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View Full Version : Bolt on Mod dyno results in CHP



Pismo
06-17-2007, 10:00 AM
Good article in CHP about bolt on mods, here are some dyno results they posted


Electric Water Recirc Pump: +23hp, 335hp to 358hp on a 383ci.
Underdrive pulleys & serp belt: +25hp, 335 to 360hp on a 383ci
Exhaust Headers: +8hp, 473hp to 481hp on a stock LS7
Roller Rocker upgrade: +22hp, 344 to 366 hp on a 350ci
K&N air filter: -1hp, 583hp to 582hp on a 406ci
Nitrous kit: +211hp, 602 to 813hp on a 588ci
Blower: +116hp, 390 to 506 hp on a 355ci.


So the smallest, simplest things like water pump, pulleys, and roller rockers added decent gains, 20+hp each, while exhaust did very little. I am sure exhaust would add more in a marine setup. The K&N did nothing of course. Blowers and nitrous for big time gains. Others that did little; carb swap +10, intake change +11, mass airflow sensor +12, new chip +2. They did heads too, factory iron to Holley aluminum, with +68hp (307 to 375hp on a 355ci) but that would vary so much between apps. Nitrous +211hp!! (but for how long)

gcarter
06-17-2007, 10:18 AM
Hey guys, I've been suggesting electric circ pumps for a long time!!!!:)

MOP
06-17-2007, 01:15 PM
They are definitely interesting, some what over stated in some write ups. I nearly put one on mine and still may. Another test write up below.

http://www.superchevy.com/technical/engines_drivetrain/accessories_electronics/0408sc_pump/

Formula Jr
06-18-2007, 06:48 PM
"K&N air filter: -1hp, 583hp to 582hp on a 406ci"

Man, Thats gotta hurt morale over at K & N. I can lose twenty HP just by pulling a sparkplug wire...and that doesn't cost anything.....

:wink:

DickB
06-18-2007, 09:37 PM
An electric pump will load the alternator. Did they take that into account when they made the measurements?

gcarter
06-19-2007, 05:39 AM
An electric pump will load the alternator. Did they take that into account when they made the measurements?
I'm glad you brought that up.
The large Meziere pump I had on the Minx (55 GPM) is rated @ 12 Amps full load, so 12 Amps X 12 Volts = 144 Watts, 144 Watts/750 Watts(1 HP) = 0.19 HP.
So how can this electric pump be so efficient? If you look at the typical automotive pump, the impellor is bent up sheet metal w/straight vanes radiating at 90* to the axis so that it can run in either direction. At best because of this very poor design it is probably only about 30% (or less) efficient. In fact, an open impellor w/straight vanes expends much more energy generating turbulance in the water moving through it rather than pumping.
Alternatively, the beautifully designed Meziere pump had a CNC machined, semi enclosed curved vane impellor that operates probably in the 90% efficiency range.
But there's more, V-belts soak up power also, that's why the industry has moved to serpentine belts. Any type of belt will absorb some power so eliminating them is an advantage.:yes:

MOP
06-19-2007, 06:34 AM
George have to argue the merits of stock pumps the way they are housed they move a ton of water as borne out by the following from the article I posted:

That's because, while most stock and after market belt-driven pumps can flow as much as 100 gallons of water per minute and racing pumps can flow even more, most electric pumps flow less than half that amount. It's a simple matter of physics and a giant paradox of performance. In order to flow enough water through the system, the pump requires a power source strong enough to move a large quantity of liquid. The gains from moving lots of water through the system are better cooling. The losses are measured in horsepower. An electric motor, on the other hand, does not cost horsepower to run, but instead it trades volume for power and cannot flow as much water. If you built an electric pump with a motor big enough to flow the huge volume of water equal to that of a belt-driven pump, it'd be so massive that you probably couldn't fit it under your hood. And the electrical power requirements for such a pump would make it impractical for use on any car.

BUIZILLA
06-19-2007, 06:58 AM
the electric pump is fixed speed, hence fixed volume..... the standard pump is volume specific on pulley diameter and belt speed...

gcarter
06-19-2007, 07:14 AM
George have to argue the merits of stock pumps the way they are housed they move a ton of water as borne out by the following from the article I posted:
That's because, while most stock and after market belt-driven pumps can flow as much as 100 gallons of water per minute and racing pumps can flow even more, most electric pumps flow less than half that amount. It's a simple matter of physics and a giant paradox of performance. In order to flow enough water through the system, the pump requires a power source strong enough to move a large quantity of liquid. The gains from moving lots of water through the system are better cooling. The losses are measured in horsepower. An electric motor, on the other hand, does not cost horsepower to run, but instead it trades volume for power and cannot flow as much water. If you built an electric pump with a motor big enough to flow the huge volume of water equal to that of a belt-driven pump, it'd be so massive that you probably couldn't fit it under your hood. And the electrical power requirements for such a pump would make it impractical for use on any car.
I'm not sure I believe the 100 GPM.....I suppose some do, but I doubt it on automotive applications. Besides I doubt if you could get 50 GPM through a thermostat. It's just too restrictive even wide open.
I'm in the water treatment business, and when you look at the cV rating (the amount of water you can move through a valve w/1 PSI of pressure drop) of a particular control valve, you can't help but make comparisons to engines etc (at least I do). Even flow through a 1" pipe becomes turbulant @ about 20 GPM (if I remember correctly), so I have my doubts of such numbers. Sorry, but I think that was a guess. I believe the number would be closer to 30-60 GPM. Hey, that's a lot of water.
Take a look at page 2 of this Sta-Rite water system centrifugal pump, then note the medium head curves. This pump is reasonably efficient with a closed, curved vane impellor and you will notice that 1 HP produces less than 70 GPM, and 1 1/2 HP produces less than 100 GPM, even w/"0" head...no restriction whatever.
Now compare that to an automotive type pump w/an open, straight vane impellor and I don't think tghere's any way it will do that volume.

Barry Eller
06-19-2007, 07:14 AM
The only water pump I have in my set up is the pump in the King Cobra outdrive. I use a crossover system. No horse power loss. I did have to drill holes in the thermostat for it to work.