Braking into corners

[p1esk]

R_U_LOCAL said:

vonhosen said:

R_U_LOCAL said:

Lets start off by avoiding terms like "right" and "wrong". There are a whole range of different techniques available and all of them have their own benefits and downsides.

My preference is to get the speed right ..............

Oh yeah. I see what I did there!

Ok. My preference is to get the appropriate speed.

So you can get the corner right...

Aye, it's a bit like insisting on having the right gear, which to me is a bit too prescriptive, whereas I feel happy to have a suitable gear that will do the job satisfactorily. IOW it will be OK and can't reasonably be faulted. In many cases, with a petrol-engined car and a wide engine speed range, there's more than one gear that could legitimately be used.

Just a thought....

[SK425]

R_U_LOCAL said:

Taking the gear first almost feels like you're committed then to that gear

I think that's exactly what you'd be doing by taking the gear first. But then there are only five different gears in my car, whereas there are many more than five different speeds it will go, so I don't think it's too difficult to imagine that sometimes I might be sure which gear I want to commit to before I'm sure what entry speed I want to commit to - in fact I think that's probably almost always the case. How much earlier it is varies, but sometimes it can be before I've started slowing - in which case I might choose to change gear first.

[carinaman]

From memory an old issue of Roadcraft has a plan view diagram with vectors pointing away from the wheels making the point that going around a corner there is load on the tyres and then braking adds another load that can alter grip and therefore the path around the corner.

[MagneticMeerkat]

Jon1967x said:

carinaman said:

Selecting a lower gear before, even if it feels like the engine is revving too much can be just driving on the throttle without having to think about braking.

I'm interested if this is correct driving (I don't know for sure although when I learnt to drive years ago I was told it was wrong but then a lot of that advice has been subsequently ignored!). My concerns are a, you can only do this when you have sufficient rev range and b, the higher the revs the greater the engine braking (I believe) so you're in effect using that instead of the brakes plus unless you are good at matching revs when changing gear your clutch is taking some punishment.

I think it's worth reading the acceleration sense thread to get a more complete view of this.

I don't want to sound like a troll, but most of us around here are open to comment so hope it's taken in the right spirit and no more than a discussion point

I'm not a particularly serious driver, and have no advanced training. However I have been driving too fast on back roads for a few years!

Re the above point the great thing about a manual gearbox is that it gives control to the driver to do whatever he or she likes with it. Now when learning to drive we think in terms of specific gear change up and down points. In my car it's generally: 0-10 mph 1st, 10-20 mph 2nd, 20-30 mph 3rd, 30+ 4th

I do have a fifth gear but then it's fitted to a 1.3 Fiesta! Thus I only use it for cruising. If I need to change speed up I drop down to fourth. Simply because poor little car (Vicky, not sure why name just suits) isn't powerful enough to gain speed, especially uphill, in fifth.

To return to changing gear, those speed ranges work well enough in town and on flat roads. When it's hilly they alter, when more acceleration is required they also change.

But in the country the situation is different again. I usually change 3rd to 4th at approx. 30-40 mph. Now on country roads, especially bendy ones, the usual speed range is 35-50 mph and constantly changing. Especially if you want to drive fast. Therefore low gear acceleration, braking, more accelerating and such is the order of things. In that situation I would stay in 3rd gear. This gives the car enough mid-range shove to cope with the desired speed changes. I would hold on to the lower gear for longer periods and use it at higher than normal speeds. Don't forget that none of this lasts very long. You won't harm, in fact you'll probably help, the engine by giving it a workout in that fashion.

When in a less frenetic section I'll go back to normal ranges. But that saves a bit of time in the very twisty bits, where it's less curvy rev-matching (even the infamous heel and toe) is required. So it's not incorrect driving. It probably uses more petrol and is noisier as one is using a higher rev-range. But it won't damage the car.

With regards to the other point it's all down to observation and judging the corner before you get to it.

