best speed for a 500DA

[kevinr]

95' 500DA 550hp Detroit 6V92's w/airsef's lookin for more speed cruises @ 23mph @ 1900 now..........anywhere to improve ??????????????

 

[Mick & Denise]

Interesting...... Mine cruises at about 26-27mph at 1900. Maybe thats the Cats with 600hp? Max rpm is 2350. Whats your WOT?

 

[geriksen]

I get 29/30mph at 2400 rpm
625hp Detroit DDEC 6V92's

I will post a 1900rpm number after I run the boat next

 

[bahamabreisus]

We have 8/92s in our 500, we cruise at 24-25 mph at about 1700 RPM and 32-33 WOT about 2200 RPM. We have four blades on it now, before with the three blades, we cruised same RPMs 27-28 mph and WOT was 37-39 MPH

 

[Boatingfool]

We have 8/92s in our 500, we cruise at 24-25 mph at about 1700 RPM and 32-33 WOT about 2200 RPM. We have four blades on it now, before with the three blades, we cruised same RPMs 27-28 mph and WOT was 37-39 MPH

Did you change the diameter and/or pitch of the props?

 

[bahamabreisus]

I'm not sure of pitch etc. Both sets came with boat when we bought it. I am going back to the 3 blades this spring, I feel with the better speeds from the 3 blades, we would get much better fuel efficiency. I can not tell any difference while docking between the props.

 

[Boatingfool]

I'm not sure of pitch etc. Both sets came with boat when we bought it. I am going back to the 3 blades this spring, I feel with the better speeds from the 3 blades, we would get much better fuel efficiency. I can not tell any difference while docking between the props.

If you boat turns max rpms with both sets, I'd bet you will get more efficiency with the old props as you were going several mph quicker at the same rpms.

You may already know this but when you get your boat out of the water, look at the propellers. Typicall where the shaft goes through they have the diameter and pitch (may read like 30"x31") stamped onto them. Probably the 3 blades have more pitch (the second number) which means for every revolution of the prop the boat moves forward a further distance.

 

[osd9]

That's very interesting that a set of 3 bladers will give you a higher cruise speed. I remember reading that they give higher top speed, but 4 blades are better a typical cruise rpms. Were you able to reach rated WOT RPMs with both the 3 and 4?

 

[Sua Sponte]

Thread resurrection....

Cat 3196TA's with upgraded turbos (660 HP plus whatever additional juice from the turbos, so maybe 700ish HP).

We cruise at ~28 knots at 85% load or ~2,050-2,100 RPMs.

WOT is ~32 knots.

 

[rogman]

i have 6v92s 550h.p. and have been trying to sort out what might get me a bit more performance....in fact i was speaking with an engineer from searay yesterday and our boats came with 26x27 props..4 blade mine now are 26x26 4 blade and do wish i could get a bit more top end im thinking 25 to 26 m.p.h. depending on how your loaded is about right.
i am also looking for an extra set of props if you are going back to 3 blade or if anyone else has a set let me know..i do find the 3 blades intresting what size are they??