ABSTRACT
Diesel Performance Products introduces the Powershot propane injection system for turbo diesel owners who are looking for more power for towing increased mileage and throttle responsiveness out of their vehicles.
With its innovative and patented design and method of propane delivery, this system is unique to other systems on the market and has overcome many of the drawbacks encountered with earlier designed injection systems.
The Powershot is an infinitely variable-stage vapor injection system. It is controlled, activated and proportionate to the boost pressure of the engine. The Powershot comes on slow and steady and as the boost increases, so does the flow of propane. More boost=more propane=more power! It is fully adjustable and can be customized for your specific application in minutes for towing, performance or mileage gains.
The easy-to-install Powershot system will safely and substantially increase horsepower (up to 100hp) and torque (up to 250 ft lbs). This unit is a must for towing and all- around performance increases. Modest mileage gains are an extra bonus.
INTRODUCTION
Diesel Performance Products introduces the Powershot 2000® propane
injection system for turbo diesel owners who are looking for more power for
towing increased mileage and throttle responsiveness out of their vehicles.
With its
innovative and patented design and method of propane delivery, this system is
unique to other systems on the market and has overcome many of the drawbacks
encountered with earlier designed injection systems.
The
Powershot is an infinitely variable-stage vapor injection system. It is
controlled, activated and proportionate to the boost pressure of the engine.
The Powershot comes on slow and steady and as the boost increases, so does the
flow of propane. More boost=more propane=more power! It is fully adjustable and
can be customized for your specific application in minutes for towing,
performance or mileage gains.
The
easy-to-install Powershot system will safely and substantially increase
horsepower (up to 100hp) and torque (up to 250 ft lbs). This unit is a must for
towing and all- around performance increases. Modest mileage gains are an extra
bonus.
The
system installs in about two hours and requires no permanent modifications to
the vehicle or engine. The quality of the components is obvious: Custom LP
regulators /Parker fittings, safety features such as custom auto/off rocker
switches located inside the cab, and an automotive LP fuel lock-off solenoid
valve located at the tank. All of the regulating is done at the tank eliminating
the need for under hood installations and further enhancing safety concerns.
The custom regulator maintains a constant tank pressure regardless of outside
temperatures and delivers consistent,
usable power at all boost levels.
Propane
Fumigation
Lately, I've
been getting quite a lot of e-mail from folks who are interested in the LPG
Fumigation system that I have installed on the Pusher, so it makes some sense
to have a page dedicated to that subject, with at least as much as I know about
it, and some links to other resources.
What it is...and why:
Simply
stated, Propane (LPG) Fumigation is the introduction of gaseous propane into
the air intake of a diesel engine for the purposes of attaining more power,
economy, or both. The parallel is often made between fumigation and using
Nitrous Oxide on gasoline vehicles to achieve a power increase. Basically, this
analogy is correct, although the properly implemented use of LPG on a diesel
engine will actually result in a better-running engine without the possible
damaging effects that N2O has on gas motors.
Exhaust emissions are reduced as a result, with lower quantities of unburned
hydrocarbons and fewer particulates (smoke). LPG fumigation will even clean up
the odor of diesel fuel in the exhaust, making the smell from the tailpipe of
an engine utilizing it much less objectionable.
How it works:
Introducing LPG gas into the combustion air intake of a diesel engine acts as
an accelerant, promoting the even burning of the diesel fuel, and more complete
combustion, resulting in more power being produced. Propane by itself will not
self-ignite inside a diesel-fuel compression-ignition engine. During the
compression stroke, the air/LPG mixture is compressed and the temperature is
raised to about 400?C, not enough to ignite the LPG, which has an ignition
temperature of about 500?C. When the diesel fuel is atomized into the cylinder
under high pressure, it immediately self-ignites (diesel ignites at about
385?C.), and causes the LPG to burn as well. Since the LPG is in mixture with
the air, the flame front from the diesel spreads more quickly, and more
completely, including igniting the air/fuel mixture which is in contact with
the cylinder walls, which are cool in comparison to the super-heated air inside
the combustion chamber. Much of the cleaner burning of the fuel is attributed
to this ignition against the "cooler" components of the engine, and
accounts for raising the percentage of combustion from a typical 75% for a
well-tuned diesel engine running on pure diesel fuel alone, to 85-90% with the
addition of LPG. Obviously, this more complete combustion also gives a nice
boost in power, with an accompanying increase in fuel economy and reduction of
pollutants.
