Am I plowing?

[ziggy]

Re: Am I plowing?

fyi. plowing vs planing vs displacement hull speed. http://www.boat-ed.com/nh/course/p1-2_hulltype.htm

can ya disable yer tabs, lock in up position? or remove them for a moment to see if yer bow comes up some.

 

[91rr]

Re: Am I plowing?

I know the bow will definitely come if if the tabs are removed. My current prop is not very aggressive and has almost no cupping, I have had a new one on order which just came in yesterday so I will give that a try this weekend along with making a couple of adjustments to the tabs. I just have never seen a picture of my boat in the water before so I wasn't sure if there was a problem or not. I will report back after this weekend with the results. I have kind of given up on the top speed issue an this thing and have come to accept that it is because of the altitude here in Denver that I am running at. I'm sure it would scream at sea level.

 

[HCMQA]

Re: Am I plowing?

Prop pitch is too low for top speed.

Was the boat always a V8?

My 87 19' bowrider with a 4.3 cobra will run at just shy of 50mph (gps) with a 19 prop.

Are you using gps for speed or the speedo? My speedo is way off.

 

[91rr]

Re: Am I plowing?

All it needed was an adjustment to the tabs. I now am able to completely control the bow height again using my trim. Top speed is still about the same. Damn altitude I would really like to run this thing at sea level and see what I get.

 

[bobdec]

Re: Am I plowing?

In the automotive/motorcycle performance arena they use a 'High Altitude" tune that essentially leans out the fueling and slightly increases the timing. It entails jet changes and timing adjustments on carbureted/distributor engines and a tune on computer controlled engines. I wonder if any of your local service shops have experience or know of any options like may apply for marine applications ?

 

[91rr]

Re: Am I plowing?

In the automotive/motorcycle performance arena they use a 'High Altitude" tune that essentially leans out the fueling and slightly increases the timing. It entails jet changes and timing adjustments on carbureted/distributor engines and a tune on computer controlled engines. I wonder if any of your local service shops have experience or know of any options like may apply for marine applications ?

I am tuned for the altitude. I running 12% lean and my base timing is set at 16 deg with 40 degs of total timing. I appreciate the thought but I've been all through that already. I even have the "High Altitude" gearing in my outdrive.

 

[rallyart]

Re: Am I plowing?

At Denver you will be down 20% on horsepower compared to what you would run at sea level after you have tuned it correctly. The gearing and prop pitch help on launch but your top speed is limited by that power loss.
However, the water is pure and the shy is dark blue to all is well.