A Shifting Technology
It wasn't so long ago that the quintessential driver drove a manual gearbox. No real driver would be caught dead behind a slush box, and every one of us was measured by how we could shift that box, the gearbox that is.
We spent lots of time perfecting our shifting technique. Earlier transmissions were comparatively fragile, the linkage sloppy and indirect. To drop our ET’s or lap times, we needed accuracy and speed. Some folks even built static machines for us to sit behind and to practice on.
For a while many cars came with a three-on the-tree but this tree (steering column mounted shifter) simply couldn't support the loads of a young gun trying to power shift his car and had a painfully indirect and flexible linkage connecting the lever to the gearbox. All of it terribly slow, imprecise and clunky. We were looking for a quicker way to shift which focused the attention to something we already had. The floor mounted shifter. Four-on-the floor quickly became the standard.
Floor shift cars all sported some kind of lever, but most simply weren't stout enough to support the ugly human efforts to rip it out. The best news was that the lever was often anchored directly to the gearbox itself with relatively short direct links to the shifting forks within. These became so good that you could literally feel the action of the synchronizers and the slick engagement of each gear.
So now we had the tools to get the job done but the race was on for the most resilient, the strongest, the smoothest, and quickest shift on the planet giving rise to the Hurst Shifter. From here on out, during the muscle car era, most cars had a Hurst shifter and eventually the now legendary "T" handle mounted on top.
For the longest time it was as if the shifter mechanism was the only part being looked at as a means to speed up the shift. No one seemed to ever consider how the shift was happening inside the box itself. From some poorly designed synchronizers to even the present dog clutch, gearbox internals simply did not lend themselves to speeding up the process of selecting gears even if all the stars were aligned. There had to be a better way.
Welcome the Twin Clutch Transmission. Even though there are still cars with both a standard automatic (slush box) and a standard shift (with clutch and stick), we now have twin clutch manual gearboxes that are astounding. These boxes are manual in the sense that there is no energy being lost in a torque converter, but other than the driver making a shift demand via a button or a steering wheel mounted lever, they are also automatic in their actuation and performance. Let’s look.
Although it has been my belief that the twin clutch has been around for some time in development waiting for a world debut, others brought their auto-shifting single clutch versions to the market in a rush to be first.
These early gear-boxes had computer controlled single clutches and semi-auto sequential shifting mechanisms within. For the person who wanted a manual but never quite figured out how to use the clutch pedal, this was an OK design but redefined the word slow. The last well known Italian hot-rod I drove with this pseudo manual was so slow I had time to read War and Peace before the box was done getting to 7th. I'm still wondering why they bothered.
Enter the Twin-Clutch design: Back in 2003 VW/Audi brought out the first mass produced twin clutch transmission called the DSG. Today all performance minded companies now sell cars with a version of the twin clutch transmission. Not sure where the idea first started, but I saw this in some cars I raced against years ago. The Porsche 956 had one called the PDK (for Porsche-Doppel-Kupplungsgetriebe), so clearly the Germans have been working on this for a while. It is ironic that Porsche were fairly late to the game on the open market, but like a fine wine my guess is they were waiting for the right time to market.
Today, on the street, this is it. Simply stated for descriptive reason the twin clutch transmission has a clutch that connects to the odd ratio gears (1,3,5 etc) and another that connects to the even ratios. From a stop as you release the brakes and start to add throttle , the computer engages the clutch connected to first gear. As the car accelerates the transmission’s computer thinks about what is going on and decides what is most likely to happen next so naturally in this case preselects the next higher gear in anticipation. Here is where the second clutch comes into play as the transmission will now up-shift based on either a request from the driver or when certain predetermined parameters are met (as if it were a true automatic) and it does so by releasing the first- gear clutch, and engaging the second-gear clutch. As you can imagine this happens simultaneously which translates to almost instantly.
The still common manual gearbox where you must use the clutch and row the shifter, it would take a very good and aggressive driver at least .2 of a second (which is 200 milliseconds) to complete the shift. Compare that to the latest DSG gearbox’s .07 of a second (which is 70 milliseconds) to accomplish the same shift and you can see the staggering gains. So consider this: back in the day, to shift from first gear to fourth during acceleration would take a herculean effort to do so in at least .60 of a second (for the 3 shifts). The DSG box can do the same 3 shifts in .210 seconds. Almost two thirds less time.
Along with that you get the added benefit of perfectly matched downshifts as the same computer blips the throttle for you when you slow and downshift resulting in perfectly matched gear selection with no accompanying rear tire chips from a typical human mismatch.
As a decided techno-freak you would think I'd be done with my rant but alas you'd be wrong. You see, I love to work on good shifting technique alongside practicing my heal-toe abilities needed to match the engine speed to the gearbox needs. Nothing stirs my soul more than a well executed downshift while braking hard into a corner without any outward signs of the task beyond the rise and fall of the engine. Marvelous, simply marvelous.
Meanwhile, enjoy the technology. Cars continue to get better with every passing day and I'd expect the latest round of go-green mania will accelerate this further. It will be the next spectacular technology wave and associated growth.
Life still comes at me plenty fast so electronic speed shifting has no real attraction beyond the technology for me. Until then, I will continue to enjoy the simple pleasures of matching the shifts myself.
