Holley Sniper on '71 Charger: install thoughts/opinions

[Greg - Mopar2U]

I wanted to share some thoughts and opinions I had in adding the Sniper EFI to my 71 Charger. At the time, I couldn't find information on some of this setup. I hope this information helps someone to do a better/quicker job than me. Let me know if you have questions/suggestions.

Car: '71 Charger w 383, stroked and bored to 413 w 270 Comp Cam. Tremek 5 speed and 3.91 gears in 8 3/4" rear.

Holley Sniper Installation instructions: Read them and follow the recommendations. Read them and follow the recommendations. Read them and follow the recommendations.

Timing: When used w the Holley distributor, the Sniper controls the timing (SNE 550-511K, SNE 550-305. I used the Holley Coil Driver - not MSD box). You set the timing you want for Crank, Idle, Wide Open Throttle and Cruise. On a car w a stock distributor, you have to set the initial timing, then choose weights and springs and adjust the vacuum advance to guess what the final timing might be - according to engine knock. Once the Sniper is set to the engine everything else is a number you set on the Hand Held. (My car loves idle timing @ 20, but I have crank set to 0 and total at 34.)

Gas: The Sniper has a closed loop calculation w the oxygen sensor in the exhaust - it sends gas accordingly. It learns and adjusts to your driving habits and drive conditions. Carburetors work great, out of the box, but then you have to adjust metering rods and/or jets and accelerator cam(s). To do this properly you'll need to monitor AFR in a variety of conditions . . . and adjust accordingly. (I have AFR's set to 13.5 at idle, 14 at cruise and 12.5 at Wide Open - recommended numbers from the Holley Instructions. ) Initially - I tried to reuse the gas tank and use an external pump, the used/original tank clogged the fuel filters. I replaced the tank with one that has an internal pump (AEI 18162). Run new lines.

Cooling: The Sniper can control 2 electric fans (This one has 2 speeds: DER-16217) . . . That turn on when needed.

Electrical: Electric fuel pump, electric fans. If making additional changes/additions upgrade the altinator. (140 amp on CVF serpentine)

'The Pink Wire': Sniper needs the Pink wire to have clean power during Run and Crank key positions. If you've got the Holley distributor - you don't need the ballast resistor, but the power wires to the resistor are Run and Crank. Originally I attached them w a diode to prevent any current going the wrong way, but there ended up being a flat spot between the run and crank in that key position that disrupted the Sniper computer. I added a 'Delay Relay' to this circuit. (74985 www.delcity.net ) The delay relay triggers on the Run wire and keeps the pink wire energized for a (user) specified time through the time of crank. This solved the crank/start problem, but also allows the cooling fans to run after I turn the car off. (up to 3 minutes)

Misc: 'Throttle Extension' Summit SNE 20-16 drastically improved the ease of throttle pressure. (The aftermarket linkage that makes the Sniper secondaries work separately than the primaries was discouraged from Holley Tech.)

Misc: This throttle cable bracket worked great (Mancini MREAR134S ) . . . was worth the money. It held the throttle cable and gave room behind the Sniper to wrap the misc cables and Coil Driver.

Misc: I installed the Sniper over top of a 1" spacer . . . I found recomendations to do this, and didn't want to re-do anything afterwards.

I hope this helps.

Greg

 

[70chall440]

Awesome write up. So given all this information, how does it run/work and what would you do different?

 

[gkent]

So you're using a canister-style coil (hence the use of the coil driver) ?

SNE 550-305

This should read 565-305 (I think)

 

[1WILD440]

I wanted to share some thoughts and opinions I had in adding the Sniper EFI to my 71 Charger. At the time, I couldn't find information on some of this setup. I hope this information helps someone to do a better/quicker job than me. Let me know if you have questions/suggestions.

Car: '71 Charger w 383, stroked and bored to 413 w 270 Comp Cam. Tremek 5 speed and 3.91 gears in 8 3/4" rear.

Holley Sniper Installation instructions: Read them and follow the recommendations. Read them and follow the recommendations. Read them and follow the recommendations.

