Lets talk fuel system

[hypersnyper694788]

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[mdub707]

I'm still looking for more info on this too, it seems like the options are limitless on these things!

I think I've got some of the basics, but man there are so many different pump setups, fuel bowl deletes, injectors (differing flow rates vs. actual CC's). Someone should do an extensive write up!

[TEXAScrusin6.0]

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[hpprose]

Originally Posted by mdub707

I'm still looking for more info on this too, it seems like the options are limitless on these things!

I think I've got some of the basics, but man there are so many different pump setups, fuel bowl deletes, injectors (differing flow rates vs. actual CC's). Someone should do an extensive write up!

what do you want to know?

[Granny]

I also have the ITP Reg. Return and AirDog II and am very pleased. I know the RR is not needed but it has been in place for a while. I will offer this tidbit of advice. DO NOT get a FASS. I have had 2 failures and they did not warranty either one of them. I know of at least 3 more failures that were not covered by them either. They do not stand behind their product. It left me on the side of the road more than once and one time it was half-way across the country from where I was going. I was stranded in a hotel room with a dog and a cat for a couple of days before I was able to get back on the road again, NO THANKS to FASS! I love my AirDog II and the install was not a problem according the old man. Ok rant over, back on topic.

[mdub707]

Originally Posted by hpprose

what do you want to know?

Well first, I dont quite understand all the different FASS/Airdog pump numbers... 150/150 95/150, and so on and so forth, kind of confusing. What do they stand for and how do you know what pump to select.

What about the lines coming from the tank to the pump to the motor, when should these be replaced? Do some pumps come with them? At what point are larger lines needed?

[work&play]

I have the ADII 130/75 and an ITP RR kit and they work great.
I had the RR kit then I had to put the pump in.

[hpprose]

Originally Posted by mdub707

Well first, I dont quite understand all the different FASS/Airdog pump numbers... 150/150 95/150, and so on and so forth, kind of confusing. What do they stand for and how do you know what pump to select.

What about the lines coming from the tank to the pump to the motor, when should these be replaced? Do some pumps come with them? At what point are larger lines needed?

Good questions.

FASS has two different series of fuel pumps. The smaller series is called a 95 the larger series is called a 150. That is what the first number represents.

The second number represents the fuel that the pump is rated at. When searching for a Power Stroke pump, make sure you are looking at the pressure rating of that pump. There are high volume pumps that only put at 20 psi or so. That will not work for a 6.0. You need to make sure it is capable of pumping out at least 50 psi at the rated volume you need. I personally like the see the pressure higher but 50 works just fine.

As far as fuel lines sizes go:

The factory fuel lines to the fuel pump and to the fuel filter housing are 3/8". If you are upgrading your fuel pump, you realize that the fuel system cannot support your fuel demand. So, I believe in using the largest lines I can within reason and making sure that everything is matched to flow the maximum amount. Since the fuel rails in the cylinder heads are the smallest point, I like to start there and figure out how big of a line I need. The cylinder heads are drilled out for approximately a 3/8" line. A 3/8" line has an area of .110391" add up the two lines and you get a total area of .220781". So, we need a feed line with an area of .220781 to equal the flow of the lines to the cylinder heads. A 1/2" line has an area of .19625" which is too small. A 5/8" line has an area of .306641", which is larger than the .220781". So, a 5/8" line will work. I'm not going to go into parasitic loss of flow over distance, but just know that the 5/8" line has a lot of room for loss and works well in this application.


Secondly, if your fuel pump is a regulated fuel pump like a FASS or AirDog, the fuel is regulated at the pump, located roughly at the back of the cab, which can be 10 to 20 feet from the furthest injector (by the time it runs the frame rail, up to the engine, around the engine and though the cylinder heads and finally to the last injector. That means the fuel demand is fairly far from the source. So, as fuel demand increases, there can be a slight delay before the regulator senses the increase and increases the volume output. By having a larger line, the amount of fuel on reserve is higher, which can support larger demands in fuel without fuel pressure dropping as much.

This is less important with a regulated return system but you still need a non-regulated fuel pump to take advantage of this