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View Full Version : Is the old "addage" true..... 1 mph increase = $1K?



gold-n-rod
11-27-2006, 08:44 PM
Years ago, I was told that a mile per hour in a performance boat (above baseline) costs $1000.

I referred to this in another post and it's caused quite the discussion.

Your experience?

chappy
11-27-2006, 09:23 PM
I've heard and read that those dollars equal that increase, but my engine and drive are still intact for now:crossfing , I'll let you know when I hear BOOM.:cool!:
Rich

Mr X
11-27-2006, 09:27 PM
No......it all depends on the boat. An Imco shorty drive is good for around 5 MPH on a Donzi Classic. It costs around $1500.00 for the housing.
Do the math......

Carl C
11-27-2006, 09:35 PM
No......it all depends on the boat. An Imco shorty drive is good for around 5 MPH on a Donzi Classic. It costs around $1500.00 for the housing.
Do the math...... Don't forget to figure labor, materials and the new prop.

DonCig
11-27-2006, 10:40 PM
13 mph ; $13,000

I think that it is all releative; but then the numbers are the numbers!

Do not ask me what LOVE costs; it makes boating look cheap.

Don

zimm17
11-28-2006, 03:32 AM
I think it's dead on:

Exhaust $2000 = 2mph increase

Cam and heads ($3000 for AFR marine heads, $2000 for roller cam, lifters, rockers, pushrods, guideplates, gaskets) should get around 5mph

Last Real Texan
11-28-2006, 07:11 AM
IMco Shorty $ 1800 w/labor = 3 mph not bad BUT NEW PROP $ 600.00 brings the total to $2400. makes it almost fit the cost bill for the equation of $1000 per mph.
Now I am installing a M3 SC @ 5 lbs of boost I scored a smokin deal on it however. I should be completely installed and reprogrammed for under $4500, ECM,and guages and labor here. I hope to pick up 10 mph and the shorty may help even more in the higher speeds, if I do pick up ten that will make a total of 13 mph over when I got the boat for $4500+$2400= $6900 thus equalling $ 530 per mph gained. Of course this is all Hypothetical until the speed increase results from the Pro charger, it could be worse if I pick up less or it could be better if it actually picks up more than ten....we will see.
Still makes me cringe when I really look at the numbers.:shocking:
just my 2 cents
Bryan

Carl C
11-28-2006, 07:20 AM
It is a graduating scale. Increases come relatively cheap at first but sqeezing more and more speed becomes harder and more expensive. Randy's adage is a rough average.:alligator

blackhawk
11-28-2006, 10:05 AM
Boy I stirred the pot didn't I?

Like I said in my other post these "rules", "adages", whatever you want to call them simply don't work as boats are too subjective.

Yes, it CAN cost $1000 per 1mph. But, my point is it doesn't HAVE too and to use it as a "rule" simply doesn't make sense. Hell, you can swap props for $300 and pick up 2mph!

For strictly engine work I think you're right. Paying labor to swap cams, buy new exhaust, etc adds up quickly. I don't do it that way. :D

When I had my U19 it had a factory 250hp 350 in it and ran right at 60mph. Took the motor out and replaced it with a full dress marine 320hp 350 for $6k. Sold my motor for $2500. I had $3500 into it and I picked up 8mph. $440 per mph.

I remember arguing with someone because they were telling me how dumb it was to do what I was doing to pick up only 70hp because it took 25hp to equal 1mph! :rolleyes: I was close to 10hp equalling 1mph! :D

Point is, it depends on your speed and hp starting points, weight, hull efficiency, etc, etc. There is no set "rules" for boats. If it cost me $1000 per 1 mph I wouldn't even bother. While others would be thrilled to get 1mph per $1k!

