EFI Recommendation
 

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!


Sent from my iPhone using Tapatalk

pro flo 4 is the way to go, super close to firing mine up

Using the Sniper with timing control. After the initial set-up and gremlins (not associated to the Sniper) I am extremely happy with it on my 455.

I've had good luck with Fitech.
My next build is going to have the Pro-Flo 4 system on it, if Edelbrock ever gets my 100# injectors in stock.

Since you're already using a Performer RPM, that kind of takes out the Pro Flow 4 from the equation, unless you're cool with selling that and running the torker ii the system is designed around.

The FiTech and Holley Sniper units are near as makes no difference, identical from a hardware perspective. They both use off-shore GM sensors and I'm all but certain that the ECU's are similar if not identical. It honestly would not surprise me at all if the same plant in China builds them. The software is different however and there are positives and negatives in both directions but IMHO the software edge goes to the Sniper simply because it has a larger VE table.

Specifically for timing control, I would choose Holley, simply because you can get their integrated modules that make it a breeze to setup. The FiTech is not hard to get setup for timing control, but it's not as straight forward as the Sniper.

Bottom line, you can't really go wrong with these three offerings. The biggest thing that you need to consider is what may be wrong with the car now that the carb doesn't care about, but that EFI will. Is the car wired and grounded well? Are there vacuum or exhaust leaks?

Additionally, don't cheap out on the fuel system. Buy a new tank with an internal sump, put a quality fuel pump in the tank and run the lines you need/want. The fuel system supports the EFI, if you can't give it constant, stable fuel, it'll never run correctly.

What HP rating do you suggest given my 400 build spec?


Sent from my iPhone using Tapatalk

What HP level does your Sniper support? Thanks


Sent from my iPhone using Tapatalk

Thanks, what HP rating do you recommend based on my 400 specs?


Sent from my iPhone using Tapatalk

Agreed 100 percent with JLMounce. Switching over in my 1976 from carb to EFI was well worth the effort for me, but as mentioned, Gremlins demanded patience. For me it was mostly grounds and wiring-MSD box-coil positioning, attention to detail, and proper wire connecting. To clean the current I also ran it through a MSD75643 Solid State Relay. Just took time and process of elimination. But grounds were key. Even good looking old grounds need to be pulled off and cleaned. For timing control, I already had a Pro-Billet dizzy so all I hade to do was swap to an adjustable rotor for phasing (MSD84211). Fact is, installing it was relatively quick, working through the gremlins on an old car took the time. But, others have no hassles. On your HP question, I have about 575 or thereabouts.

You need the standard 600hp models for either the Sniper or Fitech. Timing control at least in the FiTech line doesn't exist on the GoStreet 400hp model.

The Pro Flow 4 should support about 500 hp with it's supplied injectors. I think you'd be fine there, but you'll likely be running them around 80-90% duty cycle so you'd effectively be capped there for future expansion without an injector change.

I'm making these assumptions at around 450-470hp for your build.

I hear you on the Gremlins, having totally dismantled the car and now reassembling I’ve encountered several “3 hour projects” on what should have been simple fixes. Appreciate the input.


Sent from my iPhone using Tapatalk

The recommendations so far are good if you're bolting something onto the RPM intake. Just make sure of all your long term goals. Such as, will you want mpfi (injector per cylinder, batch or sequential), will you want coil per cylinder at some point etc. I started off with the FAST ezefi which worked well. But later decided I wanted to try my hand at sequential fuel and spark. A standalone ecu allows for many options. Buy once cry once basically. FWIW

If you want to over-build for more power or future proof, the Sniper Xflow says it can support upwards of 800 HP.

I run a Pontiac 24x setup. Coil packs , multiport, ect. It can do transmissions also depending on what ECU you run. Currently I run a Gen 3 LS ecu.
Here's a video of it in operation. Send me a PM or use the contact info in the video for more info.

https://www.youtube.com/watch?v=vhTHRymPSlM

I dont have any experience with an "electronic carb", but I have some experience with MPFI. People I've spoken with and worked with that have used kits like Snipers and FITech's have sold them and gone MPFI in the end and ended up with way better drivability and economy. Watching this Haltech video on transient fueling (https://www.youtube.com/watch?v=DMT9kVO7fUU), it will help you understand why MPFI helps with throttle response and drivability. Most ECU's these days will take a locked distributor input signal, but you'll be left with a batch fire injection system. To get the best benefit of an EFI system, sequential is the way to go. Coil per cylinder is even better because you don't have to worry about things like distributor phasing or needing to use an MSD spark box to get enough spark from a single coil at higher RPM's where inductive coil's don't have enough dwell time. My 2c.

EFI system
 

I went pro Flo 4 too, so happy so far

Damn - that is super cool!