How it works:
Introducing LPG gas into the combustion air intake of a diesel engine acts as
an accelerant, promoting the even burning of the diesel fuel, and more complete
combustion, resulting in more power being produced. Propane by itself will
not self-ignite inside a diesel-fuel compression-ignition engine. During the
compression stroke, the air/LPG mixture is compressed and the temperature is
raised to about 400?C, not enough to ignite the LPG, which has an ignition
temperature of about 500?C. When the diesel fuel is atomized into the
cylinder under high pressure, it immediately self-ignites (diesel ignites at
about 385?C.), and causes the LPG to burn as well. Since the LPG is in
mixture with the air, the flame front from the diesel spreads more quickly,
and more completely, including igniting the air/fuel mixture which is in
contact with the cylinder walls, which are cool in comparison to the
super-heated air inside the combustion chamber. Much of the cleaner burning
of the fuel is attributed to this ignition against the "cooler"
components of the engine, and accounts for raising the percentage of
combustion from a typical 75% for a well-tuned diesel engine running on pure
diesel fuel alone, to 85-90% with the addition of LPG. Obviously, this more
complete combustion also gives a nice boost in power, with an accompanying
increase in fuel economy and reduction of pollutants.
Types of systems:
The first, I call the "dump" system, which means that you pick a
value of propane to feed to the engine, either by calculation, or by
trial-and-error, and you simply "dump" it into the air intake.
Little provision is possible for correcting gas flow depending on engine
load, so the system is probably only optimized for one type of load demand.
The advantage is that this type of system can be cobbled to together by
backyard experimenters like myself at a low cost. The disadvantages are that
you will probably need to error on the side of caution to make sure that you
aren't overloading your engine with too much gas, and that the system doesn't
compensate for variations in engine speed, load, etc.
The second system is much more sophisticated, and uses a variety of sensors
and controls to monitor engine performance and load, and adjust the gas flow
to suit the need at the moment. Most commercially available systems will be
of this type.
In order to determine the load on the engine in a N/A system, a venturi must
be placed in the air intake, as diesel engines have no natural intake
manifold vacuum. A sample of the vacuum produced by the venturi is fed to a
metering system, either electronic or mechanical, which adjusts the gas flow
to suit the circumstances.
Turbo engines have a great indicator of load built in. It's a fairly simple
process to take a sample of the boost pressure developed by the turbocharger
and use that to control the metering system. Most commercially made systems
are designed for turbo engines, both for this reason, and because of the
greater power gain that the turbo realizes from fumigation. Since boost is
such a reliable indicator of engine load, higher values of fumigation can be
realized, with tighter control over the results.
The Tank and Regulator:
What type of tank you use may depend a lot of what type of vehicle you intend
to use it on. If you are adding a system to a large truck or a motor home,
you will probably have plenty of room for a frame-mounted horizontal tank. If
it's a motor home, you may not need to add a tank at all, just use the
existing one, although an additional regulator may be necessary, depending on
the type of system you install. The smaller the vehicle, the more difficult
the job of finding a suitable location to mount the tank, and the more
difficult it will be to find a tank the right size and shape.
Should you be tempted to mount the tank in the enclosed trunk of your car, remember that DOT (Department of Transportation) rules forbid such installations unless the enclosure (your trunk) is well ventilated to allow any seepage or leakage of gas to readily escape. If you want to know how well ventilated it needs to be, go visit a motor home or travel trailer dealership and see how propane cylinders on recreational vehicles are mounted. Unless you plan on wearing a racing fire suit while driving, forget mounting the gas cylinder inside the passenger compartment. The size of the tank will also depend on your usage. If this is a long-haul truck or RV tow rig, you will probably want the gas on full-time, in which case you will need a sizeable cylinder. For occasional hill climbing or passing on the road, you might be able to get by with a capacity of only a few gallons. Installations in cars meant for racing or speed exhibition will need only a small reservoir of fuel, perhaps with several tanks that can be interchanged when emptied.
During my initial trials, I used a Coleman camping fuel bottle as a source
for gas. This picture is posted elsewhere on the site, and has been picked up
by several discussion forums as an example of how not to do it (like I
always drive around with a propane cylinder balanced on the drive train
hump...). The small cylinder was good for about 60 miles of continuous use,
but has been replaced by a 1? gallon cylinder with a proper shut-off valve.
This image also shows the BBQ regulator and 12 volt solenoid valve that I
used to test the system. These components will be discussed in greater detail
later in this page.
This does bring up an important point. Any containment vessel you choose for your system should be properly and securely mounted to avoid damage to the equipment during driving. Any wiring or plumbing from the tank or associated components should likewise be properly secured out of harm's way.
The regulator you use will depend on how much pressure and flow is needed.
The BBQ regulator shown above was perfectly adequate for my purposes on the
VW N/A engine, operating at 25,000 BTU per hour. It cost me $2.00 at a
salvage yard, and produces 11 inches of water on a manometer (.397 PSI). If your fumigation system will be for a turbocharged engine,
or if your engine is of a high displacement, you may want to purchase a
regulator that has an adjustable output pressure. Turbo'd engines generally
require pressures of 4-6 PSI, at greater flow rates than a household
low-pressure regulator can provide.
A regulator of the type use on oxy-acetylene welding equipment is one type
suitable for an LPG system. Just make sure that any regulator you use is
rated for the pressure of a propane cylinder (approximately 250 PSI) and is rated for flammable gas duty. Two-stage
regulators will be less affected by changes in altitude, barometric pressure
and temperature.