I plan on adding 100hp for less than $3k and picking up 7 mph with that 100hp this year. $430 per 1mph. :D

fasttrucker
11-28-2006, 04:15 PM
It is a graduating scale. Increases come relatively cheap at first but sqeezing more and more speed becomes harder and more expensive. Randy's adage is a rough average.:alligator
This is true,I fiqured it out to be $750 per mile for the first 10mph increase.The next 5mph costs more so $1000 per mile is about right.

rustnrot
11-28-2006, 05:39 PM
This is an easy-to-predict self-fulfilling prophecy. By the time we get done arguing this, $1k per mph will seem like a bargain!!!

Donziweasel
11-28-2006, 06:39 PM
To bring up my summer project on my 16C, I increased mph dramtically for much less that $1000 per mph. My boat had a 350 w/ 2bbl carb and non-vortec heads. Top speed (GPS) was around 48.5 at 6000 ft above sea level. New vortec heads, cam, carb, and intake and the boat ran honest 56 with more left. I had (and still have) a hesitation when the secondaries kick in, but that is another story and the fine tuning will have to wait until spring as the lakes are frozen already. I think total bill was around $1,400.00 and I gained 8 mph. That is $175.00 per mph. Unfortunatly, that is all I can really do cheaply. Any more power or MPH would entail a supercharger, a major re-build with high performance parts or perhaps a fuel injection at this altitude. None are cheap.

BigGrizzly
11-28-2006, 07:15 PM
The higer the speed the more $s per mile. Tex we can beat that $600 prop deal providing you don't count my dinner on our visit.

Last Real Texan
11-28-2006, 08:18 PM
The higer the speed the more $s per mile. Tex we can beat that $600 prop deal providing you don't count my dinner on our visit.
Big grizz ....you have a deal but as stated you must eat cheap!

Formula Jr
11-29-2006, 07:42 AM
I guess you would have to ask Ken Warby about the 1K per 1 MPH thingy....

317 MPH ain't bad with a $70 dollar motor...... :wink:

Rootsy
11-29-2006, 07:48 AM
taking what i did with the 16....lets add it up and see... forgive me as some of the figures are a bit rusty and i may forget one or two of the make-up sales here and there but we'll get close

alpha SS : $2000
Alpha Gen II : -$1500
Hydraulic steering : $750
GLM / IMCO Exhaust : $800
Stock merc exhaust : -$150
valvetrain : $1000
Intake : $200
Carburetor: $400
Cylinder Heads: $600
Gaskets, etc: $250
Propeller: $600
Fuel lines, regulaters, etc $150
Ignition: $600
stock heads : -$200

TOTAL: $5500

Stock OUT OF BOX SPEED : 54.6 GPS
Max Speed after modifications : 81.3 GPS

Speed Gain : 26.7 MPH

Price / MPH : $205.99

Please be aware i did and still do ALL of my own mechanical labor... that would probably AT LEAST double the cost / mph...

The Hedgehog
11-29-2006, 08:08 AM
The first mph comes real cheap. After that I would probably agree with the $1,000 rule. In the case of my situation with the 16, there is so much that can be done it does not even come close.

You can buy a procharger setup for around $5k. That will get you a min of 10mph or more.

Carl C
11-29-2006, 08:29 AM
alpha SS : $2000

Hydraulic steering : $750
GLM / IMCO Exhaust : $800


Intake : $200
Carburetor: $400
Cylinder Heads: $600
It looks like you got some good deals!!!!

Rootsy
11-29-2006, 08:38 AM
It looks like you got some good deals!!!!

what do you mean? i thought those were fair prices....

Donzigo
11-29-2006, 09:12 AM
.............and where is the absolute top on the 16,18,or 22? Well, even that is relative, isn't it? Turn one of those babys up to the next level, strap on a rocket booster and you could probably break 1,000 MPH, (vertical, of course).

Cost:

(1) Rocket booster set up - say a used one ($3,000,000) could be bought from a terroist group, who got it from Iran, who got it from a third party, who got it from a US supplier, who got it from the US manufacturer

(1) Installation team - say $1,000,000 - one could always find some guys who who SAY they know how to do it, could be dicey

(1) Cape Canaveral launch pad (one that's no longer used) - Heck, the US Govt would love to rent it for $2,000,000 to recoup the cost of some of those $250 toilet seats, the pentagon buys.

