Altitude question

[Luckydogs]

I have an interested buyer who lives in Colorado and I live and boat in Texas. I have an 02 280DA, T 4.3 w/Alpha drives and the question about change in performance due to the altitude was asked and I didn't have an answer for him. If this person bought my boat and hauled it to Colorado would there need to be mods done, thanks!

 

[garryowen]

lucky;yes if he uses it any where from the front range west he will need to reprop for altitude.
not sure what elevations are involved from the front range east though.
the props are the only thing he will need to worry about.

do you know where in co he is planing on using it? what is your elevation there where you boat?

 

[Hampton]

The props may be the only change required, but depending on the boat, it may be severely underpowered. I don't know about the power of your boat, but going from close to Sea Level to around 5,000' will have a significant effect on the power of the boat due to lack of Oxygen.

I bought my first boat in Lubbock, Tx, two weeks prior to moving to San Antonio even though it was constructed in Austin (much closer to San Antonio). The reason I did this is that the builder would not put a V-8 in that boat unless it was going to the mountains or other high altitudes (Lubbock was at 3353' above sea level).

When I towed it to San Antonio, it was extremely over powered, but well worth it. I flew it out of the water once on a calm lake (Lake Dunlop - New Braunfels River down stream from Canyon Lake). The last speed I saw was 59 mph, then the speed went to zero as the tip of the sensor came out of the water and the bow rose up.

It was a 1989 Classic 190 (Name and Model), 19' open bow with an I/O 5.0 Merc and Alpha 1. I bought it new, owned it for 4 years and sold it for a slight profit.

 

[Boulder GT3]

Estimate a power loss of about 3-4% per 1000' in a normally aspirated motor and 2% with forced induction.

The boat is probably injected so fuel air ratios should be fine but he'll down on power 15-20%.

 

[Scottbenson]

I boat regulary from 4500 to 6500 feet here in Utah. I only have the 4 cly motor and I can definitely feel a small power loss at the highest altitude, it is not a major issue. Proper propeller pitch makes the most difference for me. If you go down a pitch or two on the prop, he will have no problems

 

[redmoncpa]

I have a 240 Sundancer with a Bravo III drive and 26 pitch props. The boat is moored in Lake Tahoe el 6200' and was told that a drop to 24 would make all the difference. Any thoughts?