How To Downshift
05-10-2007, 03:14 PM
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If you have an automatic, please stop reading now.
The heel-and-toe downshift helps drivers accomplish faster times around a racetrack, while also reducing vehicle wear-and-tear and overall improving driver control.
WHAT IS IT
A complex action that involves both your feet, your right hand, all three pedals, and the gear shift lever. It may seem bizarre to the general populace, but racecar drivers use it all the time.
PURPOSE
To smoothly match engine speed to wheel speed.
RULE: NEVER FORCE A GEAR INTO PLACE, even when racing do you RARELY see a driver slamming a gear into place Fast and the Furious style to save 1/16th of a second, NO. no, no, no, no, NO. The only time I've seen such actions are when two drivers are double-wide into a turn and one is trying to outrun the other for placement and may go crazy with the shifting..
anyways..
First let's go over how you normally down shifts a car.
Let's say your in your tiburon driving around town and you find yourself approaching a right hand turn at 50mph in 4th gear. You're going too fast to make it around the turn so you brake until you are down to about 25mph. As you're turning you see your revs drop, so you push the clutch in. Now you're around the corner and ready to accelerate but see that you're still in 4th gear so you shift to second, let the clutch out and motor away.
The result is not a smooth shift. The car is going to buck a little.
WHY
Because you are going around the corner with the clutch in, and the engine rpms have dropped to idle. When you release the clutch after the turn, the mechanical locking effect between the engine and the front wheels forces the engine rpms to match the rotational speed of your rear wheels (25mph, roughly 2,600 rpm).
So the buck you feel is your engine being forced from idle (800) rpm to 2,600 rpm as you let the clucth out and motor away. Not only are you spilling your passenger's coffee but your causing undue wear and tear on the clutch, engine mounts, and transmission.
THE SIMPLE SOLUTION
give the car some throttle before letting the clutch out, specifically enough throttle to raise engine revs to 2,600rpms. This way, the engine speed matches rear wheel speed and the shift is much smoother.
For racecar drivers, the simple solution above is not enough. This takes too long and involves pushing the clutch in while going around a corner, big NO-NO.
THE HEEL-AND-TOE SOLUTION
A racecar driver must brake and downshift at the same time. Using the same example above, a racecar driver would have downshifted while braking for the corner. This way you have power control around the corner and can quickly accelerate out.
So let's go through the example again with a heel-and-toe downshift.
Start braking with your right foot, but position your foot so that it is canted a little to the right (closer to the throttle pedal).
Push in the clutch with your left foot.
The hard part, with your right foot still on the brakes roll the outside edge of your foot outward and downward to press on the throttle. Some aftermarket pedal designs make this easier (I've yet to see one made for a Hyundai Tiburon though..) Now use the outside of your right foot to blip the throtte, temporarily raising the engine rpms to match wheel speed. The exact amount of blippage is dependant on a lot of factors but most commonly will be around 1,000 to 2,000 rpms more than the current engine rpm for a one gear downshift.
Move the shifter to 3rd gear with your right hand.
Release the clutch with your left foot.
The "heel-and-toe" doesn't actually use the heel and toe of your foot (although it is possible to do so). It's more of a ball-and-side-of-your-foot technique, but that takes longer to say.
Go practice in your car with the car OFF. Most likley your first few times will be botchy. The hardest part is blipping the throttle to get the correct amount of engine rpms to match wheel speed (which can't be practiced with the car off unfortunetly). Too much or too little of a blip and you'll know it because the car will jerk. Either way the engine revs are being forced up (not enough blip) to match wheel revs or forced downed (too much blip) to match wheel revs.
If you feel nothing at all, and neither did your passengers then you know you did it right. Plus you'll have a satisfied smile on your face knowing your car is always in the best gear to achieve maximum acceleration.
The heel-and-toe downshift helps drivers accomplish faster times around a racetrack, while also reducing vehicle wear-and-tear and overall improving driver control.
WHAT IS IT
A complex action that involves both your feet, your right hand, all three pedals, and the gear shift lever. It may seem bizarre to the general populace, but racecar drivers use it all the time.
PURPOSE
To smoothly match engine speed to wheel speed.
RULE: NEVER FORCE A GEAR INTO PLACE, even when racing do you RARELY see a driver slamming a gear into place Fast and the Furious style to save 1/16th of a second, NO. no, no, no, no, NO. The only time I've seen such actions are when two drivers are double-wide into a turn and one is trying to outrun the other for placement and may go crazy with the shifting..
anyways..