Note that systems which demand a lot of vapor will need a regulator which can
supply the specified flow without freezing up. At some point, large gas flows
will require you to install an evaporator system like those used on LPG fueled
spark-ignition engines, and the tank will need to feed liquid LPG to the
evaporator/regulator.
The Solenoid Valve:
This piece of gear seems to be the sticking point in many of the LPG systems
that I hear about. Essentially a solenoid valve is an electrically actuated
valve that is used to control the flow of gas into the engine. It needs to be
rated for the pressure that it is being asked to control, and be safe for
flammable gases. The electrical rating needs to be 12 volts DC, continuous
duty. The valve I am using was purchased from C and H Sales, a company which
specializes in surplus equipment sales. It is stock number #SV9903, and the
price was $5.00. See the "Links" section at the end of this page
for more information on C & H. Other solenoid valves are available from
suppliers of fumigation equipment, so also check the links to those sites as
well.
Tuning it up
Adjusting the orifice and/or gas flow for optimum performance could be tricky.
Basically, increase the LPG flow incrementally until you see/hear detrimental
effects. The first, and most noticeable is hard knocking, or pinging from the
engine. If it sounds like someone threw a handful of ball bearings inside
your motor when your turn on the gas, by all means TURN IT DOWN!!! The
rattling you are hearing is the "colliding flame fronts", and is
also the sound of your pistons being turned into molten aluminum. If
anything, adding LPG to a diesel engine's intake air should make the engine
quieter.
Another thing to watch for if your engine has a pyrometer (exhaust gas
temperature gauge), is EGT's dropping. LPG promotes more complete combustion,
so some of the heat that used to escape through the exhaust pipe is now being
converted into mechanical power and transferred to the wheels.
Diesel engines do not react well to LPG fumigation when they are cold.
Turning on the gas before the engine has warmed properly will result in rough
idle and bogging, or lack of pulling power. Let the engine come up to
something near operating temperature before turning on the gas. Another
reason to have a dash-mounted control switch.
Intakeair:
First and foremost, remove any and all possible flow restrictions. Several
low-restriction air filters are available, such as the K&N brand filters.
Increasing the diameter of the intake ducting is also important. On the VW
diesel engines, the "snorkel" which leads into the air filter box
is designed to minimize intake noise ~not~ maximize flow. Converting to a larger
pipe will mean that the engine has less pulling loss, resulting in more air
per piston intake stroke, which means you can stuff more fuel (and/or LPG)
into the engine, resulting in more power. Check out the 3" ducting on my
engine in the photo above in the "Supplying gas to the Intake"
paragraph above. This ducting is fed by a cowl scoop at the back of the hood.
I like to think that I get at least a little boost pressure out of it.
Temperature of the air is also important. Cooler is better. Cool air is more
dense, more oxygen to aid in combustion. The intake end of the pipe leading
into the air filter should be supplied with the coolest air possible.
Usually, this means from either the grille, a hood scoop or under the front
bumper of the car. What you don't want is air that has been warmed
after coming through the radiator, in other words, engine compartment
temperature air.
Turbo engines benefit from installation of an intercooler, which is
essentially an air-to-air heat exchanger that removes the heat produced when
the intake air is compressed by the turbine. Cooler boost air will allow
greater gains in power through increased fueling, either through adjustment
of the injection pump, by fumigation, or both.
Exhaust gases:
Getting rid of exhaust gases
quickly is also very important. Diesel engines do not benefit from controlled
back pressure like gasoline engine do. In all cases, larger diameter exhaust
pipes are better. Low restriction exhaust manifolds, down pipes and mufflers
all add to power and performance, in dramatic ways.
If you are trying for ultimate power, a good old fashioned cylinder head
port-n-polish of the intake and exhaust ports works wonders, as do exhaust
headers.
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- Simplicity is the key to getting
the performance you want out of your truck.
- Our patented design means: No
mixers, sensors, evaporators, or switches to hassle with or adjust.
- Easy installation and
maintenance.
- Cleaner burning fuel.
- Better fuel economy.
- Increased torque and horsepower for towing.
- The Powershot 2000™ Propane
Injection Kit is the perfect addition for your turbo diesel engine to gain
horsepower at an affordable price.
- The Powershot 2000™ is boost
pressure activated, injecting propane into the engine as the boost
pressure of the engine increases producing a throttle control, that you
will definitely feel behind the wheel.
- Safety features such as: Power
switch inside the cab so driver has full control of turning the system on
and off. Fuel lock off valve, stops the flow of propane unless the vehicle
ignition and system is on.
- Fits all FORD, DODGE AND GM TURBO
DIESELS.
- An adjustable orifice allows you
to change flow rates from towing to performance effortlessly in minutes.
- Variable flow rate delivers smooth, steadily increasing power, proportionate to the boost pressure.
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