EFI Or Carbureted

[GT53]

Hello All,

I will be ordering my FF Roadster kit tomorrow (April 12) so with that in mind I pose the following question as I ponder engine choices:

Being that a Blueprint 427 with EFI is about $2000 more than the carbureted version, is it worth the savings to have to "tune" the carbureted version from time to time. I know there are purists out there that would never have a motor with EFI and there are those that swear by EFI for "ease of operation" so I'll throw it out there for all to comment. BTW, I am in neither camp at this point although my initial instinct was to go EFI.

The last time I tuned a carbureted engine was on a 1962 E-Type Jag, and it was a long time ago and it was a PITA to get it right. Carburetors have come a long way since 1962 so I would guess that is quite a bit easier than back in the stone age when I last did it.

What say all of you?

Greg

[Wbauman]

Having cars with both I’ll say for a occasional driver carb is ok. If your going to use more than that FI. My current roadster is FI.

Yes carb has come a long way but My factory style FI has been flawless for 14 years. No jet changes no fuel pressure changes just turn key and go.

You are going to get an earful around here for both maybe try a little search function first.

[GT53]

Having cars with both I’ll say for a occasional driver carb is ok. If your going to use more than that FI. My current roadster is FI.

Yes carb has come a long way but My factory style FI has been flawless for 14 years. No jet changes no fuel pressure changes just turn key and go.

You are going to get an earful around here for both maybe try a little search function first.

I figured I would get a bunch of "input" from both sides but I like as much info as I can muster so thanks.

[chmhasy]

Greg, It's your car. Build it the way that makes you happy.

[Papa]

Consider what is making you ask the question to begin with and then weigh the pros/cons and go from there. For me, the driver to go EFI was the altitudes that I live and drive at. I had a carbureted car before starting my roadster build and swore I'd never do that again. Garage smelled like gas all the time, car wouldn't idle when cold and was super rich. Tuning for conditions are only good in those conditions, so seasonal tuning was needed. Tuning EFI can be done remotely, so no need to have an expert in your area. Download the tune and send it off to an expert unless you want to learn to do it yourself. I've done a little of both. The great part is, if the new tune doesn't work, you just reload the previous one and in a few seconds you are right back to a known point. No need to remember how many turns of the screws you've made or what jets are installed.

Can you tell which camp I'm in? :p

[NAZ]

Greg, I grew up with carbs and used to make my living tuning them. As a drag racer, I'm very good at tuning carbs. And anything you decide on will require you to learn about that system and how to tune it unless you want to take it to a pro and pay him or her to tune it for you. So there is not much chance of a plug and play option that actually is optimized for your combo -- plan to tune no matter what system you decide on.

If you live in the east or flyover country where the world is mostly flat, a carb can work very well if sized and set-up properly. But here in the mountain west, the altitude variation can be a significant factor in the decision. My street legal race car can be at ~10,000' DA one day and at 2,000' DA the next. That requires a main jet change of four sizes before you even start the tuning process. And during a race I can make several changes from morning to afternoon on my carb. Once set-up properly, modern EFI will adjust for those changes and run like a champ without all the drama.

And if you really get into the carb tuning thing like a drag racer, you can spend thousands on change parts and tuning equipment so the first cost differential between carb and EFI doesn't tell the whole story.

Your life will be easier with EFI if you choose the correct manifold. So unless you just like to tweak on things or you have some wild cam and engine combo that won't work with EFI like my car, stay away from the carb.

[GoDadGo]

My car is carbureted because I wanted simplicity; however, altitude is NOT an issue for me.
I may be 100'-150' above sea level if I'm North of Lake Pontchartrain or as low as 10-15 below sea level depending on where I am in the Metro New Orleans area.

[mburger]

Here in FL., I’m about 18’ above sea level, unless I’m in northern, eastern western or southern Florida, then I’m about 18’ above sea level. :p I have under 700 miles on my blueprint 347. I opted for the Edelbrock Pro Flo 4 EFI only because I like the idea of injecting the fuel directly into the cylinders versus having it get sucked down the throttlebody through the intake at somewhat varying degrees to each of the cylinders. Perhaps I fell in love with the EFI marketing wizards but engines have run with carburetors since there were engines and they run just fine. The PF4 works well and if I could only get rid of the annoying popping and crackling on deceleration and in between shifts I would say it works excellently.
Knowing what I know now, I’d probably still go EFI but perhaps go with the sniper pro.
Carburetors today run well right out of the box so you won’t go wrong either way.

[GT53]

Gentlemen,

If nothing else I love all of your “senses of humor.” Ohio surely isn’t as flat as Florida or Louisiana nor are there any mountains to climb on foot or in car as in Colorado, so I reckon I could go either way. I like tinkering as much as the next guy but there is most assuredly something to be said for the simplicity and consistency of merely climbing in the cockpit, turning the key and heading out without the slightest fear that should I get lost and end up in thin air I’ll be good to go until I find my way back home.....or not. I’ll spring for the EFI.

