Torque Steer

We should have a trackday, with a selection of Elks scattered about the place...

-- JackH

I concur, lift off oversteer requires fairly low speed and a wet road, and brutal treatment of the throttle, i.e. dive into a roundabout fast, flat out in 2nd, lift off very sharply after turning very sharply.

Where?

Bugger!

Just had a sudden urgent need of an air bag.

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

From Wikipedia:

Snap oversteer also known as lift-off oversteer. The virtue of weight over the drive wheels also makes the rear end of the car exceptionally light. In a hard cornering situation, slight weight transfer to the front of the car (ie from lifting off throttle) can easily result in a unrecoverable spin, certain cars such as Peugeot 306 Xsi and Porsche

Yet Pug 306's are noted for it.

The bit about 306s is true, however, although the 911 sufferst from lift-off oversteer, it's for different reasons.

Becase Im old, bright, have been involved in various types of bike and car motorsport including writing for and testing for magazines both track and strip, done god only knows how many miles in all kinds of bikes/cars/racers and have built and set up cars, engines, bikes, dynamometers, nitrous and turbo systems for 30 years.And I mean SCRATCH built. And I UNDERSTAND physics and can drive? Your vast experience is?

YES

No its an illusion. they have roughly the same transmission losses and often the same engines. Why and how can the have more engine braking? Physics says you are wrong and it dont lie!

Only the same as a rear drive. But now your tyre needs both braking AND cornering forces!

No again physics says you are wrong. And if I brake hard while cranked over on a bike I can lift the rear wheel whilst cornering and it does NOT try to overtake me more one way than the other. In fact it can slowly drift either way so physics is correct. Think about extreme cases where there is NO weight over the rear or front! I can wheelie a bike out of a corner and it still does not understeer because all the weight is now on the rear.

No in ALL circumstances increasing the load increases grip. Double the weight on any tyre doubles the grip. Almost but the tyres construction gets progressively weaker as a percentage of load so not quite in reality. But unfortunately the increase in grip came from braking and weight transfer. Now half the tyres grip is used up braking so the net gain is zilch or worse.

Tyre pressures alter feel loads they dont change groip levels much at all. Just allow more or less movement. On soft surfaces, or when in snow ir something low pressures help a little. We are talking minor effects here not really relevant to the argument..

According to your abilities and perception maybe. but not in this universe.

If one end has no suspension or something on purpose (same effect as oiling the tyres then obviously it will lose the crap end first. Manufacturers try not to do this! With average cars and decent tyres and motable suspension this will not happen.

Your corner speed is dictated by the lower grip levels. If you have

Here is the problem. YOUR DADS sierra? How old are you? I had 5 sierras. None showed any understeer! NONE! 2.3 estate, 2.0 gl. 1.6 saloon, xr4i, burton 2.1 race engine, v8 nitrous. With every possible combo of tyres wheels, suspension etc. Do you really understand that understeer refers to constant speed x angle slip angles?

No but I dont need to. the badge does not make physical laws. All cars will feel like they understeer as speed increases on the mythical constant speed roundabout. But you feel the understeer slip angle on the front because you are holding the steering wheel. It may be 15 degrees at the tyre or half a turn in the car! Thats not understeer if bthe sip angle of the rear tyres is greater! Bur thats much harder to feel unless it lets go which it aolways will do first if you go fast enough.

FACTS? reasons? They only work the controls. they do not alter the undr over steering of front rear drive.

Because tempory rotational (yaw) inerrtia, helps them. Usually after a sudden turn in the adds energy in the form of momentum. But it soon dissapates and then the understeer continues.

ore experience of different FWDs before

In physics yes. But in cars espesially front drive we need a simple to understand reference between foot on and off because the effect on weight transfer

The only time that the grip for cornering can be equal at both ends is when you are in gear with a fancy computer controlling the throttle so that the gearbox output exactly equals the cars freewheeling slowdown speed and neither ads or removes any energy from the car. In other words if you took out the engine and transaxle!

turning in very sharply adds some inertia in the yaw plane and braking the front wheels allows this to turn the car a little further around in yaw. Its a short term tempory thing and as soon as you use up the rotational yaw energy it returns to a nasty understeering fwd trolly... If you made the shell from lead, and oiled some crosply remoulds on the back you could even get it further roung for about a second...

It's because of paranoia that under certain extreme conditions the A class could roll, that it got the suspension mods (which probably cause the component failure problems) rushed in at the last minute. I know more people who've rolled Ford Kas than I do A classes.

"Vitara"

That'd be the least of the reasons not to take a diesel, auto, A class on a trackday.

Ahhh Wikifiddlers at their best.

"rear end exceptionally light" and "porsche 911" in the same sentence.

So? It still oversteers.

Thank you.

Much more so. The 306's chassis is relatively tame.

I don't doubt it. Me too.

But then I only know one person with an A-Class...

ROFL.

Actually, more like, ROTL.

stop crossing your ells.