DUAL-CLUTCH TRANSMISSION... HERE TO STAY?

By: Michael Schaapherder

I'm sure you have heard the terms: "DSG, Flappy-paddle, DCT, Vrrrr Pahhh" and the list continues.

When I was a kid, automatics were considered "old peoples" cars, or for the lazy or the non-car enthusiasts. For the most part, especially here in South Africa, this is still the mindset. Much like the United States, autos have grown in popularity in a huge way over recent years though, and this, in my opinion, makes sense. Face it, you're spending 80% of your time in your car sitting in traffic, so why then would you ever consider a manual transmission?

Yes, manual cars do give the driver a sense that you are engaged with the car a whole lot more, it gives you the satisfaction of feeling more in control as well. However, over the past few decades, manufacturers were trying out new concepts for auto transmissions such as DAFs CVT systems, which slowly grew in popularity over the years and perfected by Audi in their Multi-tronic systems. But the cons were quite obvious. Such as these transmissions making the vehicle feel a bit underpowered when taking off as well as a hesitation or a slow throttle response from the stop lights, but that is likely because you aren't feeling that characteristic shifting from first to second, and on up. Once you get up to speed, you notice a much smoother ride.

Although exchangeable with many marketing terms, the ability to opt for a Tiptronic gearbox skyrocketed sales principally because now auto drivers had the option to change to a more manual gear change on command with the use of paddle-shifters or the gear stick, but still with an automatic gearbox. From here on, automotive mechatronic engineers raised the question, how could we make a transmission system so advanced, precise and smooth, and at the same time be so quick in a gear change that no manual car can come close in comparison?

The concept was not intended predominantly for speed and accuracy, but rather for safety as a driver with both hands on the steering wheel while changing gears manually was a lot more safe on the road. The system was already in place with the Tiptronic gearboxes, however, the system was sluggish.

Volkswagen and Audi were the first to release a Duel-Clutch Transmission, branded the Direct Shift Gearbox or in simple terms, DSG. It was first fitted to the Golf 5 R32 and the Audi TT 3.2 Quattro, which makes sense because they shared exactly the same engine. Essentially, a Duel-Clutch Transmission, or DCT, is an automated manual transmission which uses two separate clutches, one of each, odd and even gear sets. So it almost seems like a DCT is two manual gearboxes stuffed into one housing. These DCTs are normally operated much like a standard automatic transmission, with a simple PRND gear selector and no clutch pedal. They can also work just like an automatic transmission, shifting gears on their own, or can be manually controlled, via paddle shifters or a separate gate on the gear selector.

It works like so: one clutch has an odd number gear engaged, the computer figures out which even number gear you will need next, have the second clutch ready with that gear and simply switch clutches when the time is right. The idea is to give customers the ability to creep along in automatic mode, much like they would with a standard torque-converter automatic, or shift gears manually if they so choose. The DCT is supposed to be the best of both worlds, and it’s about as close as we’ll ever get to that.

For the world of performance modification, DSG or DTC gearboxes are most definitely popular. The only downside when reaching the maximum potential for performance modification on your engine is that a DSG can't handle as much torque as a pure manual box, but either way when you consider performance upgrades, expect to race, break, curse, fix, repeat!