GeneralTso

I was reading through that thread by Project 951, and I didn't want to hijack that thread with a technical question....

Maybe this is a dumb question, but does 4WD really help with braking during a panic stop? The only way I could imagine it helping is through engine braking, but in a panic stop wouldn't having the brakes fully applied nullify any benifits of engine braking? It's hard to imagine engine braking coming into play while the Evo's ABS is working...

Thoughts?

tifosiman

LOL, you gotta love that irony. Tso, you just made my day with that comment! LOL.

Nope, shouldn't help at all. Maybe the original poster meant "4-wheel-disc" instead of "4-wheel-drive" . Yeah, that's the ticket.........

Phi1720

Tifo beat me to it, but thanks for starting my day with a smile

As already stated, 4WD only powers the wheels to move or move faster. Discs and pads make a car stop.

M758

Sad thing is today's kids think that with 4wd the car stick to any thing. Wrong. The only thing awd does on dry or even wet paved road is to distribute the power between 4 wheels rather than just two. So if you have issues putting hp down awd will tend allow you to accelerate our a little quicker.

It is zero impact on cornering or and minimal impact on braking (engine braking only).

Tom R.

One of my favorite memories is driving back from a week at mount snow in a snowstorm. Yes we were driving home like fools.

As we were muddling through in my friends moms RWD maxima trying to keep the wipers from freezing a fool in a blazer/jimmy blasted past us in the right shoulder where it wasnt plowed. Yes, 4wd will help in those situations. whether it will help on a relatively flat surface with all seasons more than a set of snows on a FWD car is up for debate.

Well, maybe a half hour later we see einstein on his side on the side of the road. i guess the laws of physics and high center of gravity etc. outweighed the benefit of traction under acceleration. 4WD does nothing to stop you faster. Brakes and tires make you stop.

It is my opinion that a FWD car with 70% of the weight over the front wheels and a decent set of snow tires will get the driver through as much snow as a 4WD vehicle. On the road that is. I am not talking about off roading.

BlueDog944

Don't confuse 4WD with AWD. Two completly different things. The EVO is AWD. An pickup like an F250 is 4WD.

I would beg to differ.. .having had several FWD cars, 4WD (trucks) and AWD (Audi), no way a FWD can go through nearly as much. With FWD once you loose the slightest bit of traction you loose your ability to steer as well. With AWD its much more forgiving in the snow.

Now I would be willing to bet I can go through much more with my Audi allroad than my F250 4x4.

GeneralTso

There's definately benefit to 4wd for engine braking when you're off-road in a jeep in low-range going .2 MPH down a steep hill on loose terrain...but I think you guys are right that it's all about brakes and tires when you're trying to stop on the road/track.....

Thanks for the sanity check, guys!


Jeff

spazegun2213

Yea, after tracking my subaru a lot, and going to my 944, I can tell you all that AWD does not help a car stop but it does help it go

however the differentials in the subaru may effect braking a tiny tiny amount....

Tom R.

my FWD car with four snows against your AWD audi with four all seasons.

my point being most people buy awd cars and think they can get through anything with all seasons. I think i can get through as much (and perhaps more depending on tread left) on the road with FWD and snows.

I think we need mythbusters for this one. But madison avenue is their sponsor, and madison avenue has the general population "needing" awd cars.

Jon Moeller

It never ceases to amaze me that people will push the limits of traction on a track in a RWD car still question it's abilities in the snow. The only thing that I can figure is that it's some legacy caused by the front heavy muscle cars and pickups that most people think of when you say "rear-wheel drive".

Regardless, the driven wheels have no impact on maximum braking ability of a car. Assuming that the brakes are powerful enough to lock up the tires, the tires are the limiting factor in braking performance. Better tires mean better braking ability. Changes that better set the brake balance can maximize the performance for given tires, but again, ultimately, braking performance boils down to tires.

The kid that started the other post has a severe knowledge deficiency. I don't think there was any educational content in there, whatsoever.

Edit: TomR, I couldn't agree with you more. I'll take all comers in a BMW (a real RWD Bimmer with LSD, not some POS AWD) with snows. 50/50 weight distribution can't be beat.

-Jon (with an Audi A4 Avant Quattro that I'd happily trade for a nice RWD BMW wagon)

ANORXIC'51'

Sad to say, as much as I dislike computers driving the car for you...I'd take the AWD system of an R32,33,or 34 GTR over the 50-50 distribution of the 944 series any day of the year.

Of course the extra icing is the nice little RB26DETT holding down the front of the Skyline :-)

959Lover

But if you let go of the accelerator in the FWD car, you would regain control (assuming you were understeering)

Rally Guy

I have spent something beyond 200 hours competively driving AWD rallly cars in the snow and ice. I've outpaced many accomplished drivers of FWD cars who just could not lay down the power in the snow and ice like I could with a good AWD system (viscous center and torsen rear difs).

However - I've also been soundly beaten by a FWD Tercel (!) driven by a total master. No, he could not launch, nor get up hills like I could - but his abiilty to carry speed though the twisties (driver's skill) made up for that. But many times he'd lament his inability to get going with just FWD. We were both on brand new Blizzaks (sometimes tractionized).

So, except where the driver is incredibly talented and seasoned (and you'll already be winning rallies, so you know who you are) AWD is going to outrun 2wd everytime.

RK

fork_included

i would disagree if we are talking moderate power and dry pavement

if a RWD can power out of a turn and not burn out due to power, then if it was AWD instead the effect would be the same

AWD is for poor weather conditions, as demonstrated by almost any auto-cross outing on a rainy day where subaru's will dominate, while they get spanked by civic's when its dry.