By Thomas P.

Having in mind that the Tempest plus and Revolution match very well with the combination of Pegasus 20 with the E-TEC 175hp, we tested them in different pitches in order to compare and analyze their efficiency.

Tempest plus 23'' - Revolution 21''

Our predictions regarding the boat performance came true, confirming once again that the theory is verified in practice.

Having just 70 liters of fuel in the tank of Top Line we gave the opportunity to the Tempest to reach its maximum and show us the best of itself against the Revolution.

Tempest plus 23'' - Revolution 21''

Looking at the table above we see that the Revolution:

  • Keeps the boat on plane at a lower speed and lower rpm
  • Provides quicker time of plane
  • It is more economical at mid-range rpm despite its smallest pitch
  • Allows the engine to raise more rpm at WOT due to its shorter pitch
  • It has clearly less slippage at the whole range of rpm

On the other hand, the Tempest plus:

  • Turns the engine with less rpm at WOT
  • Gives higher top speed
  • It is faster at low and medium engine rpm, due to its longer pitch

Regarding the behavior of the two propellers, the Revolution:

  • Runs softer and smoother, offering better handling of the boat, which is very clear particularly at high angles of trim
  • Offers more stability
  • Has a better bite in the water
  • Provides greater stern lift
  • Shows less ventilation rate at the whole rpm range, but also in sharp turns
Tempest plus 14 5/8” x 23” pdf

 

Tempest plus 14 5/8” x 23” pdf

 

So which is the most suitable prop for the above combination of boat-engine?

  • As it has been mentioned many times, the main factor that defines the choice of the right propeller is the level of rpm the propeller allows the engine to increase. So having our tachometer as a guide, it is obvious that none of these propellers is suitable for this combination.
  • So we have to choose between a Tempest plus 21΄΄ and a Revolution 19΄΄, so as to allow the engine to reach at least the average of its maximum rpm limit (close to 5400 rpm).

Tempest plus 23'' - Revolution 21''

Tempest plus 23'' - Revolution 21''

  • The final choice between the two mentioned propellers-Tempest 21΄΄and Revolution 19΄΄-depends directly on the use our boat is intended for. If we are interested in the highest possible top speed and we don’t use to overload the boat, then Tempest plus 21΄΄ is a very good choice. But if our goal is to travel with loads, to have better grib, greater accelerations and optimal behavior of the boat in rough seas then the Revolution 19΄΄ is the right choice.
...keep Ribbing!