WEVO has been developing Porsche aftermarket products for 17 years. In that time, we have consistently focused on the engineering excellence and reliability of Porsche and the modularity of design that has prevailed continuously and often spread across multiple model ranges.
That philosophy directed us towards a completely Porsche-centric solution for the 356 5-speed. With so much engineering resource embodied in every part of a Porsche, it is a natural decision for a small company like WEVO to carefully study the opportunities that are created out of modular design and the relatively slow specification changes that occurred at Porsche in the late 60’s and early 70’s.
It is widely understood that Porsche, in demonstrating engineering expertise, had developed a unique transmission synchroniser design for gear synchronisation and selection in the KDF project for VW. Subsequently used extensively by VW and Porsche, other companies like BMW and Alfa Romeo used Porsche synchronisers under license. In the passing of time, even Porsche has capitulated and moved to using the global standard, Borg Warner-type synchroniser, as have all the other manufacturers making manual transmissions.
The Porsche Synchroniser
That tangential engineering decision in the 1930s to create the unique Porsche synchroniser design is one of the tactile signatures of driving any air-cooled Porsche transmission built before 1987. The Porsche synchroniser has a distinctive feel to its unique mechanical operation, familiar to 356 drivers and understood by technicians accomplished in the service and rebuilding of Porsche transmissions. For WEVO, the use of a Porsche synchroniser was one of the early technical waypoint decisions.
Using components from a donor transmission allows the greatest access to donor and spare parts, assembly know-how and logical initial market confidence. So the decision to use a donor transmission for internal components was another critical technical way point. The convergence of these two decisions lead WEVO to the use of an existing Porsche transmission to source the internal components for the 356 5-speed kit.
Choosing the Porsche 901 Transmission
Using components from any of the series of transmissions originally installed in 356 chassis’ does not satisfy the requirement for adequate parts supply. Even the most prolific 356 transmission – the 741-series – is now difficult to buy either new or used parts for. Additionally, 356 transmissions are not strong enough to allow for the increases in engine power or mechanical (tyre) grip which accompany the current trend in building Porsche 356 hot rods and highly-tuned cars.
Chronologically, the Porsche 901-series transmission introduced in 1964 with the Porsche 911 is the next in sequence. The 901-series transmission architecture prevailed in 911 and 912 chassis until the end of 1971. In the 914, the series continued until the end of 1975. Twelve years of production and more than 200,000 units manufactured offers us the perfect Porsche-synchronised donor transmission. A significantly high percentage of those 200,000 transmissions are the 5-speed units required for the WEVO 356 5-speed kit.
Matched with the 2.2-litre engine in the 1971 911, the 901 (labelled as a 911 transmission) was transmitting the 180hp and 150 ft-lbs of torque available from the 911S. Therefore, 901-series transmission components have the durability headroom to service almost any engine and tyre upgrade imaginable for a 356 chassis.