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The Great EFI Debate

37K views 192 replies 59 participants last post by  journeywork 
#1 ·
As I'm busy ordering replacement parts online for my classic, i constantly find my finger hovering over the Holley EFI kit... don't know why I'm itching.

I love the idea of an easy reliable turnkey system, but I'm new to this carb game and have yet to really experience it.

Am i missing out? If i board the EFI train will this kill the classic car experience?

What are the experiences of members who have done this and for those who have not, why haven't you?

Im in no rush, so far the car has not given me any issues and she's a once or twice a week kinda gal (not a DD). So rather than adding the kit to my shopping cart, it's been added to the wish list.

Happy Monday!

JB

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#2 ·
Thing is, a carb is really reliable when it's properly tuned and you do even a little tiny bit of maintenance to keep it going (you know, things like making sure the floats are good and the filter's clean).

The thing that a lot of people don't consider about fuel injection systems is that "the cost is not the cost". That is, the price of the throttle body itself does not usually include the price of all the lines, the fittings, the filters, the pump (most end up modifying their gas tank and putting in an in-tank pump to keep it quiet and happy), the extra vent for the gas tank, etc. A lot of ticky tack little stuff adds up and can get you in a thousand bucks deeper if you're not watching it.

In the end, there are 3 things that throttle body fuel injection systems do better than a well-tuned carb:
1) Start more quickly (not any more reliably, just more quickly)
2) Adjust to a number of driving conditions, most notably altitude, without you having to mess with it
3) Overcome heat soak

I have fuel injection on my car because I desired all 3 of these things. The first was less important to me than the other two since my Holley carb always started the car just fine with one pump of the gas pedal or so. The second item is important to me because I take my car all over the country and I don't want to screw around tuning the fuel system for performance between 14,000 feet and sea level. And the third is important because my car is a daily driver in Texas, and it gets hot as hell, and I get real mad if my car's heat soaked when I get back from grabbing food because the fuel's been boiling in the engine bay to the tune of 115*F ambient temps.

The EFI train can be a real PITA sometimes. It's expensive initially, and it can be annoying trying to sort out things like gas tank venting (which is something I'm still not happy/satisfied with, 4 years after the initial install). It is truly awesome though when you just need convenience and reliability. So whether you should go EFI or stay with the carb should probably be based on what you need from your car. For a car that's already proven reliable with a carb that's not a daily driver, I'd say that you have no reason to make the swap unless you really just want the convenience of a quick start every time.
 
#3 ·
I've also been considering and now wanting to do an EFI conversion. The 2 I narrowed it down to were Holley Sniper and FiTech. I've all but completely decided on the Holley setup, if I do it. I do not think it will ruin the classic car experience as you say. I suppose for purists that have a completely original car, it might. Other than that, I can't see it doing anything besides making the car nicer to drive, provided it is operating correctly. I'm looking forward to the idea of wearing less "Mustang Cologne" after being around the car with it running too much. I'm in no hurry since my carb is in great condition right now. Knock on wood.
 
#4 · (Edited)
I don't have an answer but I'm in a similar spot. I feel like I "should" put a carb on mine and learn how to tune it, but I am pretty sure I'll end up with the Holley Sniper kit as well. You might already know this, but don't forget to add an EFI style fuel tank, high pressure pump and likely need for a fuel return line to your "cart". Also maybe the Holley Dual Sync distributor so you can utilize the timing control feature.

Looking forward to others replies...
 
#5 ·
I'm also looking at 115 degrees summers where I'm based! Will this be an issue with my carb engine? What would happen? I don't want to neglect the car all summer!

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#6 ·
some carbs requires more maintenance than others. Do you like to open the hood and fuss over of the engine ? If not, keep the Autolite carb or get the Summit Autolite look-a-like. The Autolite can go years without a bit of fussing over, maybe decades. That's if you will driving the car on a regular basis. You can't just park it for months or years either. Not going to drive the car in the winter ? Then at least adde some Stabil or even better, drain the gas.


If you're not willing to do things like that, then start modernizing the car. You WILL be diluting the classic car experience, but the pure classic car experience is like drinking Tequila straight outa' the bottle.

Exhilarating, but not for everybody.


Z
 
#14 ·
interesting analogy Z, and probably pretty close to accurate.

