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Holley Sniper

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dkrtgood View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dkrtgood Quote  Post ReplyReply Direct Link To This Post Topic: Holley Sniper
    Posted: Jan/05/2022 at 2:01pm
Purchased 4150 Sniper EFI and the Hyper Spark efi controlled distributor and will be installing into my new motor and was curious if anyone out there has installed both? Looking for any ideas or tips.

70 390 10:1, 292H, Stick car, Torker with mods

These things self learn but I know it can be tuned to add fuel, timing etc to give the most power and best mpg. 
Dave Goodwin
President of Tampa Bay AMC

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77 Matador Coupe AKA "The Beave"
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel Machine Quote  Post ReplyReply Direct Link To This Post Posted: Jan/05/2022 at 4:19pm
Originally posted by dkrtgood dkrtgood wrote:

Purchased 4150 Sniper EFI and the Hyper Spark efi controlled distributor and will be installing into my new motor and was curious if anyone out there has installed both? Looking for any ideas or tips.

70 390 10:1, 292H, Stick car, Torker with mods

These things self learn but I know it can be tuned to add fuel, timing etc to give the most power and best mpg. 


I've got both in my AMX.

-Steve-
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Post Options Post Options   Thanks (0) Thanks(0)   Quote pit crew Quote  Post ReplyReply Direct Link To This Post Posted: Jan/05/2022 at 5:08pm
Originally posted by dkrtgood dkrtgood wrote:

Looking for any ideas or tips.
Got both plus the Hyper Spark CD box on the 401 in my Hornet.

My suggestions are:

Keep all wires as far from the ignition wires as possible. They can pick up interference.
Pay close attention to the instructions on O2 sensor placement.
Use a return fuel line.
An in tank fuel pump keeps the pump cool and cuts down on the noise.
For better street manners consider changing the throttle linkage to progressive instead of locked. I have mine set to 30%.
Find someone with the laptop cable and use the Holley tuning software to smooth out the timing curve. Out of the box it defaults to stair step timing instead of a real curve.

Go out an have a lots of fun with it.


73 Hornet - 401EFI - THM400 - Twin Grip 20
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dkrtgood Quote  Post ReplyReply Direct Link To This Post Posted: Jan/05/2022 at 8:53pm
Originally posted by pit crew pit crew wrote:

Originally posted by dkrtgood dkrtgood wrote:

Looking for any ideas or tips.
Got both plus the Hyper Spark CD box on the 401 in my Hornet.

My suggestions are:

Keep all wires as far from the ignition wires as possible. They can pick up interference.
Pay close attention to the instructions on O2 sensor placement.
Use a return fuel line.
An in tank fuel pump keeps the pump cool and cuts down on the noise.
For better street manners consider changing the throttle linkage to progressive instead of locked. I have mine set to 30%.
Find someone with the laptop cable and use the Holley tuning software to smooth out the timing curve. Out of the box it defaults to stair step timing instead of a real curve.

Go out an have a lots of fun with it.

Plan to do all that...but never heard of the progressive throttle
What is the advantage? I bought the usb cable and have 
Software loaded on laptop and learning as much as I
Can on it before I swap motor out.
Thanks for the info and yeah i need to buy cd box also
Dave Goodwin
President of Tampa Bay AMC

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77 Matador Coupe AKA "The Beave"
70 Javelin 360 / Auto - BBG


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel Machine Quote  Post ReplyReply Direct Link To This Post Posted: Jan/05/2022 at 9:25pm
I've got the Hyperspark CD box, pretty much the same as MSD but all the connectivity is built in.

After you get it installed give the system time to learn. Don't whack the throttle aggressively, the system doesn't have the fuel map populated out of the box.

-Steve-
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Post Options Post Options   Thanks (0) Thanks(0)   Quote troutwilly Quote  Post ReplyReply Direct Link To This Post Posted: Jan/05/2022 at 10:02pm
dkrtgood, x 2 what pit crew said.  I have almost the exact setup as you, except on a 304.  But its not on the street yet.  And I'm already switching to in-tank pump, but because of reasons other than heat.
And I googled "progressive throttle linkage" cause I didn't know either, and basically it brings in the secondaries a little later than the stock setup. Another something I may be doing.
Bill O.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote pit crew Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2022 at 8:17am
Originally posted by dkrtgood dkrtgood wrote:

Plan to do all that...but never heard of the progressive throttle
What is the advantage?
Out of the box the Sniper has the primary and secondary throttle plates in lock step. Some people find that setup produces a little too aggressive acceleration from a standing start. Holley has an adjustable linkage you can buy to replace the stock one with. Then you can "delay" the opening of the secondary throttle plates based on a percentage of the primary ones.

Not really required but it does keep you from having to feather the throttle at stop signs and red lights. It is more of a "comfort" thing than a performance issue. Cuts down on jackrabbit starts. I would suggest you try it with the "locked" linkage first as you can always add the progressive linkage later.

If your thinking about going the progressive route keep in mind you have to tell the software you are doing so and what the percentage is. There are good instructions available through Holley and several EFI websites.

The Holley part number is 20-122.

Oh, one last thing. Make sure you have full (100%) throttle travel. If you should ever flood the engine you can floor the throttle, hold it there, and then crank the engine. When the Sniper see 100% throttle on startup it assumes your clearing a flood condition and will keep the injectors turned off. Trust me, if you ever let an old timer drive your car they will pump the throttle on startup just out of habit and could cause a flood condition. Ask me how I know. LOL. This is also covered in the Holley instructions.


Edited by pit crew - Jan/06/2022 at 8:30am

73 Hornet - 401EFI - THM400 - Twin Grip 20
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Post Options Post Options   Thanks (0) Thanks(0)   Quote blue68AMX Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2022 at 8:54am
I am thinking about doing the same thing to my 70 AMX and would like to know how you did the in tank pump with out cutting up the trunk floor.

Thanks
Al
Al

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Post Options Post Options   Thanks (0) Thanks(0)   Quote dkrtgood Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2022 at 12:32pm
thanks for all the replies and info, will check into that progressive linkage. sounds like a smart thing to do.

Also I see you can install a knock sensor so it can back off timing if it senses ping...anyone install or take advantage of that option? They say to install in an open port on block (Say the coolant drain down bottom of block by pan) and it will listen for a certain frequency noise. Sounds like you could run better advance and then it can back down if needed on the fly.
Dave Goodwin
President of Tampa Bay AMC

70 Mark Donohue BBO 390 5-speed
77 Matador Coupe AKA "The Beave"
70 Javelin 360 / Auto - BBG


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Post Options Post Options   Thanks (0) Thanks(0)   Quote cone Quote  Post ReplyReply Direct Link To This Post Posted: Jan/06/2022 at 1:24pm
I have one on my 401 and it far from "self learning". Unless you are good with computers, which I'm not, it is a pain in the rump to tune right. One of the injector fell out of place, I guess it is a common problem because there is a fix for it on youtube using zip ties. I still have a pinging issue I'm working on. If you have a manual tranny starting off without squealing the tires can be tricky because all four barrels open up at the same time. So I bought the progressive linkage but you then have to reprogram system to use it and I could not figure out how to do it so I called Holley and they told my the system isn't designed for that linkage. They sell an extension arm that attaches throttle linkage and that helped. 
1987 J20, 87 Grand Wagoneer,70AMX,
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