Fuel System

[bobcowan]

Finally got some time to start working on the roller. The "assembly manual" leaves a lot to be desired. So, I'll be asking a lot of questions.

There's no fuel pump in the car. Since the car will be fuel injected, with a blower, I need something sorta hefty, but nothing outrageous. Edelbrock doesn't really recommend anything more than the stock Mustang pump. But a little extra never hurts.

Anything too big will require some additional wiring, which I really don't want to mess with. But, the car seems to be set up for a carb and distributor, so I'll probably have to re-wire the fuel pump circuit anyway.

First Question: Any recommendations for a good fuel pump that will drop in without a lot of fabrication? I'm not really concerned about cost, I want the best quality available.

Might also need a matching pump controller.

Second question: There is only one fuel line from front to back. Not a big deal, as the stock late model Mustang only uses one line. What kind of fitting is that on the end of the line in the engine bay? It's a flared fitting, but doesn't look like AN.

[eschaider]

Bob, both Walbro and Bosch make excellent in tank pumps that will support well beyond 1000 HP. The pumps are easily installed with one of the hats from Fore Innovations. Here is the link to their hat hardware, click here => Fore Innovations

You need to determine the type of EFI and size of injector nozzles you will need to use. I have attached three files two are XL files one is for a Mac and one is for a Windows PC. They are platform specific fuel system calculators. Select the proper file for your computing platform.

You will also find a pdf instruction file that will help you to understand how to use the calculator. The calculator will allow you to size a MAF properly, in the event you elect to use a Mass Air Flow system. If you elect to use a Speed Density system the Mass Air Flow Calculation will allow you to calculate airflow capacities for intake system components including properly determining the throttle body size your application will require.

On page 2 of the calculator you will be able to size fuel injectors for the duty cycle you intend to deploy and you will also be able to size fuel pump capacity based upon the engine's fuel demand.

The calculator uses a Brake Specific Air Consumption (BSAC) model so you do not need to try to figure out what your Brake Specific Fuel Consumption (BSFC) for the engine you are building might be in order to properly size your fuel system components.

Page 3 of the calculator allows you to select a fuel and its spgr for use in the fuel demand calculation. Page 4 is a conversions page to help you to navigate between different units of measure.

The Fore fuel pump hats can easily be installed in the top of an existing fuel tank. If you elect to run return style you will need to plumb a return line and get a fuel pressure regulator and possibly a pump controller. If you elect to use one of Ford's aftermarket returnless systems then you will not need the fuel pressure regulator or the pump controller.

The Ford FRPP aftermarket systems have a variety of tuning software packages available for them. If you prefer to use a non Ford EFI system I would highly recommend the MegaSquirt 3 Pro system from DIY Autotune. Click here => MS3Pro.

These systems are far from all being created equal and the most popular systems are not always the correct choice. You are beginning a complex process of discovery that will at times be more than a little challenging. When you ask questions that receive answers that are not responsive to your questions or are buried in layers of technobabble, you may well be chasing the wrong system and you are definitely talking to the wrong person.


Ed

p.s. The file sizes for the Instruction pdf and the XL spreadsheets exceed the Forum's file size limits of 38KB so I can not attach them to this post. However I can link to another page where you can down load them to your computer. Here is the link to that page => Fuel System Calculator

[eschaider]

Forgot to comment on the Ford OEM fuel fitting, apologies Bob.

That is a OEM quick disconnect fitting. Actually quite nice in terms of its connect / disconnect mechanics. It's flow capacity is low for a n/a engine of moderate proportions and wholly inadequate for a supercharged engine. Convert to AN hardware — more reliable and available in almost any size you want.


Ed

[bobcowan]

Well, I'm really looking for something more specific to the Backdraft.

This is what the car comes with:


I'd like something that matches this pattern. If there's nothing readily available, then I'll fab something out of heavy alum plate, and then install something like the Aeromotive Phantom system. I'm not a huge fan of Aeromotive, but.......

[bobcowan]

Ohhh, look what I found! I'm liking this.

https://www.holley.com/products/fuel...s/parts/12-133

Who knew shopping could be so much fun?

[spdbrake]

That flange pattern looks like its for a Tanks installation (16 bolt)

Fuel Pumps and Accessories

Summit also sells them
https://www.summitracing.com/parts/tnk-pa-4/overview/

Aeromotive makes the OEM to AN adapters you'll need for the fuel rails. MMR also makes some nice billet fuel rails but you'll have to ask about clearance on the SC housing.
https://www.aeromotiveinc.com/produc...apters/page/4/
Making Connections: Adapting Factory Quick Disconnect Fuel Lines To AN Hose Ends - Power & Performance News

[Morris]

Bob

Will you put one in each corner of the tank???