OP i have two classics that i am working on, a 64 falcon with the inline six, and a 66 mustang with the 289. both are keeping their respective engines, the six will definitely get EFI of some sort though, but it will be far more challenging than the 289 to put EFI on since there is no bolt on kit for that engine.(perhaps there is a market there...........)

unlike Z however, i dont think adding EFI to a classic is diluting the classic car experience, if that is all you do. but after adding four wheel disc brakes, modern 17" wheels, tubular suspension components, aluminum radiators, modern sound deadening, and many other modern upgrades that we all like in our modern daily drivers, THAT is diluting the classic car experience.

that said, you still get that experience, you just have to remember that you added orange juice and grenadine to your tequila. you still get that hit of the tequila, you just take a bit of the edge off the unmodified hit.

the choice is yours, carbs are just fine for the most part, though they tend to be less flexible than EFI is, but EFI does have its share of issues as well. mostly the tuning of the system for your vehicle, and modern ones are self learning. carbs are easier to troubleshoot, but EFI is more reliable overall. carbs are less expensive, but require more service overall.

but both can be made to run for many years with little attention.
 
#7 ·
I've upgraded from my stock 2bbl to an Edelbrock 4bbl with electric choke. Guess this replacement would make things more efficient somewhat.

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#8 ·
I was in the market for a new carb on my stang and ended up with the fitech(watched fitech at hot august nites two years ago put one a 289 in the parking lot of a hotel and it ran great!) Anyway i am very happy with great start ups and a lot cleaner smelling garage.
 
#9 ·
So you did not convert to EFI?

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#11 ·
I would go efi in a heartbeat and not look back. I did my 'cough' orange engine vehicle (Fitech) and couldn't be happier. I don't think it took away any experience from the drive, unless you consider smelling like exhaust part of the package (still there a touch, but nowhere near as bad after a couple hours of cruising, it's a convertible so you get it all.) The easy starts if the car sits for a couple months are another bonus, and the tune on the fly is a great touch also. I have a Holley Terminator in the trunk of my Mustang waiting for a couple good weekends to install. It's not quite a bolt on and go, the rest of the fuel system needs to be modified, pump, return, etc, but I think you will be happy with the results. I grew up with carbs, I can tune one, but after the initial install I find the EFI stuff much better to work with. 60 degrees out? No problem. 95? Still no issue. Quick mountain cruise? Still runs the same. Sits for 6 months? Turn key, let it prime, start the vehicle, drive away if you want. That's really my favorite part.
 
#12 ·
I went FI on the '68 back in 2003 before all the really easy systems
available today were on the market. It's the original Edelbrock Pro-
Flo. I got it not long after its appearance at the SEMA show.
Resonant chord regarding the additional money Kelly mentioned
to get the system installed exactly like it needed to be. Out of the
box, the plumbing for the return was a joke. (like rubber hose the
entire length of the car, etc) Didn't like the braided hose under the
hood...... stuff like that.
I was happy once my FI install looked like something that could have
come OE from Ford. That took some doing though.
The wife drives this car and doesn't like setting chokes, etc. FI fixed
that issue. I wanted "set it and forget" and the FI does well here too.
The FI squeezed it the last little bit to 20 mpg highway, so it equals
the best the car got when my folks picked it up in 1968, no mean feat
since the rear tire hp is considerably more than the original flywheel hp.
(now through a small block C6 and 9" no less)
 
#15 ·
I pieced together an EFI setup on my 65FB. I am using a Microsquirt controller and an EFI FAST throttle body I got on flea bay. I still had to add a crank sensor, coolant sensor and wideband O2 sensor in addition to the sensors already in the throttle body (MAP, TPS and IAT). I also swapped in an EFI tank and ran new fuel supply and return lines. It's a lot of work and it adds up.

The Microsquirt is not plug and play. It requires quite a bit of initial tuning. However, you have 100% control over all aspects of the tune, including ignition timing (I am running wasted spark with no distributor). I now have it pretty well dialed in and it is amazing. It starts right up no matter the temperature outside. No more permanent gas smell in the garage. Finally, it runs like a bat out of hell. While I am sure that my carb could have been tuned for the same high end power, there is really no way to tune it for the same overall drivability. You basically get to set the AFR and timing for any condition your car will encounter. This means I can get a stable low and cool idle, terrific throttle response, great cruise millage and super high output performance. I also dumped my dual plane intake for a single plane and it works great. I do not think I would get the same idle and low RPM response with a carb and the single plane intake that I do with EFI.

