James, that explains why my vRS was behaving "badly" when I was using both legs ! .

Rev matching is a forgotten art. I just do not feel the need to do it (and thanks for the good explanation ) to achieve smooth and dynamic downshifts. Without rev matching you are using your clutch 50% less often than with rev matching - easy maths in my book . As for keeping the motor in the power band when racing you want to keep it within certain rev range where it makes most power and torque on deceleration when downshifting which usually means higher part of the rev range and without throttle application you can't do it and it bogs down. You can do it without double clutching but if you do not mind replacing your clutch pack very often and usually there is no time to double clutch. DSG does it for to and rev matches between swapping clutch packs or allows for small slippage. When in manual I noticed best is to upshift at 6,5k-6.75k rpm so it drops to circa 5,5k and downshift at 4k rpm as this slots it right bang into 5,5k where blower achieves the biggest boost.

I drove trucks and WWII Jeeps without synchro, becomes second nature really fast to double clutch all the time. Also when your clutch packs up this skill is rather handy.

Chris, time to process and execute as well as reading the road ahead are the mainstays of smooth driving. My goal today on my way from work to the swimming was to use the brakes as little as possible. I was gin smacked how well it worked when I fully applied it. Adjusting your speed well ahead of hazards allowed me to simply slot into the oncoming traffic on roundabouts without changing speed at all, where road configuration and traffic conditions allowed of course. No need to double clutch

Sounds good and it'll all fall into place quite quickly - I think it's just getting used to it and feeling the benefits

I think there's a thread about this with a few ideas, but in essence, I think there are two approaches which may work - treat the approach as two hazards (the first hazard being stalling and the second the roundabout) and run through the System twice and effectively selecting an intermediate gear, or brake later and more firmly such that you are clutch down for a much shorter period of time.

Yep the idea is that you arrive at the hazard in the correct position and at the correct speed such that you can then select the correct gear for the speed and negotiate the hazard. One of the eureka moments I had (which now seems quite obvious ) is that because each of the phases happens in sequence, you need to leave yourself an appropriate amount of space to process them before you arrive at the hazard, otherwise it'll get a bit messy and rushed

Enjoy!

Chris

Cheers Chris,

The guy seemed quite a character and we hit it off straight away ( I was cheeky and asked the local IAM secretary if I could have someone with a dry sense of humour!) What was obvious to me was I wasn't getting the S & G phases done quickly enough before the hazard but it'll come. I did my advanced riding years ago so though I've forgotton a lot I know some of what to expect, just a case of trying to get it to sink in and understanding the subtle dfferences between the practicalities of what I can remember about advanced riding and what the IAM want me to do driving wise- e.g. to me the S & G phases seemed to be easier on a bike from what I remember as you can't block change!

What was also refreshing was that he was open about what would be expected on the test but pragmatic about what advanced drivers normally do

all the best

Ade

Rev matching is a forgotten art. I just do not feel the need to do it (and thanks for the good explanation ) to achieve smooth and dynamic downshifts. Without rev matching you are using your clutch 50% less often than with rev matching - easy maths in my book .

May be some more confusion Rev-matching is lifting/dropping the revs when the car is in neutral. So, if you do a "normal" gear change you are clutch down, change gear, clutch up (1 use of the clutch). For a rev-matched down change, you might do clutch down, change gear and lift revs, clutch up (1 use of the clutch). If you are rev-matching by double-declutching then you will use the clutch 50% more, but that is not the only way to rev-match. On the flip side, if you don't rev-match you are likely either letting the syncro's do the work (accompanied by a jerk) or dragging the clutch to smooth things out (increased clutch wear).

As for keeping the motor in the power band when racing you want to keep it within certain rev range where it makes most power and torque on deceleration when downshifting which usually means higher part of the rev range and without throttle application you can't do it and it bogs down.

