. Understeer is not caused, nor fixed by having AWD.

 

To that end... I would LOVE to see how it performs on one of those racks where you can enable/disable the wheels grip. I'd like to see how the Evo performs in those situations.

 

Both the evo and the STi have won many rally races, however, data shows that the STi does not require superstar skills to win.
Most of the evo's wins have been with Tommi Makinen, and Mitsubishi has NEVER won a WRC without TM driving.

 

Oh... well case closed then! The STi is definitely better.

 

This has nothing to do with the STi being better, however, the car should be able to win championships with a professional driver.
Please view very useful info :
pg 2 post 11 Carl T
http://backfires.caranddriver.com/fo.../224599?page=2

 

Differentials with clutch plates like the stock Evo's will fall on their face. With 0 traction, they act as open differentials. Even with low traction, their torque transfer rates is poor.

Gear differentials like the Quaife ATB units are a different story.

Same with the Wavetrac differential.

In terms of which one is the best for racing, rally, etc. I think it comes down to situation. I know clutch plate differentials have turned in better times on the track than other types (apples to apples: Quaife vs Cusco vs OS Giiken on an S2000). With rallying, you would probably favor the Quaife ATB or Wavetrac units as there is lower traction.

edit:
Also, the only biasing to front wheel drive that the Evo has is driveshaft slop. The front differential is fed straight from the center differential. The rear differential is fed from the driveshaft. If you consider the axles the same length, then the only difference in how quickly the torque is applied is the the driveshaft slop + the difference between rear differential and front differential slop from input torque.

 

Yes, point made... drivers win races, not cars. But that isn't new, and there are other factors in play, such as the fact that Mitsubishi essentially was non-existent as a factory sponsor for WRC from basically the Evo 7 onward.

Right. I wasn't necessarily saying that it would out-perform anything, I was saying it would be interesting to see how it handled itself.


On a thread related note, don't confuse Mitsubishi's OTHER AWD systems with the Evo's system. They're similar the way a porsche and a beetle are similar, but one is built for performance, and the other is built to get people through the parking lot at the mall.

 

The Evo is much more balanced than an STI which will leave you under steering the whole way home. The only thing an STI is good for is bumper stickers.

 

ive had my evo for 8 years and when my wife got a legacy gt back in 2006 i prefered her car to drive. i never could put my finger onto why but subie has the better awd setup in my opinion. it just makes you feel safer and more controlled.

 

That thread has about as good of information as this thread started with. That Carl T guy is a moron and as far as I can tell, no one in there is actually putting out any information besides crap found on wikipedia. Lap times/wins are a combination of car setup and driver skill. How those are applicable to the drivetrain is beyond me.

 

Has anybody in this thread mentioned that you can rearrange the plates (or go to 12 or 16 plate setups) in the USDM Evo rear diff, which gives it power oversteer? The Evo already spanks on the STI with its understeer-y incorrectly locking rear diff, but once you mod it to how it's supposed to be... the STI gets left even further behind.

 

While it isn't comparing apples to apples (neither is comparing the two cars of the same year really, but they're much closer) I will say that my '08 STi had much better handling/awd system than my '03 Evo did. The Carrera 4 I owned for a while was better AWD for in the dry while still being decent in the snow (IIRC it is a 20/80 split of power unless it senses need to switch and then it can go all the way to a 40/60 split).

That all said. Hands down the best AWD system of any car I've ever had the chance of driving many times both hard in the dry and in the snow is Audi's quattro, particularly a 2003 Audi TT 2.0t. I had to drive the family car one time the Porsche was in the shop, it had summer tires on it and there was a few inches of snow on the ground. The Audi ate through it like it was nothing.

Even more so, that all said about AWD. I'm blown away on a daily basis at how well VW has set up the electronic stability control on the GTI in that it feels more like an AWD car in the dry when cornering (still slippy front tires in the wet/snow though). I'm amazed at how much less my FWD car understeers compared to my Evo and STi. Point is: technology just keeps getting better and better so I'm guessing of equal years the Evo and STi are probably very close in terms of how their AWD works.

 

Your '03 USDM Evo didn't even have front LSD, and it also has the lame USDM Evo rear diff. Worst handling USDM Evo by far. Not a fair comparison. '04 RS, 05+ Evo's, or X is a better comparison.