22 January 2025
Mark Ingram
Technical Director
In the world of high-performance and motorsport engineering, precision and reliability are paramount. With decades of experience and a reputation for excellence, Hewland possesses the skills and expertise necessary to optimize manual transmission shift quality, delivering unparalleled performance and driving satisfaction.
Manual transmission shift quality is a critical factor in driving performance and driver experience. It encompasses a range of attributes, including tactile feedback, shift effort, synchronization, and noise, vibration, and harshness (NVH). Achieving an optimal balance requires a blend of engineering expertise, state-of-the-art tools, and a commitment to innovation—qualities that Hewland embodies.
Left: The HSC-200 is a complete replacement for the Getrag G50, designed specifically for Porsche 911 restomods.
Extensive Shift Quality Analysis has been undertaken to ensure smooth and precise gearshifts.
Shift Quality can be broken down into several areas. The driver perception takes many inputs, from steering wheel forces, pedal forces, seat forces/ergonomics and the gearshift forces. The balance and blend of inputs can make or break the driver experience.
When assessing Shift Quality, we think in terms of Shift Effort, Shift Feel and Gate Definition Metrics, but must also recognise they have to sit well with the other perceptions (above) the driver feels too.
We start by determining at Design calculation level, the inputs that drive Shift Effort; from synchroniser sizing, transmission layout, gear ratios, clutch inertia, shift mechanism & detenting, shift rod or cables through to handset and placement.
Did you know that changing the balance of forces stored in the shift cables can change shift performance dramatically; even changing the amount of mass on the transmission shifter or the mass of a gear knob can have a great effect.
Gate Definition is key to brand differentiation. Have you ever gone into a car showroom and sat in a car? If it was a manual, you probably tried the static shift performance, tracing the outline 1-2, 2-3 etc. The transmission and the handset combined provide the level of definition and/or compliance in the right places. We have the tools to assess and develop the right feel for you.
Shift Feel is mainly about the dynamic performance of the shift (shifting whilst driving). We take measurements across a range of shift aggressions to develop a profile that tells us how well each shift performs. Through benchmarking, these metrics can tell us how good the shift really is. Once we have clarified the benchmarks and targets, the optimisation / development can begin through careful revisions in hardware to dial in the type of “Shift Quality” you require. We have the tools (design, calculation, simulation), technique (measurement) and experience to deliver to your requirements.
We are ready to take you to the next level in Shift Quality!
Right: Performance restomod applications require the best shift quality possible where Hewland is best-placed to provide off-the-shelf and bespoke solutions.