Thanks to all.

Greg

[BradCraig]

Here in FL., I’m about 18’ above sea level, unless I’m in northern, eastern western or southern Florida, then I’m about 18’ above sea level. :p I have under 700 miles on my blueprint 347. I opted for the Edelbrock Pro Flo 4 EFI only because I like the idea of injecting the fuel directly into the cylinders versus having it get sucked down the throttlebody through the intake at somewhat varying degrees to each of the cylinders. Perhaps I fell in love with the EFI marketing wizards but engines have run with carburetors since there were engines and they run just fine. The PF4 works well and if I could only get rid of the annoying popping and crackling on deceleration and in between shifts I would say it works excellently.
Knowing what I know now, I’d probably still go EFI but perhaps go with the sniper pro.
Carburetors today run well right out of the box so you won’t go wrong either way.

Does the Edelbrock have a Decel fuel cutoff setting? I had the popping under deceleration and enabling that setting eliminated it.

[GoDadGo]

You Gotta Got To Head Down Here After COVID Is Over!

With that said, hit it Harry!

https://youtu.be/DXTQpB7QHe8

[CraigS]

I think it depends on what you are more comfortable w/ working on. From a lot I have read here, the aftermarket efi are not always so plug and play as their sellers want you to believe. I went car be cause at the time efi was 3 times as expensive as a good carb. I also enjoyed learning what I needed to know about carbs. But I spent easily as much on mixture reader via O2 sensor tool and skillions of jets as I did on the carb. But in the end, after the first couple of minutes running, my carbed 408W drove just as nicely as my wife's 15 Mustang GT.

[Mike DiGiorgio]

The Answer to this in my opinion is largely based on the owners comfort level with the two fuel systems. Carbs have come a long way, But so has EFI. Systems like Holley's Sniper make it very simple. but there is still a larger time and money investment into parts/knowledge when installing EFI than a carburetor requires.

The part I do not think that gets talked about enough with EFI is the secondary benefits, like having a Map-able ignition system that is not reliant on a vacuum capsule, or weights to advance timing under load. Or smaller things like cooling fan control built in, or ability to adjust idle speed when Air Conditioning is engaged. To me these included functions more than make up for the price difference.

[Avalanche325]

Garage smelled like gas all the time, car wouldn't idle when cold and was super rich.

Sooo.....What's the bad part?


For me. I wanted a car that was pretty much like a Cobra. If I want to get in and go without warm-up, be able to stomp the gas to the floor in 4th gear at 1000rpm, get good mileage, etc. I have an Infiniti for that.

You will have to tune a carb or EFI. The self tuning EFI stuff is usually "OK" for a cruiser. But if you are turning the wick up, it takes a proper tune. So that is more of a which one do you want / like to work on.

Some of you guys make it sound like you can't drive a carbureted car over a speed bump without changing the jets. I certainly never had to pull over and change jets on any of my many carbureted cars when I left the coast. But to be fair, I lived on the east coast with my carbed cars, so never went above 6000 ft. They certainly made it without a fuss.

From my 10+ years on the forums. Guess what has sent more of these cars home on a flatbed than anything? EFI. I know a guy with a Backdraft that does long distance and even cross country drives in his Cobra. He has EFI. But, he keeps a carb and low pressure fuel pump in his trunk after getting stranded. He has used it twice.

[GT53]

Sooo.....What's the bad part?


For me. I wanted a car that was pretty much like a Cobra. If I want to get in and go without warm-up, be able to stomp the gas to the floor in 4th gear at 1000rpm, get good mileage, etc. I have an Infiniti for that.

You will have to tune a carb or EFI. The self tuning EFI stuff is usually "OK" for a cruiser. But if you are turning the wick up, it takes a proper tune. So that is more of a which one do you want / like to work on.

Some of you guys make it sound like you can't drive a carbureted car over a speed bump without changing the jets. I certainly never had to pull over and change jets on any of my many carbureted cars when I left the coast. But to be fair, I lived on the east coast with my carbed cars, so never went above 6000 ft. They certainly made it without a fuss.

From my 10+ years on the forums. Guess what has sent more of these cars home on a flatbed than anything? EFI. I know a guy with a Backdraft that does long distance and even cross country drives in his Cobra. He has EFI. But, he keeps a carb and low pressure fuel pump in his trunk after getting stranded. He has used it twice.

Avalanche... Thanks for the input. I never thought about modern cars having issues with EFI because cars are generally so reliable these days but the Cobra is most assuredly a different beast. I pulled the trigger today and ordered the kit with the plan of a Blueprint 427 EFI but being as the wait time for the kit will be until September I will have plenty of time to think it over and change it up if I choose to do so.

