Holley Sniper EFI Returnless Kit 510-550-510D

[tonycap]

I am going to install in an EFI system on my cobra but had a look through the instruction manual and found that my fuel tank does not have the appropriate connections for EFI.
What I was thinking of doing was to leave the original fuel tank in the cobra and set up some sort of surge or additional tank that will feed the EFI system.
The original fuel tank with be higher than the surge tank so the fuel will flow (by gravity) into the surge tank and the surge tank will have the proper setup (internal fuel pump), return line etc.
Will this type of setup work? To replace the original fuel tank I would need to remove the body so I want to avoid doing that so if anyone has any suggestions for any alternatives that would work.
I would like to use the Holley Sniper EFI Returnless Kit model: 510-550-510D
Currently I am running a Ford 460 engine with a Quickfuel SS-750 carburettor in my cobra but would like the convenience of an EFI system.

[eschaider]

The conversion to EFI is not as simple as it appears at first glance. The Hollry Sniper system is a throttle body speed density system that starts around $1400 for the base Holley kit and depending on the kit can creep up to $1,800 or more.

The Holley system architecture is similar to the 1970's early EFI systems out of Detroit that used throttle body style injectors. Eventually (and eventually may not take as long as you think) either you or the car will outgrow the Holley system and you will want to migrate to a port injection system. That means essentially everything you have bought is unusable, a throw away or sold at steep discount.

It would be to your advantage to go the port injection route initially rather than 'down the road' so to speak. The price will be higher because you will need to source a suitable manifold, injectors, fuel rails etc. but you will eventually experience all those costs anyhow. The big difference is you will not have initially sunk the monies into the Holley system so the conversion will be less expensive by the price of the Holley system you did not purchase.

Holley's system uses a speed density fuel model, which is a very popular EFI fueling model today. Something to remember about speed density systems is that they do not measure air mass they infer it based on a wide range of variables you specify in your tune file and they monitor in operation. Change your air cleaner, your heads, your cam, your compression, your cam phasing, the ambient temperature, the ambient air pressure and on and on and you will need to retune the EFI to get back to the smooth seamless operation you had after initial installation and tune. This is a big deal — especially at current tune prices.

If you use a Mass Air Flow (MAF) fueling model like Detroit uses on all modern EFI systems you don't need to do any of that because a MAF based system directly measures the air mass being consumed by the engine and fuels the engine accordingly. Many if not most of the F-1 cars today use this same system because of its ability to compensate in real time for a wide range of environmental change(s).

You're not F-1 but the same tuning issues apply and the most common are weather changes and altitude changes as the car goes to higher and lower ground. Of course don't forget the silly stuff like air cleaner changes.

Do your wallet a favor and tap the brakes a bit before financially committing to any particular system. Something to keep in mind also is that some EFI manufacturers will produce plug an play EFI systems that literally plug right into an OEM EFI wiring harness.

The OEM harness route brings reliability, robust protection and appropriate EFI signal shielding where required without any effort on your part. The EFI system does not care what size your engine is — you get to specify that during ECU setup. This means that if you think you might want to play around with power adders later, you can get a system that is already setup for power adders and just not enable the feature(s) you aren't using. Later if you want, it is literally a couple of mouse clicks in the ECU setup s/w.

Here is an example of what I was just talking about. It is a aftermarket system offered for supercharged 03/04 Cobra's. It supports, turbos, centris, roots, and screw blowers or no blower at all. It has traction control, nitrous support, engine failsafes for temperature, oil pressure fuel pressure etc. It uses OEM Ford sensors, GM sensors or non automotive commercially available sensors so you don't need to buy OEM sensors that have been repackaged and repriced. Here is a link => 03/04 SVT Cobra Plug and Play EFI.

BTW if you have never built an engine wiring harness, it is an experience you would like to have avoided if you knew in advance the headache that comes with it. P-n-P with an OEM harness has beauty and simplicity that is only visible after you have built your first wiring harness.

Take your time, look around, learn the technology and learn the systems alternatives before you spend your hard earned money. It will save you a few thousand dollars and lots of aggravation. FWIW I use a P-n-P system for all the reasons above.


