Muppet oversteer on RWD
Discussion
Bit of a numpty question this, but after parking an Elise backwards in a hedge last year, I want to avoid making the same mistake again. I am about to buy a cracking little Caterham but am a little nervous following my elise "incident". I crashed the elise by backing off the throttle during a fast, progressive LH bend, it was a classic lift-off oversteer moment. Only problem was when the elise stepped out, it happened so fast I caught it and held it, but ran out of road before the car corrected. Will the Caterham snap out as fast if I go wrong, and what are the general rules about cornering in a RWD.
PS - My car history is Golf and Pug Gti's and Scooby's, so am clearly not a RWD expert.
Also, can anyone recommend a RWD driving course in the Kent/Sussex/Surrey area??
Cheers
PS - My car history is Golf and Pug Gti's and Scooby's, so am clearly not a RWD expert.
Also, can anyone recommend a RWD driving course in the Kent/Sussex/Surrey area??
Cheers
The more practise I get, the luckier I become....every slide is different...it`s all about building a feel for what you can get away with....a trackday would be the thing to spend time feeling what it does on the way in and out of corners...stay in 2nd if your provoking oversteer on the road ...it keeps the speed down and you will be less likely to 180..slow in fast out ...rushing in sometimes generates understeer...my 2 bobs worth of RWD craft....
Something else to consider:
You induced a rear wheel slide by lifting. You can induce a seriously big one by braking.
The only reason (I can think of!) for braking in a corner is because something has happened around it that you couldn't see - and a brake was absolutely necessary. It means that your corner entry speed is too high to be able to stop in the distance you can see to be clear.
Of course - some corners you can see all the way through - but most aren't that way.
So whilst you are getting some tuition you might find you want to do an Advanced Driving course where they teach you about "Limit of Visibility" (Limit Point) cornering - a useful technique for judging corner entry speed so you don't go in too fast (or too slow for that matter).
A handling course is brilliant fun and I recommend it completely - but you should couple it with some general road driving tuition too as by itself its just a more skilful way to put the car in a hedge.
If you want something concentrated you could spend a day with RideDrive. If you want something inexpensive (£85!) you could consider the IAM or Rospa.
You induced a rear wheel slide by lifting. You can induce a seriously big one by braking.
The only reason (I can think of!) for braking in a corner is because something has happened around it that you couldn't see - and a brake was absolutely necessary. It means that your corner entry speed is too high to be able to stop in the distance you can see to be clear.
Of course - some corners you can see all the way through - but most aren't that way.
So whilst you are getting some tuition you might find you want to do an Advanced Driving course where they teach you about "Limit of Visibility" (Limit Point) cornering - a useful technique for judging corner entry speed so you don't go in too fast (or too slow for that matter).
A handling course is brilliant fun and I recommend it completely - but you should couple it with some general road driving tuition too as by itself its just a more skilful way to put the car in a hedge.
If you want something concentrated you could spend a day with RideDrive. If you want something inexpensive (£85!) you could consider the IAM or Rospa.
Don said:
Something else to consider:
You induced a rear wheel slide by lifting. You can induce a seriously big one by braking.
The only reason (I can think of!) for braking in a corner is because something has happened around it that you couldn't see - and a brake was absolutely necessary. It means that your corner entry speed is too high to be able to stop in the distance you can see to be clear.
Of course - some corners you can see all the way through - but most aren't that way.
So whilst you are getting some tuition you might find you want to do an Advanced Driving course where they teach you about "Limit of Visibility" (Limit Point) cornering - a useful technique for judging corner entry speed so you don't go in too fast (or too slow for that matter).
A handling course is brilliant fun and I recommend it completely - but you should couple it with some general road driving tuition too as by itself its just a more skilful way to put the car in a hedge.
If you want something concentrated you could spend a day with RideDrive. If you want something inexpensive (£85!) you could consider the IAM or Rospa.
You induced a rear wheel slide by lifting. You can induce a seriously big one by braking.
The only reason (I can think of!) for braking in a corner is because something has happened around it that you couldn't see - and a brake was absolutely necessary. It means that your corner entry speed is too high to be able to stop in the distance you can see to be clear.
Of course - some corners you can see all the way through - but most aren't that way.
So whilst you are getting some tuition you might find you want to do an Advanced Driving course where they teach you about "Limit of Visibility" (Limit Point) cornering - a useful technique for judging corner entry speed so you don't go in too fast (or too slow for that matter).
A handling course is brilliant fun and I recommend it completely - but you should couple it with some general road driving tuition too as by itself its just a more skilful way to put the car in a hedge.
If you want something concentrated you could spend a day with RideDrive. If you want something inexpensive (£85!) you could consider the IAM or Rospa.
yep - thanks. My spin was lift-off induced, as the road was a little damp and I noticed a shiny manhole cover in the road at the last point. I wanted to slow a little, not stop, but I think now that if I'd stayed gently on the gas I would probably driven cleanly over the manhole cover without any problems...
