High altitude question.

I am going camping at a lake (Jackson Meadows) that is 7800' elevation. My neighbor has a I/O Crownline and he said at that elevation it is hard for him to pull a rider up on a wakeboard and that his boat doesn't run well. My question is.....my 05 PCM 330 should compensate for the elevation right?I usually run at or just above sea level.
Board More/Work Less!
J$

the best thing to do is change the prop...MC has what a high altitude prop and that should fix all your problems!

nice profile pic by the way!

(Message edited by pittsy on June 24, 2006)

Your going to notice a huge loss of power at that elevation. I run at sea level twice a year, a lake that sits at 4000' elev, and a lake that sits at 5000' elev. 4000' isn't too bad, pulls fine with full ballast and rider. 5000 is a strain with full ballast and a rider. The motor revs out to 2500 rpm until just planing over then will pick up rpm and run fine. Running around empty is no problem.

I second the loss of power at altitude. A couple of days ago we were boarding/surfing at a lake that sits roughly 5500-6000 ft. We had 4 normal size adults and rear ballast was full and front was maybe half full. The boat pulled the rider out ok but really struggled when I put the wakeplate in the up position. It was such a significant loss of power that we all thought something was wrong with the motor. It goes in tomorrow for a double check and service.

As far as your motor compensating, it will to a point but changing to a high altitude prop may be what you need.

We used to take our SAN to Union Valley alot..
I think it's about 6k feet.. There was a little power loss but not much..
A friend of mine has an older boat without fuel injection and his boat runs like crap..
I wouldn't worry about it

where i ride in california the lake is like 5000 or 5500 ft and i have full rear ballast plus 700 extra rear ballast, no front ballast 4 people in the back and had no problems out of the hole...changing the prop makes a huge difference..

You will experience a power loss, but nothing that will make you not be able to pull out a skier. It may not rip it out of your hands, but it will still pull you up easy.

if you have a motor that is computer controlled and you have fuel injection the motor will compinsate for the lack of o2 unlike a carburated motor and your 05 should have all that
Jay

his I/O will likely not perform like your SAN (or any comp boat) at high altitude.....apples to oranges. I/Os have a tough time to begin with.

There are two things that cause cars and boats to run poorly at high altitudes. One is lack of oxygen the second is poor air/fuel ratio. EFI will compensate for the second but not the first. Air is a critical component to your motor making power. If the air at that altitude is only 80% as dense as the air at sea level your motor will only be able to make 80% as much power as it makes at sea level. You can probably expect a performance drop equivalent to a step increase in prop pitch. What prop are you running? I would guess that your boat has an ACME 645? If thats the case you should be fine, it will just be a little slower than usual. If you are running a bigger prop, it might be time to consider buying a lower pitched spare/hi-alt. prop.

(Message edited by mikeski on June 25, 2006)

your boat should be fine. you'll definitely notice a loss of power, but you'll still be able to ride and ride with ballast. I ride at Jackson Meadows a few times a year. The elevation is noticable, but it won't completely bog you down.

oh, forgot to say that I do run a very aggresively pitched prop though.

Aggresively pitched inplies a tall pitch difficult for the motor to turn??? (like a more aggressive tire bites more dirt a more aggressive prop bites more water = harder for the motor to turn in both cases).

enough about that.

Is your boat propped for stronger holeshot or higher top speed? I am guessing that you have it pitched for stronger holeshot, which is good in this situation. If you truly mean it is aggresively pitched to produce a higher speed you might want to consider picking up a flatter prop for this trip.