Holley HP EFI MPFI

[cstmwgn]

Any experience / comments with this system?

[dieselgeek]

I use it a lot. I like it - but Holley offers so many features that you might be a little overwhelmed trying to get it working good if it's your first EFI experience. Having a friend or someone who has "done it before" helps a lot. As far as features for the dollar, support, documentation - Holley is near the top of the EFI help in my opinion. Good stuff and great people supporting it.

[oletrux4evr]

You're gonna need wider tires, Allen.

[BBO Javelin]

I run holley hp efi on my 4.8 turbo LS swap foxbody. It was my first experience with aftermarket efi. It was a little bit of a challenge getting it tuned but holley customer support and there forums are very helpful. I also run there boost controller and it works very nice. I ran a 10.08 at 138mph so far and drivability is great. The learn feature is also nice.

[cstmwgn]

... Holley offers so many features that you might be a little overwhelmed trying to get it working good if it's your first EFI experience...

Their literature alone has been a little overwhelming trying to understand how I would actually use all the features they provide.
It is an old naturally aspirated big block - the only electronics on the car is an MSD 6AL and a Duraspark distributor.

There are lots of things I don't understand (yet).
Why do I need to run power to my fuel pump through the ECU? I don't believe modulating the voltage to the fuel pump will change the pressure to the injectors as that should be controlled statically by the regulator. My current fuel pump wiring is good quality (proper sized wires with a relay) and more than adequate for the requirements of the new pump.

I am not sure why I need transducers for the fuel pressure (maybe so it can calculate pulse width based on injector size and fuel pressure) and oil pressure.

The car is not equipped with a knock sensor so I am going to have to figure out why I need one - what value it adds based on the features I am using and how I would add it if it is warranted.

I would have liked to have the ECU manage/control the timing but I have no idea what that involves. I am not familiar with Ford's TFI but would doubt that I would use that instead of something in the aftermarket. Perhaps this is best left for a later phase once I get the base line FI stuff working properly.

I am also concerned about injector size. Using their formulas, I need 52lb injector but it appears that Holley only offers a 48 and a 66. Since I am very concerned about part throttle driveability, I don't want to run too large of injectors. At this point I am leaning towards the 48lbers and perhaps turning up the fuel pressure a tad should my BSFC not be as good as I think or my power level actually be greater than I think (like that ever happens with a gearhead).

Any guidance or reference material would be greatly appreciated.

[BBO Javelin]

I'll try to answer what I know. As far as fuel pump if you are already using a relay all you have to do is use the wire from the ecu to trigger the pump relay. It's nice to use as when you turn on the switch it primes for 5 seconds then shuts off. I use the transducers for my boost,oil,fuel and dome pressure. Makes it easy to monitor through the lap top and can set safety's if certain things like say fuel pressure falls it will pull timing etc. so you don't hurt the engine,same for boost. If you don't want to use knock sensors you don't have to. I use 80lb injectors on my 4.8 and while cruising no boost being made it drives as smooth as a 4.8 in a Tahoe. I'm probably not much help with the ford stuff as I'm dealing with an LS.

[dieselgeek]

You only NEED the following sensors to use the Holley HP:

Coolant Temp (technically optional but a good idea)
Air Temp (technically optional but a good idea)
Throttle Position
Manifold Pressure
Crankshaft Position / distributor trigger / some type of RPM input

The rest are optional. I'd skip the knock sensor altogether. Fuel pressure and Oil pressure are nice because you will be taking data logs and you'll want to know if those degrade at any point.

The Holley should be able to wire right up to a TFI ignition! You will use the "PIP" signal wire as the Holley's tach input, and then you can use either the SPOUT wire to trigger spark in the TFI coil (those are junk) or better, trigger spark in a simple MSD 6AL (or equivalent ignition box, don't need digital or limiters onboard since they are all built into the HP).

Best thing to do is one step at a time. Get it to control your fuel injectors and make datalogs. Then use it to control ignition after those are all sorted.