Timing: When used w the Holley distributor, the Sniper controls the timing (SNE 550-511K, SNE 550-305. I used the Holley Coil Driver - not MSD box). You set the timing you want for Crank, Idle, Wide Open Throttle and Cruise. On a car w a stock distributor, you have to set the initial timing, then choose weights and springs and adjust the vacuum advance to guess what the final timing might be - according to engine knock. Once the Sniper is set to the engine everything else is a number you set on the Hand Held. (My car loves idle timing @ 20, but I have crank set to 0 and total at 34.)

Gas: The Sniper has a closed loop calculation w the oxygen sensor in the exhaust - it sends gas accordingly. It learns and adjusts to your driving habits and drive conditions. Carburetors work great, out of the box, but then you have to adjust metering rods and/or jets and accelerator cam(s). To do this properly you'll need to monitor AFR in a variety of conditions . . . and adjust accordingly. (I have AFR's set to 13.5 at idle, 14 at cruise and 12.5 at Wide Open - recommended numbers from the Holley Instructions. ) Initially - I tried to reuse the gas tank and use an external pump, the used/original tank clogged the fuel filters. I replaced the tank with one that has an internal pump (AEI 18162). Run new lines.

Cooling: The Sniper can control 2 electric fans (This one has 2 speeds: DER-16217) . . . That turn on when needed.

Electrical: Electric fuel pump, electric fans. If making additional changes/additions upgrade the altinator. (140 amp on CVF serpentine)

'The Pink Wire': Sniper needs the Pink wire to have clean power during Run and Crank key positions. If you've got the Holley distributor - you don't need the ballast resistor, but the power wires to the resistor are Run and Crank. Originally I attached them w a diode to prevent any current going the wrong way, but there ended up being a flat spot between the run and crank in that key position that disrupted the Sniper computer. I added a 'Delay Relay' to this circuit. (74985 www.delcity.net ) The delay relay triggers on the Run wire and keeps the pink wire energized for a (user) specified time through the time of crank. This solved the crank/start problem, but also allows the cooling fans to run after I turn the car off. (up to 3 minutes)

Misc: 'Throttle Extension' Summit SNE 20-16 drastically improved the ease of throttle pressure. (The aftermarket linkage that makes the Sniper secondaries work separately than the primaries was discouraged from Holley Tech.)

Misc: This throttle cable bracket worked great (Mancini MREAR134S ) . . . was worth the money. It held the throttle cable and gave room behind the Sniper to wrap the misc cables and Coil Driver.

Misc: I installed the Sniper over top of a 1" spacer . . . I found recomendations to do this, and didn't want to re-do anything afterwards.

I hope this helps.

Greg

View attachment 1582811

Thanks for sharing the info on the Sniper. I have a 74 charger se ...440 bored .50 over to a 451... I see that you have a Tremec 5 speed bolted up...I'm curious to know how you did that set up. Did you have to use an adaptor plate ect.

 

[440 PHIXX]

After dealing with recent cold start issues on my 383 daily, I’m considering the Holley Sniper on my 440 build for my ‘68 GTX.

 

[Greg - Mopar2U]

Awesome write up. So given all this information, how does it run/work and what would you do different?

I really like the Sniper now. Originally I bought an edelbrock carb and I was researching how best to do the tuning when an episode of Garage Squad ( Cristy Lee ) bolted on an EFI, and I realized the differences in tuning between EFI and Carb

I'm not going to race/beat on this, but I do like to tinker w the Sniper variables to make it run better. The data log of a lap around the block is amazing. attached

Idle timing took me a little while to figure out. The car ran hot at idle and dieseled when I shut it off. I played w AFR and then started pushing the (idle) timing up from 15. Every bum in timing increased the idle RPM and improved the vacuum. I stopped at 20 degrees, because that sounds like a huge number and I didn't want to introduce a knock at idle. Am I good at 20 or should I push it further up??

I'm not a mechanic . . . and mostly a hack compared to the builds on this site.