Ed

[twobjshelbys]

Think of it this way. Speed-density fuel injection systems have to be adjusted to your configuration, and if anything in that configuration changes, you have to adjust.

A carburetor is adjusted to your configuration, and if you change the configuration, you have to adjust.

MOST NOTABLY ALTITUDE!

A speed-density fuel injection system is essentially an electronic carburetor. They have the same amount of intelligence. One is a brick tuned by mechanics, the other tuned by a laptop. But, setting up a carb is a lot less costly in hardware, less costly in setup and less costly in maintenance.

Heed Ed's words of advice. If you aren't going to use a MAF based fuel injection system, stay with carbs.

I see some people setting up their advanced MAF systems using speed-density mode. Build that tune for sea level and put it in in Denver and you're off to a tuner for more expense than rejetting a carb. Use the MAF and (with a properly established altitude compensation table, or nowadays, automatically using O2 sensor AFR feedback) will take care of it automatically.

Good luck.

[Dana E.]

There is plenty of misinformation in this thread. Yes, multiport injection is better than a throttle body, but a modern TBI system is still better than a carb. The Holley Sniper/Terminator systems are self-learning systems. In a nutshell: they don't need retuned if you change your air cleaner or drive to a higher elevation. The Edelbrock ProFlow4 is a speed density multiport system. No, I don't have a Sniper system. Yes, I use both the Terminator and Edelbrock systems. Do the speed density and Alpha-N strategies work? Yes. Will the world end if you don't use a MAF system? Not hardly.

[eschaider]

Originally Posted by Dana E.

There is plenty of misinformation in this thread. Yes, multiport injection is better than a throttle body, but a modern TBI system is still better than a carb.

No one said, suggested or implied a carb was better.

Originally Posted by Dana E.

The Holley Sniper/Terminator systems are self-learning systems. In a nutshell: they don't need retuned if you change your air cleaner or drive to a higher elevation.

Most EFI systems available today offer a self learning capability. The self learning capability is not the same as getting the engine tuned. It will get the engine running fairly well, at least well enough to begin the tuning process yourself or allow you to drive the car to a professional tuning shop.

Originally Posted by Dana E.

The Edelbrock ProFlow4 is a speed density multiport system. No, I don't have a Sniper system. Yes, I use both the Terminator and Edelbrock systems.

Other than having used multiple systems the point you are making is not intuitively obvious..

Originally Posted by Dana E.

Do the speed density and Alpha-N strategies work? Yes. Will the world end if you don't use a MAF system? Not hardly.

The progression of systems sophistication was from early Alpha-N systems to Speed Density and finally to Mass Air Flow systems. MAF based systems are where manufacturers and professional race teams ended up in the natural evolution of EFI systems.

Whether it was Detroit with their EPA mandated emissions limits or the F-1 teams where the smallest edge can translate into a win because of how evenly the cars are matched, MAF based systems are what the people and design teams that could use anything they wanted, ended up using.

While no one is talking about the end of the world, the challenges identified with the Speed Density Systems are real. Does it mean you should not use one? Not necessarily, beauty after all is in the eyes of the beholder.

On the other hand if you are attempting to optimize an engine for power, fuel economy, drivability, emissions (not likely with our crowd) or any of several other metrics the systems that have consistently won the roses are the MAF based systems. Does it mean the others are bad? Not at all. Does it mean the best fueling models are available to you using MAF based systems — absolutely!

There are some scenarios where even if you wanted to use a MAF based system the implementation would be extraordinarily difficult and a Speed Density model would be not just easier but the prudent choice to implement. Examples would be individual runner intakes like the EFI systems that spoof the appearance of Webers. Fitting a MAF to the air inlet path would be quite difficult.

A similar example would be the tuned length Individual Runner EFI systems where the intake runners lay over the opposite cylinder bank. Same problem, managing intake air to a single path through a MAF and then to the individual intake runners. Impossible? No, but quite demanding.

Most IR scenarios are just easier to implement as a Speed Density system. Intake systems that do not employ the individual runner geometry are much easier to implement as MAF based systems.

It is worthwhile noting that MAF based systems include both Speed Density and Alpha-N logic in their code. There is a reason for the inclusion. Each fueling model has particular strengths and can perform some aspect of the engine fueling model better than either of the other two.

