Fwd slower?

[lukeh]

I am very intrested in Fwd. I only know a few reasons why they arent as fast a Rwd and 4wd. could people please tell me why they are slower?

[Matra et Alpine]

Traction.
When a car accelerates the weight trasnfers to the rear. With less weight on the fronts the tyres are more likely to slip and NOT bite. With RWD the weight trasnfer IMPROVES the traction With 4WD it depends on the diff setups !!

Handling.
Some aspects of FWD handling is better, the ability to enter a corner at MUCH higher speed and lift off to remove the unersteer and to left-foot-brake to initiate oversteer can make for faster transition on some corners.
Some aspects are worse, as the wheels are turned in a corner there are torque forces in the driveahafts which are trying to straighten the wheels. Fighting these can be a "challenge".

On VERY slippy conditions , AWD is clearly best, then FWD as it 'pulls' the car and hence the car will follow the direction of the front wheels ( well most of the time ) whereas a RWD car can 'push' the car OUT of alignment adn require lots of driver input and CAN be irrecoverable.

There are many other lesser effects, but those are the biggies.

and then the most obvious POWER.
Trying to control torque-steer measn there is a limit on usable power to the front wheels. The BEST chassis max out at the 280-300 range. So as more power/torque measn more speed ( all else equal ) then being able to put more power through the rear wheels means more speed !! IF you built solid front shafts then the power woudl NOT be an issue just the first corner you came to

[Sweeney921]

matra's got it right, no surprise.

[henk4]

Traction.
When a car accelerates the weight trasnfers to the rear. With less weight on the fronts the tyres are more likely to slip and NOT bite. With RWD the weight trasnfer IMPROVES the traction With 4WD it depends on the diff setups !!

It is however a fact the FWD traction is better in snowy conditions. I have seen RWD struggle to clim a snowy pass without chains, where FWD just got enough grip and weight on the propelled wheels.

[lukeh]

thanks for that but i know one idea of trying to stop the weight transfere happening and that is with the Dodge neon drag car in America it has the um.... what do you call it in drag racing you have the 2 small wheels and that is connected to the rear of the car and keeps the fronts wheels on the ground. whatever its called but that 1 idea do you know of any others.

[Quiggs]

thanks for that but i know one idea of trying to stop the weight transfere happening and that is with the Dodge neon drag car in America it has the um.... what do you call it in drag racing you have the 2 small wheels and that is connected to the rear of the car and keeps the fronts wheels on the ground. whatever its called but that 1 idea do you know of any others.

Wheelie bar.

[lukeh]

Wheelie bar.

that was anoying me i couldnt think of what it was

[Tuscan666]

FWD is also better for the "everday" car. You get more space inside.

[Roy Visser]

It is however a fact the FWD traction is better in snowy conditions. I have seen RWD struggle to clim a snowy pass without chains, where FWD just got enough grip and weight on the propelled wheels.

thats because the acceleration is so slow, that there isnt allot of weighttransfer going on.

if you would have a Porsche 911 versus a Ford Focus on a snowy hill (regardless of power) the porsche would have more (slightly) traction (depending on acceleration, and so the weighttransfer)

[Matra et Alpine]

thanks for that but i know one idea of trying to stop the weight transfere happening and that is with the Dodge neon drag car in America it has the um.... what do you call it in drag racing you have the 2 small wheels and that is connected to the rear of the car and keeps the fronts wheels on the ground. whatever its called but that 1 idea do you know of any others.

That doesn't stop the weight trasnfer.
The weight has ALREADY done it by the teim those rear wheels touch.
They are there to stop the car rotating about the rear yreas - which are gripping the tarmac VERY well - and flipping the car.
Once a front wheel has lifted even 1mm off the road then ALL the car weight is on the 2 rear wheel.

[Matra et Alpine]

thanks for that but i know one idea of trying to stop the weight transfere happening and that is with the Dodge neon drag car in America it has the um.... what do you call it in drag racing you have the 2 small wheels and that is connected to the rear of the car and keeps the fronts wheels on the ground. whatever its called but that 1 idea do you know of any others.

Those wheels do NOT touch until the car accelerates - otherwise they induce drag and steering input - BAD
That doesn't stop the weight trasnfer.
The weight has ALREADY done ALL its trasnfer by the time those rear wheels touch.
They are there to stop the car rotating about the rear tyres - which are gripping the tarmac VERY well - and flipping the car.
Once a front wheel has lifted even 1mm off the road then ALL the car weight is on the 2 rear wheel.

[Blue Supra]

matra knows too much... mr know-it-all...
j/k good work mate.

[targa]

if you would have a Porsche 911 versus a Ford Focus on a snowy hill (regardless of power) the porsche would have more (slightly) traction (depending on acceleration, and so the weighttransfer)

well, yeah. the the 40/60(f/r) weight distrobution couldnt have anything to do with that, could it?

[sutton4481]

They are there to stop the car rotating about the rear tyres - which are gripping the tarmac VERY well - and flipping the car.

But this is a front wheel drive car (I know, front wheel dragster, what will they think of next? ), if we are talking about the same car, then the rear tires aren't doing much gripping at all. I tried but couldn't find a picture of the car, it's sponsored by mopar, is blue and white with barbed wire on it if anyone remembers. It had staggered tires, big slicks in the front, little tiny ones in the back, I don't remember a wheelie bar.

Edit: ahh here's one...

[jcp123]

Yeah, we had a minivan with FWD which was excellent in the snow, almost as good as AWD. That's because you have most of the weight over the front wheels, and when you turn, you don't have physics trying to use the power of the engine to put the rear wheels in front of the front wheels.

But in drag racing, the weight transfer of the acceleration puts more of the weight over the back wheels, and takes some from the front, thereby making it easier to lose tration.

This is why most drag cars are RWD and use realitively soft suspensions - to facilitate weight transfer to the rear wheels and enhance traction.

As far as handling goes, the weight of the engine and transmission right over the drive wheels hurts as it promotes understeer and makes any oversteer pretty much impossible to do. The car then just plows and turns wider than the radius desired. RWD allows both parts of the car to assist in the steering and maneuvering of the car, takes some of the weight bias off the front of the car, and also doesn't force one set of wheels to do the powering AND the steering, but rather distributes these forces somewhat more evenly across all the wheels and makes more full use of the traction available to you.