That said, I am not willing to put a comb over modern factory type efi on my car. When you pop the hood on my 65, it looks like it should until you notice that the distributor is missing and there is a fuel pressure regulator. Still, those differences are subtle and do not distract from the overall look and feel. Also, my car had a modern (circa 1992) drive train (302 roller and T5). If it had been the original 289 and 4 speed Top Loader, I would have been more hesitant. But, as they say, it's only original once and that ship sailed before my car ever came my way.

So I say, unless you want to maintain originality, there is no reason not to go efi.

Baxter
 
#16 ·
".....So I say, unless you want to maintain originality, there is no reason not to go efi.
No reason, except for the expense and time spent getting it dialed in. I'm condensing your own words in your post, but you are mentioning those things yourself.


Z


PS my garage (and I) never smelled like gasoline in any carb'd car I've owned, including the one in my sig pic. If a gassy smell is coming from a car, blame the person in charge of tuning it, not the technology, or lack of it.
 
#17 ·
Right, so I've gone and ordered this because it's bound to happen eventually and i want some predictability with my classic when if i travel for 2 weeks and come back i don't want headaches starting plus i live in a warm climate so would like to use the car over summer as well in 115 degrees!

https://www.summitracing.com/parts/FIF-31003

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#23 ·
Right, so I've gone and ordered this because it's bound to happen eventually and i want some predictability with my classic when if i travel for 2 weeks and come back i don't want headaches starting plus i live in a warm climate so would like to use the car over summer as well in 115 degrees!

https://www.summitracing.com/parts/FIF-31003

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Man, that is not a bad price for the entire kit. I would have suggested the Holley sniper, but I think now-a-days they are both about comparable.

That said, I am not willing to put a comb over modern factory type efi on my car. When you pop the hood on my 65, it looks like it should until you notice that the distributor is missing and there is a fuel pressure regulator. Still, those differences are subtle and do not distract from the overall look and feel.

So I say, unless you want to maintain originality, there is no reason not to go efi.

Baxter
Yeah, the comb over. I installed the 5.0 EFI with the comb over (I use that term all the time too) and never did care for it. It did not look right and never ran right.

I went from the Ford 5.0 EFI and EEC to the Holley Terminator TBI with the HP ECU. It runs great and looks better than the comb over.

I switched to EFI because I wanted the convenience of PC tuning and trending. I had the 2v carb tuned fairly well on my 289, but it still was not perfect. I know with some more tweaking, I could have got it to start perfectly, every time, and I could have gotten the AFR to the perfect setting that the garage did not smell, but it is a convenience to be able to tune it from a PC, or have it self tune.

My only suggestion is, stay away from the Ford TFI distributors. They might seem like a cheap means to control the timing with EFI, but it is +30 yo technology. Either skip the PC controlled ignition and get a ready-to-run or an aftermarket controlled distributor (Holley dual sync, etc).
 
#19 ·
I don't see what the temperature has to do with running a carb. When my DDs had carbs (1 Holley, 2 Carter AFBs and several Q-Jets) I never had issues or a need to re-tune when the temps went from summer 90s to the sub-zeros of winter and back. I also never had heat issues even in Chicago rush hour traffic during the summer when driving a carbed car.

I can't comment much on altitude issues other than I did take a trip up the great divide (to Yellowstone N.P) in a 68 Camaro (Q-Jet) and we didn't have to touch the carb once on that trip. The 2 speed PG trans gave that engine a workout across the full RPM range. I will admit disc brakes would have been nice on some of those long downhill stretches.

As for fumes my garage never has gas or exhaust fume smells nor do my wife and my clothes smell from gas after an afternoon's ride in either classic car.

Since we have 2 classic cars (both with carbs) they take turn sleeping while the other is out playing but that still doesn't cause starting issues. The only time they don't want to start is the first start of the spring when they haven't been run for 6 months. Even then it only takes an extra couple of pumps and cranks to get either started.