When you use a MAF based system you actually have all three systems included in the EFI system's logic. In normal operation the EFI code will switch dynamically between the three different fueling models selecting the best model for the environment at hand.

In the final analysis, Detroit could not meet the strict EPA imposed emissions standards everywhere in the country with a Speed Density system. Similarly in the thin air of F-1 racing the engine designers / developers could not reliably produce optimum power across varying weather, climate and altitude conditions without using MAF based systems.

Even a basic grocery getter with the lowest purchase price point will use a MAF based EFI system because of the EPA imposed mandate to meet very specific emissions targets — everywhere in the country. We, or at least most of us, do not need to worry about emissions. What we do intuitively want however is an engine that will reliably and predictably start in all weather, at all altitudes and in all climates. It should be as reliable and predictable as that grocery getter you drive to the corner in. A MAF based system will do all this and properly tuned, do it in spades.


Ed

[bobcowan]

Originally Posted by tonycap

I am going to install in an EFI system on my cobra but had a look through the instruction manual and found that my fuel tank does not have the appropriate connections for EFI.
What I was thinking of doing was to leave the original fuel tank in the cobra and set up some sort of surge or additional tank that will feed the EFI system.
The original fuel tank with be higher than the surge tank so the fuel will flow (by gravity) into the surge tank and the surge tank will have the proper setup (internal fuel pump), return line etc.
Will this type of setup work? To replace the original fuel tank I would need to remove the body so I want to avoid doing that so if anyone has any suggestions for any alternatives that would work.
I would like to use the Holley Sniper EFI Returnless Kit model: 510-550-510D
Currently I am running a Ford 460 engine with a Quickfuel SS-750 carburettor in my cobra but would like the convenience of an EFI system.

Surge tanks work, and some race cars use them. But they don't work on gravity. You need pressure and volume to fill the tank. Makes for a lot of complexity.

You will be time and money ahead with an inside the tank pump. If you have room, you should consider this: https://aeromotiveinc.com/product/un...si-6-10-depth/

If not, consider replacing the tank with something already set up for EFI.

[cycleguy55]

Originally Posted by tonycap

I am going to install in an EFI system on my cobra but had a look through the instruction manual and found that my fuel tank does not have the appropriate connections for EFI.
What I was thinking of doing was to leave the original fuel tank in the cobra and set up some sort of surge or additional tank that will feed the EFI system.
The original fuel tank with be higher than the surge tank so the fuel will flow (by gravity) into the surge tank and the surge tank will have the proper setup (internal fuel pump), return line etc.
Will this type of setup work? To replace the original fuel tank I would need to remove the body so I want to avoid doing that so if anyone has any suggestions for any alternatives that would work.
I would like to use the Holley Sniper EFI Returnless Kit model: 510-550-510D
Currently I am running a Ford 460 engine with a Quickfuel SS-750 carburettor in my cobra but would like the convenience of an EFI system.

Schematically, I believe what you're proposing would look like this diagram: https://docs.google.com/presentation...it?usp=sharing

I don't know how you'll get the surge tank low enough that it can be gravity fed by the fuel tank, but that could easily be solved by using a low pressure pump to feed the surge tank from the fuel tank (page 2).

[bkozlow]

Look at the FiTech Force Fuel System, FiTech 50004, from Summit or Jegs about $429 and as stated before you can use a low pressure pump to feed the FiTech.

Bill K

[cycleguy55]

Originally Posted by bkozlow

Look at the FiTech Force Fuel System, FiTech 50004, from Summit or Jegs about $429 and as stated before you can use a low pressure pump to feed the FiTech.

Bill K

Edelbrock has a fuel sump kit as well that doesn't require a return line. It's 9.5" long, 3.75" wide and 9" high - small enough to fit in our cars.



https://www.edelbrock.com/adjustable...psi-36031.html

[spdbrake]

The Edelbrock swirl pot does require a return line.
https://edelbrock-instructions-v1.s3...rock/36031.pdf

However the written instructions (all without the need for a fuel return line) contradicting the the diagram instructions (5/16” FUEL LINE (NOT INCLUDED) MUST
BE ROUTED FROM THE SUMP OVERFLOW
VENT BACK TO THE FUEL TANK.)

