The 2017 Subaru WRX STI comes with only one gearbox, the 6-speed manual rower. It’s a good transmission for performance enthusiasts, but Subaru could take the performance of the STI up a notch with a new direct-shift gearbox commonly known as a DSG. If Subaru wants to seriously upgrade the performance sedan, they should develop a six-speed variant like VW Golf’s DSG.
The gearbox is capable of ultra-fast shifts that even the most proficient user of a manual rower simply can’t match. The first “dual-clutch” transmissions were developed in-house by Porsche for their 962 racing cars in the 1980s. Since then, VW has perfected the unit.
WRX has the “Sport” Lineartronic CVT
Subaru offers the 2017 WRX with their new automatic “Sport” Lineartronic CVT. It’s a good option for new customers Subaru is attracting to the brand. But the high-performance STI enthusiast wants something that will significantly improve the driving dynamics. The STI needs a DSG to realize its full potential. Surprisingly, Subaru says a high percentage of sales of the WRX are with the new CVT. Sales of the WRX STI would also benefit with an automatic. Performance enthusiasts would get the biggest benefit from a DSG transmission option. Here’s why.
How a DSG works like a manual
The DSG is basically a manual transmission, that happens to be automatically controlled, which is different than a traditional automatic with planetary gears. As explained in the video below from Engineering Explained, a DSG “uses two wet, multi-plate clutches to activate separate drive shafts which send torque via the even or odd gear sets.” In this case, the VW DSG has six gears to choose from.
They explain how the gear sets are on separate shafts, which allows for preselecting the next gear, allowing for nearly instantaneous gearshifts without a total loss in torque. Thus the gear selection can be either automatic or manual, but does not require the use of a clutch pedal as it’s all activated automatically by the electronics unit. It’s a perfect set-up for the STI.
The Volkswagen Golf R uses this DSG transmission, and Subaru would be wise to develop their own direct-shift gearbox for the WRX STI. It would be a serious upgrade as an option for those not wanting to shift gears with a clutch pedal. The gearbox is capable of ultra-fast shifts. Subaru could take the performance of the WRX STI up a notch with a new direct-shift gearbox.
Watch DSG transmission: by Engineering Explained
Source: Engineering Explained