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With a low hp car, a fwd version is going to be faster than the awd version because of parastitic losses, the awd version faster in a high hp car. What's the hp/lb at which they are the same?

And on a normal road course, autox, whatever, when is one faster than the other?

There is a point at which traction becomes more of a benefit than the weight advantage, but a lot of it depends on how a car is driven. I'd submit that two otherwise equal N/A EJ22 cars, one with FWD, the other AWD, would have very different lap times on an autocross course. An AWD car, even with an open rear differential, is going to offer far better traction in corners than the FWD car. Entrance speed may be slightly higher on the FWD, but AWD should exit faster. On a road course, where weight and acceleration have more of an effect, things might be a bit closer.

Try racing two comprable Skylines in GT3/4...

I noticed my FWD got up pretty quick, as compared to mashing the gas on my 92, which is AWD. But then again, it's comparing red apples to ..some other fruit I don't like, becuase the awd is also an auto. I like the stability and predictability (read: less understeer) with awd than fwd.

I can't compare apples to apples, because the car is now mt vs at. But I will say that the FWD does scoot along really good. They're probably close now since power isn't being lost through the AT.

On handling....I will say that it's freakin amazing how much more grip you have. I can still get a little squirly when doing a u-turn if I get on it...but it's really quite awesome.

With the same tires on identical vehicles and the only difference is AWD/FWD, the FWD will only be faster in a straight line from a roll. This includes long sweeping corners with medium speeds, too.

The horsepower point is only where the FWD can start smoking a tire, so it depends on the power AND the tires.

Brat4by4 wrote:The horsepower point is only where the FWD can start smoking a tire, so it depends on the power AND the tires.

Wouldn't the same improved tires help an awd or fwd car the same amount? Or does a fwd car respond better to tires? This assumes that the awd car has the power to smoke the tires.

scottzg wrote:

Brat4by4 wrote:The horsepower point is only where the FWD can start smoking a tire, so it depends on the power AND the tires.

Wouldn't the same improved tires help an awd or fwd car the same amount? Or does a fwd car respond better to tires? This assumes that the awd car has the power to smoke the tires.

Scott,

The same improved tires will help both types of drivetrain platforms the same, however the AWD already has an advantage before tires come into play, and therefore the advantage will continue, and in certain circumstances can be amplified.

The FWD has a higher hp/weight ratio and less inertia for straight line and gentle curves and other stuff that does not break the traction of its tires. Once it starts to break traction, then it loses any advantage because when AWD does spin a wheel, it is still putting power down somewhere else.

AWD is faster than a FWD...when the FWD is stuck in the mud, sand, snow.


I have a switch on my dash which turns the AWD off an on. I don't do it for speed, just for gas milage.

Ok, similar question. You have 2 cars, they are same model/trim/trans, but one is awd and one is fwd. How much hp do they need to have before the awd is faster in a 1/4 mile?

You don't. The awd will be faster than the fwd. 60' time determines everything. The fwd is only faster from a rolling start. What are you getting at?

If you have 8hp, fwd will be faster because of drivetrain loss.

I'm just wondering.

scottzg wrote:Ok, similar question. You have 2 cars, they are same model/trim/trans, but one is awd and one is fwd. How much hp do they need to have before the awd is faster in a 1/4 mile?

Depends on what you mean by faster? Are you looking for elapsed time or trap speed? TYPICALLY (given some drag radials on both cars and equal power) fwd will have a higher trap speed while awd will have a lower et.