First let's go over how you normally down shifts a car.
Let's say your in your tiburon driving around town and you find yourself approaching a right hand turn at 50mph in 4th gear. You're going too fast to make it around the turn so you brake until you are down to about 25mph. As you're turning you see your revs drop, so you push the clutch in. Now you're around the corner and ready to accelerate but see that you're still in 4th gear so you shift to second, let the clutch out and motor away.
The result is not a smooth shift. The car is going to buck a little.
WHY
Because you are going around the corner with the clutch in, and the engine rpms have dropped to idle. When you release the clutch after the turn, the mechanical locking effect between the engine and the front wheels forces the engine rpms to match the rotational speed of your rear wheels (25mph, roughly 2,600 rpm).
So the buck you feel is your engine being forced from idle (800) rpm to 2,600 rpm as you let the clucth out and motor away. Not only are you spilling your passenger's coffee but your causing undue wear and tear on the clutch, engine mounts, and transmission.
THE SIMPLE SOLUTION
give the car some throttle before letting the clutch out, specifically enough throttle to raise engine revs to 2,600rpms. This way, the engine speed matches rear wheel speed and the shift is much smoother.
For racecar drivers, the simple solution above is not enough. This takes too long and involves pushing the clutch in while going around a corner, big NO-NO.
THE HEEL-AND-TOE SOLUTION
A racecar driver must brake and downshift at the same time. Using the same example above, a racecar driver would have downshifted while braking for the corner. This way you have power control around the corner and can quickly accelerate out.
So let's go through the example again with a heel-and-toe downshift.
Start braking with your right foot, but position your foot so that it is canted a little to the right (closer to the throttle pedal).
Push in the clutch with your left foot.
The hard part, with your right foot still on the brakes roll the outside edge of your foot outward and downward to press on the throttle. Some aftermarket pedal designs make this easier (I've yet to see one made for a Hyundai Tiburon though..) Now use the outside of your right foot to blip the throtte, temporarily raising the engine rpms to match wheel speed. The exact amount of blippage is dependant on a lot of factors but most commonly will be around 1,000 to 2,000 rpms more than the current engine rpm for a one gear downshift.
Move the shifter to 3rd gear with your right hand.
Release the clutch with your left foot.
The "heel-and-toe" doesn't actually use the heel and toe of your foot (although it is possible to do so). It's more of a ball-and-side-of-your-foot technique, but that takes longer to say.
Go practice in your car with the car OFF. Most likley your first few times will be botchy. The hardest part is blipping the throttle to get the correct amount of engine rpms to match wheel speed (which can't be practiced with the car off unfortunetly). Too much or too little of a blip and you'll know it because the car will jerk. Either way the engine revs are being forced up (not enough blip) to match wheel revs or forced downed (too much blip) to match wheel revs.
If you feel nothing at all, and neither did your passengers then you know you did it right. Plus you'll have a satisfied smile on your face knowing your car is always in the best gear to achieve maximum acceleration.
05-10-2007, 09:27 PM
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This is a newb question, but I have never been good at figuring the revs needed to match wheel speed. Is there some sort of formula you used to determine that 25 mph = 2600 RPM or do you just learn that from driving the car and practicing? My downshifts aren't terribly jerky, but you can definitely tell that its a standard transmission and not an autotragic
05-10-2007, 10:31 PM
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Nice write up. The hardest part doing this is trying to hit the gas a bit while trying to control ur braking pressure.
I tried it before and it seem to be that th brakes get pressed a bit more and jerk a bit.
just a heads up.. complex but practice makes perfect.
I tried it before and it seem to be that th brakes get pressed a bit more and jerk a bit.
just a heads up.. complex but practice makes perfect.
05-10-2007, 10:43 PM
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thats not how i do it. i don't do it the first way, nore the second (correct) way. say if i was approaching a right hand corner going 90 mph in 4th and needed to be at 55, i would simply lightly apply brakes (avoiding locking them up) then shift into third and floor it once past the apex.
maybe i do it wrong, but that seems to be the fastest way.... ill give this a shot tho.
maybe i do it wrong, but that seems to be the fastest way.... ill give this a shot tho.
05-10-2007, 11:25 PM
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getting the action all together its pretty easy, i guess the hard part is how much blip you give it.
now why is there a Focus on those pix... you could've used a tib dude. booooo... naw jus kiddin. good write up.
now why is there a Focus on those pix... you could've used a tib dude. booooo... naw jus kiddin. good write up.