Once again noted in item 10 & 11 in instructions.

Finally in the last section warning does it really spell out that the return line is a fuel vent line and not constant flow fuel return line it appears.
WARNING!
The fuel sump vent line is a critical part of the Fuel Sump installation. These instructions MUST be followed for safe
and proper system operation. A fuel rated hose must be routed from the vent port (see figure #4) back to the fuel
tank. The fuel tank must also be vented if not originally equipped with a vent line or vented cap. If the vehicle has
a vent line, you can tee into this line. If no existing vent line to the fuel tank exists, you must plumb a new line to a
point above the maximum fuel level of the tank (at the top) or in the fill neck. DO NOT run a vent line from the Fuel
Sump to OPEN AIR in the engine compartment or pointed to the ground. DO NOT run the vent line into any part of the
air intake system. Proper routing of the vent line is not an option. This procedure is mandatory for your safety.
Edelbrock is not responsible for any fires, personal injuries, property damage or any other issues pertaining to
improper vent line routing and or failure to follow these instructions.

[bkozlow]

Maybe someone could tell me why this would not work. It appears your problem is the return line from the regulator. Under your gas cap you should have a flange with a tube for your rubber hose to connect to the gas tank. If you have this remove it, between the flange and where the rubber hose attaches drill a hole for an AN bulkhead straight--90 degree fitting since it is off the car it is best to have it welded in place with the 90 facing down into the tank. Attach an AN teflon hose long enough to go down into the tank close to the bottom. Put it back together and attach your return line to the AN fitting. You didn't have to remove the tank and because you performed all operations on the flange piece off the car there is not a problem with particle contamination from drilling the hole. Use the Holley in line pump and I believe they have a regulator at goes very close to the pump so your return line to the tank would be fairly short. Just a thought.

Bill K

[ERA 626]

https://aeromotiveinc.com/tech-help/phantom/

I used this in my EFI build and it works perfectly... thank me later

[6TNCRZY]

I could be wrong but, I believe the "return line" on the Edelbrock sump is only a vent line and is routed to the fuel tank for emissions purposes only.

[spdbrake]

I think you're correct on the vent, as the FiTech swirl pot I used to have installed the vent line was usually dry but would vent raw fuel if the case pressure deadheaded and rose too high. I had initially left it off but would randomly get a burp of fuel as the engine keyed off.

I later ran my vent line to the existing tank vent line by adding a Tee fitting at the top of the filler standpipe vent pickoff. Much like what bkozlow described in his post.

[Roylerumble]

Bkozlow, I've heard those Phantoms are great, $500.... a bit steep but prob worth every cent

[ERA 626]

Originally Posted by Roylerumble

Bkozlow, I've heard those Phantoms are great, $500.... a bit steep but prob worth every cent

YES THE PHANTOM WORKS GREAT.... a bit steep? wow...no comment

[ERA 626]

look on my build thread CSX 6079... The phantom works better than great, I forget its even there. I have a 482" 650 hp EFI crossram. it performs perfectly even in 100 degree heat. it starts perfectly, idles perfectly and runs perfectly. I seriously dont understand why a lot more people dont use tham... $500 is nothing in comparison the the issues you will have with the wrong setup.

[Imlumpy]

Initially I cringed at the return line prospect . I went with fitech . Moro so makes a nifty item . It’s about a 4 inch long piece of tubing with a return line fitting in it . You cut your filler tube and put this piece in and you’ve got your return line . I’ve put 2,000 miles on the fitech system . Started, ran perfectly . No issues . I bought a system with the force fuel unit . O2 is in tube #4 on the driver side .I’m not a rookie , been a mechanic , owner of a repair shop for twenty years . This was the best improvement I made to the car .and to add, my car is a 428 , aluminum heads , fully built , roller cam , rockers , all the usual build stuff , radical cam . The system has no problem running properly with a lumpy cam and high compression. My experience has been a good one .

[Imlumpy]

This , it’s really simple. It’s just a return line for a fuel injection kit . It doesn’t need to be rocket science .