[64speed]

I need some input about the Sniper. I am having the fuel pump relay wiring issue that I posted about in the other post which lead me to some deep research. I have read both success and horror stories and I am not just talking installation errors, I am talking about outright failures and stranded drivers. I feel like if the sniper fails me on something like Power Tour for example I am stranded. If my double pumper starts to flood a can of carb cleaner and a rebuild kit kept in the trunk and I am back on the road. I am not a carb master by any stretch but I can tune and set timing with a light etc. There is a speed shop around here that will tune it to its max for 200 bucks. This is not a half ass job I have the complete sniper kit, cdi box, distributor, fuel tank, the whole damn thing. I just don’t know. I can sell everything I have right now and recoup more than enough to buy a carb and MSD box and all I need.

[25stevem]

It’s a very tuff call without question!!!

I love the easy tuning of a FI system, but I mainly repair electronics for a living and as such I know the potential failure rate of solid state semiconductor’s as compared to the low amount of issues that can take place with a Carb set up.

I know how a common static discharge like when you have certain clothing on and your body discharges that ( 1000 VDC minimum ) to a door knob is more then enough to take out FI system or ingition system SS electronics.

I have seen the high level static from a lighting strike that took place 40 ft from a parked car take out the cars electronics.

If it where me and I had a good carb set up to run, I would use that for your planed long mileage trip and then take your time and get your Ducks in row to get the FI installed the right way, like on a separate feed from the battery with a separate as needed fuse and a on/off switch.
One things for sure, it’s far less costly to have in your trunk a spare old carb that works fine and a electric fuel pump then a spare FI system and it’s fuel pump!
If you could work on your own carb then a spare float & gasket kit and fuel filter could be considered all you need for a long trip.

[mgarblik]

EFI vs Carburetor is becoming the age old question, now that conversions have been around so long. IMO, EFI is continuing to close the gap. In the past, EFI was way, way more expensive, and required a PHD in computer science to tune. That has all changed dramatically, of course. It all depends on your comfort level, and tuning with each system. I can say with absolute certainty, that EFI WILL NOT outperform a great carburetor, properly tuned, with a properly curved distributor on the engine dyno. We have proved that time after time on the dyno. In real life driving, in all weather conditions, fuel economy, general light throttle cruising, EFI might have a very slight edge if professionally tuned. In the right hands, either can work equally well. Reliability wise, I like to think of EFI like a light bulb. It works beautifully until it doesn't! When it quits, you need a new part, and you have to figure out which one. A sensor, a wire, a connection, an ECU. When a carburetor has an issue, it's mechanical. Your choice.

[25stevem]

My Subaru is 21 years old with 240k miles on it and has never had a failed a injector or fuel pump or computer, just both ox sensors where changed at 160K.
When a aftermarket EFI can equal that life span then I will consider using one, that is if they can achieve that goal before gas stops being made anymore!

Every aftermarket item of electronics that goes into that items is made to a price point, and with all of those individual price points / quality levels you get the total reliability of the final item you payed for!

[Cliff R]

"EFI vs Carburetor is becoming the age old question, now that conversions have been around so long. IMO, EFI is continuing to close the gap. In the past, EFI was way, way more expensive, and required a PHD in computer science to tune. That has all changed dramatically, of course. It all depends on your comfort level, and tuning with each system. I can say with absolute certainty, that EFI WILL NOT outperform a great carburetor, properly tuned, with a properly curved distributor on the engine dyno. We have proved that time after time on the dyno. In real life driving, in all weather conditions, fuel economy, general light throttle cruising, EFI might have a very slight edge if professionally tuned. In the right hands, either can work equally well. Reliability wise, I like to think of EFI like a light bulb. It works beautifully until it doesn't! When it quits, you need a new part, and you have to figure out which one. A sensor, a wire, a connection, an ECU. When a carburetor has an issue, it's mechanical. Your choice."




Very well said and I'll add a few things.

First and foremost I don't care what anyone uses to put fuel to their engine. My goal if any is to make sure folks get a good end result with these things.

These "electric" carburetors are not true "fuel injection". They still use a wet-flow intake, not a system with 8 individual injectors in bungs in the intake spraying well atomized fuel directly at the intake valve sequentially.

