The following performance estimates are based on the actual measured performance of the 37% model.

Pcat Performance Estimate March 4 2002

Performance data from 37% model. 7.4 Kn with 2.5 HP engine. The engine was chokey and had under pitch prop. The boat weight was 10% over design. I have factored in these and normalized the model performance to 8.0kn with 2.5 HP.

Scaled to 100% 13.15 Kn at 49.4 HP. Further normalize for the larger engine by taking this speed ^3 X 1.06 for 55.3 HP = 14.0 Kn

Tankage 250 U.S. gallons. Range number represent a 10% fuel reserve.

There are two sets of estimates in the chart. One based on a prop factor of N2.2 which would be for a standard prop and one of N2.7 for the ducted props in use. The ducted props absorb more horsepower from the engine at the same RPM.

The specific fuel consumption is listed for the engine and the maximium continous HP rating. For the N2.7 case about 2750. This produces a speed of around 13kn or about 320 kn miles per day. Range would be around 1200 kn miles in that case.

Likely fast cruise would be at around 2000 RPM and 10 kn with a range of about 2000 kn miles.

Standard cruise would be at just under 1600 RPM at 8 kn with a range of 2800 kn miles at about 12 kn MPG and .7 GPH fuel consumption.

Doing our Nordhaven impersonation would be at 1150 RPM and 6 kn with a range of 3900 kn miles and at 17 kn MPG and .35 GPH fuel consumption.

										
				
RPM	Specific Fuel	MAX Cont HP	HP N2.2	Speed	Kn MPG	Range	HP N2.7	Speed	Kn MPG	Range	GPH
3000	175		49.9		55.3	14.0	4.7	1049	55.3	14.0	4.7	1049	3.0
2900	175				50.5	13.5	4.9	1108	51.3	13.6	4.9	1098	2.8
2800	172		46.8		45.9	13.0	5.3	1194	47.5	13.2	5.2	1169	2.5
2700	172		44.5		41.6	12.5	5.6	1266	43.9	12.8	5.4	1226	2.3
2600	168		43.3		37.6	12.0	6.1	1378	40.4	12.3	5.9	1319	2.1
2500	168		41.5		33.8	11.5	6.5	1469	37.0	11.9	6.2	1391	1.9
2400	166		40.6		30.3	11.0	7.1	1587	33.8	11.5	6.6	1486	1.7
2300	166				27.0	10.5	7.6	1701	30.8	11.1	7.0	1571	1.6
2200	164		36.9		23.9	10.0	8.2	1852	28.0	10.7	7.5	1684	1.4
2100	164				21.1	9.5	8.9	1996	25.2	10.2	8.0	1794	1.3
2000	162		33.8		18.5	9.0	9.7	2186	22.7	9.8	8.6	1934	1.1
1900	162				16.1	8.5	10.6	2376	20.2	9.4	9.2	2074	1.0
1800	162		32.6		13.9	8.1	11.5	2595	18.0	8.9	9.9	2223	0.9
1700	160				11.9	7.6	12.8	2885	15.9	8.5	10.8	2424	0.8
1600	160				10.1	7.1	14.1	3183	13.9	8.1	11.7	2628	0.7
1500	164		25.8		8.5	6.6	15.3	3444	12.0	7.6	12.4	2800	0.6
1400	164				7.1	6.2	17.1	3837	10.3	7.1	13.6	3069	0.5
1300	168				5.8	5.7	18.8	4228	8.8	6.7	14.6	3293	0.5
1200	168				4.7	5.2	21.3	4797	7.4	6.3	16.2	3653	0.4
1100	172				3.7	4.7	24.0	5409	6.1	5.8	17.8	4007	0.3
1000	172				2.8	4.2	28.4	6393	4.9	5.3	20.3	4570	0.3




Copyright © 2003 Tony Bigras.