34 replies to this topic

[kober]

When I was in the driving school I was taught to downshift directly from 4th to 2nd gear and brake only by brakes. Then blip the throttle to match the revs and release the clutch. My friends were taught to downshift sequentially 4th - 3rd- 2nd and brake also by the engine. What are pros and cons of these techiques? Which of these are racing drivers using in cars with stickshift and three pedals(N-GT, SuperProduction...)?

[Yelnats]

Many production class racers have been modified extensivly and feature sequential mortorcycle shifting but where the stock tranny is used the heel and toe route down through all the gears is the preffered method as it provides some assistance to overworked production brakes. Jump shifting from 5th to 2nd exposes the engine to a greater the risk of over revving as the huge jump is ratios is very hard to judge.

Heel and towing around town is fun but an unecessary frill with the improved brakes provided on modern vehicles. Only when hammering down a deserted road at suicidal speeds would Il recommend the use of engine braking. All but the very best performance cars could use some assistance in the braking department at such times.

But stay away from heel and towing on slippery roads with FWD as the brake bias is heavily towards the front and the slippery roads don't provide the weight transfer required to utilise the extra retardation from the engine braking.

[Alien]

I think that doqwnshifting was done sequentially 4th - 3rd - 2nd for example (in racing). I do it that way too, so i don´t overrev the engine. Braking while downshifting is not a big deal nowadays, but in the old days some people said that you could always tell how much skill a driver had because of the way he downshifted.

I remember that i read somewhere that you shouldn´t do it in a road car, because you could damage the engine if you use it frequently, but you certainly stop faster if you engine brake while braking.

[Darren Galpin]

Advanced driving techniques (and fuel saving techniques) all recommend the use of engine braking where possible, with most acceleration changes coming via a change in the position of the accelerator. That's not to say that you shouldn't use your brakes, but that they shouldn't be used as often as you suggest. However, you should be using one or the other, and not relying on both at the same time.

[PAD]

Darren - I am afraid that I have to contradict you. I am an "observer" for the Institute of Advanced Motorists - I assist people to getting to the standard of the IAM test (for legal reasons I am not allowed to instruct, only give advice!!)

The IAM's advanced driving method expects the driver to slow down using the brakes, and at the last moment to block shift (i.e. 5th straight to 2nd gear) - not to use engine braking.

There are two reasons for this:

1. A modern car has very good brakes, there is no need to use engine retardation. Replacing brake pads is far cheaper that replacing a gearbox and/or clutch. (As an example on the back of the UK's highway code it shows stopping from 70mph is 315 feet, of which the first 70ft is thinking distance. Apparently this is for a 1967 Ford Cortina with drum brakes all round. A modern equivalent - a Ford Mondeo with 4 disk brakes and ABS - will apparently stop in 165 ft, which still includes the 70ft thinking distance. This is a 62% improvement).

2. By block downshifting at the last moment means that the driver has both hands on the steering wheel for the maximum time and thus would be better prepared for emergency action should it be required.

When "observing" IAM members, most say they were taught to sequentially downshift when they learnt to drive and take time to change to the new method. Once the new technique is mastered it is just as natural. In fact getting it right shows a skill level in the modern driver.

I don't believe that either method would affect fuel consumption unless when sequentially downshifting you keep your foot on the accelerator (and thus get fuel flowing into the engine). Modern engine management systems cut fuel supply on decelleartion.

Note this is for road drivng, not racing.

[Darren Galpin]

PAD - However, in Roadcraft and "Pass Your Advanced Driving Test" it says that you should use acceleration sense to vary the speed of your vehicle to the conditions of the road. This includes lifting off the accelerator to slow down for the corner, and before entry you loop down into the appropriate gear. You need not use your brakes at all in this sequence - you should be anticipating the corner and thus reacting to it early, and acceleration sense is using the engine to vary the speed of the car - engine braking in other words.

[karlth]

According to Skip Barber's driving guide you should not use the gears to slow down. Wether one should shift directly down to 2 for a hairpin from 5-6 or gradually was a matter of preference. Moving gradually down through the gears is without doubt more difficult.

[Croaky]

I was taught to drive by a retired army driving instructor (it really makes you concentrate when a Regimental Sergeant Major is watching your every move!) and he taught me to downshift by going from 5th to 4th early on, then blockshifting from 4th to 2nd just before the corner. Going down the gears sequentially is alright as long as you brake early and gently, if you're braking late and hard you might find you just run out of time to get all the downshifts in, then get confused and end up in neutral.