[boat737]

When I built the car, I wanted a more historic/authentic look and feel. My setup is an Engine Factory 427w Dart, Edelbrock Performer RPM Aluminum Intake manifold, Edelbrock Victor Jr. Aluminum heads, Holley 750cfm carburetor (electric choke, mechanical secondaries.) I did want a streetable setup, so it's a slightly milder cam. It's starts right up, warm or cold (after sitting 2 weeks or more), and idles very nice (warm or cold). In my youth, it was only carbs, so that's more my comfort level. I'm very happy with my choice and setup. I also get a lot of accolades from the spectators as well. The car in general is loud, rough, smelly, and obnoxious. A lot like me. I'd do it again.

The only real problem I encountered, is that after several hundred miles, I had a slight fuel seepage that was a bit hard to find. It turned out to be a float bowl gasket that had failed. It looks like it was crushed because the float bowl may have been tightened excessively. Once that was fixed, all is good.

[Fman]

I ended up going Pro Flo 4 EFI with a Dart 427. I only have 100 miles on the car so my experience will be limited. However, I have had previous vehicles with carbs and all of them ran but none of them seem to run exceptionally well. There was always some type of issue with performance in heat, elevation changes, sitting too long, chokes not working correctly, cold starts, vapor locks, etc. I was definitely no carb expert either so maybe that played into my experience with them. On my build I decided to go EFI, so far it has been running great from the time I turned the key. The only issue I had with the PF4 was a temp sensor was reading incorrectly, they sent me a new one and it has been fine since. I chose the PF4 system because it is true multi port fuel injection and I like how the ECM is not attached to the throttle body and away from heat like other EFI systems out there. I was able to mount the ECM behind the firewall away from the heat.

Time will definitely tell but so far I have no regrets and it is meeting my expecations. Hopefully I will be saying this years down the road :D

[AtlantaCobra]

From one Greg to another........go EFI. So reliable, less exhaust stinking up the garage(unless you're into that kind of thing) and a lot of tuning options via the computer. I gained 35 HP just though a chip reprogram.

-Greg

[rich grsc]

146161

[ggunter]

Having ordered my 347 with a carb, because I have always liked the simplicity of carbs. I have two hundred miles on the car and have dealt with a stumble off idle and the high reving start ups from the electric choke that I don't like so, I changed my mind and ordered the Holley Sniper kit a couple months ago. I installed it last weekend (pretty easy) and have not run it completely through the learn mode yet as the body is off getting ready to paint it. The install was flawless, only five wires,and it runs very well so far only being able to run up and down my drive way,500ft each way. The thing I do not like, and a lot of other people, is the opening of all four barrells at once. Its like having all the horsepower at once which makes trying to feather the pedal and pulling away from a stop a bit nerve racking. I did order the progressive linkage kit and will change the maps for that upgrade, so if that takes care of that issue then I think the system is golden. I do like the instant start up and right to idle and no hesitation like modern day injection.

[BEAR-AvHistory]

It ain't as pretty or period correct as multi carbs.

https://thefactoryfiveforum.com/attachment.php?attachmentid=126382&d=1586814394

But turn the key & drive for 6 years without touching the engine its the best plan.

https://thefactoryfiveforum.com/attachment.php?attachmentid=146178&d=1618330762

For very easy meaningful power increases its also the best plan

[Otee453]

I have Holley Sniper with the Hyperspark system (distributor and ignition system for full ECU timing control). Seems like a very nice system and I like it very much, but there is a new learning curve involved. I consider myself moderately capable with the computer, but I had to learn a LOT on the computer side of the Sniper. You can pay tuners to do it but you will still need to learn an intermediate level of proficiency with timing maps, fuel maps and just how to use the software. Thank goodness for youtube. I spent two weeks pulling my hair out on timing maps, and suddenly, just like that, I got it. That was a breakthrough moment for me and I feel much more comfortable with the system.

If you're not computer savvy, you may want to watch plenty of youtube videos on tuning the sniper first, then assess whether you want to take the new journey. Ive read where many old school carb guys really struggle learning the new system or maybe better put.... unlearning their old knowledge.

[Al_C]

I’ll spring for the EFI.



Good choice! (just my 2 cents...)

[rich grsc]

I ended up going carb. Being in Michigan the car is going to be stored (battery disconnected) for 4-6 months out of the year. EFI systems do not like sitting like this. Yes you will be fiddling with the carb in the spring but once adjusted your good. The EFI will be relearning everything again like it is a new day. btw in MI temperature swings from 20-80 in a given week. Very frustrating when the car wants to relearn the world for a couple of weeks because temperature doesn't stay consistent. Carb a turn of a screw and I am good. I have had both carb and EFI in the past and landed on Carb because of this storage component. If you are not storing I would go EFI all the way not even a second thought.
My EFi doesn't lose it's memory, and the computer instantly adjusts for temperature swings. Not sure where you got that info, but it isn't correct.

[CaptB]

Carb baby!

[ggunter]

Both have their pluses and minuses but in todays world, me being an old timer and having carbs all my life this is my first time into fuel injection and it's a learning curve for me. I'm going to progressive linkage and reprogramming the ecu to a progressive map will be a learning experience for me. Hopefully it will go well....

[NAZ]

Carb baby!