 

[Greg - Mopar2U]

Thanks for sharing the info on the Sniper. I have a 74 charger se ...440 bored .50 over to a 451... I see that you have a Tremec 5 speed bolted up...I'm curious to know how you did that set up. Did you have to use an adaptor plate ect.

The car originally came w 727 automatic shift on the steering column - I bought the Tremec and the kit from Silver Sport . . . it came w everything I needed: Transmission, Bell housing, pedal assembly, hydraulic clutch, tunnel and 50 pages of instruction.

Sorry - not sure that helps you.

 

[70chall440]

I can't say if you should bump it more but I think that if you continue to play with it, it will only get better.

 

[rmchrgr]

Holley Sniper Installation instructions: Read them and follow the recommendations. Read them and follow the recommendations. Read them and follow the recommendations.

Damn straight. I admit it can be hard to actually adhere to it because like all instructions they're boring and complicated and repetitive. But until you've done it successfully, you don't know better.

Timing: When used w the Holley distributor, the Sniper controls the timing (SNE 550-511K, SNE 550-305. I used the Holley Coil Driver - not MSD box). You set the timing you want for Crank, Idle, Wide Open Throttle and Cruise. On a car w a stock distributor, you have to set the initial timing, then choose weights and springs and adjust the vacuum advance to guess what the final timing might be - according to engine knock. Once the Sniper is set to the engine everything else is a number you set on the Hand Held. (My car loves idle timing @ 20, but I have crank set to 0 and total at 34.)

I had 20 initial on a bone stock 383 that was in my '68 Coronet. Always best to run as much initial as the combination will tolerate.

Gas: The Sniper has a closed loop calculation w the oxygen sensor in the exhaust - it sends gas accordingly. It learns and adjusts to your driving habits and drive conditions. Carburetors work great, out of the box, but then you have to adjust metering rods and/or jets and accelerator cam(s). To do this properly you'll need to monitor AFR in a variety of conditions . . . and adjust accordingly. (I have AFR's set to 13.5 at idle, 14 at cruise and 12.5 at Wide Open - recommended numbers from the Holley Instructions. )

Data logging is the key here and then being able to make the appropriate adjustments based on your observations. Creating your own custom fuel and ignition tables really helps and accelerates this understanding.

Initially - I tried to reuse the gas tank and use an external pump, the used/original tank clogged the fuel filters. I replaced the tank with one that has an internal pump (AEI 18162). Run new lines.

Hate to say it but using the related components as intended is the most efficient route, especially the ignition. Yes, it's more expensive to invest in all this stuff at one time but if you get far enough into it you'll realize that doing it any other way is a mistake.

Cooling: The Sniper can control 2 electric fans (This one has 2 speeds: DER-16217) . . . That turn on when needed.

Electrical: Electric fuel pump, electric fans. If making additional changes/additions upgrade the altinator. (140 amp on CVF serpentine)

Besides upgrading the alternator, I usually suggest re-wiring the car to anyone considering EFI. Seems nuts but it's the right move. Modern fuse box, good wire.

Your wiring skills also need to be good - no twisting wires together, no jamming wires into the fuse box, no hardware store yellow crimp connectors.

'The Pink Wire': Sniper needs the Pink wire to have clean power during Run and Crank key positions. If you've got the Holley distributor - you don't need the ballast resistor, but the power wires to the resistor are Run and Crank. Originally I attached them w a diode to prevent any current going the wrong way, but there ended up being a flat spot between the run and crank in that key position that disrupted the Sniper computer. I added a 'Delay Relay' to this circuit. (74985 www.delcity.net ) The delay relay triggers on the Run wire and keeps the pink wire energized for a (user) specified time through the time of crank. This solved the crank/start problem, but also allows the cooling fans to run after I turn the car off. (up to 3 minutes)

I jumped the IGN1 and IGN2 circuits right at the ignition switch. (1968 it's in the dash) If the switch is in the column you'd have to do this in the harness somewhere. On my '71 Duster I did it behind the ignition switch connector. This is the same idea/method when you use an MSD. No break between key positions.