I also get a LOT of calls from folks who have had troubles with them. The Holley Sniper tops the list. At first most of the folks who switched liked them, even after the upfront cost and jumping thru all the hoops to get them in place., but after multiple failures they are ready to go back to a carb and a system that isn't so complicated. Just had a call Friday from the not so happy owner of a Holley Sniper conversion. He's DONE with them after 3 failures in less than 24 months. He's an anomaly because he drives the chit out of the car pretty much as his "daily driver" and puts a lot of miles on it. In contrast many folks in this hobby these days will be lucky to put 1000 miles on their muscle car in the next 5 years. So with a lot of these "high performance" aftermarket parts we don't get consistent and reliable feedback with them.

I have remained silent about all the complaints we've had here in the past few years because I did not want it to appear that I was trying to sway folks in my directly for carb work. Now that I'm retired from all that it's out of the equation. It's still difficult to critique these things as for sure someone who's well vested in one and likes it will very quickly get their panties all wadded up and we are right back to all that "personal attack" crap that made me leave this website in the first place.

If you are vested in these things and like it I'm happy for you. If you are having issues don't be shy about it, post it up here. A few of the folks who've complained to me at the shop will NOT put up their results here because of all the "drama" it creates, mud slinging, personal attacks, it works good for me so you must be an idiot, and the I've been using that stuff since Moby Dick thought he was a minnow and it's flawless, blah, blah, blah.

All we get from that sort of thing is muddied water and it doesn't help anyone anyplace.

Moving on. I can tell anyone reading this that I set-up and installed the 1977 Pontiac Q-jet I'm still using today and the HEI distributor clear back in the mid-1980's. The carb has been flawless the entire time, never once needing anything done to it and I've only taken it apart to make minor changes when moving to larger and more powerful engines, and to install the ethanol compatible parts I'm having made for them so I can find out how well those parts make the grade.

The HEI has only failed when I tested aftermarket high performance modules in it. It currently has the same 990 module I started out with clear back in the 1980's.

I've had that carb and distributor on the dyno so many times I've lost count, and no MSD in any configuration will outrun the HEI and we've never had a carburetor of any variety make more power than the Q-jet. Same thing at the track, nothing runs quicker. I personally like and prefer simplicity with these things and also like using OEM parts. Since I've had very good success with stock parts I'm going to tell anyone reading this that they will work fine in long term service and cost less than complex aftermarket parts and systems.and lastly when any of these system quit on you, it's highly unlikely you'll be sitting in front of Jegs or Summit so keep your cell phone handy so you can call for a wrecker............Cliff

[grivera]

Very good points already made. At the end of the day, it comes down to your risk tolerance vs need for convenience. I’ve had my Sniper for about 2k miles. I went through two units out of the gate - the first units ECU died within 30 minutes. I also had insane RFI issues now resolved. Now that it runs great I drive the car a lot more than I did when it had the q-jet.

I converted in the first place cause I could never nail down cold starts or heat soaked starts with the q-jet. Otherwise I loved the way it drove. With the Sniper the car can sit for a month and it starts up easily. It took me some time to have confidence in it and my first long trip (3 hrs) I carried the carb and dizzy in trunk in case I had to go back.

[JLMounce]

I've been plugging along with my early release FiTech since 2015. I have an estimated 25000 miles on it in that time.

I then went and put a later model unit on my wife's former Chevelle. That one ran, without issue since 2018 and was still on the car when we sold it last month. I think we put about 8000 miles on that system.

As I mentioned in the other thread you started, much of the issues that crop up with these systems is dirty power and improper installation. Go get yourself a 4 channel MSD solid state relay. Trigger the relay with the factory coil wire, then put the sniper on it's own channel, your ignition system on it's own channel and if you're running an electric fan, put that on its own channel. That leaves you another channel that you can use for things like cabin accessories or other electrical needs. I have this one triggered by the ACC terminal on the fuse block and run my stereo off it.

While there certainly are instances where a bad unit does make it out of the factory, you can trace issues with these 90% of the time to a crap install. If you don't think you can install it properly, there's certainly nothing wrong with a carburetor. Pick your poison.

