Looking to upgrade the donks -advice needed please

[cormorant]

Emailed a mate of a mate in the states who has had a bit to do with them and he thinks there won't be huge performance gains due to them not fully planing hull shape. Opinion was to wring the neck of the 115s a bit and use a bit more fuel and keep money for repower in your pocket. Money is tight in the states at the minute . He asked about fins on the motor as work better with them. He suggested you get onto the GB forum and get others performance figures and also mentioned the model numbers have changed but he wasn't sure which ones were which. Get sistership performance numbers to ensure you are getting best possible performance from 115s. Very good value boat in the states for a nice useful boat but never were a rocketship as you know.

PS are your speeds in MPH ? It seems slow if they are KM/h? Should be getting 40 mph with 115 unless you have hardtop etc.

[baitable]

Yes speeds are in km/h sadly. I checked the figures and I'm on par with other comparable boats out there . It is a slow boat and it seems the minute you push it over 30km/h there are diminishing returns. She can hit a top of 50 km/h but fuel usage is crazy. I've read through the fb forums but will start again with my research, I've even contacted gb themselves but to no avail.

[baitable]

She is a soft top

[cormorant]

That is odd. I am sure when years ago I looked at these the performance was better. maybe I am mistaken but if it was that low I would never have done any further looking at them. I remember F & B did a test on them . That is just a lot slow to get anywhere. I'm out of ideas

Might be worth a call to one of the other private sellers in Australia and confirm what props and performance they are getting and confirm if it is km, kn or mph. Most people don't mind a call about their boat if you are upfront in telling them you want to repower yours. . I don't know much about propping semi planing boats so I would just be using sistership data. Wonder if solas has prop and speed data ? If what you are saying is correct I am not sure throwing HP at it will do a lot as boat is hitting a speed brick wall.

[Chimo]

Interesting stuff here on hulls and design speed and also reference to GB http://www.bwseacat.com/content-25.html

Seems to be a lot of 150HPs on here http://glacierbayforum.com/forum/pop...e&TOPIC_ID=995

[cormorant]

here is a boat test with 115's . 4500 revs propped should be OK and not chew too much fuel
Blacked out address is " boat test" without space inbetween.
http://www.########.com/partners/par...id=1618&p=0&s=

Glacier Bay 2270 Isle Runner Test Result Highlights

• Top speed for the Glacier Bay 2270 Isle Runner is 34.9 MPH (56.2 KPH), burning 19.5 gallons per hour (GPH) or 73.81 liters per hour (LPH).
• Best cruise for the Glacier Bay 2270 Isle Runner is 15.4 MPH (24.8 KPH), and the boat gets 3.20 miles per gallon (MPG) or 1.36 kilometers per liter (KPL), giving the boat a cruising range of 363 miles (584.19 kilometers).
• Tested power is 2 x 115-hp Suzuki Outboard.

Full test results Blacked out address is boat test without space inbetween.

http://www.########.com/partners/par...618&p=0&s=#Top

RPM MPH Knots Total GPH MPG N MPG Stat. Mile NM KM KPH LPH KPL dBA



4000 22.5 19.5 8.4 2.67 2.33 303 264 488 36.21 31.8 1.14 77
4500 27.1 23.6 11.9 2.27 1.98 258 224 415 43.61 45 0.97 80
5000 31.0 26.9 14.8 2.09 1.82 237 206 381 49.89 56 0.89 82
5500 34.9 30.3 19.5 1.79 1.55 203 176 327 56.17 73.8 0.76 82

[baitable]

Yes I found that site. According to these figures I am on par