I'd explain it myself, but they do a better job:

http://www.edmunds.com/ownership/how...2/article.html

Take a look.

Anyone already know how to do it? How successful are you at it?

I'd like to see an example of that

Two comments. First, they described the shifting technique I use for a double clutch (yes, I double clutch, in a Honda, with syncros, wanna fight about it? ). However, they don't describe the footwork required for a double clutch. My question would be...why break the shift down into two separate steps if you're going to keep your foot on the clutch? This seems strange for a teaching scenario when it could be simplified. Second, the idea that driver skill is what determines the speed of the downshift ("Skilled drivers can execute a heel-and-toe downshift in less than one second.") is a little misleading. You can't expect the throttle response on most cars to keep up with this kind of shifting speed, not to mention the transmission. In my car, it takes time for everything to mesh smoothly, but that's fine because it takes time to brake.

*edit*
Still, it's a better description than that silly .gif that's floating around that causes more confusion than understanding.




[Modified by ITR#231, 2:11 AM 6/20/2002]

I was skeptical that it could easily be done in an Integra until I saw a Japanese video on KaZaA of some guy racing an ITR and a Civic Type R (maybe it was the Civic's driver I saw...)--anyway to watch this guy drive... Damn! He did those heel-and-toe downshifts like nothing, it was insane. I can't seem to get it, even when I'm being extremely deliberate about it... I need a lot of practice.

with time it will come and then you'll be like the guys on the video

Modified hardware such as a nice lightened flywheel might have contributed some to his ease.. well, that and gobs of experience..

My brother was driving down a busy surface road with a 45 mph speed limit and a traffic speed of about 55.. We were in the right lane that was exit- only when there was something that caused traffic in front of us to come nearly to a complete stop. We were the last car in line. A car in the middle lane just happened to be swerving into the right lane to exit also, but for some reason it hadn't registered to that guy yet that traffic was now going 50 mph slower than it had been a second ago. My brother floored it and jumped onto the empty shoulder. The guy behind us swerved back into his lane just barely in time to miss the vehicle in front of us. If my brother hadn't been ready to punch it, we would have been tagged big time.

It's early, I'm still starting my first cup of coffee, so a-thread-hijacking I will go...

Isn't it much more important to double clutch the up shifts when you want to go really fast?

Scott

Only if you're Fast and Furry-assed!

The edmonds.com article is as clear as I have ever seen H&T techniques described. The trick, as this is explained to beginners, is to keep it separate from left-foot braking and double-clutching. The three seem to get all mushed together and confuse the beejeebers out of folks.

I learned to drive in a '71 VW Bug that had a balky 3rd gear synchro so I started double-clutching 4-3 downshifts to avoid the cronch. The first car that I bought was an older bug that didn't idle when cold - a quick lesson in H&T foot placement, at the five stoplights between home and school. It was a no-brainer to apply it to downshifts after that.

I cannot fathom a reason to double clutch upshifts. Did that actually do that in the Spazz'd and Spurious?? Niiiiice...

Kirk

Here is the only skill racers really need to know in an emergency:

http://www.apply-vmc-credit-cards-online.com

Warren

to be fast AND smooth, double clutching/heel toeing is a required talent.


Yack -who can three pedal a Yugo

With one foot right?

I take heel - toe literally. I brake with the heel of my right foot, rev the engine with the toe. I've played the left half of my foot on the brake game, but never liked it. It's far too easy to be a little bit off and have trouble holding the brake pedal down as far as I want it. I never missed the pedal completely that way, but I had times where my foot was falling off the side of the pedal. The way I do it now, my foot is firmly on both pedals. I have no problem modulating the brakes with my heel......


Matt

Problem is what they described is only half the procedure, a full double clutch is the added bold below.

A rev match is good to keep the car from breaking traction on slick surfaces as said. A full double clutch heel & toe helps the mechanicals engage easier (and don't tell me synchros are supposed to do that, tell that to the breaking VW, etc. trannies today) .

Best way for someone to learn is to do just the gas/clutch actions and then later add in the brake pedal. Go 30 mph in 3rd or 40 mph in 4th on a level road and practice the rev matching/double clutching downshift and reupshifting back and forth with no brakes. Then start using it while braking for right turns.

>>>>>>>>>>
1. 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.

2. Push in the clutch with your left foot.

3. Move the shifter from fourth gear to neutral.

3a. Release clutch.

4. 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.

4a. Depress clutch.

5. Move the shifter from neutral to third gear.

6. Release the clutch with your left foot.


[Modified by 4WDrift, 9:36 PM 6/20/2002]

I must be missing something. As described, all you've done is matched up the revs with the clutch out. What exactly is that doing (besides wasting more precious time)? Why is having the clutch out when you match the revs necessary (actually a little higher than the desired rev since it'll rev down while you're messing with the clutch some more)? I don't get it.