My wife has no problem starting and driving cars with carbs. She's not afraid of starting even for the first time in spring. She loves driving her Mustang and she's even taken to getting time behind the wheel of my 69 Camaro which was built for the track. My wife has a lead foot and loves to take the Camaro and pick races with the fart-can tuner cars (she's learning how to make the tires hook).

Having ridden in a '70 Chevelle with EFI I will say you can feel the difference between EFI and carb. It's that carbed engine sound and feel that keeps drawing the wife and I back to carbed cars. I for one will never bastardize either of our classics with EFI and my wife will agree.
 
#20 · (Edited)
For the folks that recommend a carb, what do you use to tune your carbs? It can't be hearing or smell, you have some type of Air Fuel Ratio (AFR) gauge? I have been debating this as well, I know my carb is not tuned very efficiently, other then tune to get max vacuum, not sure how you change jets and other things without a good AFR gauge? I know how to change them but what tool do you use to pick the best ones? My car also has a mild cam which I know I have to tune my carb for and the EFI would handle that on its own since its less vacuum. Tuning a carb does take knowledge and time and is sort of a a dieing art, most folks make it seem like its easy and no big deal, or is it just me.
 
#22 ·
Yep the best way to tune a carbed car is with an AFR. They're worth the money it will pay for itself in fuel economy or possible lean conditions leading to engine repairs.

A little bit of a learning curve this is hobby I use to learn & enjoy (most of the time).

Bob
 
#24 · (Edited by Moderator)
I don't personally have either setup but will be buying the Holley Sniper EFI kit before the summer and have it ready to go before the weather starts getting nice again. I've heard mixed reviews on the FiTech, some of them being about the product itself in which a few members had to ship them back and exchange for another, but most of the issues were customer service related. Either you'd never get a call back or the sales associate wouldn't honor the warranty or whatnot. I think even one member lost his shorts on the FiTech because he got a couple different "lemons" and then he was out of the warranty period. I'm going to go with Holley because they've been around for almost 100 years and have had great luck with their carburetors as well as their customer service.

In terms of the argument for drivability and it driving like a classic? Well that went out the door when I first bought the car as the engine and transmission had both been replaced and then several years later I repainted the car, upgraded to 4 wheel power disc brakes, 17" wheels and tires, all brand new aftermarket suspension, a 5spd transmission and an engine that has over double the HP of a stock 289/302 with aluminum heads. Lastly, in terms of the "classic car feel", I don't know of any mustangs having had EFI back in the day, I'm sure I'll be corrected if I'm wrong, but the Corvette and other vehicles have had EFI since the 1950's and even before. While this particular style of EFI I'm sure is quite different from those early types, it's not really something that's only been around for a few years. It's been around for over 70 years in terms of automobiles and even earlier for diesel engines, aircraft engines and so on. I'd think the pro's would severely outweigh the con's and like I said, I'll be buying the Holley Sniper before summer.
 
#44 ·
"......Lastly, in terms of the "classic car feel", I don't know of any mustangs having had EFI back in the day, I'm sure I'll be corrected if I'm wrong, but the Corvette and other vehicles have had EFI since the 1950's and even before.
Some of the Corvette's did have a fuel injection option. But it was a mechanical fuel injection, not EFI.


"........I will gladly admit that I suck at tuning carbs. :)....."
I sucked at walking when I was 1 year old. But I kept working at it.

Tuning a carburetor is no different than any other kind of learning. It's not black magic, even on the Webers. They are pretty complicated, but still follow the same physics that a Autolite 2100 does. The knowledge gained on the most simple carburetor is directly transferrable to the most complex carburetor

".......Let's also not forget, for the purists, this this is not an irreversible mod. ......"
I don't keep my vintage cars "period correct" for the next owner. I do it because I get the most enjoyment from them when the total owning and driving experience is identical to what I enjoyed when cars were new.

".......The garage will stink for maybe 5 days until the fuel bowl dries up, and then no more stink..."
"........let me ask you, how long does it take your fuel bowl to dry up? I mean, eventually it should- right? ......"

there's a big difference between the float bowl drying up in 5 days, and it drying up eventually. Yes they will dry up eventually, and when they do, it will look like these carbs pictured below. They were from a Yamaha XS-1100. The owner had to go on a forced vacation at a Federal lock-up for 3-5 years with time off for good behavior. When he got back to the shed where he parked his bike, it wouldn't start, so he brought it to our shop.

