Holley Sniper EFI, my experience

So as I go along on this journey from carb to FI I'm going to post progress and notes, issues etc. I have a new QFT carb and by the time I learned how to tune all of the circuits in it I figured I might as well learn to tune FI. Also I've walked outside on plenty of sub 50 degree days in Indiana wanting to drive the car only to never get it to fire up because it was too cold. I walked out the other day on a low 40's day and it fired right off at the hit of the key. I have heard and seen a lot of negative talk about the Sniper kits and to be honest I let some of it get in my head and it delayed me finishing the install. So I've decided to work through the install in stages. I have right now installed it in the most basic the install can get which is bolting it on and hooking up 4 wires.

I had it installed and all but one wire hooked up, a buddy of mine I hadn't seen in 12 years or so comes by the house with his son and his son had never seen or heard it run. While we were sitting there bs'ing I decided to go ahead and wire the last wire in and fire it up. What a fire up it was, once everything was cycled and the software setup for engine parameters we were off and running. Literally hit the fuel pump, ignition and water pump switches and turned the key. It lit off faster than any carb its ever had on it. We let it warm up a bit and get into learn mode and started driving, first my buddy and I and then his kid and I. We drove it probably an hour that day without a hint of an issue with the system. It got a 3.23 sure-grip between the carb/FI swap and the car really liked that. Now that the other hoghead is done its time to swap it in and really have some fun.

My next goal is to wire the fuel pump in to the holley system and let it run the pump rather than me having to turn it on and off. Once Im happy with that I'm going to let the system control the ignition timing and then the fans and water pump.

When I'm confident the ignition control is right I'm calling a tuner in Houston and letting him do the remote tuning setup on it.

Impressions thus far, don't be scared of it. I was intimidated at first but if you follow the suggestions of guys that know the systems they work just fine. I wouldn't throw all the wiring on at once as IMO that's just asking for problems.



I have determined the Powermaster 55 amp alt is nowhere near enough amps to run the electrical stuff in my car. That upgrade is being figured out currently, but if anyone knows of a different bigger amp alternator that will hang off Andy's motor-plate low mount alt kit I'm all ears.




I ordered and installed the following...
Holley kit Stealth Super Sniper
Fuel pump A1000
Regulator Bypass regulator

I also have the following previously installed
MSD Pro Billet Distributor
MSD 6AL box (Analog)

I have one on my Big Hemi....Love it. Especially for cooler weather. Startups made easy. Bought mine thru FastManEFI Rich....Alternator is a big 140amp CVF chevy 1-wire...They are awesome.

I run the sniper on my procharged Cuda. At this moment it's working great with no issues. With that said, it's not for everyone. Especially if the car is a mess of wires and bad grounds. Early on I wired it up and it started up and drove great. 20 miles into my test drive the ECU went bad. Everyone blamed my wiring even though I followed the instructions. Holley sent a new sniper, I had it wired up again by somebody more proficient than me. Worked for a little while, then ECU issue again. This time I bought a new sniper since I was in a pinch. Put it on the car and plugged it into the existing harnesses and my car fired right up and ran fine. This leads me to believe that there is some quality issues with it, and I keep my spare on hand when on long drives.

I did the same thing. I love the sniper for its simplicity. it is amazing for a street car.

Have you looked into the toyota alternator ? I have put that on 3 mopars now. I love it.

No doubt about it regarding the Sniper. I installed it on my 69 Charger with the EFI ready tank from Holley as well as the Holley Hyperspark timing control. I had the same issue as you here in the winter time in Texas. My 440/512 with a QF 1000 carb, and it did not like to start. The Sniper and timing control were the best thing I ever did to my car. Now, it doesn't matter the temp, it fires right up! And the timing control is awesome! The car runs phenomenal. We have a small musclecar shop here in North Texas, and I have installed 6 more Snipers, a 63 Chevy 409 4-speed Impala, 73 Ford Gran Torino 351C. a 1970 455 Olds (Q-Jet), a 1950 Dodge rat rod, 68 Vette, and 2 others I just can't remember right now. I have also installed the Fitechs and Edelbrock systems, and how have a 68 Charger that just came in with a Summit brand EFI setup. But the Holley is superior imho.

I haven't yet. Does it look like this? If so maybe it will bolt in place and still use Andy's mount. Any certain part number you have would be beneficial.

This one is plenty big enough amp wise but there is no way its gonna work with Andy's motor-plate mount and the Doty pulley
8142

I'd like to comment that Holley's tech support has always been great. If you don't want long wait times I'd recommend joining the sniper facebook group. Grab a few names of the techs that reply. Once you have that you can direct message them on facebook and ask for a call back, or work with them via chat. In my case, I'll get them on the phone and have them call my shop if they're working on my car so they're not wasting time on hold.

if memory serves its a early 90's toyota truck alternator. but make sure to buy the pigtail too.

It appears the 75 amp will work size wise for mounting do you guys think another 5 amps at idle and 20 amps driving is enough?

