EFI Recommendation for 400
 

Hi, Im looking for EFI recommendations for my Pontiac 400 build. I want timing control and like the integrated ignition options available from Holley, but interested in forum experience. Some specs on my engine setup to establish right EFI spec:

*400 bored +.030 to 406
*10.35:1 compression
*TRW forged pistons +.080 dome (net chamber volume 6cc milled)
*Bullett Cam - Grind#280/292; Duration at 050”-228/234;Gross Valve Lift-.510”; Installed with +4*Advance
*Kaufman Racing heads - 85cc chambers - 2.11/1.66” Valves
*PRW Roller Rockers - 1.52” ratio
*Edelbrock Performer RPM intake
*RA manifolds and Pypes 2.5” X-pipe exhaust with Turbo Flow mufflers

Thanks!
70’ Formula 400

I have full engine management system for Pontiacs. Runs any ecu. Currently I run the Gen 3 LS ecu.
Works great.


Here's a video of it in operation

https://youtu.be/vhTHRymPSlM

Pm or use contacts in video for more info

Sent from my LG-G710 using Tapatalk

So far I am happy with my Edelbrock Pro Flo 4.

I only have experience with Holley and here is my advice for anyone contemplating an update to fuel injection on their old muscle car:

1) If you go with a Holley FI system, secure the full instructions off the Holley website rather than the Quick Start guide that comes with the Sniper. I read the entire 75 some pages several times.
2) Get a dry erase board and plan out your wiring.
3) Get the car as close as possible to the way a new, fuel injected car would be setup. Clean output modern alternator (not some '60s-'80s era SI model). Computer connected to directly to the battery and switched on by a relay isolating the Sniper from the rest of the electrical system. Put some care into routing any input sensor (coolant, WBO2 & handheld) wires around other wires. I added ferrite beads and RFI tape around these wires for good measure.
4) No modern car runs an external fuel pump and there is a reason.
5) Your 40-50 year old wiring harness is probably not going to cut it. Be prepared to do a lot of rethinking of your electrical. Holley's marketing makes it sound like a four wire hook up and you're good to go. While that may work for some, now is probably the time to do some updating to avoid future headaches. Most of these retrofit systems have basically zero diagnostic ability and you are your own code reader.....except with no codes to read.
6) Whatever problem you have with your existing engine is not going to be fixed by fuel injection. The problem will likely be worse and you now will be chasing that in addition to a fuel injection system that isn't able to work properly due to the underlying issue. Run a compression or leakdown test, put new plugs, wires, cap and rotor in it and set the timing correctly before starting your Sniper install.

^^^ very well put!

There are many ways to "inject" a car.
1st. BUDGET be honest about how much you are going to put into it.
2nd Multiply your BEST $$$$ estimate by 1.5 (thats what it will take to actually do it)
3rd There are several "self tuning" types out there that work wonderful but each has its own pros-cons.....so RESEARCH

Having gone through the challenge of adding EFI I couldn't agree more with the above points. I used the Sniper, but the gremlins were old car issues not the unit (they all seem to be good - and should be at this point in the development game). Gremlin chasing was the game for me, and Formula8's list is bang on. Just for added notes - I didn't have to change out the alternator (using an OEM style Power Master) but ferrite beads would have been next on my list. Never thought about the RFI tape so swapping to the Moroso Blue Max Spiral Core Spark Plug Wire Set did the job there. It has been running flawless since, but before the gremlins were solved the car would randomly die out with all sorts of error messages on the hand-held. I might add one of those guardian bells, I don't have RFI problems with my Twin Cam :>)

I put a “Powerjection” unit from retrotek (sp?) on my 462.
Had to replace every sensor and sending unit except the ecu because what they included in the kit was garbage but it runs pretty good now that it’s been completely re engineered. I heard rumors these clowns are selling yet again under a new name (v3) because they are in hiding from their original garbage.( maybe fitech??)
Using a stealth in tank pump and a return system.
Would like to take it all off and go to a system that adjusts timing and such but that’s for another time as life is currently in the way.
If you get the right system, and keep the proper perspective, it’s a great alternative to the carb for the weekend hotrod crowd.
My 2 cents.

We did a holley super sniper 8 injector on my 571 cu pontiac and my son's 454 chevelle, good units.

Forgot to add, pin-out and remove any wires from the injection system that you are not going to use. Do not just coil them behind the engine or whatever and call it done.

I use them all lol.

I have a Sniper Stealth and timing control that is going on my 461

Wow - on my regular Sniper I removed l but two wires from the 10-pin connector

Wow, nice clean car. Do you have more details on your setup?

