AWD v. RWD v. FWD

[bedabi]

Grassroots Motorsports magazine's latest issue (11/02) did a little test on different drivetrains. Representing their respective drivetrain layout were: the WRX (AWD); the RSX-S (FWD); and the BMW 330i. They were all shod with 205/55YR16 BFG KDW tires and run through a ~40 sec track at Michelin Tires' proving ground.

The results were contrary to the conventional wisdom that RWD cars handle best: (average times)

WRX times: 40.59 wet, 41.988 dry

RSX-S times: 41.58 wet, 42.284 dry

330i times: 42.02 wet, 42.44 dry (DSC off)
42.218 wet, 43.982 dry (DSC on).

The results from both the wet and dry testing reveal the Subaru Impreza WRX as the clear winner among these three cars. Its times were considerably quicker than the other two, while the car was easier to drive at the limit to boot. p. 38

[QuickSilver]

I read that same article...AWD kicks Arse!

Didn't they also have a technical guy who went over each major aspect of handling and his opinion on which of the 3 set-ups would be best theoretically? Even in theory, it sounded like AWD is a superior set-up...all things equal, AWD should win every time....well in theory that is, but the article did do actual road test in some limited fashion and the WRX ruled!

[cutlass4lfe]

I read that article too.....pretty sweet article. To me, it makes me just want to be patient and keep saving for my WRX even more......Especially when it beats a BMW 330i, which is considered one of the best handling cars around under 50 grand....at least to my knowledge.

[smokey]

I'm actually amazed that the RSX-S did better than the 330i...I always thought BMW was one of the benchmarks for handling.

Doesn't suprise me that the WRX won so handly...almost a half-second of dry and a full second on the wet course. Guess all those guys that have said "yea, but I'll race you in the rain, snow, sleet, etc..." have spoken the truth about their cars!

The WRX is a bad-ass car...but I must admit, after seeing this, maybe the RSX-S should get a little more credit. Yes, I'm biased...but coming in with the least amount of hp and supposedly the worst handling, that isn't too shabby. Honda needs to get with the program and offer LSD or something to that effect to improve its handling characteristics though...

[RSXSucks]

Interesting article but I wouldn't use it as a basis for saying AWD > FWD > RWD. I drive a FWD car and I still realize that everything else being equal, FWD is the worst layout for any type of performance competition. Doesn't mean the handicap can't be overcome but it is still a handicap.

Between AWD and RWD I'm still on the fence about which is better performance wise though. Although in streetable race cars, AWD has proven itself to be quite a remarkable platform, there MUST be a reason why the fastest racecars in the world (F1/Indy/even NASCAR) use RWD. I don't believe it is because AWD was banned in those competitions, though I guess I could be wrong.

[bluemax]

There's nothing wrong with FWD performance as long as the platform is on a light chasis. The Integra Type R is a good example of this. They do quite well in the touring class. However, when the horsepower increase, it's more prone to torque steer. When weight is increase, it's more prone to understeer. None of this is desirable when it comes to an all out performance platform.

Happy Mortoring...BlueMax

[KJ0813]

I still go back to the fact that for just about all pro non-rally track racing (F1, LeMans, etc..) the cars are RWD. Acceleration physics are on the side of RWD; it's better for powersliding and drifting. I need no magazine to tell me otherwise, my own track experiences tell me that.

I've never driven a FWD I could really trust in the twisties. On the street, fine, for most people. At the track, forget it, I just don't like the "plowing" effect of FWD cars. Maybe that's just my personal preference, but I know I am much faster with RWD.

Having said that, I do wonder about AWD. I am buying one soon(although with the EVO VIII coming I am torn between the Rexxie and the EVO), and I can't wait to see what I can do with one.

[ScoobySteve]

Originally posted by KJ0813
I still go back to the fact that for just about all pro non-rally track racing (F1, LeMans, etc..) the cars are RWD. Acceleration physics are on the side of RWD; it's better for powersliding and drifting. I need no magazine to tell me otherwise, my own track experiences tell me that.

AWD is just fine on the track for drifting. Not to mention the strong drive you get out of the turns. Drive a WRX on the track and I guarantee you'll get out of the car with a smile on your face.

Not sure why we don't see AWD in LeMans / upper levels of sportscar racing. Perhaps the rules don't allow it. Certainly it's extra weight and mechanical complexity - just more things that can break during a long race. You do see Audi A4's in the Speed Channel GT races. They seem reasonably competitive against the Porsches, Corvettes, etc. but I think they artificially balance things out in that series with weight penalties and so on.

[bedabi]

Powersliding and drifting in F1 and LeMans?

[Iruka]

Handling is all about the car doing exactly the driver's input and the most important thing is that the car's behaviour is telepathic.

RWD Powerslides and a slightly oversteer bias is actually desired for by many competitive drivers who want max control of their cars so they could get more turn-in when required. Even the Type-Rs of the past generations like DC2 and EK9 have had their FWD layout and suspensiion tuned to be oversteery on lift-off when required to tuck the car into line.

For a great RWD handling car to happen, its almost certain that BIGGER tyres are required in the back to get more grip.

In my opinion though, nothing beats AWD, especially when wet!! Well, may be the Skyline GTR's 2+2 ATTESA system and HICAS four wheel steer

[Retro]

Don't be unfair, that 4wheel steer is just too fricken much. Anyways, the fwd can be tuned to work well in short twisties as you can pull some bad azz turns at low speed; you just need a light chassis. The rwd is good for oversteer, and awd can do the same thing, but add some control in it. I would have to say though that for all these types of drive systems, the major contributing factor to how it responds is the weight distribution. An even distribution can give a more neutral feeling to awd, rear to fwd, front to rwd. 50/50 weight is not always desireable.

[Iruka]

Yeah I've read that cars that used to have exact 50/50 weight distribution are actually quite hard to catch when they're just over the limit. Its better to have a front biase, and then use tyre alignment set-ups to counter it!

But if you think a WRX is GOD thru the corners, wait til u drive the STi with the Suretrac Diff in the front - nothing except the EVO VII comes close!

[WRXed]

Originally posted by Iruka
In my opinion though, nothing beats AWD, especially when wet!! Well, may be the Skyline GTR's 2+2 ATTESA system and HICAS four wheel steer

You remind me of a write-up in one of my older Popular Mechanics about a Mercedes with active camber. In corners the camber would automatically adjust to keep the best traction. Of course, we'll never see it in the US. Well, even if we did, I'd never be able to afford it.

[Iruka]

If u know how much effort has actually been put into the EVO VII's YAW and ACD system u'll probably wonder why the heck mercs bother with any camber adjusting function or the active suspension systems!

I can't believe how the EVO VII can beat the STi and GTRs in the corners until I saw them race in the wet!

[JTREX]

Some of the more famous AWD cars, http://4wd.sofcom.com/ClassicCars/Racing.html[/URL]

Audi dominated trans-am racing in the 80's for a few years, IMSA kept adding weight to the cars until Audi said enough and left the series. They were wicked cars.