Misc: 'Throttle Extension' Summit SNE 20-16 drastically improved the ease of throttle pressure. (The aftermarket linkage that makes the Sniper secondaries work separately than the primaries was discouraged from Holley Tech.)

I did experience the on or off feeling but never used the throttle extension. I was told that sometimes the throttle blades could become cocked enough where the edges would get hung up inside the bore causing them to bind. The way to fix it was to loosen the throttle shaft and sort of reposition the blades so they don't get hung up. I never did that either before selling the car earlier this year.

Misc: This throttle cable bracket worked great (Mancini MREAR134S ) . . . was worth the money. It held the throttle cable and gave room behind the Sniper to wrap the misc cables and Coil Driver.

That's AndyF's bracket. I used one too, works good.

Misc: I installed the Sniper over top of a 1" spacer . . . I found recomendations to do this, and didn't want to re-do anything afterwards.

I hope this helps.

Greg

I ran a 1" open spacer. Not sure if it did anything or not. Didn't hurt though.

Funny, I sign my posts with my name too.

- Greg

 

[Greg - Mopar2U]

So you're using a canister-style coil (hence the use of the coil driver) ?



This should read 565-305 (I think)

Sorry - my bad the hyperspark distributor is SNE 565-305.

Holley Tech told me to use a canister coil. I'm assuming that the coil driver and the MSD box do the same thing.

 

[70ChargerRT]

I run the complete Holley Sniper X-Flo on my Charger and it was the best decision I ever made. I run a decent size cam so I had it laptop tuned and even though they are self learning I’d recommend getting all of them laptop tuned. It feels good hearing that thing firing right up on a 24 degree day and not even bat an eye. The 1” spacer isn’t a must unless you have a dual plane but if you have the room run it. It can gain you A little HP but you won’t see it until you hit the higher RPM,s. I run all factory wiring and fuse boxes but it’s all new. You definitely dont need need a modern fuse box and I have more accessories than most. You just need to understand wiring, especially on Mopars. I’m running. EFi, dual fans, vintage air, Dakota Digital Gauges, T-56 Magnum, Dual Power Seats, Big Stereo with 700 watt amp, vacuum pump for brakes, LED Lighting, using 1 wire 160 amp powermaster alt and a yellow top Optima Battery. I had 1 little hiccup on here and the guys on this page helped me get it took care of. My first alternator I had didn’t have enough idling amps so I bought the 1 wire powermaster. Since then I’ve had zero problems with any of it but you need to overground everything and use the correct size wiring when you ground and when running the wire from the alt to the battery.

 

[64fury74charger]

I started with the original sniper and had the infamous injector issue so I decided to just upgrade to the sniper 2 and what a difference. Throttle feels really smooth and not having the internal pressure regulator is good. I put an Aeromotive regulator on and it’s sweet and simple.

The hyper spark is pretty much plug and play. Being able to play with the timing and a/f ratio really makes tuning easier and you’re working in real time so the engine reacts as you make adjustments. I also used the Wagner adjustable pcv valve and that solved some issues and stopped spitting oil vapor out of the breather on the valve cover.

Yesterday I did a cold start after sitting a couple weeks and she fired up on the first try and idled smooth even dead cold on a cold day. Never had that with a carb setup.

 

[70ChargerRT]

To me the Wagner PVC valve is a waist of money because you really need to run it in the fixed orifice mode and I definitely wouldn’t have it running back in to my sniper. I jerked mine off and only use it when I go on long cruises or drives. I pull my breather off, plug it in and run it to a catch can. These are some older pics, I now have my AC configured differently.

 

[RemCharger]

I wanted to share some thoughts and opinions I had in adding the Sniper EFI to my 71 Charger. At the time, I couldn't find information on some of this setup. I hope this information helps someone to do a better/quicker job than me. Let me know if you have questions/suggestions.

Car: '71 Charger w 383, stroked and bored to 413 w 270 Comp Cam. Tremek 5 speed and 3.91 gears in 8 3/4" rear.

Holley Sniper Installation instructions: Read them and follow the recommendations. Read them and follow the recommendations. Read them and follow the recommendations.

