Under or oversteer on 159?

Does the 159 under or oversteer when applying brakes reasonably hard on a bend?

Originally Posted by Stevie28

Does the 159 under or oversteer when applying brakes reasonably hard on a bend?

Hmm, I thought I was the only one who felt this or something similar, basically the car seems to weave about/ veer slightly/noticeably when applying brakes hard. This is obviously felt when trying to brake hard in a straight line, the steering goes to the right on its own... any others who have experienced this???

Im noticing oversteer on bends when breaking. Braiking In a straight line; shes generally straight but occasionally weaving a bit as you mention if decelerating fast.

The oversteer is quite an issue, better not to brake if youve got yourself into a corner a bit fast, just ride the baby out!

Oversteer, but put the foot down and slide out

Well applying the brakes hard on a bend, or lifting off the throttle on a bend normally induces what is known as "lift-off oversteer", where the back end lightens due to the centre of balance being thrown forward, caused by the effect of deceleration. If you aren't going in a straight line, this might cause the back tyres to lose grip and you will then be in an oversteer situation.

Originally Posted by Stevie28

The oversteer is quite an issue, better not to brake if youve got yourself into a corner a bit fast, just ride the baby out!

Braking on a corner when you are going too fast is the worst thing you can do. I went up a grass verge not so long ago because of this

A ridge in the road lightened the back end, the car oversteered something terrible, and silly old me braked

If I'd have stayed on the power and let the Q2 pull the front end round the corner I would have gotten away with it Scot free

Sorry lads, think im getting my apples and pears mixed up, i think i mean she understeers, i.e. if i apply brakes hard on a bend nose pulls to the right potentially into oncoming lane.......

Originally Posted by Pud237

Well applying the brakes hard on a bend, or lifting off the throttle on a bend normally induces what is known as "lift-off oversteer", where the back end lightens due to the centre of balance being thrown forward, caused by the effect of deceleration. If you aren't going in a straight line, this might cause the back tyres to lose grip and you will then be in an oversteer situation.

What he said. Good description Pud.

Originally Posted by Stevie28

Sorry lads, think im getting my apples and pears mixed up, i think i mean she understeers, i.e. if i apply brakes hard on a bend nose pulls to the right potentially into oncoming lane.......

If you are more-or-less straight and brake into a left-hand bend then you'd probably experience understeer as it wants to plough straight on into the opposite lane - or the verge if a R/H bend.

Originally Posted by Stevie28

Sorry lads, think im getting my apples and pears mixed up, i think i mean she understeers, i.e. if i apply brakes hard on a bend nose pulls to the right potentially into oncoming lane.......

Understeer is when the nose wants to run wide, say going round a roundabout, understeer is when you can't hold the tight line, and the car's front end is sliding away, trying to leave the roundabout.

Oversteer is where the front end follows the desired line, but the back end drifts wide like it wants to overtake you, and is mucho scary!

Originally Posted by 73GTVJim

What he said. Good description Pud.

Cheers dude

Wow wee, the alfa 159 has one of the highest oversteer ratings, of 51

"How much a car understeers can be measured in the number of degrees more the steering wheel have to be turned per G of lateral acceleration"

Check this web page scroll down to the very end, only a morgan roadster v6 has a higher rating out of a list of about 30 cars..!

Understeer - Wikipedia, the free encyclopedia

Is this not good

The tendency of a car to oversteer is affected by several factors such as mechanical traction, aerodynamics and suspension, and driver control. The driving technique called opposite lock is meant to cope in this circumstance. Limit oversteer occurs when the rear tyres exceed the limits of their lateral traction during a cornering situation before the front tyres do, thus causing the rear of the vehicle to head towards the outside of the corner. More generally, oversteer is the condition when the slip angle of the rear tyres exceeds that of the front tires. Rear wheel drive cars are more prone to oversteer, in particular when applying power in a tight corner. This occurs because the rear tyres must handle both the lateral cornering force and engine torque. An oversteering car is alternatively referred to as 'loose' or 'tail happy.
Conversely, understeer is the condition in which the front tyres don't follow the trajectory the driver is trying to impose while taking the corner, instead following a more straight line trajectory. Understeer covers several different phenomena, in particular, there is a big difference between linear range understeer, typically between 0 and 0.4g, and limit handling understeer, which is at higher lateral accelerations, and is what racing drivers are talking about.

Ah, I see you've heard of Wikipedia as well




Stevie - Understeer is pretty 'safe' for the average driver.

Originally Posted by Pud237

Ah, I see you've heard of Wikipedia as well




Stevie - Understeer is pretty 'safe' for the average driver.

yup

I was taught never to brake in a bend anyway. . Braking destablises any car as does cornering, put the two toigether and the results can be disastrous. Cut the speed before the bend and use the throttle to pull you through then accelerate away.

Originally Posted by Fraser

I was taught never to brake in a bend anyway. . Braking destablises any car as does cornering, put the two toigether and the results can be disastrous. Cut the speed before the bend and use the throttle to pull you through then accelerate away.

Good advice, braking mid corner is not recommended. Lighten the rear too much and it'll swing right round, you'll leave the corner backwards

Yep always try to brake + change gear before the corner. Both of these can upset the balance of the car when cornering. Not something you want when driving on the limit!

Originally Posted by Stevie28

Sorry lads, think im getting my apples and pears mixed up, i think i mean she understeers, i.e. if i apply brakes hard on a bend nose pulls to the right potentially into oncoming lane.......

Well it depends on which way the bend is going whether this is under or oversteer.

Unless you're telling us that it always pulls to the right, regardless of which direction corner it is? If so, I'd say you've got a brake imbalance problem - there's certainly something wrong anyway.

mmm

Also imagine your suspension and tyres are all settled nicely handling the everything then suddenly not only is all the power lifted but also brakes are applied giving a massive change in mass distribution around the cars wheels.
Not a good idea.

On a handling vein

My 156 V6 has quite a heavy nose due to the big engine, once along a dual carriageway at a roundabout I was following a lady in an MX5.
She wasn't even looking at what she was doing as she went around the roundabout changing a tape or something I think.

I was working hard keeping on the ideal line my tyres squealing in protest and quite nr the limit, obviously once on the straight I had the power but it shows what a low center of gravity and light weight can do.
The MX5 handled beautifully and is near the top of the list in wikipedia

Peter

When I worked for Bentley Motors up in Crewe before we were allowed to drive any of the product we had to undergo a training session & driving test. In this they explained how best to deal with oversteer & understeer (both highly likely with cars weighing 2.5 tons and anything up to 600 bhp). Now I know this is counter intuative but the best way to deal with understeer is to wind steering lock off It was explained that once the car goes into understeer the wheels are turned at too great an angle to the actual direction of travel of the vehicle and this stops them rotating. Because the tyres have already lost grip, if the wheels stop turning then the slide will continue until the friction between the tyre and road stops the car. If however you wind steering lock off it gives the wheels a chance to start rotating again and normal grip is returned. If needed steering lock can then be reapplied to turn the vehicle around the bend.
I have used this technique several times with my GTV and I can assure you that it does work. Although the first time you try it it really doesn't feel right to be taking lock off and allowing the car to go straight on.

Post in error but can't figure out how to delete it

Originally Posted by Pud237

Understeer is pretty 'safe' for the average driver.

And is generally a built in characteristic of most FWD cars. Most competent, enthusiastic drivers tend to prefer a degree of oversteer (hence the preference for RWD) as it can be faster and feels safer to them. Joe and Ethel Public are better off with FWD.

Originally Posted by ar 145