Newage claims dramatic improvements in the performance of boats equipped with Volvo Penta diesel engines when a StepDrive is installed. The units are self-contained gearboxes that can be retrofitted to Volvo Duoprop 290 drive legs. They are installed entirely within the centre section of the Duoprop unit and are suited for use with turbocharged engines such as the Volvo Penta AD31 and 41 series as well as supercharged units up to the KAD44.

In operation, StepDrive gearboxes automatically change from low to high ratio at a pre-determined engine speed. This is optimised during installation to the individual boat and engine combination. When the boat decelerates, low gear is engaged as the engine speed falls below 1,500rpm.

Installed on the Lema Clon with a 150hp AD31 engine and DP-E driveleg, the Newage Step Drive justified its maker's claims that it typically increases boat performance by 25%.

'In timed test runs, some vessels have achieved 40% improvements on 0-20 knot times, said Newage's Marine Sales Manager Jamie Pratt.

'However, by providing an additional reduction ratio of around 25%, StepDrive units not only boost overall performance but provide the benefits of reduced creep speed, emissions and noise when manoeuvring in busy marinas or restricted waterways.'

MJ Information No: 19907