Is lift off oversteer completly undesirable?

The biggest cause yes... next would be in the rwd cars the coast torque especially on slippery surface.

Answer to the Title of the Thread: Situational No.

edit: http://www.drivingfast.net/car-control/oversteer.htm

 

Yes everything is about weight transfer.

When you lift off the throttle, weight transfers to the front of the car. If at the same time you are turning into say a right hand corner, the weight will shift to the front left tyre, thus less weight is on your rear right tyre. This rear right tyre is trying to slow down due to engine brake therefore with the lack of weight to keep it on the road it will lose traction....thus oversteer.
If you apply the brake at the same time the affect will be magnified, because more weight is being transferred to the front of the car = less weight on the rear tyres, so it makes it worse.

 

Actually, its not.. LOO is a character of mid-engine rwd cars for sure, but the elise doesnt really suffer from it in standard form. How the elise is now in ac is completely unrealistic, the car is just understeery irl.

One thing that does effect it is changing the flywheel to a light one, there just isnt the inertia to carry it spinning so the engine slows down much quicker, that can cause it to happen more so.

 

I go to the LOO to get my nose in, then, if things turn nasty I bury my foot in it to get myself out again

 

http://www.topgear.com.edgesuite-staging.net/uk/videos/1840844446

It's all about how you drive it.

 

Yes i know, if i drove in ac how i drive irl i should never get loo.. As it stands now as soon as you lift to brake the rear is already coming round on you.

 

Cool... I need to go drift that thing.

 

I've worked in the motorsport industry for the last 15 years running all sorts of race cars from late 50's to 90's ... the answer to your question depends very much upon the pilots driving style and type of car, for instance when racing classics such as Ferrari 250 GTO, 330 LMB Aston Martin DBR1 we tended to dial in predictable lift-off oversteer .... as has already been stated in other posts it's all about weight transfer and balance of the car.

Predictable lift-off oversteer (PLOO) works best on older (heavy) front engined .. rear wheel drive cars with little aero, it can help massively to get the nose in on slow and mid speed corners, leave the braking late as possible on the approach and use PLOO to get the nose pointing towards the apex .... then its a case of balancing the weight through the corner with the throttle.

PLOO can be very effective with the right car, track and driver ... from my experience it seems that those drivers who are good at left foot braking tend to be able to use PLOO to their advantage

On rear engine cars then LOO or PLOO is not so desirable as the all the weight is over the rear axel and you don't want to trigger pendulum effect, modern race cars with high downforce and efficient aero do not to relay on PLOO at all ....

Cheers
Jay

 

Thanks for all the good posts, a pleasure to read.

I love the PLOO on cars like the mx5 mod, you can break especially late and use it to get a better steering into the corner.
Especially doing lap after lap in vallelunga and try enhancing the brake points..
just so much fun!!!

 

So you are not really talking here about lift off oversteer.
It is about oversteer when decelerating which includes loo.

Ok, my mistake but I think that this specific characteristic deserves to be talked about separately.
There is one car here which should be trade mark for loo ... sadly it is not.

 

yeah, you are right probably, but what do you call loo with braking again? ^^

 

"BOOB" - back-off oversteer with braking.

That describes well my experience with the Elise around Zandvoort.

 

i like BOOB

man, i am truely sorry for bringing this discussion down

 

im partial to a bit of BIO (brake induced oversteer) especially in the ASTCM (awesome sixties touring car machine)

 

@Epocx
With brakes applied you can have turn in oversteer but, if you are forced to apply brakes mid corner than I call that a bad luck.
Loo is simply oversteer when, as the name says, you lift your foot off the throttle - no brakes applied.
The only thing that acts as a brake, is the engine. Mostly it affects you on long corners.
Sometimes it is drivers fault when he fight against understeer (too fast entry) and turn the steering wheel too much in. When he lift off, front tires bites but wheels are not pointed in right direction. Result is tank slapper or snap oversteer (most unwanted type of loo) ...

My point is, if you separate this from turn in oversteer while trail braking, you will search for possible solution on different places because you have at least one more place to search for. Or, if it is just one corner, you will adapt your driving - for loo by lifting of slower or applying brake and throttle at the same time to not allow front end squat too much ... for turn in oversteer by avoiding trail braking or using different line or whatever ...

 

I think the term Lift off Oversteer is used just to differentiate it from 'normal' oversteer.
e.g, turn exit + full throttle = back end slides out.

 

You got it sir. LOO happens way past braking phase, in long sweepers, when you are in that mild understeer under mid-high-throttle and have enough time to see that the front end won't make it and decide to back off a bit. If you need to be touching the brakes at that moment you were doing something horribly wrong

Any other case is not LOO in my mind.

 

If you're braking without lifting off ( at least a bit ) first then you're either way into advanced techniques or doing something pretty wrong, so a LOO discussion isn't relevant to braking either way if I'm going fast through S-bends in a car I left-foot brake in I sometimes tend to run with some constant brake on and adjust line by timing throttle pulses & wheel movement, so that definitely needs a responsive rear end.

In the end everything revolves around weight transfer ( other than when it's entirely about either unsprung mass or drivetrain ) including setup, so perhaps a broader discussion about that might be worthwhile.

 

I think people could get easily confused reading this topic. Lift off oversteer has nothing to do with the brake pedal only with lifting your foot off the acceleration pedal as the name implies. And you can use LOO effectively without having used your brakes at all (mostly underpowered street cars) when you are trying hard to keep momentum.

I've not driven MR cars IRL to know how the Elise should or should not handle but if it's anything like in AC in this regard, it's a very scary car to take for a spirited drive on roads. Especially when also braking.