Rather confused___understeer

[turbomachine]

I am know rather confused, I have heard that if you approach a corner too fast that a fwd car will understeer(makes sense), but i have heard that if you are understeering you should apply more throttle when this happens shifting the weight distribution to the rear right(if its a right hand bend and fwd).

I was looking at a website that said if you understeer you should back off the throttle, but not too much otherwise the weight distrbution will cause the front of the car to dip to the right and the rear left will be prone to swing out ie lift off oversteer.

So what should you do keep the power on and apply a bit more or back off a small touch and hope you don;e lift off oversteer into a wall???

[LordGrover]

I'd concentrate on not getting into the position in the first place - that's not to say I'm not interested in the answer though.

[Mroad]

turbomachine said:

I am know rather confused, I have heard that if you approach a corner too fast that a fwd car will understeer(makes sense), but i have heard that if you are understeering you should apply more throttle when this happens shifting the weight distribution to the rear right(if its a right hand bend and fwd).

How can you shift weight to the rear with a car that is already understeering? The fact that the car is already understeering means front end traction is lost, accelerating more will have no effect except increasing the understeer.

If you are understeering into a corner then it's a combination of a few things why it's happening.
Your steering angle and vehicle speed is too great for the corner and the front tyres lose traction.
To correct it you need to regain traction where it's been lost, i.e. the front end.
To regain traction at the front you can either reduce the steering angle, reduce the speed or you can transfer weight to the front to increase the load on the tyres (reducing speed also helps to transfer weight to the front).
So reduce the steering angle, come off the accelerator gradually (avoiding lift off oversteer) or the advance technique is left foot braking (stay on the accelerator and dab the brake with the left foot which transfers weight over the front wheels thus regaining grip, often leads to oversteer though as the weight is transferred away from the rear tyres).

It's all a matter of physics.

(Disclaimer: Do not try left foot braking for the first time on the road! It will bite you in the bum!)

Edited by Mroad on Friday 12th September 16:26

[p1esk]

LordGrover said:

I'd concentrate on not getting into the position in the first place - that's not to say I'm not interested in the answer though.

I'm with you, your Lordship.

Where's that fellow from Eaton Socon when you need 'im?

Best wishes all,
Dave.

[BOF]

turbomachine said:

I am know rather confused, I have heard that if you approach a corner too fast that a fwd car will understeer(makes sense), but i have heard that if you are understeering you should apply more throttle when this happens shifting the weight distribution to the rear right(if its a right hand bend and fwd).

I was looking at a website that said if you understeer you should back off the throttle, but not too much otherwise the weight distrbution will cause the front of the car to dip to the right and the rear left will be prone to swing out ie lift off oversteer.

So what should you do keep the power on and apply a bit more or back off a small touch and hope you don;e lift off oversteer into a wall???

Robert,

Read 'cornering forces' and 'bends' in this link...might be of help?

http://www.ridedrive.co.uk/tipoffs-index.htm

BOF

[turbomachine]

Cheers BOF,

There is so much information on that link.

I have also bought a copy of Roadcraft from amazon, so that should help me understand what is going on. I am a student so I really only get to drive my parents car during the holidays, its not ideal but its better than not driving, I used to do things in car that proved just how bad a driver I was, when actually I really thought I was Schumacher!!.

Anyway after a lengthy conversation with some traffic cops at my local pub the other night, (they were off duty I hasten to add!!!!) and basically pointed out what it means to be a good driver compared to those who think they are good i.e, myself who would wheel spin away from jucntions and see how fast I could go in 3rd gear, they also said what happens at a fatality and having to inform the family.

I can honestly say that it was the best night down the pub in along time and I no longer what to drive like a idiot. Hence why I bought a copy of roadcraft the next morning.

[BOF]

If you meet the Trafpols again in the pub...ask them if they will give you a drive in your car at some time...most of them are very happy to pass on experience to younger drivers who show an interest...might cost you a pint and a donut.

Roadcraft is the Bible...the Roadcraft DVD is interesting and worth a look...I start with a new driver Tuesday, if he has the DVD I will mail you my copy to look at...if not, I will move him on to another DVD in about three weeks and mail it to you then...mail your address via the Forum if you are interested...I WANT IT BACK!

