Cutwater 28 max RPM

[weston]

I am curious what you current c-28 owners consider "normal" wide open RPM for your Volvo D4? I was aboard a C-28 the other day for a sea trial and was disappointed with the following numbers:

WOT 3100RPM
WOT 21 knots

There were four adults , full tank of diesel, clean hull with fresh bottom paint, clean running gear.
Are these numbers typical?

Thanks you!

 

[it4llc]

The other day I was WOT and hitting about 3050/~20 knts, with a full tank of diesel and water, with just me on the boat. I talked to my dealer who suggested making sure the bottom was clean first. Once I had the bottom cleaned well, I was back to 3450, and hitting 24 knts with roughly the same load. I hadn't thought the bottom would make that much difference but now know.

 

[Automaticman865]

When I first got my Cw28 I was only able to get to 3300 rpm’s. Volvo got involved and had the prop changed from 19x23 to 19x21. When I launch in the beginning of the season I can hit 3600 rpm’s and at the end of season still pull 3500 or 3450. Volvo wants you to be really no lower than 100 rpm’s below the redline of 3500.

Stuart

 

[S@LTD]

I typically hit 3600 at WOT with full tank of fuel and water at sea level two adults and a dog, loaded for cruising with a dinghy, motor, extra solar panel and a Thule box. I lose about 200 rpm once above 4500 ft under the same conditions so I drop to 1/2 tank of fuel in order to get the same results at our home port in Tahoe 6200 ft.

 

[Headlee]

We hit 3400+ at times (with a clean bottom and favorable currents), but mainly in that 3250 to 3350 range. This is with the factory prop and typically with 3/4 fuel.

 

[weston]

Thank you all for your replies...

 

[KlaassyC]

My new to me 2018 C28 will hit 3630 lightly loaded, 25 kn


Sent from my iPad using Tapatalk

 

[mferguson]

I saw 3500 brand new and empty, but more loaded I get 3460 - 3490, 26 kts on my 2018 with a clean hull and factory prop...

Mike

 

[robinsroost]

As a newbie . . . what is it that one "cleans" off the bottom hull to increase RPM?

 

[it4llc]

Growth...plant life...barnacles... I get the green slime on our bottom, with the boat kept in a marina in fresh water. It gets bad enough to impact speed and RPMs fairly quickly.