[Scott65]

Originally Posted by JLMounce

I've been plugging along with my early release FiTech since 2015. I have an estimated 25000 miles on it in that time.

I then went and put a later model unit on my wife's former Chevelle. That one ran, without issue since 2018 and was still on the car when we sold it last month. I think we put about 8000 miles on that system.

As I mentioned in the other thread you started, much of the issues that crop up with these systems is dirty power and improper installation. Go get yourself a 4 channel MSD solid state relay. Trigger the relay with the factory coil wire, then put the sniper on it's own channel, your ignition system on it's own channel and if you're running an electric fan, put that on its own channel. That leaves you another channel that you can use for things like cabin accessories or other electrical needs. I have this one triggered by the ACC terminal on the fuse block and run my stereo off it.

While there certainly are instances where a bad unit does make it out of the factory, you can trace issues with these 90% of the time to a crap install. If you don't think you can install it properly, there's certainly nothing wrong with a carburetor. Pick your poison.

Ditto this. Proper installation is key. I've been on efi, 2 different versions, with no issues with either since 2009 or 10. All of these units will suffer from the garbage in/garbage out syndrome. Give it a solid foundation.

[64speed]

My nephew is a Clemson electrical and mechanical engineering grad, I was a history major (Go Tigers) anyway he knows about all this stuff so I am plumbing everything this week and he is coming to wire it this weekend.

[mgarblik]

He probably knows all this but: For best installation in a high vibration, high heat, high moisture, electrically noisy environment. 1. No Scotch Locks, period, ever, no matter what, for ANY electrical connection. 2. Fuel and ignition circuits need to be routed away from each other. 3. No spade terminals under the hood unless they are housed in plastic connectors to positively locate them. 4. Weatherpack, or similar connectors should be used on all under hood connections. 5. If not practical, all terminals need to be heat shrink type crimp connections or soldered . 6. Ring terminals preferred to all other types of general terminals. Good luck.

[Kenth]

I just read the instructions for the Sniper:
https://documents.holley.com/techlibrary_199r11324.pdf
Wow, 76 pages, what could go wrong?

But if the only gain is better cold starts i prefer replacing the mechanical fuel pump with an electric fuel pump to achieve the same result as with the Sniper and save some money for better tires.
And really, how hard is it to adjust the points and Qjet once a year?

JMHO

[Formulajones]

Originally Posted by 64speed

I need some input about the Sniper. I am having the fuel pump relay wiring issue that I posted about in the other post which lead me to some deep research. I have read both success and horror stories and I am not just talking installation errors, I am talking about outright failures and stranded drivers. I feel like if the sniper fails me on something like Power Tour for example I am stranded. If my double pumper starts to flood a can of carb cleaner and a rebuild kit kept in the trunk and I am back on the road. I am not a carb master by any stretch but I can tune and set timing with a light etc. There is a speed shop around here that will tune it to its max for 200 bucks. This is not a half ass job I have the complete sniper kit, cdi box, distributor, fuel tank, the whole damn thing. I just don’t know. I can sell everything I have right now and recoup more than enough to buy a carb and MSD box and all I need.

My take on it after doing several of these installs and having the Super Sniper Stealth on two cars here.

First it's super important to do a clean and proper install. Good clean power connections and grounds, and running directly to the battery. A good clean power on while cranking with very little voltage drop is also critical.

From there reliability is really out of your hands. It's an electrical EFI device and like anything electrical parts can and do fail. Stepper motors like the IAC and TPS are 2 moving pieces that can possibly have issues. I've already found that sensors like the CTS can be inaccurate right out of the box leading to tuning issues. Not a big deal to fix though.

Bottom line, if you are really worried about this thing failing and leaving you stranded, then I'd probably stay away from electronic stuff all together and sleep better at night. If you plan ahead, and want to go on something like a power tour, bring along a spare TPS CTS and IAC and toss them in the glove box. Cheap insurance and not a horrible road side fix. Usually having that stuff on hand, nothing happens. Not having it is generally when a problem arises. If an 02 fails, and that does happen, as long as you have a good tune in the car you can run without it. Having a tune saved that is open loop is an easy backup plan and only takes 10 seconds to shut the car off and load that in and you're on your way.

