Phantom 25 and Verado 400R

Toffen Gunnufsen

Junior Member
Joined
Mar 19, 2016
Messages
8
Hi!

I hope you are well.

I have a Phantom 25 from 1984. Its made a little heavier than a standard P25 according to Steve Baker. in 2016 i reinforced the foredeck with Divinycell, so its even more heavy now. But stiffer and better in high seas.

I have owned several engine configurations during the 20 years I have owned it; Johnson 300 V8 GT3,6 Offshore, Promax 300 SVS, 2 x Merc 2.5 EFI SS PCU, Verado 350 Sci and now a Verado 400R. Its been a very fun journey :)

The boat ran 75-76 mph with the Johnson and Promax engines. 86-87 on a best day with the twin 2.5 EFI SS engines and 80-81 mph with the single Verado 350 Sci.

Last year when I bought my 400R we managed 85-86 mph with a REV4 25 pitch propeller at 7,040 rpms. The gear ratio is 1:1,75. Propshaft 0,5 inches above the bottom.

I bought a new propeller this Spring. Its not cheap but it proved to be a success. Its Max5 five blade 25 pitch propeller. This propeller was made for the new Sportmaster lower unit mounted to the 400R. Its a high rake 15 inch propeller.

We managed 86,3 mph out of the box with the propshaft even with the bottom. Next run we managed 86,7 mph with the propshaft 1 inch above. Next time 87,7 mph with the propshaft 1,75 inches above the bottom. Two weeks ago we did a new test run and did several 88,6-88,8 runs with the propshaft 2 inches above the bottom. We managed in the end 89 mph at 7,060 rpms with the propshaft 2 inches above. So the trick is to get the engine as far up you can go before loosing waterpressure and bite.

We are now hitting the soft limiter at 7,060 rpms, so I will add 0,5 inches pitch. This will bring the rpms down to 7,000 rpms where the engine makes most horsepower. And we will most likely cross the 90 mph speed :)

Great fun with a classic that runs so good in high seas and smoke most of the new hulls around with equal horsepower.

Cheeers, Toffen
 

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Congrats on the results of tweaking your setup, it never ends does it.
 
That's very good work and provability with your tests, you obviously are running a lifter, I'd be interested to know how far is your setback..?
To be able to run 2" above the "V" you must be right on the limit of water pickup...!!
Top work
 
Hi!

Thanks :) I strengthened the foredeck with divinycell, and replaced my rubrail with a stainless steel one. This added approx 25 kg to the boat, and the balance changed. As we know Phantoms are weight sensitive and run flat. I lost approx 2 mph doing it, but the boat is much much stiffer. Instead of adding a spacer to the jackplate, we made a notch of approx 7 inches. So now its 7 inch notch, 4,5 inch setback of the jackplate plus built in setback in the verado of approx 3,5 inches. In total approx 15 inches setback. So thats the reason why 2 inches above the bottom most likely is 1 inch in real world.

Cheeers, Toffen
 
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Sure hutchy ran his high 80's low 90's with bridge boards. He's the guy you need to speak to
 
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