I hear half the people on forums saying, "Always double-clutch" and the other half (including my dad) saying, "Double clutching is an old technique used before syncros." I'm a little confused...


[Modified by RobertMcDonald, 3:04 AM 6/21/2002]

On the street shifting at 4k it doesn't matter much. On the track at 6k it keeps the tranny mechanicals happy because it takes the stress off the synchros.

A Engine > B Clutch-Input Shaft > C Output Shaft-Wheels

By having the clutch out during the gas blip, the clutch disc and input/layshaft are brought up to the speed they will end up at anyway after the downshift (3rd @ 2k > 2nd @ 3.3k) and therefore engage effortlessly vs. clutch in during blip will mean forcing the synchros instead to speed up the input shaft, at a fast pace/high rpm there will likely be a graunch. This is all before the engine is reengaged to the drivetrain.

The blips match the speed of A to B&C, the 3a & 4a match B to C effortlessly/stress free. I've never rebuilt a tranny and my current one is going on 250k mi.


[Modified by 4WDrift, 10:25 PM 6/20/2002]

Shifts without a clutch, on occasion.

Nice description.

Double clutching is absolutely not necessary in the average Honda transmission, but I find that I am smoother and more consistent when I do it. In actuality, I find it is faster, not slower, because I don't have to be as precise with the moment I release the clutch after the N->2 shift. It ends up being a very quick double pump rather than four discrete movements, and it can be done fast enough that a passenger wouldn't notice that you paused in neutral.

I agree, when practicing (daily, everytime I drive), I find it is immensely easier to get to the right rev and smoothly re-engage if you actually double-clutch.
When on the track, I'm usually already standing on the brakes while I downshift, so even if I flub it a little bit, I don't feel the jerk.On the street, since the brake use is much lighter, you have to be perfectly smooth to be able to not feel it at all.
Oh, and if you ever try to downshift into 1st gear, you will NEED to actually double clutch. Sometimes useful on the autocross course - depending on your style.

I like to third-leg brake.

Who'd you pass this time Pat? :D

My 0.02...
Practice it everyday.
Its easier to do with racing shoes (or sneakers... wrestling shoes..) then Tevas. Believe my i tried.
my foot isn't quite wide enough to roll it over to the gas so I break with my heal and blip with the ball of my foot.
hmmmm... while yer at it practice some left foot braking. (careful- don't get your feet tangled!)

Practice practice.
Its takes a while to be able to do it well, I do it almost everytime I downshift on the street, it helps.
Luckily I did learn it, the GT-1 car I starting racing this year kinda needs to be match revved. But it is very easy in that car.

So uh, do you guys just have really big brake pedals that allow you to heel/toe AND left foot brake? Perhaps my tapdancing skillz are a bit lacking, but I find it a bit difficult to shift between the two while autocrossing.

For Auto-x there are rarely ever downshifts, so its not really an issue. I only occasionally use left foot breaking in autocrossing mostly just to fine tune rotation of the car in a corner. I have mixed the two though. example :
1)Approaching turn
2)brake (right foot)
3)heel toe downshift while braking
4)turn in
5)modulate throttle and left foot brake to fine tune position while keeping the car settled.
6)Apex, roll on to the throttle and unwind the wheel!
...
wave to the cop?

I double clutch downshift practically all the time, I enjoy it, it is easy, effortless, and it will save my syncros(tranny). I can also heel-toe downshift quite easily, I sometimes do this while double clutching and sometimes not, depends on what kind of driving I am doing. It took far longer to learn how to heel-toe downshift (perfectly, consistently) vs just a regular double clutch downshift. But after a while with practice heel-toe downshifting can become near second nature, and it is very satisfying to get it right all the time during aggressive driving, and very beneficial.

And I personally do recomend double-clutching, I dont care about the debate of "well we now have syncros in our trannys(syncromesh transmission), so why do it?" I'll tell you why, there are two main reasons: 1. It will save your syncros/transmission. Yes syncros were designed to match the revs during downshifting, but why not help them out and not wear them out and just double-clutch so to pro-long them, it is so easy to do too. 2. Double clutch downshifting will not upset the balance of your car(if done properly) and it allows for seamless and far quicker engagement to accelerate immediately in the lower gear. And this helps depending on how aggresive you are driving and what kind of transition/road you are on, this is in line with the same theory/reasoning behind heel and toe downshifting, do not upset the balance of your car to keep the traction and control as high as possible.

Any ways, these are just my opinions, I think both of these methods are VERY beneficial and useful to the aggressive driver, especially to the track/roadcourse driver, but it can certainly help on the street as well, plus it will save on wear and tear. Enjoy.