Rotating Less Worn Tires to Front - FWD Vehicle

[SteveSRT8]

Originally Posted By: fdcg27
Originally Posted By: SteveSRT8
Originally Posted By: SteveSRT8
You haven't truly lived until you get into a snap spin in a FWD car.


Also, loose is NOT the fast way around any track. At Skip Barber school we were taught that the clean line is the best, we actually used the vehicle's stability control to tell us when we got loose which slowed us down!


Getting a FWD into "snap spin" must be pretty difficult, since I've never managed it in any FWD and we've had a lot of them.
Next time you're at a track day, note that the guys who are really fast will often hang the tail. This is also a matter of how the car was set up. Understeer consumes power. Oversteer doesn't.


With your suppositions about track driving it doesn't seem to be a surprise at all that you've never experienced a "wrong wheel drive" snap spin! Amazing...

 

[mightymousetech]

Pretty much impossible to get a modern FWD car to oversteer. They are designed to understeer so badly it is ridiculous. In order to get a FWD car to be more neutral, it requires removing the front sway bar, greatly increasing the rear sway bar diameter and increasing the rear spring rate almost 10x. Even then, the car is still tends towards a little understeer, requires effort to get the back end to step out. For competition use, you want to be able to switch from understeer to oversteer at will.

A really fast FWD car will be set up to oversteer a bit so that you can be full throttle as soon as you have turned in. The sooner you can get on the throttle, the faster you are.

"hanging the tail out" is not fast. As soon as I see that on the car in front of me, I know I can take them going into the next corner.

 

[SteveSRT8]

Originally Posted By: mightymousetech
Pretty much impossible to get a modern FWD car to oversteer. They are designed to understeer so badly it is ridiculous. In order to get a FWD car to be more neutral, it requires removing the front sway bar, greatly increasing the rear sway bar diameter and increasing the rear spring rate almost 10x. Even then, the car is still tends towards a little understeer, requires effort to get the back end to step out. For competition use, you want to be able to switch from understeer to oversteer at will.

A really fast FWD car will be set up to oversteer a bit so that you can be full throttle as soon as you have turned in. The sooner you can get on the throttle, the faster you are.

"hanging the tail out" is not fast. As soon as I see that on the car in front of me, I know I can take them going into the next corner.


Absolutely agreed except for the FWD opinion. Any FWD car I have ever driven can easily be spun except the modern ones with stability control. Simply turn in hard and jam on the brakes. Happens lightning fast and is catchable if your reflexes are sharp, so most regular track folks will have no problems with it...

 

[bunnspecial]

I've had many "disagreements" with folks over my preference for driving a rear wheel drive car in the snow.

I think the key is to realize that's a situation where you WILL lose traction multiple times, and I find rear wheel drive more controllable and the response more natural when it does happen. About the only advantage I see FWD having is making it easier to get started.

Regardless of the type of drive you have, though, I think every driver should find a snowy parking lot and cut loose in it when given the chance. You can, of course, induce oversteer easily and practice bringing it back under control with little risk of hitting anything. These are perishable skills, and by keeping them sharp you can know how to react if it happens under more normal conditions.

BTW, the "Drivers Handbook" for my MG tells you how to make the car more oversteer or understeer prone by adjusting the tire pressures in the front relative to the rear. Running equal pressures tends to make the car SLIGHTLY oversteer prone.

 

[fdcg27]

Observations aren't "suppositions", but whatever.
Also, "jamming on the brakes" is never the quick way through a corner.

 

[IndyIan]

Originally Posted By: SteveSRT8
Originally Posted By: mightymousetech
Pretty much impossible to get a modern FWD car to oversteer. They are designed to understeer so badly it is ridiculous. In order to get a FWD car to be more neutral, it requires removing the front sway bar, greatly increasing the rear sway bar diameter and increasing the rear spring rate almost 10x. Even then, the car is still tends towards a little understeer, requires effort to get the back end to step out. For competition use, you want to be able to switch from understeer to oversteer at will.

A really fast FWD car will be set up to oversteer a bit so that you can be full throttle as soon as you have turned in. The sooner you can get on the throttle, the faster you are.

"hanging the tail out" is not fast. As soon as I see that on the car in front of me, I know I can take them going into the next corner.


Absolutely agreed except for the FWD opinion. Any FWD car I have ever driven can easily be spun except the modern ones with stability control. Simply turn in hard and jam on the brakes. Happens lightning fast and is catchable if your reflexes are sharp, so most regular track folks will have no problems with it...

My wagon rotates quite well when you let off the throttle, probably far more than you would want in a rwd car, but its good for corner entry and adjustment mid corner. I think with the advent of aluminum blocks in every fwd car and stronger bodies, the weight distribution of the average fwd car is much more even than it was, and they are less prone to spinning out. Also every car now has a rear sway bar and with stability control being universal, the handling can be tuned more neutrally without killing people.

 

[SteveSRT8]

Originally Posted By: IndyIan
Also every car now has a rear sway bar and with stability control being universal, the handling can be tuned more neutrally without killing people.


Well, maybe not every car. I see lots of new FWD cars without one. It's mostly the smaller inexpensive cars, commuter transit. The shorter the wheelbase the easier to spin.

With stability control it is not likely. the systems are very sensitive and highly discriminatory as the engineers know exactly what their chassis' do!

 

[SteveSRT8]

sup·po·si·tion

NOUN
an uncertain belief:
"they were working on the supposition that his death was murder" · [more]
synonyms: belief · surmise · idea · notion · suspicion · conjecture · speculation · inference · theory · hypothesis · postulation · guess · feeling · hunch · assumption · presumption

I think one of these synonyms fits well...

 

[IndyIan]

Originally Posted By: SteveSRT8
Originally Posted By: IndyIan
Also every car now has a rear sway bar and with stability control being universal, the handling can be tuned more neutrally without killing people.


Well, maybe not every car. I see lots of new FWD cars without one. It's mostly the smaller inexpensive cars, commuter transit. The shorter the wheelbase the easier to spin.

With stability control it is not likely. the systems are very sensitive and highly discriminatory as the engineers know exactly what their chassis' do!

I forgot to mention the clearest case of a fwd snap spin I've seen at autocross was with a Jetta diesel, late 90's. It seemed to rotate around the engine bay, but I'm sure the twist beam rear axle wasn't helping either. My iron block Neon seemed to be more prone to spin than my wagon as well, but again I think having much less weight on the rear, plus significant weight in front of the front axle helps promote some fast rotation with old fwd cars.

 

[NGRhodes]

Most cars (any wheel drive) are set up to be safest for the average road driver and to allow electronic aids such as ABS and stability control work most effectively for safety (not performance).