Fuel Cooler
- Thread starter WisconsinHick1
- Start date
So this may be a dumb question to ask here but how should I be plumbing my fuel cooler? I've got a regulator underhood for my fuelab returning all the unused fuel as well as my injector/cp3/relief returns.
Should I plumb the regulator return (-10) through a cooler or the injector/cp3/relief returns (-8)?
Should I plumb the regulator return (-10) through a cooler or the injector/cp3/relief returns (-8)?
I would install the cooler on the return line just before it goes into the tank. The fuel in the tank does most of the cooling anyways. The more fuel in the tank, the cooler the fuel will be.
Correct, but I have 2 return lines with this fuel setup. I am using a fuelab prodigy setup going to a regulator underhood that is setup on its own return as well as a separate line for all of my high pressure returns.
I'm guessing I'll see more benefit installing it on the return line from the 2x cp3s/injectors/relief valve than I would on the regulator return circuit.
I'm looking at going with a Derale stacked plate cooler with a fan wired to be on when the key is on. It isn't a daily driver, 1-3 times a week. Mainly sled pull and will be hitting the strip with it.
I can’t imagine that fuelab pump will be adding much heat to the fuel. I would just return it right to the tank and run the CP3 and injector returns through the cooler to knock some heat out before dumping into the tank.
That was kind of my thought since its a vane style pump set at lower psi (10-12, whatever it lets me idle properly at when the truck is running).
I've been looking into this more and just bought a fuel temp guage I'm going to mount in the truck. Where is everyone putting the temp sensor? Supply or return?
The fuel inlet temperature has a significant influence on the performance levels
of internal combustion engines, and this is particularly true for
diesel engines. As a result, many passenger car manufacturers
take this into account and incorporate a fuel temperature control
system into their high-performance, latest-generation diesels.
HSDI passenger cars are utilized around the world, often operating in extremely high and low ambient temperatures. As a consequence, the engine's power and torque levels can be reduced to such an extent that the machine's performance is severely limited.
Decisive for these requirements are the results of optimizing air intake, engine breathing, fuel injection and combustion chamber geometry, all of which affect the combustion process. Diesel
engine development concentrates on such aspects as varying the shape of the combustion
chamber and the size of the piston bowl in conjunction with precise control of
the fuel injection timing, pressure and quantity. Particular progress has been achieved
with electronically controlled engines, and, in the process of minimising gaseous emissions,
it has been possible to maximize performance levels.
The conflict of interest which engine developers are often faced with is how to improve
one particular criterion without negatively affecting others. An efficient combustion
process requires a homogeneous mixing of the charge air and the injected
fuel. This process is assisted if the diesel fuel is heated.
A higher fuel temperature improves the diesel fuel's fluidity (kinetic viscosity),
which is important for the injection process and the mixing characteristics. An improved
kinetic viscosity lends itself to an optimum formation of the injection spray,
which in turn leads to reduced gaseous emissions, significantly influenced by the
evaporation properties of the injected diesel spray.
With a starting point of 100 % power with the reference fuel temperature
of 45 °C, without cooling, without heating, HSDI engine performance values decrease
or increase, as the fuel temperature rises or falls respectively.
Of particular interest is the initial fuel heating of 10 °C from 45 °C to 55 °C,
Which leads to a significant performance reduction of 7.5 %. A drop in the diesel fuel inlet temperature from 45 °C to 25 °C results in a performance increase of 5 %, and raising the fuel temperature from 45 °C to 80 °C leads to a performance reduction of 14 %.
Performance continuously falls by 19 % with rising fuel temperature
(from 25 °C to 80 °C), but the fuel consumption remains constant throughout.
The injected fuel volume falls with rising temperature, which is the direct result of a decreasing diesel fuel density with rising temperature. The lowest fuel consumption occurrs at a fuel temperature of 45 °C. As mentioned above, this is the reference temperature
used in the diesel engine industry for establishing combustion processes.
The injected energy quantity continually falls with rising fuel temperature, from 25 °C to 80 °C.
The specific fuel consumption also stays relatively constant, the best point being at
25 °C fuel temperature and increasing insignificantly up to 45 °C. Compared with
the absolute fuel consumption, the lowest calculated specific fuel consumption occurs
at 25 °C, as a result of the power increase of 5 %.
HSDI engine fuel temperature tests demonstrate clearly that
changing the fuel inlet temperature from the standard temperature of 45 °C has a significant
effect on performance levels. From 45 °C to 80 °C, the power drops by 14 %, and
when the fuel is cooled from 45 °C down to 25 °C, performance increases by up to 5 %.
With this fundamental characteristic (increasing fuel temperature results in decreasing
engine performance) fuel consumption does not decrease at the same rate, but remains virtually constant. The reduction in engine performance with increasing fuel temperature is predominantly
due to the accompanying decrease in fuel density, which in turn results in reduced injected
fuel quantities and therefore energy content. The combustion process in the engine clearly is less efficient at higher fuel inlet fuel temperatures.
State-of-the-art HSDI passenger car engines are developed with a standard reference
fuel inlet temperature of 45 °C.
