Can someone explain Subaru WRX's AWD?

The current 2010 Subaru WRX does NOT have front or rear LSD correct? It only has the center differential?

How does that make the car better or worse than a front wheel drive 6-speed with LSD. Namely the 2010 Mazdaspeed3?

I've been confused as all hell about the WRX's drivetrain and the goofballs at NASIOC are all turds that are too JDM to respond.

Thanks.

hey, I'm on NASIOC

are you asking about how is it better in snow or on the track, or what? Obviously the driving dynamics are going to be different when half the power is going to the rear drive wheels (whereas the MS3 rear wheels are just along for the ride).

The dynamics are different for handling. The AWD obviously gives a better capability for launches, particularly on slick surfaces, due to weight transfer.

Also the fact that with FWD car all power and steering is being provided by the front wheels, whereas in an AWD car that is not the case.

I hate to sound simplistic, but without knowing the context of your question, it's hard to know exactly what you're asking. The MS3 on an autocross course or track is pretty comparable in times to the new WRX, but if snow or rallycross is your concern, then the AWD, even with open diffs, is going to be superior to a FWD with LSD....

me = previous owner of several FWD cars with LSD and currenty an 09 WRX, by the way.

and...

irish44j wrote: and...

LoL. You made my day. Thanks for the quick response irish44j.

In terms of performance. I mean, High Performance Driving Days. I currently drive a 2005 Dodge SRT-4 which has a front LSD.

Since the 09 WRX has no LSD in the front or rear, how does that make for a track vehicle? What sort of performance loss is there when compared to an STI drivetrain that does have a Front and Rear LSD.

In regards to a vehicle like the MS3 or SRT-4, how does having AWD with a center differential differ on the road course when compared with a FWD vehicle with a LSD?

Let's talk cornering, turn in, wheel slipping, power transfers.

Damnit, drink the kool-aid!

Reasons why AWD is worse: weight and complexity, which leads to higher buy-in and repair costs and more power loss through the drivetrain, which leads to worse fuel economy.

Reasons why it's better: In a FWD setup, the rear wheels are basically there to hold the rear end of the car up, and that's it. Sure, they add a little braking power, but that's it. If you have traction, power is applied to all four wheels, so shifting your weight rearward under acceleration does take traction away from your powered wheels. In the LSD FWD, the only slipping tires that can be compensated for are the fronts, and then only if just one is slipping. With the only center-LSD of the WRX, you can slip side-to-side, but power will be adjusted fore-aft unless the combined front and rear slip is under the locking threshold in the differential.

FallenAngelHIM wrote:

irish44j wrote: and...

LoL. You made my day. Thanks for the quick response irish44j. In terms of performance. I mean, High Performance Driving Days. I currently drive a 2005 Dodge SRT-4 which has a front LSD. Since the 09 WRX has no LSD in the front or rear, how does that make for a track vehicle? What sort of performance loss is there when compared to an STI drivetrain that does have a Front and Rear LSD. In regards to a vehicle like the MS3 or SRT-4, how does having AWD with a center differential differ on the road course when compared with a FWD vehicle with a LSD? Let's talk cornering, turn in, wheel slipping, power transfers.

I'm going to think on this and get back to you tomorrow. I'm not good at verbalizing "the way cars drive."

I'll leave you with this: the WRX and an MS3 are going to put up similar times in either open track or autocross duty generally-speaking (assuming comparable tires). Having driven both, I think the WRX is far more fun to drive.

And, you can always add an LSD in the rear.

You can't add AWD to and MS3 :)

the post above mine is dead-on, btw.

FallenAngelHIM wrote:

irish44j wrote: and...

LoL. You made my day.

I'm betting few people here will get the reference, hah..

one of my good friends hangs out with Ville quite often.

and while I'm postwhoring.....

Unlike the new Mazda3's....WRXs don't have smiley-face grilles

irish44j wrote: and while I'm postwhoring..... Unlike the new Mazda3's....WRXs don't have smiley-face grilles

Sedan actually doesn't look that bad. I always thought the new Sedan's looked like butt, but yours might make me a believer.