As a final point there have been mentions of semi-automatic gearboxes and other expensive fripperies. I think the answer is to get back into something a bit cheaper.... A small hatchback from a long time ago doesn't offer the same degree of insulation from the environment. Additionally a low-powered engine requires greater involvement from the driver. With almost no power, I have approximately 60 BHP for reference, even just keeping up with traffic requires maximum extraction of what's there. As such the driver naturally has to, for want of a better word, drive more!

[RWD cossie wil]

Is there any consideration given to the vehicle you are driving when deciding what technique to use? Personally when I drive my 911, you need to carry some braking right upto the apex to keep the weight balanced (due to the rear engine), any acceleration prior to having the car turned really unsettles the balance & makes the nose want to push wide. However in my BMW 5 series, the car responds a lot better to being settled prior to turning in on a neutral throttle.

[R_U_LOCAL]

RWD cossie wil said:

Is there any consideration given to the vehicle you are driving when deciding what technique to use? Personally when I drive my 911, you need to carry some braking right upto the apex to keep the weight balanced (due to the rear engine), any acceleration prior to having the car turned really unsettles the balance & makes the nose want to push wide. However in my BMW 5 series, the car responds a lot better to being settled prior to turning in on a neutral throttle.

I have some limited experience in Porsche 911s and I find that on the road, they respond well to a "slow in fast out" cornering technique.

As you've identified, the location of the engine is the issue and it's important to very carefully manage the weight transfer from braking, into steering and applying the power. 911s have a light front end with little weight over the front wheels to encourage the front tyres to grip. It's more noticable in air-cooled cars which I always thought felt a little skittish at the front end, but with a good technique, a 911s advantages can be exploited - the advantage is traction through and out of corners as the power is applied and the rearward weight transfer increases traction on the driven wheels.

Keeping some braking on as you turn in to the corner may be an effective method to encourage the front wheels to turn in initially, but I wouldn't recommend it for the road. On the track, you've little else to think about other than your physical actions in the car and little else to worry about than your ultimate speed through the corner and onto the next straight. So for track driving, trail braking up to the apex whilst downchanging with a heel/toe technique is probably the best approach.

On the road, however, I'd advocate sorting everything in a straight line before you get to the turn-in point, then making the initial turn of the wheel with no throttle input. This means that, after braking and changing down, there is still a little forward weight transfer (the throttle is shut so there is still a little retardation from the engine) to assist the front tyres in starting the turn.

Once the car has started turning, start gently applying the throttle until you're at the apex and then increase the throttle input as the corner starts to open up.

Cornering a 911 is a little intimidating at first because of their reputation, but I found them to be fabulously responsive cars and they seemed to respond nicely to a measured, smooth and accurate technique.

I've never tried a 4 wheel drive 911 though, so I can't comment on any differences in approach for those cars. The weight is in the same place though, so I suspect a similar approach would be required - I suspect the biggest advantage of the additional traction would allow an earlier application of power once the car is settled in to the bend, but I'll reserve judgement until someone lets me have a go in one!

[SVS]

Hi Will,

I've driven a 4 wheel drive 911 Turbo (what a fantastic car!) and agree with RUL's comments:

R_U_LOCAL said:

I have some limited experience in Porsche 911s and I find that on the road, they respond well to a "slow in fast out" cornering technique ...

... I'd advocate sorting everything in a straight line before you get to the turn-in point, then making the initial turn of the wheel with no throttle input. This means that, after braking and changing down, there is still a little forward weight transfer (the throttle is shut so there is still a little retardation from the engine) to assist the front tyres in starting the turn.

Once the car has started turning, start gently applying the throttle until you're at the apex and then increase the throttle input as the corner starts to open up.

Cornering a 911 is a little intimidating at first because of their reputation, but I found them to be fabulously responsive cars and they seemed to respond nicely to a measured, smooth and accurate technique.

I agree. That's been my experience too.

Anyone who owns a 911 is very lucky - such fun to drive!