Yup, carburetors are still very popular and are sure to be with us until the last IC engine is replaced by electric motors. They can be made to run very well and in some applications, make more power than EFI. And some engine combinations EFI is not even an option so your choice is between a carb and mechanical FI. Trouble is, unless you have gray hair and grew up tuning carbs you probably think they are set-up right out of the box. And some think "tuning" a carb is a matter of turning the idle adjustment screw and setting the idle RPM. There is far more to it than turning idle mixture screws.

Lets take a look at the most popular carb as an example, the Holley 4150 "Double Pumper" and its clones. The most "tunable" carb on the market. If you think that turning the idle adjustment screws and setting the idle RPM is "tuning" then here are some of the change parts and adjustments beyond the idle adjustment screws that facilitate actually tuning that carb: float level, float & valve type, transfer slot adjustment (primary & secondary), idle jets, idle air bleeds, emulsion jets, main jets, power valve, power valve channel restrictors, high-speed air bleeds, accelerator pump size, accelerator pump cams, squirters, and secondary linkage. Those are just the common change parts and simple adjustments. Then there are the modifications that are sometimes required to get the carb dialed in when you have a big cam like I run in my car.

Yup, the simplicity of a carb -- that's what I'm talking about. Choose wisely...

[Avalanche325]

Most guys with EFI and a battery disconnect run a fused memory hot wire. I've got one to my clock.....being all high tech like I am.

[FF33rod]

I did order the progressive linkage kit and will change the maps for that upgrade, so if that takes care of that issue then I think the system is golden. I do like the instant start up and right to idle and no hesitation like modern day injection.

You'll like the progressive linkage, only 1 setting to adjust in the software. The other way around the "twitchiness" is to extend the throttle arm on the Sniper that the throttle cable attaches to - it will open up less for the same gas pedal travel.

Steve

[ggunter]

I did order both the linkage to the secondaries and the extended throttle arm which I will try first. Like you said I just want to take out the twitchiness and make a smoother off the line acceleration and if the arm does that then it's the fastest fix.

[phileas_fogg]

ggunter: If you have Forte's mechanical linkage, you can slide the rod end (the one under the air cleaner, NOT the one in the foot box) down in the slot to make the throttle less responsive. This would have the same effect as extending the throttle arm. In the picture below, my throttle was like an on-off switch; I moved the rod end down about halfway & the car is much more drivable for me.

GT53: NAZ nailed it in post #6: plan to tune no matter what system you decide on. Most out-of-the-box EFI tunes *tend* to run rich. To get the tune right, you'll learn more about whatever system you choose than you ever thought you would.


John

P.S. Note that in the picture below, I had not yet installed my throttle return springs.

https://live.staticflickr.com/4321/35455980284_17157da9a0_k.jpg (https://flic.kr/p/W28aEU)IMG_3511 (https://flic.kr/p/W28aEU) by jhsitton (https://www.flickr.com/photos/91016165@N07/), on Flickr

[narly1]

I have a ProFlo4 on order for my 302 build.

Recall this was an 88 MY engine with factory EFI.

I decided to go this route rather than trying to get the factory EFI (in unknown condition) to run correctly after the engine rebuild.

I not confident that it would work correctly with all the top end changes I've made.

My decision to go with the PF4 was based on:

1. It's multiport fuel injection scheme.

2. The electronics module is offboard from the engine and thus is not subjected to heat and vibration and more also easily/readily accessible for service if needed.

[rich grsc]

Info based on own experience on EFI systems that I have owned in the past. This kit car is not the first project car that I have owned. If you aren't losing memory then you have to be keeping the system hot somehow which defeats disconnecting the battery so you must not be storing the vehicle that long. And yes when you reconnect the battery in the spring with the temperature shifts it does extend its relearning time. Once again if are only driving it on a temperature range of 70-80 degrees then you are correct shouldn't be an issue. But I was driving my cars the minute the salt stopped hitting the road.

Heck just watch the video when Dave is showing engine choices and the difficulties he had starting his sons car because it went into recalibration from sitting. Link below

https://www.youtube.com/watch?v=fpjwKZEgzj8

Go to 35 min in and see all the proof you need.
Well I have several years of experience, and know my system does not lose its tune. So I don't need any proof, other than my own car. I don't disconnect the battery, zero reason to do so. I drive my car almost year round, from temps in the 20's and up, it's been from sea level to the top of Pike's Peak. Just because you had poor system doesn't mean everyone does.

[Papa]

From Holley:


The settings and adjustments are not kept in volatile memory so there is no time limit for keeping the battery disconnected. As long as you wait a few seconds after you shut off the car to disconnect the battery the settings will not be lost.

[BEAR-AvHistory]

Typical volatile memory stuff are radio stations etc. Engine controls are retained without a battery connection.