[PAD]

Darren - Glad to see you have read those books. What you have said is correct, but only for small speed changes - try taking that side turning from the dual carriageway with engine braking alone ;)

I don't have my copies of the books to hand, I think it is page 27 of "Pass Your Advanced Driving Test" that it shows the "System of Car Control" - Information, Position, Speed, Gear, Acceleration. You will note that speed comes before gears in the sequence, i.e. reduce the speed of the vehicle as appropriate before selecting the correct gear. This allows for both engine braking (small speed adjustments) and normal braking (larger adjustments), but without using the gears

BTW. have you passed or are trying for your advanced driving test?

[Darren Galpin]

I think that we are purely arguing semantics here - I'm not arguing that you shouldn't use braking, just that some people should use more engine braking as they rely entirely on their brakes. I agree that for most slip roads off dual carriageways I would use brakes, but for a lot of motorway slip roads I use mostly engine braking, but that is because I can also use the incline of the slip road to aid the braking. It also varies with your car - my Nissan Micra has little engine power, so engine braking is sometimes minimal. On other cars with larger power engine braking effects can be far larger.

I'm a Senior Observer with the IAM in Bath, although a younger one - most of my associates seem to be older!

[Crazy Canuck]

What I've been taught, read, and practice is that you should not use the engine/gears to slow down. The reason is as follows:

1. Brakes are designed to slow a car down.
2. The engine and drivetrain are designed to accelerate the car.

Engine braking, as it is called, introduces loads and stresses that your cars drive train isn't really desiged for. Would you use a toaster to heat your house? Use the controls the way they were designed and your car will last longer.

I learned that technique at a race school and read about it in Prosts book and JYS' book about competition driving. I'm not sure if this thread is intended for racing techniques or street driving techniques. That said, I use the same theory driving to and from work in my road car!

CC

[PAD]

Darren - Howdy collegue from Guildford

[Ross Stonefeld]

I just got back from an extensive test session at Road America in Skip Barber's new sequential 5-speed equipped Reynards. Due to the nature of the track there was mostly 5-3/4-2 downshifts, with one 5-2 and a 5-1.

Going into the 5-1 corner I was downshifting with clutch and blip, releasing the clutch in each gear. If you were on top of things you could do it this way and get all your downchanges done before the corner. I think most guys were leaving the clutch in and blipping each gear but not letting the gear engage until the gear they were going to use for the apex. I later learned that often the blip was paired with a un-aware release of brake pressure. That is as I was rocking my foot to blip the throttle I was slightly coming off the brakes. I discovered this watching another session where the quick guys were braking at the 3 marker for a high-brake corner whereas I was at the 2. So the ideal way, and the one used by the quick guys was to get on the brakes as late as they could, and towards the end of the braking put the clutch in, bang it down as many gears as they needed, give it one BIG rev, and let the clutch out. Unfortunately my final session was canceled due to a faulty batch of front lower suspension A-arms, which grounded the entire fleet; so I was unable to test it myself

[unrepentant lurker]

Can someone explain "heel and toe technique" for me? Thanks.

[rdrcr]

The technique combines braking and downshifting at the same time.

Here is a step-by-step guide on how to heel-and-toe downshift. It will explain how to shift from fourth gear to third gear, though the technique will work for any downshift.

Begin braking for the corner with your right foot. The location of the pedals and the size of your foot will dictate where you position your foot on the pedal, but most likely it should be canted a little to the right, closer to the throttle pedal.

Push in the clutch with your left foot.

Move the shifter from fourth gear to neutral

This is the hard part. With your right foot still applying pressure to the brakes, roll the outside edge of your foot outward and downward to touch the throttle pedal. The pedal design on some cars makes this easier to do than on others. Use the outside of your right foot to blip the throttle. Blipping the throttle means temporarily raising the engine rpms to match the wheel speed. The exact amount of revs needed is dependent on a variety of factors, but it is usually between 1,000 rpm to 2,000 rpm more than the current engine rpm for a one-gear downshift.

Move the shifter from neutral to third gear.

Release the clutch with your left foot.

As you can see, "heel-and-toe" is a misnomer. It actually involves the ball of your foot and the side of your foot. I'll be the first to tell you that heel-and-toe downshifts aren't easy. I've found that a good way to practice is to just sit in your car in your garage and pretend you are doing a heel-and-toe downshift with the engine off. Keep repeating the steps until you are familiar with the process. Once you are ready, try it out for real. Most likely, your early attempts will be botched. Keep trying, though. Practice each step slowly and then work your way to making them all one, fluid motion. Skilled drivers can execute a heel-and-toe downshift in less than one second.

The trickiest part is getting the correct amount of rpms to match the new gear. If you blip the throttle too much, the engine has too much speed compared to the wheels and is forced to drop down to the wheel speed when you let out the clutch. If you don't blip the throttle enough, the engine rpms are forced to rise up. Either way, you know you didn't do it right as the car will jerk a little.

