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Re: 5 mph increase dreaming

Posted: October 4th, 2018, 4:14 pm
by rjr
Viper I agree. The engines are already maxed out with the turbos. Will make sure next year all excess weight is removed. I keep telling the admiral this is a motor yacht, not an express cruiser.

BTW, my engines do not have ECMs so flashing is a moot point.

Thanx for input.

Re: 5 mph increase dreaming

Posted: October 4th, 2018, 8:44 pm
by Viper
rjr wrote:Source of the post..... BTW, my engines do not have ECMs so flashing is a moot point....

Was wondering about that. Thought it was a strange suggestion.

Re: 5 mph increase dreaming

Posted: October 5th, 2018, 9:15 am
by km1125
I'm confused. We're branching into engine mods when the OP isn't even using the throttle with what he has. Wouldn't the FIRST thing to do would be to run the engine at a higher load than 50% to get more speed?

Re: 5 mph increase dreaming

Posted: October 5th, 2018, 3:46 pm
by rjr
Waybomb & Viper - I agree. Engines are already maxed out with turbos. CAT dealer said engines do not have ECMs so flashing is moot.

Will let you know next spring. Thanx for input.

Re: 5 mph increase dreaming

Posted: November 14th, 2018, 12:52 pm
by Cooler
rjr, I know this is way to obvious, but have you tested your trim tabs frequently to find your most efficient setting? You do not have to change attitude very much to increase 3 to 5mph, so maybe that will help. I reset trim tabs on every cruise, and get a 3mph increase as soon as I get close to correct attitude for the water condition. The other thought, and one a lot of boaters neglect, is make sure the trim tabs are functioning correctly, and the tabs themselves are adequate size for the hull. Carver matches those components very smart, so size if most likely appropriate. You can check this out on the hard. Check owner's manual for which engine switch needs to be in "on" position for the tabs to engaged. Good luck!

Re: 5 mph increase dreaming

Posted: November 14th, 2018, 6:03 pm
by Cooler
Follow up: if you decide to test your trim tabs, remember that the correlation between tab switch and physical location of the tab is crossed. I.E. the tab switch that indicates port side down/up actually controls the tab on the starboard side. Also, let's do a little math. I believe you have 500 gallons fuel capacity, which converts to 3575 pounds, and water tank is around 170 gal, which is 1360 pounds. Dropping both to half tank capacity would save you more than a ton of weight. That is significant, but be careful if you do long range cruising. Although your vessel weighs somewhere around 25000 lbs. dry, I do not think it is impossible to get some more speed out of that combination. Happy motoring!

Cooler

Re: 5 mph increase dreaming

Posted: November 15th, 2018, 4:36 pm
by rjr
Cooler: I use trim tabs constantly. I haven't found the sweet spot yet but will next year. Your point about weight is well taken. I'll be sure to pump out the holding tanks as well!

BTW, I agree - it is cooler by the lake.

Thanx

Re: 5 mph increase dreaming

Posted: November 15th, 2018, 5:18 pm
by Cooler
Funny story....when I bought Cooler last spring, I asked the previous owner why the trim tabs did not work. His answer was, don't know, never used them. I looked at the pump and the screw to hold the cover down was still taped to the inside of the cover. He truly never used them as the delivering dealer never filled the reservoir. We bought some fluid at the marina just prior to the sea trial, they worked like brand new because they were. We had a good laugh about that because he didn't realize how much of a difference they made. Great guy though.

I talked to a Carver owner with a 390 Aft. He said he always has his tabs full down when cruising. That is his best performance. You guys do have a lot of hull in the water. I am going for a cruise next week. Going to go to Little Sister Bay, in my mind only. Sit in the cockpit in storage and fantasize the trip. Can you tell I'm losing it too early in the off season? Take Care. Cooler