[rich grsc]

Non-volatile memory, that's what I was trying to explain, was having a brain fart. :rolleyes:

[BradCraig]

The "lose config when battery disconnected" thing seems to never go away, the Sniper will not lose it's tune if it loses power. As several have stated, there is still a LOT of tuning you need to do on EFI and other challenges to overcome (RFI, leaky exhaust, etc). It's a new skill that you need to learn and I thought it was fun to tackle. Someone also mentioned progressive linkage...either it works or doesn't, some combos just do not like it (mine). Holley actually doesn't support it although they have the config option in the software. Overwhelming consensus for fixing the touchy throttle is the extension for the throttle arm.

[NAZ]

Volatile memory -- is that what causes the doorway effect when you get older? You know, walk into a room and forget what you went in there for.

[rich grsc]

Volatile memory -- is that what causes the doorway effect when you get older? You know, walk into a room and forget what you went in there for.
You are 100% correct. :rolleyes: and thats why I couldn't think of it

[caesarmascetti]

Hello All,

I will be ordering my FF Roadster kit tomorrow (April 12) so with that in mind I pose the following question as I ponder engine choices:

Being that a Blueprint 427 with EFI is about $2000 more than the carbureted version, is it worth the savings to have to "tune" the carbureted version from time to time. I know there are purists out there that would never have a motor with EFI and there are those that swear by EFI for "ease of operation" so I'll throw it out there for all to comment. BTW, I am in neither camp at this point although my initial instinct was to go EFI.

The last time I tuned a carbureted engine was on a 1962 E-Type Jag, and it was a long time ago and it was a PITA to get it right. Carburetors have come a long way since 1962 so I would guess that is quite a bit easier than back in the stone age when I last did it.

What say all of you?

Greg

FWIW I converted from FI (Mass-Flo) to a carb nearly 10,000 miles ago and I couldn't be happier. I used a 650cfm Quickfuel with vacuum secondaries (per Mike Forte's recommendation) the carb was easy to set up, the engine starts with the electric choke even after 90 days of hibernating in the garage over the winter. Just my experience

[nucjd19]

I have really enjoyed reading the pros and cons of EFI and carb threads. I have a 600CFM Holley carb on my BPE 347. Been tweaking carbs on my fun rigs for years. My biggest tweaking of carbs is when my Rock crawler ( FJ40 Landcruiser) is at some really violent angles rather than tweaking for best performance on the street with a Ford engine. So I have a ton to learn about tweaking my Holley carb in my current setup. With that being said I am really excited to learn and do a deep dive so I feel somewhat competent on this setup. If it does not work out down the road or if I get an itch, I can spend an off season retrofitting a sniper.

[mburger]

Does the Edelbrock have a Decel fuel cutoff setting? I had the popping under deceleration and enabling that setting eliminated it.

Hey Brad. Yes it does the system defaults to 1500 and the minimum is 1000. Anything less than 1400 and my engine will consistently stall between shifts or coming to a stop at a light.

[Papa]

Hey Brad. Yes it does the system defaults to 1500 and the minimum is 1000. Anything less than 1400 and my engine will consistently store between shifts or coming to a stop at a light.

I don't know about other EFI systems, but the Holley Sniper Decel Cutoff feature only kicks in above a specific RPM, 3k if I recall. The symptoms of popping on decel can be caused by either raw fuel getting into the headers/exhaust and igniting or by a lean condition. I had a popping issue also, and after some assistance from a few folks on this forum as well as on the Holley Sniper forum, I was able to properly diagnose the cause and correct it. In my case, it was a lean condition and by bumping the fuel up in the low RPM, low vacuum range, I was able to clear it up. Listen to the first 60 seconds of this video after a little tuning of the fuel map:


https://www.youtube.com/watch?v=Ay8SRyLU6cY

[Papa]

Here is a video before I was able to resolve the popping. Right as I start to coast at about 42 seconds into the clip, you will hear the popping until the engine is back under some amount of load. It's really noticeable at the end of the clip as I'm coasting down hill.


https://www.youtube.com/watch?v=Ny6ynbeHP58

[NAZ]

I have really enjoyed reading the pros and cons of EFI and carb threads. I have a 600CFM Holley carb on my BPE 347. Been tweaking carbs on my fun rigs for years. My biggest tweaking of carbs is when my Rock crawler ( FJ40 Landcruiser) is at some really violent angles rather than tweaking for best performance on the street with a Ford engine. So I have a ton to learn about tweaking my Holley carb in my current setup. With that being said I am really excited to learn and do a deep dive so I feel somewhat competent on this setup. If it does not work out down the road or if I get an itch, I can spend an off season retrofitting a sniper.

I too have a lot of experience setting up carbs on offroad vehicles -- float bowl levels can be a challenge both from whoops and steep angles. I started as a desert racer.

If you want to dig deeper into Holley carbs and their clones, start with this book -- it's a very good tuning reference: https://www.corvettemods.com/David-Vizards-How-to-Super-Tune-and-Modify-Holley-Carburetors_p_20014.html?gclid=EAIaIQobChMI_cbFjJb _7wIVix6tBh03TA7uEAQYBSABEgJETfD_BwE

Anything written by David Vizard is worth reading. Have fun, it's personally rewarding to tune carbs and optimize them for a specific application.