You'll also know it when you did it right. A proper heel-and-toe downshift is so smooth and so satisfying that, once done correctly, you'll find yourself using the technique all the time. The great thing is that you don't have to be a racecar driver or be on a racetrack to use it. Additionally, using the heel-and-toe downshift technique on the street can improve safety. In certain emergency situations, you might be required to brake heavily and then accelerate quickly. By heel-and-toe downshifting, your car will be in the best gear to achieve maximum acceleration.

For a really good description and illustrations
go to:

http://www.turnfast....g_heeltoe.lasso

[Top Fuel F1]

It's been too long ago since I did this to be able to detail the actual procedure. I use to be able to shift with out using the clutch, period.

[ferrarifan2000]

here's a question, how does one downshift without the clutch with a sequential transmission? therefore, allowing one to left foot brake. our sae car has paddle shifting, but the r6 m-cycle engine is stock with no modifications to ****** the timing on downshifts. i was thinking that if you started braking with you left foot, brush the throttle pedal with your right and then go to the next lowest gear, it would work. I havent had a chance to try it though. one teamate tried to downshift without the clutch and he just stood on the brakes and tapped the left paddle. i think from fourth to third it was ok, but it wasnt very smooth going from third to second, and second to first. i also dont think that our tranny would last very long if we continued to do it that way.does anyone have any experiences with left foot braking and clutchless downshifting? any ideas? Thanks everyone.

BG

[Croaky]

I've seen BTCC footage with a camera pointed at the drivers feet to see how they use the pedals. They guys that left foot brake just keep their right foot over the gas pedal and give it a little blip every time they go down a gear.

[Sean L]

Having just passed an advanced driving course I'd like to add that PAD is correct. Although it didn't come naturally at first and feels boring to drive that way, they teach you to do all your braking with both hands on the wheel until the car is stopped or the required speed is achieved. Then select appropriate gear. I still down-shift occasionally if I'm driving quickly though.

Down-shifting was used when drums all round was the norm. Efficient disk brakes are now more than adequate for stopping.

[rdrcr]

Originally posted by ferrarifan2000
here's a question, how does one downshift without the clutch with a sequential transmission? therefore, allowing one to left foot brake. our sae car has paddle shifting, but the r6 m-cycle engine is stock with no modifications to ****** the timing on downshifts. i was thinking that if you started braking with you left foot, brush the throttle pedal with your right and then go to the next lowest gear, it would work. I havent had a chance to try it though. one teamate tried to downshift without the clutch and he just stood on the brakes and tapped the left paddle. i think from fourth to third it was ok, but it wasnt very smooth going from third to second, and second to first. i also dont think that our tranny would last very long if we continued to do it that way.does anyone have any experiences with left foot braking and clutchless downshifting? any ideas? Thanks everyone.

BG

In gearbox karts the clutch is used only for the start. The entire race is done without one, just speed shifting on the way up, and then under braking, just pull back however many times on the shifter paddle to select the appropiate gear for the corner or manouver.

In the DSR classes and some CSR cars, the methodology is pretty much the same, some use the clutch on the down shift where smoothness of transition is desired or if just suits their style. Others just bang down to the desired gear... So far I'm not aware of transmisson failures out of doing this. Of course there is quite a bit of inspection and maintenance going on, to help insure against failure. We examine the drivetrain and other critical areas like brakes and suspension before each event.

The problem I could see your driver having is, that if he selected to low a gear by mistake, he could lock up the rears and skid out of control.

[Ross Stonefeld]

In a clutchless sequential downshift, how do you blip the throttle? Do you try to time the pause in between gears to rev the engine?

[Janzen]

In normal driving i will use engine braking when coming down from larger speeds, for example pulling of the the highway ramp. And go through the gears. But in more tight corners and less speed I will use the brakes and select the gear that i need for the corner usually it will be just one hop but sometimes it might be 4 to 2. I think even driving harder I would wary between these technigues and use them mixed.

[rdrcr]

Originally posted by Ross Stonefeld
In a clutchless sequential downshift, how do you blip the throttle? Do you try to time the pause in between gears to rev the engine?

I brake as late as possible (this of course is a relative thing, depending on conditions and my sense of 'being on my game' that day)... then, somewhere between 80% to 90% of my braking completed, I pull on the left paddle to the gear that I want for the corner, then when I feel that the limit of adhesion has been reached, I'll mash on the gas and drive through the corner.

There is some engine braking going on but not much, only the last 10% - 15% or so of braking is augmented with engine braking. The chassis takes a nice set and the routine is consistent to help set a rhythm.