I know that you can add LSD later, but if I'm buying a car might as well get as much goodies in early on as possible from factory. I came to the realization that $35k for an STI was unrealistic for me and that led me back to the WRX vs. MS3.

ReverendDexter wrote: Damnit, drink the kool-aid! Reasons why AWD is worse: weight and complexity, which leads to higher buy-in and repair costs and more power loss through the drivetrain, which leads to worse fuel economy. Reasons why it's better: In a FWD setup, the rear wheels are basically there to hold the rear end of the car up, and that's it. Sure, they add a little braking power, but that's it. If you have traction, power is applied to all four wheels, so shifting your weight rearward under acceleration does take traction away from your powered wheels. In the LSD FWD, the only slipping tires that can be compensated for are the fronts, and then only if just one is slipping. With the only center-LSD of the WRX, you can slip side-to-side, but power will be adjusted fore-aft unless the combined front and rear slip is under the locking threshold in the differential.

So based on this, even if either the Front and Rear axles on an AWD are slipping, the center differential should more than accommodate the corrections needed? In that case the AWD would do more in terms of power compensations for any wheels slipping than the FWD with LSD since both rear wheels aren't doing anything?

Now, would you be able to breakdown how the entire STI AWD system words with Front, Rear, and Center differential?

FallenAngelHIM wrote:

irish44j wrote: and while I'm postwhoring..... Unlike the new Mazda3's....WRXs don't have smiley-face grilles

Sedan actually doesn't look that bad. I always thought the new Sedan's looked like butt, but yours might make me a believer. I know that you can add LSD later, but if I'm buying a car might as well get as much goodies in early on as possible from factory. I came to the realization that $35k for an STI was unrealistic for me and that led me back to the WRX vs. MS3.

lol thanks....I like the low-key look of the sedan. NObody notices you :)

MIne has a bit of cosmetic mods (all the chrome trim blacked out, grille blacked out, spt dual exhaust, and STi springs for about 1/2" drop...and my Rotas in that pic). BOne-stock they look kinda lame, but a few key cosmetics can take care of that.

Here's the back end with the SPT duals :)

FallenAngelHIM wrote:

ReverendDexter wrote: Damnit, drink the kool-aid! Reasons why AWD is worse: weight and complexity, which leads to higher buy-in and repair costs and more power loss through the drivetrain, which leads to worse fuel economy. Reasons why it's better: In a FWD setup, the rear wheels are basically there to hold the rear end of the car up, and that's it. Sure, they add a little braking power, but that's it. If you have traction, power is applied to all four wheels, so shifting your weight rearward under acceleration does take traction away from your powered wheels. In the LSD FWD, the only slipping tires that can be compensated for are the fronts, and then only if just one is slipping. With the only center-LSD of the WRX, you can slip side-to-side, but power will be adjusted fore-aft unless the combined front and rear slip is under the locking threshold in the differential.

So based on this, even if either the Front and Rear axles on an AWD are slipping, the center differential should more than accommodate the corrections needed? In that case the AWD would do more in terms of power compensations for any wheels slipping than the FWD with LSD since both rear wheels aren't doing anything? Now, would you be able to breakdown how the entire STI AWD system words with Front, Rear, and Center differential?

^^ exactly.

The best part about the STi system is the ability to change the torque split from the static 50/50 in the wrx to (as I recall) up to a 20/80 split front or rear....

irish44j wrote: Here's the back end with the SPT duals :)

Even better. The back end of the Sedan was what turned me off. You, sir, have a very nice WRX.

I guess I'm kind of a snob when it comes to buying it new. That's why I posed the question to understand better. I assumed FWD 6-Speed with LSD was better than AWD 5-Speed no Front and no Rear LSD. I was just being a geek and wanted a damn LSD. Now, I know the difference.