[nucjd19]

Thank you NAZ!! I appreciate the info more than you know!

[ggunter]

After taking a good look at Mike Forte's mechanical linkage I will order that today. The FFR cable I threw away and bought the Lokar cable which worked much better but still takes a lot of foot effort and I'm not sure how well it will be effected by long term engine heat from the headers. The Forte setup is very adjuststable so you can adjust mechanical leverage to your advantage. I'm glad I'm doing this now while the body is off otherwise I probably would have put up with a stiff pedal.

[BluePrintEngines]

Hello Greg,

Thank you for choosing BluePrint Engines, we greatly appreciate you all. Can you give us a call, so we can compare the Holley Sniper Kit to our Holley Carburetors. We would love to help you decide what is the best option for your application.

Thank You, Jose

[ggunter]

I'm on the fence as to whether to keep the sniper or not. I have questions about changing over to progressive linkage and loosing the vacuum advance on the distributor. I bought the Forte mechanical linkage and will install that this weekend. Hopefully that will help with mechanical leverage advantage.I did order the longer throttle lever but that won't ship till May8th. That should help a bit. The all or noting throttle is really a pain to deal with. My body is off the car right now for paint so go karting around to make the ecm learn is a bit difficult right now. I did put turn signals and tail lights and a tag on it but I think I would get nailed by a cop even with them on there. I would love to know from anyone out there who has used the progressive linkage option on the hand held if that was all that was needed or another download was necessary. I really want to keep the Sniper because I like fuel injection but so far I'm not convinced. On the bright side I changed over to Wilwood brakes and my braking issues are a thing of the past. They are great.

[Papa]

I'm on the fence as to whether to keep the sniper or not. I have questions about changing over to progressive linkage and loosing the vacuum advance on the distributor. I bought the Forte mechanical linkage and will install that this weekend. Hopefully that will help with mechanical leverage advantage.I did order the longer throttle lever but that won't ship till May8th. That should help a bit. The all or noting throttle is really a pain to deal with. My body is off the car right now for paint so go karting around to make the ecm learn is a bit difficult right now. I did put turn signals and tail lights and a tag on it but I think I would get nailed by a cop even with them on there. I would love to know from anyone out there who has used the progressive linkage option on the hand held if that was all that was needed or another download was necessary. I really want to keep the Sniper because I like fuel injection but so far I'm not convinced. On the bright side I changed over to Wilwood brakes and my braking issues are a thing of the past. They are great.

Keep in mind that the learning that these EFI systems do is minimal. They essentially create a "learning" fuel table that needs to be merged to the base table and cleared and then adjusting the learn parameters for the areas of the map you are happy with to dial it in. Eventually, you will have the learn parameters either disabled completely or set to very minimal values. I think out of the box, they are at something like 50% across the board. This can contribute to learning "bad" behavior over time as well, or relearning things you tuned out at one point, but didn't adjust the learn parameters to retain those values.

I find it interesting that some experience the on/off throttle, as mine is very smooth and drivable with the standard cable layout. Are you using the FFR supplied throttle pedal? What is the angle set at on the throttle pedal at the pivot point? If I recall, there is a template in the manual to set that angle.

Dave

[ggunter]

I have the FFR pedal but got a Lokar cable and when I had the carburator on it, it was fine, but the Sniper spring tension of all four barrells at once seems to turn on more power and make it difficult to modulate when i'm coming away from a stop sign and I have tried various pedal heights.Seems the higher the pedal the easier to control but then if its the same height as the brake pedal then I find myself double pedaling gas and brake. thats the problem with large feet. I try to keep the pedal an inch lower then the brake pedal to stop that.I really need to drive it to finish the learn process then I'll make a determination of what I'm going to do with it. I really want to keep it but it has to work correctly for me. I did not recall seeing a template for the pedal angle. I have been using a slide adjustment up on the cable adapter at the throttle body to change pedal angle.

[bobl]

If you are using the ecu timing control you can improve the on/off a bunch by building a new timing table with a laptop. The default one is not very good. The progressive linkage also will help a bunch. If you are not using the ecu for timing you probably should. Sniper can be made to work very well.

[ggunter]

I have to tell you the Sniper set up is new to me and so far, being “plug and play” I’m not all that impressed. Some of it is due to my ignorance of this system. So far it runs horrible upon startup and until it gets some heat in the motor it doesn’t want to idle if you blip the throttle. It then will have the IAC kick in and run the idle up to 2000 rpm for 20 seconds and then calm down. I don’t know if it is still learning or not. I would like to install the Hyperspark system but don’t want to do that till this part is running right. I guess I’ll have to wait till I get the body back on and just drive it to see if it calms down.

[D Stand]

I had the same experience at first as well. Have you adjusted the throttle plates yet to get the IAC around 2-10%? Page 44 of the full manual explains how to do this.. mine was at 70% and would not idle very well at all. The other thing that helped me was once I got it to idle and warmed up I checked how much vacuum I had. The sniper says to start out with a mild cam setting if you don’t know if it a street/strip or race cam. Mine is only creating 9psi of vacuum so that puts me in their street/strip range. After making this change it has started right up and gets to idle right away. Page 40 has the cam information.

