Joined IAM - Too slow?
Discussion
vonhosen said:
....As you do this the wine drops without spilling & you then take an unhurried gear change if required & should have clutch up & left hand back to the wheel ready to pull the steering on for the turn in.
If you have the timing spot on, you will just have time to check your watch for the time on it's way from gear lever to wheel & then pull the steering a split second after the hand gets to the wheel. If you can do that you were spot on, if you have more time than that you've outbraked it, if you've less time your system was late.
When do you get the power back on, and how?
7db said:
....As you do this the wine drops without spilling & you then take an unhurried gear change if required & should have clutch up & left hand back to the wheel ready to pull the steering on for the turn in.
If you have the timing spot on, you will just have time to check your watch for the time on it's way from gear lever to wheel & then pull the steering a split second after the hand gets to the wheel. If you can do that you were spot on, if you have more time than that you've outbraked it, if you've less time your system was late.
When do you get the power back on, and how?
As the clutch is released, you will be feeding on the power to maintain constant speed & offset the effects of steering into the curved path.
victormeldrew said:
Actually, thinking about it, do auto boxes change down as you brake, or do they wait until you lift off the brake?
Depends how much speed you are losing & how you do it.
Autoboxes don't tend to take down shifts (following a result in fairly sharp speed loss) instantaneously. They'll pause for thought before selecting what they consider the appropriate gear.
They will however change down whilst you are still on the brake where your speed loss is very gradual & not firm.
As a result when driving an auto to "the system" where you are losing quite a lot of speed reasonably firmly prior to the hazard, you have to brake away from the hazard pretty much as you would to leave room for a seperated gear change in a manual car, because the auto box needs time to settle & sort out a gear prior to your entry into hazard. It is however a common mistake for people to not make that room & brake right up to the hazard as they don't see any action required for them to get the gear. This results in the autobox not having selected a gear as they enter & them not actually being "on the drive" until they are well into the curved path.
It will depend on the implementation by the manufacturer (auto boxes can vary quite a bit in their behaviours between different manufacturers), but it should be evident to you when the gearbox is ready.
The system is in essence about safe simplicity, it's never been about what's quickest. Speed is the last of the 4 S's and never takes primacy over the previous three S's.
>> Edited by vonhosen on Monday 8th May 23:37
vonhosen said:
As the clutch is released, you will be feeding on the power to maintain constant speed & offset the effects of steering into the curved path.
Forgive me for drilling further as I'm thinking about how to develop my style at this stage of the corner entry...
Feeding on the power initially stabilises the vehicle. I want to set all the power before starting the steering, so that I can use minimal deflection with understeer killed off. So if that level of power is neutral in steering it must be accelerative prior to starting to steer in. The car settles and we start to steer.
Is there anything else going on?
EmmaP said:
Is it not more correct to call that 'cruising'?
Well whatever you want to call it, it's the thing that happens while you're changing gear if you're not allowed to brake at the same time.
It means that in the situation I described you're stuck out in the main traffic stream at very low speed for much longer than necessary.
TripleS said:
Thanks for the comments so far.
I will end this post here and post again after more observed drives. Will probably take me three weeks or so before I have two more observed drives due to other commitments of myself and observer. At least I am getting on fine with my observer.
May I offer you my best wishes for the rest of the course Phil, and hope everything clicks into place for you.
Dave.
Thanks for the best wishes. I am reading all the posts in this thread with a keen interest. As I said in an earlier post I will post again after I have completed another two observed drives. My observer only wants to do weekends so it will be two weeks between drives as I am away, on average, every other weekend.
I have thought of asking for a diffrent observer for the fourth drive to gain a different perspective on my driving. What do you all think? A good idea or should I stick with one observer? Changing observers seems to be the norm with some groups, but not mine.
7db said:
As the clutch is released, you will be feeding on the power to maintain constant speed & offset the effects of steering into the curved path.
Forgive me for drilling further as I'm thinking about how to develop my style at this stage of the corner entry...
Feeding on the power initially stabilises the vehicle. I want to set all the power before starting the steering, so that I can use minimal deflection with understeer killed off. So if that level of power is neutral in steering it must be accelerative prior to starting to steer in. The car settles and we start to steer.