All of the fast guys in Karts do it this way. At least this is what I was told by Don Bootes and Eddie Lawson, two of the fastest guys out there. Thus the transition to bigger cars using left foot braking was easy for me. One has to be very certain as to what gear they are in so not to over-rev the engine, causing rear wheel lock-up and engine damage to the valve-train etc. In all DSR and some CSR cars using the large Motorcycle engines this is the routine for sequential downshifts. If you notice, on the WSB and other large displacement motorcycles they never use the clutch to downshift, just prodigious use of the brakes and stomping on the gear lever to pick their gear, they go through some pretty extreme chassis flex and rear wheel lock-up but it's due in part I think to the lightness of the vehicle and the extreme brake bias towards the front.

[Ross Stonefeld]

paddle? eh? Im talking more like a Formula or Indycar where you have a lever in the traditional sense.

[Croaky]

Did you see in World SuperBikes a couple of races ago, Troy Bayliss destroyed his clutch on a tight twisty track. It turned out to be because his clutchless downshift technique was putting a huge strain on the clutch each time he banged it down the gearbox. He started using the clutch on downshifts for the second race and his clutch was fine.

[MattPete]

Originally posted by unrepentant lurker
Can someone explain "heel and toe technique" for me? Thanks.

rdrcr gave a good description, but for a street car with synchromesh, you can simplify it a bit.

1) Start braking with the left side of your right foot (medial side: big toe or ball of foot).
2) Before you hit the apex, push in the clutch and down shift.
3) with the clutch still in, use the right side (lateral) of your right foot (the left or medial side is still mashing the brake pedal) to blip the throttle and match the revs.
4) Release clutch

If you did everything correctly, the engine speed was perfectly matched with the transmission speed, and the balance of the car was not upset.

As far as using engine braking in a street car -- fuhgetaboutit! Brakes are for braking. Rotors and pads are cheap. Clutches aren't. If you are going to heal and toe on the street, don't bother to release the clutch (and therefore engine brake) until a second or two before the apex. Or even better, don't even try to heel and toe. Use a method similar to what Ross experienced at RA: hold in the clutch, jam it into the next gear, wait until you are at the apex (or just past), get off the brakes, give the throtle one hellish blip, and then let the clutch out.

[The Tiger]

Originally posted by Ross Stonefeld
In a clutchless sequential downshift, how do you blip the throttle? Do you try to time the pause in between gears to rev the engine?

In racing, while using a sequential gearbox, you do not use the clutch, neither to upshift nor downshift. That reason being that sequential gearboxes where developed to specifically change gears in two or three milliseconds, so the time you would have to press the clutch, change the gear, blip the throtle and release the clutch has been taken out of the equation. The thing is, once you have about 70% of your braking completed, you can start downshifting, that way you can ashure that neither your engine nor your tires will suffer. The only thing that is supposed to suffer during braking, are your brakes alone.

While using non-sequential boxes, I, have also been taught not to use the clutch. I race Formula 3 (Reynard 933) cars in Mexico, and most us do not touch the clutch for the whole duration of the race. I also down-shift one by one, I feel the technique helps to maintain the car stable while braking. Also, while down-shifting one by one, you will have the necessary torque to react with the gas in case your car pops out.

[Ross Stonefeld]

So with no syncromesh, how do you avoid the gears grinding on downshift? We were forbidden from attempting to downshift without the clutch, I figured it was a reliablity thing

[schuy]

ciao,
my friends, in racing cars, you can't do block downshifting, if i recall correctly!
i drove a FORMULA PALMER Audi, and, the car, doesn't have a synchromesh, which means, you have to do each gear at once.
and, it's much faster though, guys.

ciao,
liran biderman.

[Ross Stonefeld]

I drove the Palmer Audi car last week as well. Its a standard H pattern with a dog leg first. However it must be something specific about the brand of gearbox they use, because by about turn 3 I was left foot braking and doing perfect clutchless downshifts.

[schuy]

ciao ross,
wow, clutchless downshifting mate?
so, you induced some throttle during the braking?
turn 3, as in the left turn, or do you call it, the chicane?

ciao,
liran biderman.

[RJL]

Schuy,

In my F2000 days I spent an entire season downshifting without using the clutch pedal. An F2000 "hewland" trannie is the old-style "H" pattern. Just blip as you pass through neutral. If anything, the lack of a syncro just made things easier, because there was nothing to hang you up. just make sure the revs are matched precisely. Many guys were skipping gears entirely.

[schuy]

ciao,
hmmm, i understand RJL.
hey, thank-you so much for your help, i just understood why it works beautifully.
you are right, it would have worked fantastically.
especially, as i was having problems, doing the rev-matching, at the beginning.
hmmm, i need my next oppurtunity.
thanks for the assistance.

ciao,
liran biderman.

[ffiloseta]

Brakes=Stop
Engine=Go.

This worked OK while racing my F.Ford.

[schuy]

ciao,
brakes=stop
engine=go
ok, me thinks i got it, mate.
thanks for the help.

ciao,
liran biderman.