I do not have my car on the road yet so time will tell. I will be paying attention to the on/off effect based on your experience.

[Dave 53]

147139

[ggunter]

When I installed the system I did set up all the parameters as they wanted. When idling the tps is at zero and the iac is around 8. So that part works ok but if you blip the throttle cold the iac kicks the rpm up to about 2000 and you hear that annoying sucking sound from the air bleed till it calms down. The cam that came with my BPE 347 is not wild so I believe the vacuum is on the high side even though I haven’t checked it. I really believe it will calm down after I drive it for about 20 miles. The only real complaints that I have is, getting a smoother throttle response which I hope after I install the forte mechanical linkage will give me the mechanical leverage and adjustability to smooth out the abruptness of all four barrels opening. If I can’t make that happen and have to go to progressive linkage, I didn’t want to loose the metered vacuum port for the distributor. If that happens I’ll go to the hyperspark system. Either way I’ll get it all figured out or go back to the carb.

[BradCraig]

FWIW, the best way to cure the throttle sensitivity on the Sniper is the throttle arm extension. The progressive linkage is a hit or miss prospect and there really doesn't seem to be any rhyme or reason to tell when it will/won't work and run like crap. Technically, Holley does not support it although they have the setting in SW for it. https://www.efisystempro.com/sniper/sniper-efi-system-components/sniper-efi-throttle-extension-lever-20-16

[ggunter]

Ok here we go. I almost feel stupid explaining this, but the most simple fix worked the best. I had bought Fortes mechanical linkage kit with all the adjustability I could get mechanical leverage and make the throttle smooth and found it wouldn't work because my battery cut off switch is mounted on the firewall right where the linkage rod would go which would require making up new battery cables and moving the switch. Plan B, Make a new throttle lever 1.5" longer with a couple of hole options, and lube the cable with WD40. It worked so well I had to put one of the return springs back on. Very easy and manageable throttle responce. Then I took it out in go kart form and put 10 miles on it in the back roads and let it learn. Now it idles and starts well and runs great. Luckily no cops. I had ordered the longer throttle lever but its not shipping till the 8th. So moral of the story for me is don't over think it. KISS worked the best.

[BradCraig]

Ok here we go. I almost feel stupid explaining this, but the most simple fix worked the best. I had bought Fortes mechanical linkage kit with all the adjustability I could get mechanical leverage and make the throttle smooth and found it wouldn't work because my battery cut off switch is mounted on the firewall right where the linkage rod would go which would require making up new battery cables and moving the switch. Plan B, Make a new throttle lever 1.5" longer with a couple of hole options, and lube the cable with WD40. It worked so well I had to put one of the return springs back on. Very easy and manageable throttle responce. Then I took it out in go kart form and put 10 miles on it in the back roads and let it learn. Now it idles and starts well and runs great. Luckily no cops. I had ordered the longer throttle lever but its not shipping till the 8th. So moral of the story for me is don't over think it. KISS worked the best.

Awesome!!! Yep, that's the best fix. I have the same issue on my Camaro but it's a drop base air filter to clear the hood so can't use the extension.

[ggunter]

So another question. Some people say the IAC works better with a spacer under the throttle body. Just curious why, and I do have a section of the intake divider removed on the intake. I have a 1/2" phoenolic spacer but then not sure if it will raise the aircleaner up against the body once it's back on.

[Mike DiGiorgio]

So another question. Some people say the IAC works better with a spacer under the throttle body. Just curious why, and I do have a section of the intake divider removed on the intake. I have a 1/2" phoenolic spacer but then not sure if it will raise the aircleaner up against the body once it's back on.

this depends on your intake manifold design. if the plenum is open, or even has a slot in it to connect both banks the IAC will work fine. if it does not it will only control idle on half the cylinders. the spacer is simply a way to allow air to move freely between both banks.

[NiceGuyEddie]

How often do you shave?

Every day or every other day - get EFI.

Whenever - get a carb.

:D

[Joel Hauser]

I'm using a more or less stock Ford fuel injection from my donor...except all the parts have been replaced - at least once - because I could never get it to work right. There's an entire alphabet soup of parts that go with the stock system, like the PCM, MAF, IAC, IAT, TPS...Then there are different size throttle bodies and plenums; cold air intake; a variety of fuel pressure regulators; fuel pumps; O2 sensors; and don't forget the fuel injectors, that start at 18 lbs, and go up into the 40 plus range. And every time you change one of these variables, you have to reprogram the PCM.
My 1968 triumph 650 tiger has a one carburetor. Same with my cub cadet lawn mower. Same for the VW beetle and ford falcon I used to own. So much simpler. If I could convert my roadster to a carburetor, I would do it this weekend. But I can't, so I'm stuck with what I've got.
Did I mention I'm 67? I don't enjoy dealing with new fangled technology.