Is there anything else going on?
Yes it will be mildly accelerative intially & the balance maintained with accurate use of the throttle whilst steering.
>> Edited by vonhosen on Monday 8th May 23:46
GreenV8S said:
Is it not more correct to call that 'cruising'?
Well whatever you want to call it, it's the thing that happens while you're changing gear if you're not allowed to brake at the same time.
I've been thinking about this since reading the site, coasting is when the vehicle is moving either in neutral, or with the clutch in, which one should not do. So I think cruising may be a better description.
Maybe I am missing something, but I cant quite grasp the problem about "while you're changing gear if you're not allowed to brake at the same time. When I had a "manual box", I used to simply "double de clutch" to change down, which was just one swift fluid movement of hand, and feet, (for the benifit of our younger readers who may not know), in clutch, into neutral, blip throttle, in clutch, into lower gear, (the blip on the throttle will increase engine revs to match lower gear to speed)out clutch.
Am I missing the obvious?
P.S. Whoooops should just add, that when I learnt to drive, which was in a Bedford RL, (3 tonner), we were taught to always double de clutch, and it is something I always found easy to do in a car, ovbiously in modern cars, you just dip clutch, and change down in one movement, with a blip on the gas at the same time.
>> Edited by vipers on Tuesday 9th May 00:45
>> Edited by vipers on Tuesday 9th May 07:08
Philbes said:
The steering takes you around the curved path, the throttle is modulated to hold you on the chosen line & speed.
Using the throttle to modulate the course of the car? This is necessary within the speed limit on public roads? Gosh, I have got a lot to learn!
Even at speeds within our NSL SC limits, if you are not on the throttle to maintain the constant speed through the curved path, your speed will scrub off & this will lead to your steering becoming exaggerated, with you coming off the desired chosen line and ending up on a weaker shallower one.
Control on the throttle like this doesn't mean you are near the limits of grip. You are merely controlling the balanced resultant force (the line you hold), from the forces placed on the car by your inputs. If you have that balanced state, if you make changes in one area (reduce throttle), it will affect another area (effect of steering & line held).
>> Edited by vonhosen on Tuesday 9th May 07:08
Just to add in to von's point above, the thing to understand is that when you turn the wheel, the 'grip' generated has two components - the bit that turns you around the corner and a bit of drag that slows you down (induced drag for those who like physics or have an interest in aerodynamics). If you apply power while cornering this two has two components - the bit that increases your speed and a bit of cornering force.
If you match the power application correctly the bit that increases your speed matches the bit of drag and you are balanced. If you apply more power than this then you actually get more cornering grip for the same amount of steering deflection. It's one of the reasons that 'slow-in fast-out' is the quickest point-to-point method on the road - You enter the corner at a speed slightly below the maximum speed you are comfortable with and then, providing vision etc. are compatible you can accelerate (gently at first then increasing as the limit point moves away) through the bend using less steering.
It also gives you plenty of time to cherry-pick your cornering line to take a late apex and get on the power earlier.
If you match the power application correctly the bit that increases your speed matches the bit of drag and you are balanced. If you apply more power than this then you actually get more cornering grip for the same amount of steering deflection. It's one of the reasons that 'slow-in fast-out' is the quickest point-to-point method on the road - You enter the corner at a speed slightly below the maximum speed you are comfortable with and then, providing vision etc. are compatible you can accelerate (gently at first then increasing as the limit point moves away) through the bend using less steering.
It also gives you plenty of time to cherry-pick your cornering line to take a late apex and get on the power earlier.
victormeldrew said:
Actually, thinking about it, do auto boxes change down as you brake, or do they wait until you lift off the brake?
Auto boxes "change down" when you engage the accelerator again usually...or at least...the ones I used to own did. Which is why in order to be "systematic" in an auto-box I find it is best to have finished braking and be back on the gas before turn-in. That way you know what gear you will be in as you negotiate the hazard.
Interestingly we had an Observer's Meeting last Saturday. Apparently it is an IAM Fail if your auto-box changes gear mid-corner or "hunts" is a sequence of bends. The idea being that you have not preselected the suitable "hold" gear to prevent it. (When I say "fail" - I mean a "black mark" - enough of them and you actually fail the test).