Honestly, the two cars I installed the Stealths on are not our daily drivers. Although I have not been afraid to go on 200+ mile trips in these cars (did 420 miles in one weekend).....they are not something I want to trust day in and day out.
I've said it many times, our daily drivers have no electronics on them, just a carburator and points on both cars and I trust them to go across country as they have nothing on them that I can't fix on the road side in a few minutes with cheap parts and simple tools. I do like simplicity.

[JLMounce]

Originally Posted by Kenth

I just read the instructions for the Sniper:
https://documents.holley.com/techlibrary_199r11324.pdf
Wow, 76 pages, what could go wrong?

But if the only gain is better cold starts i prefer replacing the mechanical fuel pump with an electric fuel pump to achieve the same result as with the Sniper and save some money for better tires.
And really, how hard is it to adjust the points and Qjet once a year?

JMHO

That's really not an accurate descriptor of what it takes to install a Sniper. Yes the total manual is 76 pages. Installation instructions start on page 8 through page 18, with some added pages after for information specific to certain types of installation. Fuel only, timing control, timing control with a CDI box etc.

The remaining parts of the manual discuss things like nitrous usage, setting up two steps, launch retard, feature definitions etc. The vast majority of users will never have a need or even a desire to use any of that.

You're trying to obfuscate the simplest part of running a carburetor with the most advanced and complex part of running EFI.

[PAUL K]

Only advantage I see to EFI ion an old muscle car s you can have a remote starter. Being a Holley/MSD/QF dealer I sell a LOT of EFI kits. Sadly most folks feel these EFI kits are going to work as well as their late model cars.... It's not going to happen.

[Formulajones]

There are a couple of benefits I've found. And I've mentioned this in the past and probably the biggest reason I even wanted to try one.

Elevation changes.....

We deal with elevation changes here daily, with DA numbers that rocket over 10,000 feet in the summer time, or I can be racing at the track with DA numbers at 1000 feet, on rare occasions even less.

With carbs it requires jet changes pretty frequently. I can kind of fudge the jetting and live with the car a bit fat up high and maybe a bit lean at the lower elevations and live with it. That's what I do on the daily drivers. But the cars we race a lot, if you're a tuning nut like I am you'll wish the carb just had a damn zipper on it. Eventually to save the carb bodies the box of helicoils have to come out, from removing the bowls so often.

With the EFI, commanding the AFR you're looking for is a few simple key strokes, without even opening the hood. I can also play with the fuel curve in certain areas, like peak torque and higher rpm to fine tune things much more accurately.

Something else I've noticed after purchasing them is these Stealth 4150 throttle bodies are quite a bit larger than the 4150 950 HP's they replaced, plus the lack of boosters, so the air flow potential is better.


Other than that, there really isn't a big advantage. Cold starts were never a problem for me with carbs so I don't care about that.

[bhill86]

I have nothing to offer but do have a question, just out of curiosity, to branch off of Cliff’s example of them being more of an electric carburetor. Would it be safe to compare them more to something like throttle body injection than a multiport EFI?

[geeteeohguy]

The elephant in the room is that these aftermarket 'fuel injection' systems are simply 1980's style throttle body, wet intake systems. Not true port injection at each cylinder. I know a gent who owns his own hot rod shop and he's a younger guy and won't use the new aftermarket T-body injections due to too many issues and upset customers. He runs carbs. I just retired from 42 years in the auto industry and have run the original Tripower on my '65 GTO for the past 40 years with zero issues, and the original Q-jet on my '67 GTO for the past 39 years, also, with zero issues. Talking tens of thousands of miles of service here.
TBI Fuel injection is better for altitude changes and that's about it. Real fuel injection, dry manifold with 8 injectors, is excellent, but not what we're discussing here.
I'll keep my old reliable stock, non computerized carbs, thank you.

[Formulajones]

Originally Posted by bhill86

I have nothing to offer but do have a question, just out of curiosity, to branch off of Cliff’s example of them being more of an electric carburetor. Would it be safe to compare them more to something like throttle body injection than a multiport EFI?

Correct, they are basically a throttle body injection.

[JLMounce]

I would run a TBI over a batch fired port injection system any day of the week. Not all EFI systems are created equal. Just because it's throttle body based doesn't make it crap any more than having 8 or more injectors makes it awesome.

