Sniper EFI On Dual-Plane Intake

[Nova]

Hi, I had issues with Edelbrock running good one day, and running like crap the next. So I have Sniper EFI & Tanks Inc fuel system on order. This is for a new Vortec 350 stock, but has headers, no cats & mufflers. Also has an Edelbrock RPM that I had the center section milled down 1/2 inch like the Air Gap. It brought the fuel ratio from being 12.9 (pass side) & 11.9 (driver side), to 12.3 (pass side) & 12.0 (driver side) with the Edelbrock carb on it. But had a bad stumble like for 5 seconds before picking up with the Edelbrock, so that's why I ordered the Sniper EFI. I have the RPM on a stock engine because I plan to get a bigger cam once the warranty is up. My question is, how good does the Holley Sniper EFI work with dual-plane intake? I hear the Terminator EFI doesn't like the dual-plane at all.

[cmyer]

We have had great success with the many customers running a Holley Sniper EFI System with a dual-plane manifold. I don't think you'll have any problem.

[Danny Cabral]

Of course, use the appropriate intake manifold type & model for your engine application/combination.
http://documents.holley.com/199r11193.pdf (Holley Sniper EFI Quick Start Manual - Read page 2.)

[rel3rd]

My question is, how good does the Holley Sniper EFI work with dual-plane intake? I hear the Terminator EFI doesn't like the dual-plane at all.

With the center divider not in the way, they work great. Here's how my Sniper EFI works with my Weiand Stealth dual-plane: https://youtu.be/vjFK18vmfsw. LOL.
I have a wideband O2 sensor on the left side, and the Sniper EFI wideband O2 sensor on the right. They are always in sync with each other, regardless of load or RPM.

[Jay@HAP]

Engine Masters did an episode where they did a carb/EFI comparison where they used the Sniper EFI. They had all sorts of problems and it ended up being some sort of airflow/fuel distribution problem with the dual-plane intake.

[Danny Cabral]

It's already been discussed several times on this forum. It was simply the wrong intake manifold for the engine combination.

[bingo2]

My Sniper EFI works great on a dual-plane Air-Gap; although it's on a Ford engine.

[eDecisions]

I'm just sharing my experience. I was running a dual-plane air-gap, could not get a smooth idle, off idle hesitation, poor fuel economy, and would not tune very well. I called Holley and learned the following: The Sniper has 4 injectors, they fire at random, the Sniper has no ability to add or increase fuel based on the left bank or the right bank, it reads only the one WBO2 Sensor and either takes away or adds fuel. The best option is the single-plane.

Today is 1/23/18, I installed my single-plane one week ago on 1/16/18, I've driven about 30 miles after the change, and here's what I noticed:
1: Off idle hesitation gone.
2: Idle quality, near new car.
3: Fuel smell gone.
4: MPG about 5 MPG better.
5: Learn with the dual-plane 25% to 30%, single-plane -3% to +3%.

I suggest the single-plane, works great, and best ride. If you're a race car driver stick with your dyno, if you drive the streets single-plane.

[rel3rd]

So one week & 30 miles, and you've had miraculous results? LOL.

[Danny Cabral]

I know many successful dual-plane Sniper EFI users. It was probably the wrong intake manifold application.

[eDecisions]

I know many successful dual-plane Sniper EFI users. It was probably the wrong intake manifold application.

I had noticed the difference within seconds of starting the car. The manifold was correct, it actually seemed to drive "OK" on the dual-plane, and that's my point. I did not want "OK", I wanted a new car feel with TBI/EFI. What I'm sharing is from a call to Holley and they way the injectors work. I noticed the difference the moment I started the car the fist time after the manifold switch. If anything, the single-plane I put on is rated much higher RPM range. The dual-plane was rated from IDLE up, the single-plane was rated 2000 up.

Unlike a carb, the Sniper randomly fires the injectors, maybe left bank, maybe right bank, and if your running dual-plane, the Sniper can't choose which bank to add more fuel to, it just randomly fires, call Holley. It's amazing how may users want to argue theory when presented facts. Argue for your limitations, and sure enough they're yours.

[Matt]

I had noticed the difference within seconds of starting the car. The manifold was correct, it actually seemed to drive "OK" on the dual plane, and that's my point, I did not want "OK" I wanted a new car feel with TBI/EFI, and what I'm sharing is from a call to Holley and they way the injectors work. I noticed the difference the moment I started the car the fist time after the manifold switch, if anything the single plane I put on is rated much higher RPM range, the dual-plane was rated from IDLE up, the Single Pane was rated 2000 up.

Unlike a carb, the sniper randomly fires the injectors, maybe left bank, maybe right bank, and if your running dual plane the sniper can't choose which bank to add more fuel to, it just randomly fires, call Holley. It's amazing how may users want to argue theory when presented facts, Argue for your limitations, and sure enough they're yours.

I would like to state, so misinformation is not spread, that the Sniper injectors do not fire "randomly". There is an injection strategy for the Sniper EFI injectors.

We have done extensive testing here at Holley, the Sniper EFI works well on both Single & Dual-Plane intakes. The thing about TBI injection, is it still requires the fuel to be distributed through the intake manifold. Lots of dynamics can effect the distribution of air & fuel into each cylinder, however, the Sniper EFI was designed to be used with both dual & single-plane intakes. Snipers test with success on both Single & Dual-Plane intakes.

[Mikes87Camaro]

With the center divider not in the way, they work great. Here's how my Sniper EFI works with my Weiand Stealth dual-plane: https://youtu.be/vjFK18vmfsw. LOL.
I have a wideband O2 sensor on the left side, and the Sniper EFI wideband O2 sensor on the right. They are always in sync with each other, regardless of load or RPM.

Did you remove the center divider? If so, how? Do you have any pictures?

[BrianSanDiego]

Just so I'm clear on this, isn't it batch-fire on the fuel injectors? Where they all "go off" at the same time, but more/less frequency depending on RPM and varying duration depending on fuel requirements? Just want to make sure.

[rel3rd]

I would like to state, so misinformation is not spread, that the Sniper injectors do not fire "randomly". There is an injection strategy for the Sniper EFI injectors.

We have done extensive testing here at Holley, the Sniper EFI works well on both Single & Dual-Plane intakes. The thing about TBI injection, is it still requires the fuel to be distributed through the intake manifold. Lots of dynamics can effect the distribution of air & fuel into each cylinder, however, the Sniper EFI was designed to be used with both dual & single-plane intakes. Snipers test with success on both Single & Dual-Plane intakes.

Thanks for sharing the actual facts, Matt.

Did you remove the center divider? if so how? Do you have any pictures?

The Weiand Stealth came out of the box with about a 2" notch in the divider. Never, ever had a problem, used with three different carburetors, a FiTech, and a Sniper...street & strip.