Two for the Road is a hangout for mystery writers Tammy Kaehler and Simon Wood to chat, reminisce, gossip, speculate and argue about all things motorsport.

Wednesday, August 3, 2011

Three Pedals, Two Feet (Part 1)

(Note from Tammy: Since Simon's laid up with a busted wing, Steve Ulfelder's going to hang around and talk racing with us for a week or two. Think of this as our own Le Mans, and the Two For The Road Team is bringing in our superlative third driver....)

You love cars. You love racing. So there’s a pretty good chance your car has a manual transmission.

Shifting for yourself makes you feel like you’re really driving, rather than just shoving the thing in D and oozing about like the rest of the zombies. You upshift when you want to, not when a computer calibrated by lawyers and the EPA tells you to. Oh, and the glorious zing-zing! of a nicely rev-matched downshift. Heaven!

Well. Maybe for you. How would you react if I told you that I and most of the racers I know are not only happy with an automatic transmission on our street cars, but look forward to the day when our race cars use slushboxes?

I know, I know: I should have my string-back driving gloves confiscated for even thinking such a thing (except that I don’t own such gloves and am not entirely sure, frankly, what they are).

Here’s a quick refresher for those who are unsure about why manual transmissions are a hot topic among performance-oriented drivers:

Upshifts are a piece of cake. When it’s time to shift, you put the clutch in; lift your foot from the throttle just a hair (unless you’re a 19-year-old boy driving a Mustang, in which case you keep the gas pedal pegged until your motor blows up, which should be about three minutes from now); pop the shift lever into the next highest gear; and simultaneously release the clutch and get back to the throttle.

Simple.

But eventually, you’ll need to downshift. And if you’re racing, simply reversing the order of the procedure above isn’t good enough.

Why?

Because if you’re downshifting, you’re probably braking – hard – at the same time. And if you simply shove the shift lever from fourth gear (for example) into third, then let the clutch out all at once, you will transfer an ungodly amount of weight from your car’s rear tires to its front tires. The fronts will probably lock up and slide. That’s bad. The rears will probably lose adhesion and try to spin you out. That’s also bad.

What to do? Heel-toeing to the rescue!

Heel-and-toe rev-matching is a clever technique in which your two feet operate three pedals at once.

Let’s picture our four-three downshift again. You arrive at your braking zone and begin to brake hard. Soon (in tenths of a second, or even hundredths), it’s time to downshift. Your left foot has it easy: it need only operate the clutch. But your right foot, which is already braking for all it’s worth, gets an extra-credit assignment: it must continue to apply pressure to the brake while simultaneously rolling to its right to blip the throttle. (In spite of the technique’s name, nearly all modern racers use the ball of their right foot to heel-toe.)

Why blip the throttle?

Because this increases engine RPMs, which in turn prevents that ungodly weight transfer that wants to spin you out and flat-spot your front tires.

If you’ve watched much NASCAR road-racing, you’ve probably seen “foot-cams” that beautifully illustrate the heel-toe technique. And indeed, a well-executed rev-matched downshift is a joy to behold.

But do you know what? It’s also a pain in the ass, an opportunity to screw up. We racers have plenty of chances to screw up, believe you me, and are never sad to see one go away.

I fear I’ve run long here, so let’s do this: check out some Youtube foot-cam footage from one of my favorite racing series, Australian V8 Supercars. Note that this driver, like the heroic 19-year-old piloting our Mustang, does not lift his foot from the throttle when upshifting. That’s fine when somebody else is buying your motors.



Unless Tammy and Simon chase me off the blog for daring to mock manual transmissions, I’ll be back soon with Part 2 of this post: Why I would be perfectly happy with an automatic transmission in my race car.

2 comments:

  1. Heel-and-toe downshifting is a tough thing to learn, when you go to racing school. I struggled with it, and I kid you not, I kept saying to myself, "you can tap dance! you will figure this out, too!" I finally got it, but it's a tricky bit of timing to manage, in almost every corner.

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  2. thanks for filling in, steve...

    oh yeah, you're a heritic. :-)

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