Ds650rida
09-04-2013, 07:51 AM
"Granny shifting, not double clutching like you're supposed to" - Dominick Toretto
I've heard a lot of debate over the years from "smart" people saying that double clutching is only used on old cars and 18 wheelers. And they always love to bring up that famous line from the fast & the furious. The most common reasoning behind this is because our newer cars have synchros which alow the speed of the gears to be matched. While this is true in regards to upshifting, I use it 98% of the time when downshifting. And I'd like to use this time to explain why; mainly because I'm bored at work.
Theory:
http://cdn.shopify.com/s/files/1/0035/3472/files/DSC02753.JPG?1252396648
This is a blocker ring. Used in all modern manual gearboxes. Its typically made of bronze, but I believe that old T5 trannies used a steel ring with a paper type of friction material inside. Its sole purpose is to slow down the next gear so that the synchronizer collar can easily slide over the dog gear and engage the next gear.
Now bronze is pretty soft stuff (forget about the t5 paper) and its using friction, regardless of the oil in the transmission, to slow down the next gear. So my theory is that when downshifting, instead of trying to slow down the next gear you want to select, it is now trying to speed up the gear. And we should all be able to figure that this will create more wear and therefore shortening the service life of your transmission. This is the same reason why you wouldnt (shouldnt) downshift without rev-matching the engine.
So when double clutching, you are simply rev-matching the engine AND transmission. And therefore the blocker ring can go back to doing its job (slowing down).
Technique:
I've personally been using this technique for years and on various types of cars. Anytime I need to select a lower gear, I just give the throttle a blip while in neutral with my foot off the clutch.
When coasting towards an intersection in neutral, I'll give the gas pedal a flick before pressing the clutch and selecting a gear.
While it was hard to mentally train myself to remember to do this everytime, and even harder to perfect, the results speak to me loud and clear when I get it right.
Every time I get a smooth engagement into a lower gear, no pushing or forcing. The shifter just falls right into place.
Just to name the cars that I've driven and used this technique on: NA Miata, E36, Scion TC, S14, Integra, SW20 MR2, Evo 8, STI. Thats a pretty wide array of age and layouts, so I think its safe to say that this can be universally used.
I suggest anyone who reads this to try it and impress your passengers with your seamless downshifts. Yes, its confusing as hell at first. However if you think about how much you drive your car and how many opportunities you have to practice, you should be able to get it right within a week or 2.
Btw, the 2% that I dont use this technique is when I simply forget and when I'm using heal-toe coming into a corner (although I've tried).
Edit: please check out this video, this guy sort of reinforces my theory http://www.youtube.com/watch?v=Z9HVkGSa694&feature=youtu.be
I will go back later and proof read this on the computer so please forgive any errors.
Here is a video displaying a heal-toe double clutch downshift http://www.youtube.com/watch?v=0j-3xIZK-Bk
Sent from my iPhone using Tapatalk - now Free (http://tapatalk.com/m/)
I've heard a lot of debate over the years from "smart" people saying that double clutching is only used on old cars and 18 wheelers. And they always love to bring up that famous line from the fast & the furious. The most common reasoning behind this is because our newer cars have synchros which alow the speed of the gears to be matched. While this is true in regards to upshifting, I use it 98% of the time when downshifting. And I'd like to use this time to explain why; mainly because I'm bored at work.
Theory:
http://cdn.shopify.com/s/files/1/0035/3472/files/DSC02753.JPG?1252396648
This is a blocker ring. Used in all modern manual gearboxes. Its typically made of bronze, but I believe that old T5 trannies used a steel ring with a paper type of friction material inside. Its sole purpose is to slow down the next gear so that the synchronizer collar can easily slide over the dog gear and engage the next gear.
Now bronze is pretty soft stuff (forget about the t5 paper) and its using friction, regardless of the oil in the transmission, to slow down the next gear. So my theory is that when downshifting, instead of trying to slow down the next gear you want to select, it is now trying to speed up the gear. And we should all be able to figure that this will create more wear and therefore shortening the service life of your transmission. This is the same reason why you wouldnt (shouldnt) downshift without rev-matching the engine.
So when double clutching, you are simply rev-matching the engine AND transmission. And therefore the blocker ring can go back to doing its job (slowing down).
Technique:
I've personally been using this technique for years and on various types of cars. Anytime I need to select a lower gear, I just give the throttle a blip while in neutral with my foot off the clutch.
When coasting towards an intersection in neutral, I'll give the gas pedal a flick before pressing the clutch and selecting a gear.
While it was hard to mentally train myself to remember to do this everytime, and even harder to perfect, the results speak to me loud and clear when I get it right.
Every time I get a smooth engagement into a lower gear, no pushing or forcing. The shifter just falls right into place.
Just to name the cars that I've driven and used this technique on: NA Miata, E36, Scion TC, S14, Integra, SW20 MR2, Evo 8, STI. Thats a pretty wide array of age and layouts, so I think its safe to say that this can be universally used.
I suggest anyone who reads this to try it and impress your passengers with your seamless downshifts. Yes, its confusing as hell at first. However if you think about how much you drive your car and how many opportunities you have to practice, you should be able to get it right within a week or 2.
Btw, the 2% that I dont use this technique is when I simply forget and when I'm using heal-toe coming into a corner (although I've tried).
Edit: please check out this video, this guy sort of reinforces my theory http://www.youtube.com/watch?v=Z9HVkGSa694&feature=youtu.be
I will go back later and proof read this on the computer so please forgive any errors.
Here is a video displaying a heal-toe double clutch downshift http://www.youtube.com/watch?v=0j-3xIZK-Bk
Sent from my iPhone using Tapatalk - now Free (http://tapatalk.com/m/)