[rich grsc]

I'm using a more or less stock Ford fuel injection from my donor...except all the parts have been replaced - at least once - because I could never get it to work right. There's an entire alphabet soup of parts that go with the stock system, like the PCM, MAF, IAC, IAT, TPS...Then there are different size throttle bodies and plenums; cold air intake; a variety of fuel pressure regulators; fuel pumps; O2 sensors; and don't forget the fuel injectors, that start at 18 lbs, and go up into the 40 plus range. And every time you change one of these variables, you have to reprogram the PCM.
My 1968 triumph 650 tiger has a one carburetor. Same with my cub cadet lawn mower. Same for the VW beetle and ford falcon I used to own. So much simpler. If I could convert my roadster to a carburetor, I would do it this weekend. But I can't, so I'm stuck with what I've got.
Did I mention I'm 67? I don't enjoy dealing with new fangled technology.
So you want your cobra to run like a cub cadet? :confused:

[edwardb]

So you want your cobra to run like a cub cadet? :confused:

My Cub Cadet has EFI. Runs like a champ. :cool:

[Papa]

I'm using a more or less stock Ford fuel injection from my donor...except all the parts have been replaced - at least once - because I could never get it to work right. There's an entire alphabet soup of parts that go with the stock system, like the PCM, MAF, IAC, IAT, TPS...Then there are different size throttle bodies and plenums; cold air intake; a variety of fuel pressure regulators; fuel pumps; O2 sensors; and don't forget the fuel injectors, that start at 18 lbs, and go up into the 40 plus range. And every time you change one of these variables, you have to reprogram the PCM.
My 1968 triumph 650 tiger has a one carburetor. Same with my cub cadet lawn mower. Same for the VW beetle and ford falcon I used to own. So much simpler. If I could convert my roadster to a carburetor, I would do it this weekend. But I can't, so I'm stuck with what I've got.
Did I mention I'm 67? I don't enjoy dealing with new fangled technology.

I don't think you can compare trying to use original factory EFI system from a donor with a modern system like the Sniper or others. The new systems are full integrated and are designed to replace a carburetor in the simplest cases. I understand what you're saying, but it's definitely an apples to oranges comparison.

[weendoggy]

I'm using a more or less stock Ford fuel injection from my donor...except all the parts have been replaced - at least once - because I could never get it to work right. There's an entire alphabet soup of parts that go with the stock system, like the PCM, MAF, IAC, IAT, TPS...Then there are different size throttle bodies and plenums; cold air intake; a variety of fuel pressure regulators; fuel pumps; O2 sensors; and don't forget the fuel injectors, that start at 18 lbs, and go up into the 40 plus range. And every time you change one of these variables, you have to reprogram the PCM.
My 1968 triumph 650 tiger has a one carburetor. Same with my cub cadet lawn mower. Same for the VW beetle and ford falcon I used to own. So much simpler. If I could convert my roadster to a carburetor, I would do it this weekend. But I can't, so I'm stuck with what I've got.
Did I mention I'm 67? I don't enjoy dealing with new fangled technology.

You answered your own issues. Putting "parts" on because somebody makes them doesn't mean they'll work together. Correct that some may need recalibration, but if you go that route, be prepared. Aftermarket systems aren't your run of the mill factory type systems. They won't give you the same "comfortable" feeling, but can come damn close if tuned right. They also come with the alphabet soup parts as well, just have to make sure you match "like for like". I'm close to your age and still love dealing with new technology in the industry, mainly because I was in it my entire life through all the changes from carb to efi and everything in between. Call me a gluten for punishment. :)

[BradCraig]

So another question. Some people say the IAC works better with a spacer under the throttle body. Just curious why, and I do have a section of the intake divider removed on the intake. I have a 1/2" phoenolic spacer but then not sure if it will raise the aircleaner up against the body once it's back on.

Rumor has it the older Snipers had IAC issues with a the full dual plane due to the air path of the IAC, new ones will not have that issue and since you have a milled down divider it isn't an issue anyway. Most of the time, folks are doing the spacer to eliminate the Sniper "whistle" that you sometimes get. Personally, I use a 1/4" non-metallic spacer for heat isolation given the ECU is in the throttle body. Electronics hate heat and the non-metallic spacer makes a HUGE difference in how hot the Sniper gets. My $.02.

[ggunter]

I'm kind of amazed that the Sniper ECU sits right on top of the engine in all that heat. I wonder how many heat failures they have had? I could see how a phoenolic spacer could help to insulate some of the heat away. There is still al lot of heat with or without the spacer.

[BradCraig]

I'm kind of amazed that the Sniper ECU sits right on top of the engine in all that heat. I wonder how many heat failures they have had? I could see how a phoenolic spacer could help to insulate some of the heat away. There is still al lot of heat with or without the spacer.

Correct. A lot of folks go to the Terminator or other solutions that place the ECU elsewhere for heat and RFI reasons but of course those are a bit pricier. I've been running mine for three years without issue.