Timing: When used w the Holley distributor, the Sniper controls the timing (SNE 550-511K, SNE 550-305. I used the Holley Coil Driver - not MSD box). You set the timing you want for Crank, Idle, Wide Open Throttle and Cruise. On a car w a stock distributor, you have to set the initial timing, then choose weights and springs and adjust the vacuum advance to guess what the final timing might be - according to engine knock. Once the Sniper is set to the engine everything else is a number you set on the Hand Held. (My car loves idle timing @ 20, but I have crank set to 0 and total at 34.)

Gas: The Sniper has a closed loop calculation w the oxygen sensor in the exhaust - it sends gas accordingly. It learns and adjusts to your driving habits and drive conditions. Carburetors work great, out of the box, but then you have to adjust metering rods and/or jets and accelerator cam(s). To do this properly you'll need to monitor AFR in a variety of conditions . . . and adjust accordingly. (I have AFR's set to 13.5 at idle, 14 at cruise and 12.5 at Wide Open - recommended numbers from the Holley Instructions. ) Initially - I tried to reuse the gas tank and use an external pump, the used/original tank clogged the fuel filters. I replaced the tank with one that has an internal pump (AEI 18162). Run new lines.

Cooling: The Sniper can control 2 electric fans (This one has 2 speeds: DER-16217) . . . That turn on when needed.

Electrical: Electric fuel pump, electric fans. If making additional changes/additions upgrade the altinator. (140 amp on CVF serpentine)

'The Pink Wire': Sniper needs the Pink wire to have clean power during Run and Crank key positions. If you've got the Holley distributor - you don't need the ballast resistor, but the power wires to the resistor are Run and Crank. Originally I attached them w a diode to prevent any current going the wrong way, but there ended up being a flat spot between the run and crank in that key position that disrupted the Sniper computer. I added a 'Delay Relay' to this circuit. (74985 www.delcity.net ) The delay relay triggers on the Run wire and keeps the pink wire energized for a (user) specified time through the time of crank. This solved the crank/start problem, but also allows the cooling fans to run after I turn the car off. (up to 3 minutes)

Misc: 'Throttle Extension' Summit SNE 20-16 drastically improved the ease of throttle pressure. (The aftermarket linkage that makes the Sniper secondaries work separately than the primaries was discouraged from Holley Tech.)

Misc: This throttle cable bracket worked great (Mancini MREAR134S ) . . . was worth the money. It held the throttle cable and gave room behind the Sniper to wrap the misc cables and Coil Driver.

Misc: I installed the Sniper over top of a 1" spacer . . . I found recomendations to do this, and didn't want to re-do anything afterwards.

I hope this helps.

Greg

View attachment 1582811

Curious as to what exactly you mean by bored and stroked to 413?

 

[Greg - Mopar2U]

After dealing with recent cold start issues on my 383 daily, I’m considering the Holley Sniper on my 440 build for my ‘68 GTX.

I'm new to this Forum - I like it.
There's alot about the Sniper I like too. Mostly I like the adjustability from the Hand Held. There's a 'Prime' enrichment, Coolant temp enrichment, Acceleration enrichment, Load enrichment based off MAP, timing and AFR. It's more expensive than a Carb, but if you want to tune and play w numbers .. . it's great.

Curious as to what exactly you mean by bored and stroked to 413?

I gave the stock 383 to an engine builder with instructions to stroke and bore it for torque. I don't have alot more than that - I'm assuming he put in a crank for a 413 and built it to that spec. I am looking at the build sheet let me know if you want specific #'s, but I don't know if he shaved the heads, or what the final compression/ratio is.

Greg

 

[RemCharger]

I'm new to this Forum - I like it.
There's alot about the Sniper I like too. Mostly I like the adjustability from the Hand Held. There's a 'Prime' enrichment, Coolant temp enrichment, Acceleration enrichment, Load enrichment based off MAP, timing and AFR. It's more expensive than a Carb, but if you want to tune and play w numbers .. . it's great.