(1) U.S.Navy recovery vessels - Cost unkown, but sure to be high

(1) Driver - cost unknown - anybody know who might volunteer for nothing? Gene Drago around anymore? Jefe might do it; but, wouldn't want to dare risking his "special purpose equipment", so who?

...............yup, the pursuit of speed is all relative.

A last thought - is there someone out there who could do a Corel draw thing and show us what a Donzi strapped to a rocket booster would look like?

The Hedgehog
12-01-2006, 03:58 PM
.............and where is the absolute top on the 16,18,or 22? Well, even that is relative, isn't it? Turn one of those babys up to the next level, strap on a rocket booster and you could probably break 1,000 MPH, (vertical, of course).
Cost:
(1) Rocket booster set up - say a used one ($3,000,000) could be bought from a terroist group, who got it from Iran, who got it from a third party, who got it from a US supplier, who got it from the US manufacturer
(1) Installation team - say $1,000,000 - one could always find some guys who who SAY they know how to do it, could be dicey
(1) Cape Canaveral launch pad (one that's no longer used) - Heck, the US Govt would love to rent it for $2,000,000 to recoup the cost of some of those $250 toilet seats, the pentagon buys.
(1) U.S.Navy recovery vessels - Cost unkown, but sure to be high
(1) Driver - cost unknown - anybody know who might volunteer for nothing? Gene Drago around anymore? Jefe might do it; but, wouldn't want to dare risking his "special purpose equipment", so who?
...............yup, the pursuit of speed is all relative.
A last thought - is there someone out there who could do a Corel draw thing and show us what a Donzi strapped to a rocket booster would look like?


Heck, I think I could get a JATO tube a good bit cheaper. What do you think my takeoff speed would be?

zimm17
12-03-2006, 08:24 AM
It seems that the guys getting under the $1000/mph barrier are starting with low powered engines which are easily swapped for higher HP stock engines. (2bbl small block to a bigger 4bbl small block, or a 330hp 7.4 to a 385hp 454 mag). The typical 454/502 mag with bravo outdrive already has about the most HP for the money. To get more power you are looking at high dollar heads and valve train ($5000), forced induction ($6000-10,000), or a bigger engine ($15,000-20,000 for a 540). Oh, and external steering too.

This is where you get into the realm of having a HP upgrade cost half or as much as the value of the boat. So it comes down to blowing 5-20k to get that last 5-15mph over a stock boat or try to be happy with 70mph. It's hard, but everytime I get passed by a 38' fountain, I just remind myself that my boat is paid off and his fuel bill would make my visa card cry.

Of course that doesn't stop me from constantly drooling over prochargers, whipples, and built 540 long blocks....

fasttrucker
12-03-2006, 10:18 AM
It seems that the guys getting under the $1000/mph barrier are starting with low powered engines which are easily swapped for higher HP stock engines. (2bbl small block to a bigger 4bbl small block, or a 330hp 7.4 to a 385hp 454 mag). The typical 454/502 mag with bravo outdrive already has about the most HP for the money. To get more power you are looking at high dollar heads and valve train ($5000), forced induction ($6000-10,000), or a bigger engine ($15,000-20,000 for a 540). Oh, and external steering too.
This is where you get into the realm of having a HP upgrade cost half or as much as the value of the boat. So it comes down to blowing 5-20k to get that last 5-15mph over a stock boat or try to be happy with 70mph. It's hard, but everytime I get passed by a 38' fountain, I just remind myself that my boat is paid off and his fuel bill would make my visa card cry.
Of course that doesn't stop me from constantly drooling over prochargers, whipples, and built 540 long blocks....
Your right,Its insane.:bonk: ...crazy..:bonk: ..mad......:bonk: ...Why.Why.Why.....:boggled: ..... I cant stand it.:hyper: Oh well, you know your are going to die someday.:anchor: Might as well have some fun along the way.:yes: Iam spending around $6,000. this winter.ouch!:eek!: