BL6

This was in March 2008, report on 35' Fountain w/ 525's, p. 60.
"All Lightning models now come with staggared engines. This type of installation.... reduces drag by placing drives 15" closer together. When compared to a 35-Lightning with side by side engines of the same power, the staggared version gained 18mph."

Wow - is that true?

Revd Up

That's a huge increase! You know those magazine's tend to exagerate a little !

bouyhunter

How can I stagger a single to gain that much
Ummmmmm

tomtbone1993

iTrader: (3)

From what I have read in the Fountain forum, Shrogen saw huge numbers from the staggared 35 version.

4mulafastech

I read that too and thought "huh?". I'm trying to figure out how drag is reduced by simply moving the drives closer together. You have the same frontal area of the drives in the water. Maybe the hull can ride "higher" since the props are closer to the keel?? Or does it have to do with the change in CG. I dunno... In any case, I can't believe 18 mph gain given the same HP.

TxHawk

iTrader: (2)

18mph is accurate if you are saying that a side by side 525efi 35 only runs 85. I have personally been in a new 35 Staggar at 101 straight from the factory, Wyatt Fountain himself came to drive it and couldnt do any better. It did take miles to get there. Either way... thats fast.

In my opinion, the additional top speed is not worth the pain in the a$$ they are to get on plane.

T2x

I don't know about 18 mph, but I can attest to the fact that since the earliest twin outboard vee bottoms we always did everything possible to squeeze the engines(drives) together as tightly as possible. This is simply because by putting the props behind the deepest part of the hull, you reduce frontal surface and drag from the lower unit and you maximize prop bite and water contact. Handling also improved because you did not raise one prop inordinately as the hull rocked from side to side and thereby aggravate the "chine walking" tendency in vees. Back when we ran in the high 60's putting the engines closer together was worth 3-5 mph. With todays props it might very well have been more. .

By the way this also works on Cats with significant dihedral in their sponson designs. On relatively flat bottomed monohulls and cats the placement means much less.

T2x

Sydwayz

iTrader: (1)

I don't think its apples to apples in this case on the two versions of the 35 Fountain. The older 35 w/ side/side engines was a heavier boat. The new ICBM 35 (staggered) is completely redesigned, and appears to be a lighter boat due to just having less "stuff" in it.

stainless

What less "stuff" does it have?

Sydwayz

iTrader: (1)

For one, the cabin is smaller since the engine compartment is lengthened, and the cockpit looks a little tighter too. Hence, the boat appears to have fewer compartments. I like the design. Its a lean and mean go-fast. But like I said, they started from scratch on the new boat. They didn't just stagger it, and get 18mph +/- all of a sudden.