FallenAngelHIM wrote:

irish44j wrote: Here's the back end with the SPT duals :)

Even better. The back end of the Sedan was what turned me off. You, sir, have a very nice WRX. I guess I'm kind of a snob when it comes to buying it new. That's why I posed the question to understand better. I assumed FWD 6-Speed with LSD was better than AWD 5-Speed no Front and no Rear LSD. I was just being a geek and wanted a damn LSD. Now, I know the difference.

now, go drive the damn cars and see which one is more fun already!!!

(figured someone into HIM would like the blackout of the car, lol)

FallenAngelHIM wrote: Even better. The back end of the Sedan was what turned me off. You, sir, have a very nice WRX. I guess I'm kind of a snob when it comes to buying it new. That's why I posed the question to understand better. I assumed FWD 6-Speed with LSD was better than AWD 5-Speed no Front and no Rear LSD. I was just being a geek and wanted a damn LSD. Now, I know the difference.

Having been in enough awd and fwd cars on and off track, almost all of the time I would say I would prefer an awd car except in very specific circumstances. And, if you drive your car on the street, the advantage (in my mind) actually becomes more pronounced in an awd car. There is nothing, I repeat, nothing, like sliding massively sideways in an awd car in the snow (even rwd ends up being not as fun IMO). Big massive power through two wheels is cool, but big massive power is amazing when going through 4 wheels.

One thing I think you are failing to consider is that unless there is slip, power is distributed quite evenly throughout an awd system. Therefore, there is also less chance of tire spinnage due to the fact that there is not as much use of said tire's friction to begin with, compared to a 300whp fwd car.

HiTempguy wrote: One thing I think you are failing to consider is that unless there is slip, power is distributed quite evenly throughout an awd system. Therefore, there is also less chance of tire spinnage due to the fact that there is not as much use of said tire's friction to begin with, compared to a 300whp fwd car.

That is a good point.

I think you are over stating the importance of an LSD in a AWD car. With AWD you really don't need it. I had a A4 with open diffs and a torsen center, a Talon run with both a welded center and viscous center with a limited rear both configurations. Traction was never an issue with either. The Talon was always a rally car and I did rallyx with the Audi. The only real difference was at speeds over 90 in the Talon on gravel with the welded center it felt like it wanted to dance more. The Audi I could keep sideways longer in the snow for fun (almost forever if you didn't find a traction patch).

irish44j wrote: and...

My friend once asked what I thought of H.I.M. I said it sounded like popish metal for 14 year old girls. She thought that was pretty funny, as she had just moved here from Finnland. I guess they are huge there, as that's where they are from. She really likes them. She like American Idle as well.

Joey

I at the time didn't know they were from finnland when she asked, by the way. I guess that makes the story a little funnier.

Joey

My GVR4 was originally equipped with a LSD center diff and open front and rear diffs. I think the question you were originally asking is "how is having 1 front and 1 rear wheel receiving power better than having 2 in front?". To that I offer this... Even before I upgraded to a rear LSD, I was able to consistently pull off 1.7 sec 60" times at the drag strip on unbranded all season tires. That's 0-60 in just over 4.5 seconds on generic 15" rubber. Even though it doesn't seem like it'd work on paper having only 1 driven wheel in the front and the back, it still does.

So is anyone actually going to answer his question? "The current 2010 Subaru WRX does NOT have front or rear LSD correct? It only has the center differential?"

AWD makes anyone fast, and is very forgiving, I owned a WRX and while it was a very quick car it sort of let me down a bit, IMHO driving a 2WD car as quick as an AWD car shows that you can drive, the reverse means you are in an AWD car.

This is just my opinion, and I prefer RWD anyway.

I agree with aussiemg RWD wins in my book. You can power the car with the rear wheels whilst using the fronts to steer! Amazing concept right?

I'm not sure that the center diff has the capability of splitting power 50/50 in the WRX. There is a notorious video on Nasioc of a WRX with a 2x4" in front of the front wheels, and the rear wheels in the air. The car couldn't muster enough power to the front wheels to climb over a 2x4" with the rear wheels off the ground.

Personally, I hate monster torque steer, so that's enough justification to pick AWD over FWD for a high-powered autox'r / daily driver.