For a given gear, a particular number of revs will translate to a particular road speed. So, it's the choice of gear which determines whether the speed you want will be in the power band and nothing to do with rev-matching. Btw, the bogging down could well be the syncro's at work from a poorly rev-matched change

Chris

The guy seemed quite a character and we hit it off straight away ( I was cheeky and asked the local IAM secretary if I could have someone with a dry sense of humour!) What was obvious to me was I wasn't getting the S & G phases done quickly enough before the hazard but it'll come. I did my advanced riding years ago so though I've forgotton a lot I know some of what to expect, just a case of trying to get it to sink in and understanding the subtle dfferences between the practicalities of what I can remember about advanced riding and what the IAM want me to do driving wise- e.g. to me the S & G phases seemed to be easier on a bike from what I remember as you can't block change!

Nice to hear of a positive IAM experience and that you're enjoying it.

Chris

I find going from 5th to 3rd or 4th to 2nd helpful when 'spirited' driving as it seams to unsettle the backend better and more predictable than using the brakes alone, giving slight overstear rather than understeer. I don't mean dumping the clutch and i still use the brakes in conjunction but the engine braking seams to give you more control over a corner at speed you can almost move the car around the roundabout / bend without to much steering input. If that makes sense. I generally use all the gears when getting upto speed though the ratios are there for a reason.

I find going from 5th to 3rd or 4th to 2nd helpful when 'spirited' driving as it seams to unsettle the backend better and more predictable than using the brakes alone, giving slight overstear rather than understeer. I don't mean dumping the clutch and i still use the brakes in conjunction but the engine braking seams to give you more control over a corner at speed you can almost move the car around the roundabout / bend without to much steering input. If that makes sense. I generally use all the gears when getting upto speed though the ratios are there for a reason.

Right effect; wrong reason I think.

Your increased control comes from the extra weight transfer forward under braking, and the extra power allowing easier/more transfer sideways/backwards through and out of the corner.

I find going from 5th to 3rd or 4th to 2nd helpful when 'spirited' driving as it seams to unsettle the backend better and more predictable than using the brakes alone, giving slight overstear rather than understeer. I don't mean dumping the clutch and i still use the brakes in conjunction but the engine braking seams to give you more control over a corner at speed you can almost move the car around the roundabout / bend without to much steering input. If that makes sense. I generally use all the gears when getting upto speed though the ratios are there for a reason.

Interesting technique - what are your feet doing during this and at what point in the sequence do you steer for the corner?

I'm no expert in vehicle dynamics (which I suspect is plainly obvious from my posts ) but I would have thought that as the brakes have the ability to lock the wheels, I'm not sure what else engine braking would be able to offer in terms of slowing down over the brakes .. at least in FWD where the brake bias and weight transfer will be towards the front of the car?

Chris

Interesting technique - what are your feet doing during this and at what point in the sequence do you steer for the corner?

I'm no expert in vehicle dynamics (which I suspect is plainly obvious from my posts ) but I would have thought that as the brakes have the ability to lock the wheels, I'm not sure what else engine braking would be able to offer in terms of slowing down over the brakes .. at least in FWD where the brake bias and weight transfer will be towards the front of the car?

Chris

Well im not sure why it works it just does.

'Where conditions Permit' Aproach to round about at speed back off the throttle initially and brake to scub most of the speed then on entry to round about drop two gears the actual gear would depend on speed and severity of corner. take racing line throught the roundabout i.e clip the apexes straighten out as much as possible as someone said above the weight transfers forward more with engine braking the back end will go light and aid the movement around the corner Then exclerate hard on exit this will stop the overstear turning into a sideways moment. This works for standard suspension if it was lowered and stiffened i use a different aproach.

With the skoda I find no need to blip the throttle inbetween gear changes as the torque sweet spot is quite low as you have dropped 2 gears you are already in the powerband before the exit of the roundabout. In my old cliosports / williams i would be constantly blipping the throttle to keep the revs high while changing up or you would lose most of the power.

So are you coming off the brakes during the gear change and when do you get back on the throttle? I still can't see the engine braking having an effect unless the brakes aren't really being used to their full effect and I think you would get a similar effect carrying more speed into the bend, using trail braking to the apex, get gear and then powering out?

What would you do differently in a car that was lowered and stiffened?

FWIW, the blipping of the throttle is nothing to do with needing to keep the revs high - the revs will always "land" in the same place when you re-engage the clutch for a given speed because the gear ratios are fixed and if you're not lifting them yourself, you're forcing the syncro's to do the work which isn't very mechanically sympathetic or comfortable for passengers Changing up the box, you can probably get away with it if the revs fall the necessary amount at a similar rate to the time it takes to change gear.