PC
We spent lots of time perfecting our shifting technique. Earlier transmissions were comparatively fragile, the linkage sloppy and indirect. To drop our ET’s or lap times, we needed accuracy and speed. Some folks even built static machines for us to sit behind and to practice on.
For a while many cars came with a three-on the-tree but this tree (steering column mounted shifter) simply couldn't support the loads of a young gun trying to power shift his car and had a painfully indirect and flexible linkage connecting the lever to the gearbox. All of it terribly slow, imprecise and clunky. We were looking for a quicker way to shift which focused the attention to something we already had. The floor mounted shifter. Four-on-the floor quickly became the standard.
Floor shift cars all sported some kind of lever, but most simply weren't stout enough to support the ugly human efforts to rip it out. The best news was that the lever was often anchored directly to the gearbox itself with relatively short direct links to the shifting forks within. These became so good that you could literally feel the action of the synchronizers and the slick engagement of each gear.
So now we had the tools to get the job done but the race was on for the most resilient, the strongest, the smoothest, and quickest shift on the planet giving rise to the Hurst Shifter. From here on out, during the muscle car era, most cars had a Hurst shifter and eventually the now legendary "T" handle mounted on top.
For the longest time it was as if the shifter mechanism was the only part being looked at as a means to speed up the shift. No one seemed to ever consider how the shift was happening inside the box itself. From some poorly designed synchronizers to even the present dog clutch, gearbox internals simply did not lend themselves to speeding up the process of selecting gears even if all the stars were aligned. There had to be a better way.
Welcome the Twin Clutch Transmission. Even though there are still cars with both a standard automatic (slush box) and a standard shift (with clutch and stick), we now have twin clutch manual gearboxes that are astounding. These boxes are manual in the sense that there is no energy being lost in a torque converter, but other than the driver making a shift demand via a button or a steering wheel mounted lever, they are also automatic in their actuation and performance. Let’s look.
Although it has been my belief that the twin clutch has been around for some time in development waiting for a world debut, others brought their auto-shifting single clutch versions to the market in a rush to be first.
These early gear-boxes had computer controlled single clutches and semi-auto sequential shifting mechanisms within. For the person who wanted a manual but never quite figured out how to use the clutch pedal, this was an OK design but redefined the word slow. The last well known Italian hot-rod I drove with this pseudo manual was so slow I had time to read War and Peace before the box was done getting to 7th. I'm still wondering why they bothered.
Enter the Twin-Clutch design: Back in 2003 VW/Audi brought out the first mass produced twin clutch transmission called the DSG. Today all performance minded companies now sell cars with a version of the twin clutch transmission. Not sure where the idea first started, but I saw this in some cars I raced against years ago. The Porsche 956 had one called the PDK (for Porsche-Doppel-Kupplungsgetriebe), so clearly the Germans have been working on this for a while. It is ironic that Porsche were fairly late to the game on the open market, but like a fine wine my guess is they were waiting for the right time to market.
Today, on the street, this is it. Simply stated for descriptive reason the twin clutch transmission has a clutch that connects to the odd ratio gears (1,3,5 etc) and another that connects to the even ratios. From a stop as you release the brakes and start to add throttle , the computer engages the clutch connected to first gear. As the car accelerates the transmission’s computer thinks about what is going on and decides what is most likely to happen next so naturally in this case preselects the next higher gear in anticipation. Here is where the second clutch comes into play as the transmission will now up-shift based on either a request from the driver or when certain predetermined parameters are met (as if it were a true automatic) and it does so by releasing the first- gear clutch, and engaging the second-gear clutch. As you can imagine this happens simultaneously which translates to almost instantly.
The still common manual gearbox where you must use the clutch and row the shifter, it would take a very good and aggressive driver at least .2 of a second (which is 200 milliseconds) to complete the shift. Compare that to the latest DSG gearbox’s .07 of a second (which is 70 milliseconds) to accomplish the same shift and you can see the staggering gains. So consider this: back in the day, to shift from first gear to fourth during acceleration would take a herculean effort to do so in at least .60 of a second (for the 3 shifts). The DSG box can do the same 3 shifts in .210 seconds. Almost two thirds less time.
Along with that you get the added benefit of perfectly matched downshifts as the same computer blips the throttle for you when you slow and downshift resulting in perfectly matched gear selection with no accompanying rear tire chips from a typical human mismatch.
As a decided techno-freak you would think I'd be done with my rant but alas you'd be wrong. You see, I love to work on good shifting technique alongside practicing my heal-toe abilities needed to match the engine speed to the gearbox needs. Nothing stirs my soul more than a well executed downshift while braking hard into a corner without any outward signs of the task beyond the rise and fall of the engine. Marvelous, simply marvelous.
Meanwhile, enjoy the technology. Cars continue to get better with every passing day and I'd expect the latest round of go-green mania will accelerate this further. It will be the next spectacular technology wave and associated growth.
Life still comes at me plenty fast so electronic speed shifting has no real attraction beyond the technology for me. Until then, I will continue to enjoy the simple pleasures of matching the shifts myself.
PC
posted by Price Cobb at 3:18 PM
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