I gave the stock 383 to an engine builder with instructions to stroke and bore it for torque. I don't have alot more than that - I'm assuming he put in a crank for a 413 and built it to that spec. I am looking at the build sheet let me know if you want specific #'s, but I don't know if he shaved the heads, or what the final compression/ratio is.

Greg

Ah OK thanks. Probably a 432 or so.

 

[rmchrgr]

Mostly I like the adjustability from the Hand Held.

Not trying to argue with you but based on my own experience, I found the hand held to be somewhat lacking especially in regards to data logging. If you're going to use the data logging feature, you'll need to use a laptop with the Holley software to see it.

Even after converting to EFI, I find a lot of guys still scoff at using a laptop to tune the car. I get that but IMO plugging into the ECU via laptop is really the best way to monitor things and make changes on the fly. The Holley software is actually pretty good and once you get used to it you will see how limited the handheld is.

There is an adapter cable that allows one to plug a laptop with a USB port into the CAN connector. The newer versions have M8 connectors.

 

[gkent]

I find a lot of guys still scoff at using a laptop to tune the car.

They're living in the past !!

 

[rmchrgr]

They're living in the past !!

I've had direct experience with this exact scenario. A neighbor of mine with his own '60s muscle car would see me driving my Dodge around the neighborhood and decided he was going to convert his car to EFI. Good guy and all but just the wrong dude to be doing this type of thing. He is definitely not someone who was willing to spend much if any time trying to optimize the car with the equipment it already had or even researching the pros and cons of EFI. Like I said previously, EFI won't magically make stuff run any better by virtue of just bolting it on in place of a carburetor.

Let's be honest, when someone who is considering converting to EFI repeatedly says they're not a computer guy, they probably shouldn't be messing with this type of thing. It's not that you need to be a 'computer person' per se but what that really means to me is that there is a certain mistrust of anything computer-related and/or a lack of desire to learn how stuff like that works. Let's be honest though - if you can't figure out by now how to navigate software menus, populate blank fields, perform simple commands like "save as" or upload a file to another device you're going to have a tough time with it.

Ultimately I agreed to help the guy do the conversion. Every suggestion I'd make though he'd brush off or even do the opposite 'cause "he knew what he was doing." The wiring in the car was a mess but somehow he didn't grasp that. The main battery cable was probably the original or at least 40+ years old and was literally hanging on by one strand of copper. I suggested several times that he rewire the car before doing the conversion but it wasn't registering with him. Eventually he replaced a couple of the really bad wires but by and large it was still a mess and it eventually came back to bite him.

Even after offering to go through the install with him step by step, he did it on his own without telling me. That's when my phone started ringing because shocker, he couldn't get the car to run. It was tough to help him after that because I had no idea what he did (he didn't either) but more importantly he didn't understand the underlying ideas behind the whole thing. I don't have the time or patience to play guess-the-mistake with stubborn, cynical people.

I knew he didn't read the directions either because Holley says over and over again to put the main power cable directly to the battery and if I remember right he ran it to the cigarette lighter or something goofy like that. I called him out on it and he had no answer. He also wrapped up two wires that were actually needed - the white ignition trigger wire and a red signal wire. Before we figured all that out he was visibly upset and was ready to shitcan the whole thing. I talked him off the ledge and left him to cool off. He eventually got it going a few days later after a lot of time on the phone with Holley tech support.

Soon after that he gave me his SD card from the handheld so I could give him a tune. I put one on the card for him and told him to come by with his car and I would show him how to upload it to the ECU but he never did. After that, I didn't see him much and never saw the car out. A couple months went by and I found out through another neighbor he abruptly moved to another town about 20 min. away. The guy never told me he was moving and didn't ask for the card back before he moved so I know for a fact he's not doing any data logging. He should have saved himself the hassle and expense and stuck with the carburetor.

