Powertech LFS is a 4-blade propeller which is designed for Suzuki outboard engines and is ideal for the boaters who have installed a single powerful engine on their transom.
Perhaps it is the only 4-blade propeller that matches so well to the high horsepower engines of Suzuki, especially when we use to carry heavy loads or when the design and size of our hull require.
We chose to try these propellers, with the 4-blade LFS having a half pitch less so as to be more objective concerning the comparison of their performance.
The test took place on a Suzuki AP 300hp engine which was mounted on the transom of Marvel 930, at the same time, in the same sea area, at the same direction and of course with the same loads.
Observing the above tables we see that the Powertech LFS4:
- keeps the boat on plane at lower rpm
- gives quicker time of plane
- is more economical at the whole rpm range despite its shorter pitch and additional blade
- gives us higher top speed
- has faster acceleration
- allows the engine to raise almost the same rpm at WOT despite its extra blade
- has slightly more slippage at the whole range of rpm, with the exception at WOT where the engine was extremely trimmed up.
On the other hand the 3-blade propeller of Suzuki:
- gives us higher cruise speed of 1 knot at midrange rpm. Generally it is about 1 knot faster at the whole rpm range due to its slightly longer pitch, except at WOT where it lacked in the final speed
- has slightly less slippage at the whole rpm range, with the exception at WOT where the engine was trimmed out at its highest point
- is less economical at the whole rpm range despite its longer pitch and the fewer number of blades
- has slower accelerations
- gives less top speed
Regarding the behaviour of the two propellers, the LFS4:
- offers slightly better boat handling and better throttle response
- gives greater accelerations
- has slightly better bite in the water which is clearly seen at high angles of engine’s trim
- shows greater ventilation rate until the WOT, despite its additional blade, which is obvious by the change of the engine’s sound.
Perhaps the greatest advantage of the LFS4 is that it turns the engine with almost the same rpm at WOT like the 3-blade Suzuki’s prop of the almost same pitch despite its additional blade.
So, we can switch from a 3-blade Suzuki to a 4-blade LFS propeller of the same pitch, having almost the same rpm at WOT.
Moreover, due to the special design of its blade tip, the LFS4 propeller is more capable to run in extreme trim angles, to restrict its ventilation and the slippage, thus achieving higher top speed.
It is more economical, although it is a 4-blade propeller, perhaps because of the higher bow lift that achieves which is due to its shorter tube and the lower cup, but this is not easily seen.
It is worth noting that both propellers were «slow» for this combination of boat-engine with these loads, something which is also reflected by the level of the engine’s rpm at WOT.
The best choice, therefore, for this boat-engine combination, is to reduce the pitch of both propellers by almost 3 inches so as to allow our engine to approach its maximum rpm, gaining at the same time stunning accelerations and much better handling of the boat, especially when we are riding in rough seas or we are carrying heavy loads.