Chris

My mum tried the IAM and found the whole thing a very negative experience , her instructor wouldn't allow block changing or even going down the 'box when slowing , ie when approaching a roundabout she was expected to slow with the brakes (thus signalling to others) , only when ready to accelerate do you then select the correct gear so sometimes 6th to second if the roundabout was clear, she found it very alien to the way she had been driving for 40 years and struggled to adapt her technique.

Another thing she got criticised on was selecting too high a gear to accelerate up a slip road etc anyone who drives a 1.9 Fabia VRS knows they often go best when you load the turbo up with a high gear

Block changing up both my dad, my brother and grandad do it. So will often go 2nd to 4th or even 5th. They do it because they are too lazy to go through them all. In the old vRS I'd sometimes do it but it's not a problem. As for downshifts I do miss it in the new vRS but if I ever drive one of the Swifts I'll heel and toe almost every down change just because it's fun and satisfying when you get it right. The Sport is made for it. Another thing they can do that most VAG's can (without outwitting it) is left foot brake.

My mum tried the IAM and found the whole thing a very negative experience , her instructor wouldn't allow block changing or even going down the 'box when slowing , ie when approaching a roundabout she was expected to slow with the brakes (thus signalling to others) , only when ready to accelerate do you then select the correct gear so sometimes 6th to second if the roundabout was clear, she found it very alien to the way she had been driving for 40 years and struggled to adapt her technique.

The IAM experience is very much down to the quality of the observer and it sounds like your Mum didn't believe what was presented was a better way of driving than she had been doing for 40 years. The idea of the System is to provide a simple, efficient framework that any driver can use to successfully negotiate hazards Safely, Systematically, Smoothly while making progress (Speed). As such doing multiple gear changes on approach to a hazard is a waste of effort (unless the brakes have failed ) as the brakes can do the same job, better and once you've arrived at the target speed, you can then get the appropiate gear and go.

Another thing she got criticised on was selecting too high a gear to accelerate up a slip road etc anyone who drives a 1.9 Fabia VRS knows they often go best when you load the turbo up with a high gear

Without being there, it's hard to comment on this, but I would think accelerating onto a slip road from a normal road, you'd typically be looking at 3rd or 4th for optimum acceleration and minimal stress on the DPF up to NSL. Which gear was she using and what speeds were involved?

Chris

I am not sure I am getting the right enof the stick here, are we talking track/road racing driving or normal, everyday driving?

Another thing she got criticised on was selecting too high a gear to accelerate up a slip road

It's a common problem for many drivers who change up a gear and then are not being able to accelerate as briskly as they could if they had held the lower gear a bit longer.

anyone who drives a 1.9 Fabia VRS knows they often go best when you load the turbo up with a high gear

They go best when the engine speed in the next gear up is high enough, typically a little over 2000 rpm. Unfortunately many drivers change up too early and completely butcher the possibility of brisk acceleration.

Edited 23 April, 201313 yr by AnotherGareth

I am not sure I am getting the right enof the stick here, are we talking track/road racing driving or normal, everyday driving?

It applies to both.

Chris

I change up at 2000rpm in my oil burners when not in a hurry. In a little hurry around 3-3.5k rpm. In real hurry - I do not drive the oil chugger

Well im not sure why it works it just does.

'Where conditions Permit' Aproach to round about at speed back off the throttle initially and brake to scub most of the speed then on entry to round about drop two gears the actual gear would depend on speed and severity of corner. take racing line throught the roundabout i.e clip the apexes straighten out as much as possible as someone said above the weight transfers forward more with engine braking the back end will go light and aid the movement around the corner Then exclerate hard on exit this will stop the overstear turning into a sideways moment. This works for standard suspension if it was lowered and stiffened i use a different aproach.

With the skoda I find no need to blip the throttle inbetween gear changes as the torque sweet spot is quite low as you have dropped 2 gears you are already in the powerband before the exit of the roundabout. In my old cliosports / williams i would be constantly blipping the throttle to keep the revs high while changing up or you would lose most of the power.