The point of this story is that IMO, it makes little sense to do the conversion if you're not going to get involved with the tuning beyond the initial startup. Again, that's what happens when people take marketing claims at face value. They reel you in with the plug and play idea but that's really not painting the whole picture. Yes, the system will 'learn' as you drive and will generally be OK but if you're just relying on the initial 'Wizard' tune that you input through the handheld and never lift a finger otherwise you're leaving a lot on the table. The main benefit of these systems is the ability to customize and adjust things to a really finite level which theoretically can help get your car running as sharp as possible under all weather conditions and loads. The "resolution" of the programming is much finer than any mechanical part could ever proivide. Just have to decide if it's worth the time and effort to optimize it.

 

[64fury74charger]

I've had direct experience with this exact scenario. A neighbor of mine with his own '60s muscle car would see me driving my Dodge around the neighborhood and decided he was going to convert his car to EFI. Good guy and all but just the wrong dude to be doing this type of thing. He is definitely not someone who was willing to spend much if any time trying to optimize the car with the equipment it already had or even researching the pros and cons of EFI. Like I said previously, EFI won't magically make stuff run any better by virtue of just bolting it on in place of a carburetor.

Let's be honest, when someone who is considering converting to EFI repeatedly says they're not a computer guy, they probably shouldn't be messing with this type of thing. It's not that you need to be a 'computer person' per se but what that really means to me is that there is a certain mistrust of anything computer-related and/or a lack of desire to learn how stuff like that works. Let's be honest though - if you can't figure out by now how to navigate software menus, populate blank fields, perform simple commands like "save as" or upload a file to another device you're going to have a tough time with it.

Ultimately I agreed to help the guy do the conversion. Every suggestion I'd make though he'd brush off or even do the opposite 'cause "he knew what he was doing." The wiring in the car was a mess but somehow he didn't grasp that. The main battery cable was probably the original or at least 40+ years old and was literally hanging on by one strand of copper. I suggested several times that he rewire the car before doing the conversion but it wasn't registering with him. Eventually he replaced a couple of the really bad wires but by and large it was still a mess and it eventually came back to bite him.

Even after offering to go through the install with him step by step, he did it on his own without telling me. That's when my phone started ringing because shocker, he couldn't get the car to run. It was tough to help him after that because I had no idea what he did (he didn't either) but more importantly he didn't understand the underlying ideas behind the whole thing. I don't have the time or patience to play guess-the-mistake with stubborn, cynical people.

I knew he didn't read the directions either because Holley says over and over again to put the main power cable directly to the battery and if I remember right he ran it to the cigarette lighter or something goofy like that. I called him out on it and he had no answer. He also wrapped up two wires that were actually needed - the white ignition trigger wire and a red signal wire. Before we figured all that out he was visibly upset and was ready to shitcan the whole thing. I talked him off the ledge and left him to cool off. He eventually got it going a few days later after a lot of time on the phone with Holley tech support.

Soon after that he gave me his SD card from the handheld so I could give him a tune. I put one on the card for him and told him to come by with his car and I would show him how to upload it to the ECU but he never did. After that, I didn't see him much and never saw the car out. A couple months went by and I found out through another neighbor he abruptly moved to another town about 20 min. away. The guy never told me he was moving and didn't ask for the card back before he moved so I know for a fact he's not doing any data logging. He should have saved himself the hassle and expense and stuck with the carburetor.

The point of this story is that IMO, it makes little sense to do the conversion if you're not going to get involved with the tuning beyond the initial startup. Again, that's what happens when people take marketing claims at face value. They reel you in with the plug and play idea but that's really not painting the whole picture. Yes, the system will 'learn' as you drive and will generally be OK but if you're just relying on the initial 'Wizard' tune that you input through the handheld and never lift a finger otherwise you're leaving a lot on the table. The main benefit of these systems is the ability to customize and adjust things to a really finite level which theoretically can help get your car running as sharp as possible under all weather conditions and loads. The "resolution" of the programming is much finer than any mechanical part could ever proivide. Just have to decide if it's worth the time and effort to optimize it.

You are spot on about diving into the system and experimenting with all the available options to really improve how the engine performs. If the engine has any mechanical problems or other issues those need to be addressed before the installation because they will be very difficult to work around or smooth over.

Wiring is critical and also routing and separating different components as per the instructions. Relays are a good tool and clean power and ground.