Morris

[eschaider]

Originally Posted by bobcowan

Ohhh, look what I found! I'm liking this.

https://www.holley.com/products/fuel...s/parts/12-133

Who knew shopping could be so much fun?

Bob,

Here is a larger pic of a current production dual pump Fore fuel hat, click here => Fore Hat Top View. By clicking on the photo it will cycle through other views.

The bottom gasket surface is machined flat. The left circular opening on the top of your tank I suspect is your fuel level sensor. The larger one on the right appears to be an access port. If you built a flat plate that bolted to the existing BDR bolt circle there and had the Ford OEM bolt circle that Fore uses then, the Fore hat bolts right up to your existing tank.

Morris asked an important question about placing multiple pumps on opposite sides of the tank, I suspect for fuel control during cornering. EFI systems and EFI pumps do not like the pump pickups to be uncovered. They require continual submersion. Uncovering either of them will introduce air bubbles into the fuel delivery line that will minimally cause popping and occasional backfiring. Under power with a supercharged engine it will burn a piston.

The fix for the problem is building a diamond shaped baffle (like an oil pickup oil control baffle) around the pump pickup with sufficient depth (~2 -3 inches) that it will keep the pump inlets covered during cornering and less than full tank conditions.

The Hollry system is one of those popular systems that has a few rough edges. One of them is their 60 psi relief valve built into their fuel hat. Injectors are flow rated at 3BAR (43.5 psi). Everyone except Ford runs their base fuel pressure at or above 3BAR. For supercharged applications in particular, you want your fuel pressure regulator to be boost referenced. That means you will end up buying a separate boost referenced regulator to be used down stream from the pumps.

With a boost referenced regulator, as manifold pressure rises and falls so to does fuel rail pressure. The idea is to maintain a constant delta pressure across the injector nozzle to make injector pulse width calculation more precise and AFR more steady — a good thing on a supercharged engine.

If you have 20 psi of manifold pressure you will need 43.5 psi (3BAR) of base pressure plus 20 more psi of fuel pressure to restore the injector delta pressure to 43.5psi. If your system uses a higher base pressure than 43.5 psi then you need to add that to the 20 psi boost pressure in the manifold to get back to your constant delta pressure across the injectors.

A base fuel pressure of 43.5psi and a 20 psi manifold boost pressure puts the fuel rail pressure at 63.5 psi. Remember that 60 psi blow off valve in the Holley hat? It is not only already open but the story gets even worse. If you put a pressure sensor on your fuel rail and another back at the pump and then data logged the two you would see a 10 psi or higher pressure differential between the two test points.

The 10 psi difference between the two test points means that your fuel system has been leaking fuel back to the tank for a long time. EFI systems are constant pressure variable injector pulse width systems. That means that at low speeds, leak not withstanding, you would be OK because your primary fuel pressure regulator would just bypass less fuel.

At high engine speeds, under power, your engine would go lean and you would literally kill one or more pistons in an engine that for all intents and purposes looked to be properly tuned.

Fore has been making those fuel hats for a decade longer than anyone else. He literally invented the methodology for supercharged Fords when his company was called Fore Precision. This is a 12 or thirteen year old Fore hat that I bought when I first built my engine.



In some ways the selection was pretty easy because at that time he was the only game in town. When others saw his success with the product, suddenly there were many competitive alternatives. The sales pitch in the beginning frequently was something to the effect the competitive offering was "as good as a Fore."

Many of the copycat providers have faded away, some have remained. Today the EFI companies have embraced the same fuel hat style for their in-tank pump offerings. The in-tank pumps are almost exclusively built by Walbro, Bosch or TI Automotive. They are the best performing, most reliable fuel pump alternatives available today and they are cooled by the fuel they are submerged in.

Don't get me wrong I have no association with Fore other than to use his products, just like the Walbro, Bosch etc fuel pumps. I have built many supercharged modular engines and these parts simply work without drama — and drama on blown motors turn out to be burnt pistons, heads and yes even blocks.

In the end it is your build and your motor and no one is more qualified to decide what goes in there than your are. Supercharging ups the ante at the check writing table for engine parts. I'm trying to give you enough experience based knowledge so you have a better than average chance of keeping those expensive pieces operating and inside your engine where they belong.


Ed

[bobcowan]

The Fore hat looks like a pretty high quality part. I'll have to take a serious look at that.

I also like the look of the Tanks Inc piece. It looks like it might actually be a simple bolt in component, without having to to fab a base plate. That will save some time. I already have an external pressure regulator, so that's no big deal.

I love choices.

[mln385]

Originally Posted by bobcowan

Finally got some time to start working on the roller. The "assembly manual" leaves a lot to be desired. So, I'll be asking a lot of questions.