My big issue with carbs at my altitude is finding fuel that won't boil in them. If I want to fill up at any gas station I want, not worry about having to mix additives, how do I keep the car from vapor locking? E10 has a boiling point of around 165-175 degrees. Now reduce atmospheric pressure by 30% at 5000 ft, it boils even sooner. Now stick a giant hunk of iron in a small F-Body engine bay and run it at 180-200 degrees on a warm 85 degree day. There's almost no scenario where you won't start boiling fuel.

I am not Cliff or the Carb King, but I'm also not an idiot. I tried several different carburetors, phenolic and wood spacers, mixing fuels, insulating fuel lines...literally nothing I tried did anything more than get me maybe a couple more miles of use of the car. During the summer I could drive the car at night and for maybe 10 miles before it would cough and sputter.

After installing the FiTech with a pressurized fuel feed, I went from driving my car maybe 150 miles a year...to thousands. I need fuel, I stop at the nearest station. I want to go up into the mountains, I point the car in that direction. I've driven the car without making any changes in temperatures as low as 5 degrees to as high as 110.

Just remember, for every carb success story, there's an EFI success story, just as for every EFI failure story, there's a carb failure story.

[5th TA]

Pros and Cons says it best. I can’t comment on the Sniper system, but can talk about my experience with a FAST 2.0.



In the summer of 2020 I purchased a Butler Performance 461 turn-key crate engine. I bought it from an individual who had it built in 2015, shipped to his house but he never installed or ran it. The engine came with a FAST EFI 2.0 system including fuel pump, pressure regulator, dual sync distributor and E6 digital ignition. The engine was dyno run by Butler with the FAST distributor and EFI throttle body. The price I paid for the entire engine and EFI assembly was less than half of what Butler would charge for the same setup today. I toyed with the idea of running an HEI distributor and Quadrajet. But decided to go with what the engine came with.



Carefully reading the FAST EFI instructions they strongly recommend running the fuel pump mounted in the tank and running a full return fuel system. While existing fuel tank was in excellent condition the opening for the sender was not large enough to accept the FAST electric fuel pump. I had a choice of purchasing an expensive Holley fuel pump that would bolt in but was concerned as to how would work with the FAST ECU. So I purchased a new tank from TANK’s with their in tank hanger. While my car was original configured for a full return system, the return line was only ¼”, so I had to upgrade to a 3/8” return line. I ran all solid steel lines under the car wrapped in springs, just like the factory. Next issue of concern was if my factory alternator would be up to the extra current load of the EFI system at idle. I purchased a Mechman alternator rated at 146 amps at idle. I very carefully followed the installation instructions making sure the ECU and E6 ignition module were directly connected to the battery.



Setting up the ECU parameters was simple. First start was immediate and the engine ran well. All was great for several weeks. Until one day, I drove the car the night before without any issues. I try to start and the car just cranks. I get an ECU error saying the MAP sensor voltage was out of spec. Reading the manual it was out of spec, I ordered a new sensor from Amazon for $12.99. I install the new sensor and the engine starts right up but doesn’t idle well and has poor throttle response. I decided to blow away the ECU configuration and start over, same issue. I call FAST help desk, they tell me I have to drive for at least a half hour for the ECU to learn. Driving didn’t help. FAST tells me it might be an 02 sensor problem and asked me to drive it with the 02 sensor disconnected. That didn’t help. I decided to order another MAP sensor, this time a get a genuine GM sensor. I install the GM MAP sensor, engine runs great from the very beginning, no half hour driving for ECU to learn need. Since that then I have driven 1400 miles without issue. The instructions from FAST say the system has limp home mode, in my case a failed MAP sensor would not allow the engine to start.



Changing timing, advance curves and AF ratio certainly is easy with this system. If I drove at sea level then to high altitudes in the Rocky mountains it would automatically adapt to the atmospheric changes. At this point I like the EFI a lot. But knowing what I know now, if I were to do this all over again I probably would have tried to sell my system and go with a Quadrajet and HEI. While these systems are good, I don’t think they are up to the level of refinement and failsafe of an OEM system you get in a new car today.