From the bits I (think) I understand so far the approved IAM way is to reduce the speed while travelling in a straight line, then select the correct gear for the hazard, at the same time applying the throttle and releasing the clutch so engine and road speed are matched before entering the hazard. This allows the car to enter the hazard in a balanced state so the sideways forces that will be applied to the tyres will be done so evenly, thereby reducing the risk of loosing control though a skid. From point of entry to the apex of the bend the car is kept in balance by using smooth minmal throttle changes where appropriate until the apex is reached. At that point the throttle can be increased to drive out of the bend where conditions allow. Disrupting the balance/driving the car out of balance between entry and apex probably isn't suitable for the average driver as their car control would probably not be good enough to recover from any resulting loss of control?

That's correct - you're basically arriving at the hazard having got everything done in preparation so you can negotiate the hazard. Traditional Roadcraft suggests that speed should be matched to vision such that the corner is divided into three phases:

1. Braking until the limit point is matched

2. Holding neutral throttle while limit point is matched

3. Accelerating to chase the limit point when it starts to run

An alternative approach is to slow more than necessary in the first phase, such that you can be applying positive acceleration to squat the car down and increase stability and "chase" the limit point in the 2nd stage, meaning in theory a lower entry speed but a higher exit speed.

A (nice and simple) analogy I like is that you can model tyre grip as £10 which you can divide up to spend on braking, accelerating and steering. This means that the earlier you can wind off steering, the earlier you can spend more on acceleration and still remain within the envelope of grip of the tyre. For racing drivers who want to drive on the limit of grip and transition between brakes, steering and acceleration to achieve this, the Circle Of Grip model is worth a look:

Chris

Edited 23 April, 201313 yr by ScoobyChris

They go best when the engine speed in the next gear up is high enough, typically a little over 2000 rpm. Unfortunately many drivers change up too early and completely butcher the possibility of brisk acceleration.

Yep absolutely her observer/ instructor thought it was better to change up much later after 4000rpm, he had no experience of diesel turbos and drove a Rover 75 petrol with a 1.8 engine

Oh and no dpf on a Fabia vrs not that I agree with adapting your driving if you have one.

The issue I feel she had was lack of quality instruction it was variable and inconsistent , the old adage you get what you pay for with volunteers , subsequently her confidence was shattered and she became a worse driver as a result , took a considerable time for her to feel safe behind the wheel again.

Apart from some minor bad habits there was nothing much wrong with her driving she has an exemplary record and is very experienced.

I think it would've been a very different experience with better or perhaps younger instructors

I was always taught to go down the gears when approaching a hazard to ensure you are in the correct gear all the time and to make the most out of engine braking , but then I was taught to drive a large variety of vehicles

I was always taught to go down the gears when approaching a hazard to ensure you are in the correct gear all the time and to make the most out of engine braking , but then I was taught to drive a large variety of vehicles

Why do you need to be in the correct gear to pick away when you're 175 feet from a roundabout?

Suppose you're approaching it at 70mph: When you're 240 feet away you absolutely, positively have to be braking simply because you're going too fast to negotiate the turns. The same thing still applies at 175 feet in this case because you still need full braking to get stopped in case the alternative is acquiring a 44tonne bonnet ornament!! So there's clearly no need to be able to accelerate at that point. By the time you reach around 50 feet, you can see whether or not your way will be clear, and either continue braking, or transfer back to the throttle and block shift into second or third, using throttle to smooth the gear change.

Best luck trying to skip a gear in a truck , that's why you work your way down the 'box

Best luck trying to skip a gear in a truck , that's why you work your way down the 'box

Quite surprised by this comment - I've got no personal experience, but someone on another forum is an ex LGV instructor (along with IAM car and IAM LGV?) and made the following comment on a thread where someone was asking about getting into LGV driving:

Can I use AD methods? - YES, if you want to. The usual method is to select a 'covering gear' on approach to hazards but this is done for 'average' drivers. You can hold off gear selection until you know which gear you need to GO but make sure you know exactly where each gear is in the range change gearbox and at what speed each one will select before trying it.

Chris

Of course it depends on the truck but most of the stuff around when i was learning was fussy about the correct gear and would not let you either rush nor skip a gear hence the fact that's how I was taught.

Many modern trucks are auto's now.