There's no fuel pump in the car. Since the car will be fuel injected, with a blower, I need something sorta hefty, but nothing outrageous. Edelbrock doesn't really recommend anything more than the stock Mustang pump. But a little extra never hurts.

Anything too big will require some additional wiring, which I really don't want to mess with. But, the car seems to be set up for a carb and distributor, so I'll probably have to re-wire the fuel pump circuit anyway.

First Question: Any recommendations for a good fuel pump that will drop in without a lot of fabrication? I'm not really concerned about cost, I want the best quality available.

Might also need a matching pump controller.

Second question: There is only one fuel line from front to back. Not a big deal, as the stock late model Mustang only uses one line. What kind of fitting is that on the end of the line in the engine bay? It's a flared fitting, but doesn't look like AN.

Edelbrock has this set up >>>> Universal EFI Sump Fuel System Kits - E-Street - Edelbrock, LLC.

[bobcowan]

Heard back from BDR about the pump. As it turns out, the Tanks, Inc PA-4 and PA-6 is a drop in part for this tank. The bolt pattern is made for that part. I'll order one of those.

The Edelbrock SC is designed to use the stock sized single returnless fuel line. I don't plan on running a lot of boost, only 4-5 pounds or so. So I'll probably just do that. The racer in me wants to run two lines. But that's probably a lot more than this car really needs. The car already has a 3/8 hard line installed.

[bobcowan]

UPDATE: I'm always annoyed when some one asks a questions, gets help, and then never supplies the final answer. So, here's how it ended up.

As you know, the BDR comes with one 3/8 steel line installed from front to rear. And it has the aluminum tank installed, with the big hole in it as pictured above. That hole is specifically designed for the Tank's Inc. pump. To the left of the hole, there's a centroid type fuel level sender. That's important to remember later on.

The fuel pump hanger is designed to have a small collector that sits on the bottom of the tank. You have to adjust the hanger for the proper depth. It's easier if you remove the fuel level sender and use a mirror. The it bolts together with one bolt. Never being satisfied with that one bolt, I welded it all together.

It's a tight fit in there. And there's a small shelf inside the tank that interferes with the collector. So I notched the bottom to make it all fit together. In retrospect, it would have been easier to just shorten it. And then I had to cut a notch in the top for the fuel sender. All in all, it took a lot longer than it should have.


It retrospect, it probably would have been a lot faster and easier to a Holley Hydramat and skip the collector altogether.


Once everything was all in the tank, it needed to be plumbed into the stock 3/8 fuel line. The Coyote engine and Edelbrock supercharger are designed to use a single fuel line. Since I'm not racing this car, I'll use that for simplicity.


I was tempted to use a Corvette fuel filter and pressure regulator. Simple and cheap. But I wasn't sure they would flow enough. I used a Aeromotive part. I also installed a 10 micron fuel filter in an easy to access location.


I connected the regulator to the hard line with a short piece of rubber hose. Not ideal, but sufficient. To be honest, I was tired of messing with this, and ready to move on.

All in all, this took a lot longer than it should have. I was told it would come with an EFI fuel pump installed, and was surprised to see an empty hole.

[bobcowan]

UPDATE: I'm always annoyed when some one asks a questions, gets help, and then never supplies the final answer. So, here's how it ended up.

As you know, the BDR comes with one 3/8 steel line installed from front to rear. And it has the aluminum tank installed, with the big hole in it as pictured above. That hole is specifically designed for the Tank's Inc. pump. To the left of the hole, there's a centroid type fuel level sender. That's important to remember later on.

The fuel pump hanger is designed to have a small collector that sits on the bottom of the tank. You have to adjust the hanger for the proper depth. It's easier if you remove the fuel level sender and use a mirror. The it bolts together with one bolt. Never being satisfied with that one bolt, I welded it all together.

It's a tight fit in there. And there's a small shelf inside the tank that interferes with the collector. So I notched the bottom to make it all fit together. In retrospect, it would have been easier to just shorten it. And then I had to cut a notch in the top for the fuel sender. All in all, it took a lot longer than it should have.


It retrospect, it probably would have been a lot faster and easier to a Holley Hydramat and skip the collector altogether.


Once everything was all in the tank, it needed to be plumbed into the stock 3/8 fuel line. The Coyote engine and Edelbrock supercharger are designed to use a single fuel line. Since I'm not racing this car, I'll use that for simplicity.


I was tempted to use a Corvette fuel filter and pressure regulator. Simple and cheap. But I wasn't sure they would flow enough. I used a Aeromotive part. I also installed a 10 micron fuel filter in an easy to access location.


I connected the regulator to the hard line with a short piece of rubber hose. Not ideal, but sufficient. To be honest, I was tired of messing with this, and ready to move on.

All in all, this took a lot longer than it should have. I was told it would come with an EFI fuel pump installed, and was surprised to see an empty hole.