-Scott

[TheSilverBuick]

Step at a time indeed! Just because you want to or can doesn't mean you need to right now. Get the basics sound, and literally a week or two later you'll be comfortable with the fuel/spark stuff and then start adding the ancillary stuff and build from there.

[cstmwgn]

Thanks for all the input. I am taking notes.

[cstmwgn]

Still gathering information.

Clean Power - what exactly does this mean and how can I measure / verify / clean up my power? My battery is mounted under the car in front of the rear axle. I have 1/0 gauge power cable running from the battery to the engine compartment that terminates in a power distribution block. Is that considered clean power?
Does it matter that there is an in-line 250 amp fuse near the battery?
Does it matter that I am taking power to my amps off of this line before it gets to the engine compartment?

I REALLY don't want to run more wires back to the battery so I am looking for advice / options.

[silver_bullet]

Allen.
I would really tend to think that your power supply should be "clean" enough for the use intended... if there are any questions about interference, run a shielded power wire to the ecu... maybe through a choke if that doesn't work...

[cstmwgn]

Quote from Holley
The ECU main power cable MUST be hooked up directly to the battery posts/terminals. Do not connect the power to starter or some other point other than the battery. The ground needs to go directly to the battery post/terminal. Distribution blocks or remote mount posts with multiple connections are NOT acceptable.

[silver_bullet]

Damn... That's some sensitive stuff!

[dieselgeek]

Still gathering information.

Clean Power - what exactly does this mean and how can I measure / verify / clean up my power? My battery is mounted under the car in front of the rear axle. I have 1/0 gauge power cable running from the battery to the engine compartment that terminates in a power distribution block. Is that considered clean power?
Does it matter that there is an in-line 250 amp fuse near the battery?
Does it matter that I am taking power to my amps off of this line before it gets to the engine compartment?

I REALLY don't want to run more wires back to the battery so I am looking for advice / options.

Holley wants you to run a dedicated power wire back to the battery for the same reasons the OEMs do the same thing - you don't want to share that run with high current devices, which will add "power coupled noise" to that entire leg of 12v. Think of it like water from pipes, you don't want to try to take a drink from a large supply line that's feeding a firetruck, it's going to be full of pressure spikes and waves and weird stuff.

Inline fuses are fine as long as there is very minimal resistance through them.

Your amps - car audio amplifiers? YIKES - run those separate! yes it matters, those are high current and put noise into the entire power system of the car.

This isn't being "sensitive" - the OEMs do the same thing. Bosch Automotive Handbook is my goto book on this topic.

Also, clean grounds. Dedicate a ground run for the ECU and it's sensors. You are also best to have a large gauge cable from battery negative to the engine block! not through the chassis. Then run a separate ground from batt negative to the chassis as well. There are reasons for how the OEMs do this. Don't just "run a ton of grounds from here or there" - understand how much current each ground path in the car had to return to the batt negative. The entire path needs to be able to support that current, and you get bonus points in the form of "no mysterious ignition problems" if you run small dedicated grounds for the "low current" stuff (the ECU, the sensors attached to it), which in this case Holley has done for you already.

[cstmwgn]

Thanks Scott - I will stop whining about the power/ground requirement. I am not really sure how I am going to route it because I believe it can't be bundled with the existing power wires that I already have so I will have to find a new path forward.

On to more questions.

1. Are in-line (not in-tank) WALBRO pumps any good? They seem to be loved by the in-tank crowd. Holley has a new 12-800 pump that they say is a WALBRO. Any idea how loud they might be? Anyone have any experience or opinions about this?

2. Fuel Injectors - with no disrespect to BBO Javelin but my combination is no where near as serious as his is. I am still concerned about 66lb injectors with my requirements as they appear to be ~10lbs more than I need using conservative BSFC and duty cycle factors.
I am looking for other vendors for low-impedance injectors in the 55, 57 or 60 range. So far I have found Accel, AFIS, FAST and TFS. Are there others that I should consider? This thing has to be rock solid reliable as I do drive great distances from home.

Thanks again for all the input.