The caterham is both slower to break-away (front-engine, so lower moment when the back-end goes) and more predictable when it does. And given the car, some track-time is a must - it'd be rude not to, after all!!! 
Agree with most of the suggestions above - track-time or off-road courses will teach you how to control the car best when it breaches it's limits, on-road courses are a much better bet at knowing how to avoid that situation in the first place, and also how to react to different situations.
Agree with most of the suggestions above - track-time or off-road courses will teach you how to control the car best when it breaches it's limits, on-road courses are a much better bet at knowing how to avoid that situation in the first place, and also how to react to different situations.
Don said:
You induced a rear wheel slide by lifting. You can induce a seriously big one by braking.
Lifting off in a powerful rear wheel drive car is a very good way to create oversteer (weight transfer and circle-of-friction effects both tending to encourage oversteer). Braking shouldn't produce a lot of oversteer, and if it does I'd suggest there is something wrong with your car setup.
GreenV8S said:
Don said:
You induced a rear wheel slide by lifting. You can induce a seriously big one by braking.
Lifting off in a powerful rear wheel drive car is a very good way to create oversteer (weight transfer and circle-of-friction effects both tending to encourage oversteer). Braking shouldn't produce a lot of oversteer, and if it does I'd suggest there is something wrong with your car setup.
I think he meant braking while cornering, exacerbating the weight-transfer effect.
I find the caterham to be much more obvious in its handling and characteristics than an elise. However, they do vary enormousley in setup between cars probably much more so than an elise.
I always say this, so I'll do it again. "Track" track days have nasty hard things to hit and things generally go wrong quite quickly. I much prefer airfield track days or specialist handling days to get an understanding of the cars characteristics.
Use IAM, Rospa or a specialist road driving organisation to get an understanding of your own characteristics!
GRaham
I always say this, so I'll do it again. "Track" track days have nasty hard things to hit and things generally go wrong quite quickly. I much prefer airfield track days or specialist handling days to get an understanding of the cars characteristics.
Use IAM, Rospa or a specialist road driving organisation to get an understanding of your own characteristics!
GRaham
havoc said:
GreenV8S said:
Don said:
You induced a rear wheel slide by lifting. You can induce a seriously big one by braking.
Lifting off in a powerful rear wheel drive car is a very good way to create oversteer (weight transfer and circle-of-friction effects both tending to encourage oversteer). Braking shouldn't produce a lot of oversteer, and if it does I'd suggest there is something wrong with your car setup.
I think he meant braking while cornering, exacerbating the weight-transfer effect.
I did indeed. If you are cornering near enough to the limit of adhesion for a lift to destabilise the car then a brake will certainly do it...I've had the experience of doing this on track where I mistimed an overtake and instead of coming out of the corner faster than the car in front I came up on the car in the corner and had to lift/dab the brake. Cue LOTS of slidy fun...ABS/PSM kicking in etc. Taught me a lesson that did. I definitely ran out of talent that day...
Don said:
havoc said:
GreenV8S said:
Don said:
You induced a rear wheel slide by lifting. You can induce a seriously big one by braking.
Lifting off in a powerful rear wheel drive car is a very good way to create oversteer (weight transfer and circle-of-friction effects both tending to encourage oversteer). Braking shouldn't produce a lot of oversteer, and if it does I'd suggest there is something wrong with your car setup.
I think he meant braking while cornering, exacerbating the weight-transfer effect.
I did indeed. If you are cornering near enough to the limit of adhesion for a lift to destabilise the car then a brake will certainly do it.
Any sudden change can unbalance the car - any sudden input from steering, acceleration or brakes. That is not the same as saying that the brakes make the car inherently unstable. They will only do that if the brake balance is wrong. If the brakes are working correctly, then you should be able to brake firmly in a corner without dramatically changing the balance of the car, as long as the transition to braking is done smoothly. In fact if the car is set up correctly you will find that a rwd car is *more* stable under firm braking than just on a trailing throttle. Applying the brakes reduces the amount of engine braking slightly, plus production cars are usually set up with a slight forward bias on the brakes which means the car tends to straighten up and wash out as you apply the brakes. If you have to lose speed into a corner and things are getting precarious, it is usually safer in a rwd to smoothly but firmly dab the brakes rather than try to hold it on a trailing throttle. Cornering on a trailing throttle is one of the least stable attitudes to be in for a rwd car.
Especially in light of this conversation about braking/cornering, I can second the Andy Walsh Car Limits day recommendation. I've only done a half day "taster", but one of the things we got to play with there was firm braking whilst cornering and how this can help quell oversteer and/or induce understeer and how by balancing the braking you can keep the car online. It seemed counter to everything I'd been taught/read before, but it worked and was well worth playing with on an airfield where spins are no problem.
Good posts, Peter - I understand where you are coming from completely: you are the PH master of vehicle dynamics! 