BOF.

PS...
"I used to do things in car that proved just how bad a driver I was, when actually I really thought I was Schumacher"...me too, but I thought I was Jimmy Clark...

Edited by BOF on Friday 12th September 17:46

[Darkslider]

You shouldn't increase the throttle, you're already asking too much of the front tyres already so asking them to put more power down will only serve to reduce your grip further.
Back off the throttle to transfer the weight to the front of the car and give the front wheels more grip. Also it's likely when you feel the car understeering towards the outside of a bend you will pile on all the steering lock you've got, this is a bad thing to do. If you're sliding forwards on full right lock say, you want to back of the steering to the point that the tyres grip again, then continue steering in your original direction.
Sounds odd and it really goes against your instinct to turn away from where you want to go, but I'd recommend doing a skidpan day or similar to learn how the car will behave.
Understeer is a bloody horrible situation to be in, and nine times out of ten on the road by the time you realise you're understeering there's often very little you can do about it, and all your natural reactions are the wrong ones.

[supermono]

A hefty dab of the brakes at understeer transforms the cornering attitude of my Peugeot 207. If it's a bit damp and there's plenty of road to my left as I'm on a roundabout I'll do this and it nips the front up tight while getting a useful bit of oversteer to help ease it round. Adding throttle will only make it worse as others have said -- you won't have any grip left for anr (more) acceleration. Getting a bit of weight forward by using the brakes moves the balance away from the rear which has too much grip to the front which doesn't have enough.

And for the sharp intake of breath IAM brigage crossing themselves reading this, yes I do this on crowded roundabouts outside schools where there are lots of children and old people in the road...

SM

Edited by supermono on Sunday 14th September 07:53

[p1esk]

supermono said:

A hefty dab of the brakes at understeer transforms the cornering attitude of my Peugeot 207. If it's a bit damp and there's plenty of road to my left as I'm on a roundabout I'll do this and it nips the front up tight while getting a useful bit of oversteer to help ease it round. Adding throttle will only make it worse as others have said -- you won't have any grip left for anr (more) acceleration. Getting a bit of weight forward by using the brakes moves the balance away from the rear which has too much grip to the front which doesn't have enough.

And for the sharp intake of breath IAM brigage crossing themselves reading this, yes I do this on crowded roundabouts outside schools where there are lots of children and old people in the road...

SM

As I thought....complete menace....should be locked up.

Don't you realise that driving is at all times a serious business in which having a bit of fun plays no part whatsoever.

Best wishes all,
Dave.

[StressedDave]

p1esk said:

LordGrover said:

I'd concentrate on not getting into the position in the first place - that's not to say I'm not interested in the answer though.

I'm with you, your Lordship.

Where's that fellow from Eaton Socon when you need 'im?

Best wishes all,
Dave.

Busy enjoying the roads of Wales...

My answer is that it depends If the understeer is as a result of not having enough power applied in the first place (inordinately common IME), then adding power will counteract the drag you've created for yourself and liberate some grip. If on the other hand you've done too much steering (also inordinately common) then adding power isn't going to help and lifting off the throttle won't necessarily aid either.

[p1esk]

StressedDave said:

p1esk said:

LordGrover said:

I'd concentrate on not getting into the position in the first place - that's not to say I'm not interested in the answer though.

I'm with you, your Lordship.

Where's that fellow from Eaton Socon when you need 'im?

Best wishes all,
Dave.

Busy enjoying the roads of Wales...

My answer is that it depends If the understeer is as a result of not having enough power applied in the first place (inordinately common IME), then adding power will counteract the drag you've created for yourself and liberate some grip. If on the other hand you've done too much steering (also inordinately common) then adding power isn't going to help and lifting off the throttle won't necessarily aid either.

Hmm, in that case perhaps the emphasis should remain on not getting into these intractible situations in the first place. That's still my preference anyhow.

Best wishes all,
Dave.

[Holst]

When I was also young and slightly more stupid I found that on wet roundabouts I could wind on quite a lot of extra lock and continue in the same direction in my old fiesta. Lift off a litte and it would turn in more, lift off alot and it might have spun (i never tried this)

Doing the same in my prelude would probably result in a messy crash.