I found this on a TDI forum browsing around the other day and it's what got me thinking more about fuel temps
of internal combustion engines, and this is particularly true for
diesel engines. As a result, many passenger car manufacturers
take this into account and incorporate a fuel temperature control
system into their high-performance, latest-generation diesels.
HSDI passenger cars are utilized around the world, often operating in extremely high and low ambient temperatures. As a consequence, the engine's power and torque levels can be reduced to such an extent that the machine's performance is severely limited.
Decisive for these requirements are the results of optimizing air intake, engine breathing, fuel injection and combustion chamber geometry, all of which affect the combustion process. Diesel
engine development concentrates on such aspects as varying the shape of the combustion
chamber and the size of the piston bowl in conjunction with precise control of
the fuel injection timing, pressure and quantity. Particular progress has been achieved
with electronically controlled engines, and, in the process of minimising gaseous emissions,
it has been possible to maximize performance levels.
The conflict of interest which engine developers are often faced with is how to improve
one particular criterion without negatively affecting others. An efficient combustion
process requires a homogeneous mixing of the charge air and the injected
fuel. This process is assisted if the diesel fuel is heated.
A higher fuel temperature improves the diesel fuel's fluidity (kinetic viscosity),
which is important for the injection process and the mixing characteristics. An improved
kinetic viscosity lends itself to an optimum formation of the injection spray,
which in turn leads to reduced gaseous emissions, significantly influenced by the
evaporation properties of the injected diesel spray.
With a starting point of 100 % power with the reference fuel temperature
of 45 °C, without cooling, without heating, HSDI engine performance values decrease
or increase, as the fuel temperature rises or falls respectively.
Of particular interest is the initial fuel heating of 10 °C from 45 °C to 55 °C,
Which leads to a significant performance reduction of 7.5 %. A drop in the diesel fuel inlet temperature from 45 °C to 25 °C results in a performance increase of 5 %, and raising the fuel temperature from 45 °C to 80 °C leads to a performance reduction of 14 %.
Performance continuously falls by 19 % with rising fuel temperature
(from 25 °C to 80 °C), but the fuel consumption remains constant throughout.
The injected fuel volume falls with rising temperature, which is the direct result of a decreasing diesel fuel density with rising temperature. The lowest fuel consumption occurrs at a fuel temperature of 45 °C. As mentioned above, this is the reference temperature
used in the diesel engine industry for establishing combustion processes.
The injected energy quantity continually falls with rising fuel temperature, from 25 °C to 80 °C.
The specific fuel consumption also stays relatively constant, the best point being at
25 °C fuel temperature and increasing insignificantly up to 45 °C. Compared with
the absolute fuel consumption, the lowest calculated specific fuel consumption occurs
at 25 °C, as a result of the power increase of 5 %.
HSDI engine fuel temperature tests demonstrate clearly that
changing the fuel inlet temperature from the standard temperature of 45 °C has a significant
effect on performance levels. From 45 °C to 80 °C, the power drops by 14 %, and
when the fuel is cooled from 45 °C down to 25 °C, performance increases by up to 5 %.
With this fundamental characteristic (increasing fuel temperature results in decreasing
engine performance) fuel consumption does not decrease at the same rate, but remains virtually constant. The reduction in engine performance with increasing fuel temperature is predominantly
due to the accompanying decrease in fuel density, which in turn results in reduced injected
fuel quantities and therefore energy content. The combustion process in the engine clearly is less efficient at higher fuel inlet fuel temperatures.
State-of-the-art HSDI passenger car engines are developed with a standard reference
fuel inlet temperature of 45 °C.
I found this on a TDI forum browsing around the other day and it's what got me thinking more about fuel temps
I ordered a isspro guage to match what I have, I can wire it right to the factory sensor?
Only if the gauge is compatible with the factory sensor. Check with isspro.
If you are wanting to add an additional sensor I would put it post fuel cooler. That way you can compare temps with the factory sensor and actually see how poorly of a job the factory cooler does.
I'm bringing this back up, I have my fuel temp guage but haven't installed it. Where should I put it? I have a fuel sump should I use the drain hole for the temp sensor? That will give me tank temps and I could compare with the factory sensor on the return. Or I can put it under the hood before the cp3. I just don't see temps changing a whole lot from the tank to the motor. I can see return temps being higher as the fuel is coming from the cp3 and injectors.
On a stock setup the tank does most of the fuel cooling. Remember that the lower your tank fuel level the hotter the fuel. If it was my truck, I'd want the gauge sensor after factory cooler return. It doesn't matter where you put the cooler. When I sell my 6 speed trans cooler, I suggest taking the old cooler and flipping it up above the trans cooler and route the fuel into it before the factory filter. I wouldn't even drain the atf out of it. Can't hurt it. It works and it's free. I've done a lot of testing on fuel cooling.
You would put it in the return between the cooler and tank? What about the tank itself? I'm trying to understand what is more important, fuel return temps or the temp of the fuel heading to the cp3. That's why I thought about the sump. I'm glad you replied as I know you have done alot of work with this
There is only one, maybe two, sources of heat in the truck that you can control/cool. One is the engine returns (injectors, cp3, relief valve) and the other is a lift pump (if you have one installed). The engine returns is what needs to be cooled.
If you are going to monitor temps I would monitor the fuel going to the inlet of the CP3 as that is what you're concerned with.