FAST XFI Sportsman on my '73. It uses the same throttle body as the EZ 2.0 system, but the ECU is different - fully tunable, fuel & spark. I've installed EZ 2.0's on a few cars and they have all ran great, but I wanted to be able to fine-tune my motor to a higher degree. I also wanted a deeper understanding of how the various tables work. SO much nicer, being able to change fuel and spark characteristics from a laptop, rather than bent over a hot engine!

My LS tuning buddy sat in on my recent chassis dyno testing. He thought it was funny that I was only hitting about 46% duty-cycle on the injectors. I was putting ~315rwhp at that point, so that means the throttle body should support 600+rwhp.

Yep, Left them all in, and use most all of them. Only wires not used currently are for timing control, and they are in the harness ready to be used should we choose to lock out the MSD and switch to electronic control.

No big deal, they are in the bundle anyway and can't be seen. It's not like they are coiled up behind the engine somewhere.

Never did the modern alternators on either car, just kept the stock stuff with external voltage regulators, never wrapped any wires in RFI protection stuff. Just ran the harness neatly with good connections and good grounds, good plug wires on the cars etc..... Never a single RFI issue with either car. Both EFI units have run perfectly for the last year since install. I think cars that have problems in this area probably already had issues and the owner just wasn't aware. EFI will bring out those issues and magnify them 10 fold.

I will say a good fuel system is a must. Both cars already had big in tank fuel pumps and 1/2" line to and from already in place when running carbs, so the EFI switch was pretty easy with a fuel system already in place to support it.

I'm not a fan of external pump setups or reservoir tanks or any of that. Cheap way to get up and running but not a good long term solution.

Which EFI direction you decide to go is based a lot on which intake manifold you have, whether you want to change it, and how much you want to spend. Throttle body EFI's are hugely popular, I see 10 of those for every multiport setup. I like the multiport stuff but you'll get more involved with the swap and it changes the appearance a bit. Just depends on what you want.

I've enjoyed this part of it as well. We are the type with the desire to fine tune everything. The Snipers do the same if one bothers to hook up the laptop and dig into all the tuning features. Most let it self tune and never get farther than the touch screen but there is so much more to be had with a laptop. The datalog is also a sweet feature. Can't say enough how nice it is to play that back and see what's going on during a run, and tweak. Very much like my LS tuning days.

Quoted and bolded because people should read it again.

I've had my FiTech in service for about 25,000 miles now. The FiTech on my wife's chevelle has been in service about 8000 miles. I've spent time on FiTech and Sniper boards and the vast majority of problems people complain about with those 2 systems specifically come down to two things.

1. A car that had problems to begin with that were masked by the carburetor
2. A piss-poor installation, poor attention to detail, rats nests of wiring and half assed "save-a-buck" fuel systems.

EMI issues with these systems for the most part don't start to crop up until you start working with the timing control features. You have signal wires that are necessarily very close to coils, plug wires and other power wires. This is where planning your wiring comes into play.

Power wires should never run parallel to signal wires. If they have to cross, they should do so at a 90 degree angle. The car needs all of it's grounds. Battery to block, block to body, body to chassis. Although the units ground the ECU to the throttle body internally, it's typically a good idea to ground the throttle body to the chassis as well.

Neither the Sniper of FiTech with it's onboard ECU provides the lengths of harness necessary to do a truly clean install without looming power and signal wires together. The vehicle side of the harness specifically, you should plan on extending the wires as needed. A good plan of action is to run signal wires on one side of the engine bay and power wires on the other.

Did I mention grounds?

That's how I did it. Basically the power wires exit the unit towards the passenger side of the firewall and run towards the battery on that side of the car, hidden in the inner fender.

The signal wires, like the 02, the cable for the touch screen, the temp and oil pressure sensors, as well as the fuel pressure sensor sending info back to the unit all exit towards the driver side firewall and pretty much stay on that side of the engine comparment.

Pretty simple really.

Unfortunately it all comes out of the back of the unit right at the distributor on the engine, but there is nothing you can do about that other than try to split it and keep some distance as much as possible. Hasn't seemed to matter on either car though.

All the comments about having a rock solid foundation as a starting point are dead on. Here's a link to a very good book that explains all this in good detail along with answering the "why".

https://www.amazon.com/Performance-F...52630633&psc=1

And it covers many aspects of efi. I read it cover to cover several times before beginning my stand alone ecu project, which I detailed in a thread here in the street section of the forum. Whatever system you end up using, follow the advice about solid fundamentals.