Point of Dimenishing Returns ? - Bored

(bob_l) · (bob_l) **Join Date: Jul 2006** 03-09-2007, 12:50 PM

If you are bored and waiting on your local waterway to thaw, then play along...

At lunch today, a couple of us were arguing about the point of dimenishing returns on a multi-engine outboard. One had seen a picture of a drug running boat with EIGHT Mercury 250HP outboards. I pointed out that at some point, an extra engine might actually reduce the performance/speed due to weight and drag issues. For example, a 30ft Fountain with 2 250hp outboards would perform x, but if a 3rd was added, that engine would only give you 60% of the value of the second engine - and so on down the line. Assuming you have enough room on the back, at what point does the next engine add 0 to the performance and more importantly, can it actually reduce performance (speed, in this case)?

We also discussed that if one engine was turning less RPM's than the others, it might be useless (assuming they had to manually synch the RPM's). Any feedback would be interesting.

(jamieb) · (jamieb) **Join Date: Mar 2007** 03-09-2007, 12:57 PM

yeah, but the difference between 55 and 80 mph is the difference between getting caught and getting paid.

(acurtis_ttu) · (acurtis_ttu) **Join Date: May 2004** 03-09-2007, 1:08 PM

This might be a better question to ask the drug dealer who didn't get his boat siezed

(jdrcrew8) · (jdrcrew8) **Join Date: Jun 2005** 03-09-2007, 4:06 PM

Wow, thats complicated. Are you guys not basketball fans???

I would think that before you would get to the point that the extra engine does nothing for you, you would hit the maximum level of drag for the hull (that may not be saying that right). That is just a guess though completely unsupported by scientific facts or observations.

(o2binvallarta)

Nancy Reagan said you should just say no, so none of this matters.

(timmy) · (timmy) **Join Date: Jul 2001** 03-09-2007, 10:11 PM

don't worry the DEA goes to merc and finds out what the drug runners buy, and up it.

(mikea) · (mikea) **Join Date: Mar 2005** 03-10-2007, 1:05 AM

I THINK i remember a "go fast" boat guy saying when you add a second outdrive, the the extra drag consumes 90 hp.

not sure if I remember correctly or explained it correctly!

(882001) · (882001) **Join Date: Nov 2003** 03-10-2007, 5:43 AM

i agree some where along the line the motors will do nothing but create extra drag. i heard that story was false. it looks like a some sort of work boat, and they probably push stuff around with it.