After all - you wouldn't change gear mid-bend in a manual...usually. Although I've seen Mark Hales get away with it a "Club" in a Caterham without spitting it off the track - damn he must be smooth...
Of course if you have an F1-computer-rev-matched system you can probably get away with anything...
vonhosen said:
If you've got someone close behind & you are taking a tight junction left or right, then a pre-sold overlap to meet with their expectations of your braking on the grounds of safety is in order. You will still ensure you have achieved correct speed, gear & be off both brakes & clutch before you turn in.
As has been said elsewhere, it is possible that you would hold up others, but not unnecessarily so. Don't be forced to carry more speed than you can deal with comfortably (whilst remaining, safe, systematic & smooth) into any hazard.
How interesting! Personally I have never found the "need" to overlap. I aim to deal with the following traffic long before I get to the stage where I would feel "pushed" into getting out of their way.
When I say never felt the "need" - I mean "on-road" - I certainly feel the need whilst getting third on the way into Quarry whilst trying to put in a quick one...but that is another story.
StressedDave said:
Brushing the brakes for a long period prior to a hazard is hardly the best use of the £10 (apologies to Keith Code) of concentration available.
OK. Let me clarify what I mean.
On the approach to a left hand junction for example. Steam-From-Ears is behind...a little too close...but OK. I want the left junction. So.
Mirror - I know where Steam-From-Ears is.
Signal. No change in speed. Give SFE time to see the signal. A second or two. Mirror - has he seen the signal?
Touch brake pedal. Brake lights go on. NO BRAKING. Mirror - is SFE slowing? Give him time...check again...slowing?
SFE is slowing..excellent. Normal brake for junction. Smoothly off brakes, blending new gear into the end of braking whilst a small rev match with the accelerator smooths our the change.
Both hands back on steering wheel - and turn in.
Accelerate away.
At the point where, after pressing the brake pedal, I note that SFE isn't slowing...perhaps I'll abort the manouever if required.
SFE doesn't get held up more than necessary.
Personally I can judge perfectly well how hard to press the brake pedal - and I'll bet most others can too.
To be fair - when we take new Associates out on their early drives they can judge perfectly well what speed to be at for a hazard and they can usually slow down too. The bit they seem to find hard (understandably) is predicting what gear they will need. If you "go-down-the-box" you never need to predict...you just muddle through by being in whatever you've got to. Once the ability to predict what gear is necessary has been learned people seem to have a lot less trouble implementing the system - at least in my experience.
Don said:
I find it is best to have finished braking and be back on the gas before turn-in. That way you know what gear you will be in as you negotiate the hazard.
IAM Fail if your auto-box changes gear mid-corner or "hunts" is a sequence of bends. The idea being that you have not preselected the suitable "hold" gear to prevent it
Interesting, I have been driving an auto for 10 years, (previous to which I drove manual for 40 years), my current car is a 52 plate Volvo S80, what I dont follow from your comments above is this:-
1. You said "That way you know what gear you will be in as you negotiate the hazard", how so, I never know which actual gear I am in, I select "D" and thats it, the display doesn't actually show the gear ie 2,3 or 4.
2. You said "IAM Fail if your auto-box changes gear mid-corner or "hunts" is a sequence of bends. The idea being that you have not preselected the suitable "hold" gear to prevent it", how on earth can I know if it will change mid-corner, and how can I have pre-selected the suitable "hold" gear.
>> Edited by vipers on Tuesday 9th May 08:43
GreenV8S said:
I'm a little surprised that you're talking in terms of understeer on public roads, you'd have to be using far more grip than I would consider prudent before things like understeer and steering on the throttle become an issue.
My feelings exactly Peter. I keep getting surprised by these references to instability, anxiety about weight transfer, understeer, oversteer, steering with the throttle etc. in a road driving environment.
I must be too restrained with the whole process, as I never feel conscious of understeer/oversteer or any kind of instability. Generally speaking I find the car (not just my own but any car I've yet driven) does what I ask of it without any apparent threat of non-cooperation. Sorry, but that's me mystified again.
Best wishes all,
Dave.
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