8173

My 8172 is 30/55 this one is 35/75

The Powermaster tech guy said I need 90 amps at idle. I'm going to attempt to modify Andy's mount to work with this mechman alternator
Mechman 170

This one fits my stock brackets:

https://www.qualitypowerauto.com/item_557/Chrysler-Mount-Mega-Amp-Alternator.htm

I don't have stock brackets

I don't know what size that alternator is for Andy's bracket. Look up the dimensions for a GM CS130 alternator. They are 105 amp I believe. I run one and with a 5" crank pulley it charges great! I run two fuel pumps, electric water pump, two electric fans, a third fan on my fuel cooler, EFI, lights wipers, headlights, it can run them all and maintain 14.2 or so even at idle. At the track my voltage might move .1 during a pass max. It is one of the best changes I have made to the car.

I let my EFI run everything it can, water pump, fans, fuel pumps, whatever I can let it run I do. The only button I have that isn't run through the computer is my line lock. I went from a bank of switches to nothing but a key, line lock button, and a starter button and I love it that way.

What ever you one you buy make sure it will make more amps than you need by at least 20 % at full load so it can recharge the battery after starting

That's what I am running on my Dart also. 14+ volts all the time (although my idle is around 1200 so the real low end amps aren't as important).
You can get CS130's in a variety of current ratings too, some quite a bit higher than 105 amps.
For example: https://alternatorparts.com/cs130-cs130d-series-alternators.html

Just how big an alternator do you need to run an aftermarket EFI? 90 amps seems serious overkill.

It's not just for the EFI - look at the previous poster's list. Electric fans pull a lot (my Contour fans draw 40 amps on high). Fuel pumps. Headlights and accessories. Etc. Etc.
All the little things that pull an amp here and two amps there. Adds up.

You don't need a big alternator to run EFI but you do need a good alternator. EFI is susceptible to electrical noise so the alternator needs to be a late model design, preferably an OEM alternator. I use factory Denso alternators on my EFI cars. I use the 60 amp Denso unit on both of my cars.

Agreed. At idle. I'm making about 12.3 volts per the Holley "dash" sometimes as low as 11.9. The 55 amp Powermaster isn't cutting it.

So what is the original application for the Denso alternator you use? WIll it fit your brackets you sell for the motor-plate?

It's not for the EFI alone it's for


Holley kit Stealth Super Sniper, Fuel pump A1000, Regulator Bypass regulator, MSD Pro Billet Distributor, MSD 6AL box, headlights, electric water pump, Contour fans set up, stereo (not currently a need but I want the option of it) and charging the battery

While you're statement may be correct, it's not just about running the EFI. The big alternator comes into play when you have more than EFI that is electric. My Powermaster doesn't affect my Holley EFI, but it damn sure isn't putting out enough amps to keep up with the demand of the electronics and not rob the battery to help.

You need an alternator with a fast curve in it. Alternators that we’re designed for modern cars have greater output at lower rpm than old designs. Get a denso that fits a modern era car/ truck. I also recommend using a voltage regulator instead of one wire setups.

I will add I run my CS130 with a sense wire, and a charge light so its essentially a 3 wire deal. I run the sense wire to my power distribution point where 95% of my stuff gets it power.

With EFI, you have a min voltage at which it shuts off. If you go below that while at idle, the car will quit.

You have to add up all the items in your car and look at the amperage. This is what the battery will see at an Idle, you need that amount or darn close to it. If not, your battery goes dead pretty quick. I started with the Mopar OEM alternators, and those were horrible. Been running chevy 100 amp 1-wire alternators for ever. Recently though, I had to upgrade my fans and then my electric water pump. The new fans really put a load on things. I ended up trying a number of alternators. Ended up with a 140 CVF unit...Man, my idle voltage is dead steady with everything on now. For the money, nothing I have tried beats it. And had some pretty pricy ones, and found out that they stretched their specs, cause when I called them on it, they told me that most of the numbers were for above 3500rpm.....

https://www.cvfracing.com/gm-1-wire-alternator-140-amp-chrome-plated/

Running a Sniper myself with a good 'ol Toyota Denso 60A alternator as well, zero problems, charges at 13.9V per the handheld and separate can bus gauge. The Holley ignition stuff and Sniper ECU do not draw much current, basically you need 12V from a switched source to turn them on. The ignition box trigger wire is tiny so it wouldn't be able to carry much anyway.

I have the whole deal - in-tank pump, Hyperspark distributor, Hyperspark ignition box, "Sniper" TFI type coil and even the Holley gauges. I did re-wire the entire car though and it has a modern blade type fuse box. The fuel pump and headlights are on relays. Parts store mini starter, new ignition switch. I doubt the Sniper stuff would work too well with 52 year old factory original wiring.

I will say that there is not much else in my car that requires a lot of current - no electric fan, no A/C, no stereo or what have you but either way, it starts first try every time and has not had any observable electrical issues thus far.

He brings up a good point. The ONLY stuff on my car that uses factory wiring is the lights and wipers, everything else is fresh wiring.

Mine too.