Emergency braking - dip the clutch?

[0x2DLVR]

well, we, the collective we who disagree with you, are saying not to use both in an emergency.

i think we have proivided reasons for this, but you seem to think that the reason to *use both* is that you will brake quicker.

i do not think that braking distance would be significantly reduced by combining normal braking with down-gearing...

i have actually empiricaly tested this out for myself...

maybe you should do the same?

So my answer is gear down at the same time in emergency braking so you can use the engine braking(forget this bit cause you don't think it makes a difference) as well as having power ready to get out of a situation (concentrate on this bit then) I still think it's a better idea. But as you said that's only my opinion

[0x2DLVR]

If you are at maximum braking, down-gearing will give you a longer stopping distance.

How do you figure this?

[bahaimus]

I've seen people try to do that at driver training days. When instructed to brake only and forget the gears, they do in fact pull up quicker because they are fully focussed on the braking.

[phreeky]

How do you figure this?

i think the point is that at normal road speeds with reasonable brakes, the brakes power is not an issue - it's tyre grip - so combining with engine braking gives no advantage.

[tinkerbell]

as well as having power ready to get out of a situation

so your solution to an emergency situation is to be in an effective gear to accelerate?

i'm glad i have never been in one of those emergencies!!!

[KDog]

Well technically if you are at the edge of maximum braking and you let the clutch out to give you engine braking then you will lock the appropriate wheels and cause your stopping distance to increase.

[0x2DLVR]

so your solution to an emergency situation is to be in an effective gear to accelerate?

i'm glad i have never been in one of those emergencies!!!

I do 50,000km a year. I've been in all sorts of emergencies. I've been driving for 9 years and never have never been involved in an accident. So I think I have been doing something right so far

[0x2DLVR]

Well technically if you are at the edge of maximum braking and you let the clutch out to give you engine braking then you will lock the appropriate wheels and cause your stopping distance to increase.

Not if you double d clutch

[Wobbler]

I do 50,000km a year. I've been in all sorts of emergencies. I've been driving for 9 years and never have never been involved in an accident. So I think I have been doing something right so far

You must have a huge penis.

Hope this helps

[The Pupat]

Ohh get farked. No way in an emergency situation would you Heel n Toe a change. You get on the brakes as hard as you can without locking and try and pull the car up without hitting anything. Whether you have the clutch in or not is neither here nor there, just as long as you pull the car up as fast as possible, or miss the object infront of you.

[Camma]

Heavy braking is different to emergency braking and obviously requires different techniques.

I know a friends old race car with four wheel drums requires the engine to assist in braking otherwise the thing simply wouldn't pull up on the track. Not sure what the case would be in an emergency but I would assume he would require the engine to assist in braking (depends how much time is available) otherwise it would simply be a lock up and skid.

I guess thats teh key. Available time + braking power would determine how you pull the car up. If I completely relied on my brakes at the track and none of the engine I reckon they would last only a lap or two before getting too hot. If I had bigger brakes I would use less engine and more braking.

Is this correct? Some of you more experienced track drivers (rally drivers in particular) would be able to correct me.

[Tripper]

What 02PRUV is trying to say i think, is that he grabs a gear just incase the situation changes iecontinuing to brake will lead to you hitting some thing.

I have experienced this i was driving along a dirt road when a right angle turn appeared, i hit the brakes only i was going to stop in time, so instead og going into the trees and damaging the car i put in second, thurn the wheel and put my foot down.

We are talking about emergancy braking you dont know what is going to happen, is the car going to pull up before that kid that just stepped out on the road or are you going to have to drop back a gear and drive around it.

If we were talking about stopping in the shortest time possible, yes brakes only with the clutch in.

[Camma]

PS. Allan don't take offence from these fellas they can be a cranky lot with new comers.

[0x2DLVR]

Heavy braking is different to emergency braking and obviously requires different techniques.

I know a friends old race car with four wheel drums requires the engine to assist in braking otherwise the thing simply wouldn't pull up on the track. Not sure what the case would be in an emergency but I would assume he would require the engine to assist in braking (depends how much time is available) otherwise it would simply be a lock up and skid.

I guess thats teh key. Available time + braking power would determine how you pull the car up. If I completely relied on my brakes at the track and none of the engine I reckon they would last only a lap or two before getting too hot. If I had bigger brakes I would use less engine and more braking.

Is this correct? Some of you more experienced track drivers (rally drivers in particular) would be able to correct me.

Glenn you've seen the size of the brakes on my cars and I still don't rely on them for everything.

It always depends on how much time you have. But if you do it all the time then it's just part of driving. And that's how I drive all day everyday

[Jim]

Not if you double d clutch

I defy anyone to find themselves in a true emergency situation but manage to double declutch, engine brake and not lock up any wheels. :rotflol: We're not talking about a calculated procedure here, we're talking about a split second decision to not die.


IMHO in a FWD car it won't matter diddly squat in regards to locking wheels whether the clutch is in or out. All the load is on the front wheels aleady and the brakes are much larger than the rear brakes. The effect of the engine will be negligable.

having the car in any gear at all and the throttle shut you'd be lucky to notice the difference if the clutch is in or out in regards to braking efficiency. As someone else mentioned it's a good idea to have the clutch in to help prevent the engine stalling so you can then drive out of whatever situation you have found yourself stopped in.

Ina RWD car, you may find, as I have, that having the clutch out can help prevent rear wheel lockup. Depending on car of course. The crown's brake bias was shithouse, though the skyline is a rear brake locker too.

The rear brakes are a lot less effective than the fronts and there's not much weight on them, so you might find there's a difference there.

Most cars will stall regardless of whether the clutch is in or out anyway. Even the auto statesman would stall when coming to an emergency full stop.