The point I was making was really that if you are cornering on road close enough to the limit of adhesion for a lift (or a brake) to destabilise the car it is more than likely that corner entry speed was too high and not based on the ability to be able stop in the distance that can be seen to be clear...and there are some really good AD courses that teach corner judgement techniques that can help with that. Really good for getting confidence in the twisties...
The point I was making was really that if you are cornering on road close enough to the limit of adhesion for a lift (or a brake) to destabilise the car it is more than likely that corner entry speed was too high and not based on the ability to be able stop in the distance that can be seen to be clear...and there are some really good AD courses that teach corner judgement techniques that can help with that. Really good for getting confidence in the twisties...
Here's my input into this.
Without putting too much strain on your car - Clutch dumping / shift locking (dropping a gear without match revs) there are two ways in which you can provoke a RWD and to some extent a FWD to brake traction at the rear.
From the original post it sounds like you are approaching things too quickly and as has been said already eventually you will brake traction but it will be sudden and harder to control. Also most islands require you to go left before you are going right so make sure you don't get on the power too soon and that the car is traveling right before you get on the power.
Method one: Go round the island at a steady speed in second, just quick enough for you to be able to feel some push towrds the outside of the island but get the car balanced so it isn't understeering. If it is you are going too fast. Aim for an exit as though you are going to come off the island (still on the power) turn sharply back towards the centre of the island and come completely off the power (whilst turning hard). Wait until you feel the back go light and bam, back on the power and get ready to catch it.
Method two: Treat your entry into the Island as though you we going round a bend. Come in at a reasonable speed, just a tad too fast (as in your passengers would wonder what the hurry was!) as you hit what would be the apex of the bend let the car settle then power hard.
That should see you on your way to getting the rear out in the dry. I'd avoid trying to use braking techniques as the front bias will make it very difficult.
A good place to practice is Curborough (spelling). It has a nice top corner and the surface is smooth. Trouble with airfields is they're made of concrete and distroy tyres - I only managed two hours at Bruntingthorpe in the dry before I had to retire. Brutners has lots of open space though! Personaly roundabouts are my favourite - I have lots of private ones honest.
Without putting too much strain on your car - Clutch dumping / shift locking (dropping a gear without match revs) there are two ways in which you can provoke a RWD and to some extent a FWD to brake traction at the rear.
From the original post it sounds like you are approaching things too quickly and as has been said already eventually you will brake traction but it will be sudden and harder to control. Also most islands require you to go left before you are going right so make sure you don't get on the power too soon and that the car is traveling right before you get on the power.
Method one: Go round the island at a steady speed in second, just quick enough for you to be able to feel some push towrds the outside of the island but get the car balanced so it isn't understeering. If it is you are going too fast. Aim for an exit as though you are going to come off the island (still on the power) turn sharply back towards the centre of the island and come completely off the power (whilst turning hard). Wait until you feel the back go light and bam, back on the power and get ready to catch it.
Method two: Treat your entry into the Island as though you we going round a bend. Come in at a reasonable speed, just a tad too fast (as in your passengers would wonder what the hurry was!) as you hit what would be the apex of the bend let the car settle then power hard.
That should see you on your way to getting the rear out in the dry. I'd avoid trying to use braking techniques as the front bias will make it very difficult.
A good place to practice is Curborough (spelling). It has a nice top corner and the surface is smooth. Trouble with airfields is they're made of concrete and distroy tyres - I only managed two hours at Bruntingthorpe in the dry before I had to retire. Brutners has lots of open space though! Personaly roundabouts are my favourite - I have lots of private ones honest.
woodytvr said:
A good place to practice is Curborough (spelling). It has a nice top corner and the surface is smooth.
Very good in many ways, because it's a nice short circuit so if you're doing laps you still have your c*ckups from last time fresh in your memory. What's not so good is that despite its short length and apparently simple layout, the circuit is actually technically very challenging with some very unusual apex locations. Sprinting here can be very frustrating because it's almost impossible to get it right, and the lap is over almost before it's begun.
Ah Curborough...
Talking of which, I discovered a GREAT way to get the tail out while driving there (or should that be a way to get the tail out a great amount...). In a fwd car too!!!
It's simple...you just change down into the 'tail' of Curborough a little too late, as you're turning-in, and let the left-rear kiss the wet grass. You can get the tail RIGHT out if you do that!
(I got a round of applause though - went from about 40-deg one way to 40+ the other way to absolutely side-on to the track, stopped half-way down the 'tail'. Not sure how I kept it on-tarmac, think that was what the applause was for!)
Talking of which, I discovered a GREAT way to get the tail out while driving there (or should that be a way to get the tail out a great amount...). In a fwd car too!!!
It's simple...you just change down into the 'tail' of Curborough a little too late, as you're turning-in, and let the left-rear kiss the wet grass. You can get the tail RIGHT out if you do that!
(I got a round of applause though - went from about 40-deg one way to 40+ the other way to absolutely side-on to the track, stopped half-way down the 'tail'. Not sure how I kept it on-tarmac, think that was what the applause was for!)
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