(....Notice that two of the carbs are clean. That's because the bike was leaned at a steep angle (toward the right side) up against the interior wall of a storage shed. All the gas drained out of the 2 left hand carbs into the other two before it could dry out. Photos show the carburetor assembly flipped over and upside down, so the right-most carb in the photo is actually the left-most carb....)

If your float bowls in a stock Autolite are drying out without leaving a nasty residue, then they are drying out too soon. There is a reason, and it can be fixed, either by repair or replacement with a good carburetor. I don't know what was the fault in your carb, but it did have one (or more) that was causing the rapid evaporation and garage smell. Fixing the fault seems to me to be easier than ditching the carb in favor of EFI.

I drove my parents Fairlane in high school (Sr. '69), and I'm pretty sure it had an Autolite 2100 on it. No stinky garage.


Z
 

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#27 ·
The PO stated that he doesn't have any experience tuning carbs. People have chimed in with extensive experience with carbs, probably built over many decades. For those that have the experience...good on you and I wish I had some more of it. It makes it easy to tune and keep it tuned. For a carb newb though, the situation is different. In my opinion, there is nothing wrong with putting efi on a vintage mustang, especially the new throttle body systems that are hidden under an air cleaner. Looks original and, worst case scenario, has the drivability of a car with a well tuned carb. Best case is increased drivability and ease of tuning. Let's also not forget, for the purists, this this is not an irreversible mod.


If the internet and forums were around in the early 1900s, I'm sure people would claim that horses have worked for thousands of years too...why the need for motorized transportation? We are living in a golden age of rodding. sometimes it's best to embrace technology so each person gets the best experience out of our "hobbies". For me, my MSD Atomic kit is sitting in the garage for install as soon as I'm done rewiring the car...
 
#28 ·
When I got my FB, almost 20 years ago, I switched out from a 2 bbl to a Holley 4bbl. Tuned it one time and haven't touched it since. Engine runs perfect. Never have had a problem.
Stan
 
#31 ·
If I could do it again, I would do an EFI carb set up.

That said, I learned how to modify and tune my carb to the point where the EFI would not have any benefits other than adjusting itself for different weather. My carb runs noticeably leaner in 40-50* weather since I tuned it in ~85* weather. I only drive the car in 60-95* weather, and really 90% of the time in 70-90*.

If it's too cold to roll down the windows, or if I'm melting in the car, I don't drive it.

I do wonder if they make any more power at all at WOT.

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#34 ·
I can't tune anything but a Holley 1850 and they leach gas. I live in one of the 2 counties in my state, by less than 2 miles, that are "non attainment areas", so we have emissions gas during the summer and it boils out of the carb and vapor locks every time you turn the car off even with the fancy spacer.

I bought the FiTech and Spectra EFI tank. The pump in the Spectra tank fried immediately due to the, apparently still present to this day with the currently produced tanks, "black gunk". The FiTech failed soon after that was fixed with a no tach signal situation. The Spectra people are vermin offering no help and speaking in French. I took French and they were messing with me with jive French at best. Cory at FiTech was able to eventually help me get a new TBI with an updated wiring harness just before the warranty expired.

I would go with the Holley over the FiTech because they are well established company with a larger tech support base. I applaud FiTech for breaking the $1000 FI barrier, although they went to China to do it.
Once sorted out, it runs well and doesn't percolate fuel.

I would do it again with a Holley Sniper and my own in tank pump setup. Purchase a solid pre-bent 3/8 fuel line from NPD and run it alongside the original 5/16 fuel line. Use the new 3/8 line as the supply and the original 5/16 as the return. It is the cheapest and safest way to go.
 
#35 ·
I went with the sniper setup and a spectra tank and 3/8 pre bent line and will use the stock line as a return. Should have it all up and running come april!

Hidden under a factory gold stock air cleaner. With all the lines run to look factory. I can't totally hide a bunch of the other stuff, but I'll do my best to make it look like the factory intended it to be there!
 
#36 ·
I went Holley Sniper - the tech support community is strong, and the software seemed easy to understand. I just did all the measurements and engine rotation to install my distributor (MSD) and phase the rotor. The Sniper comes with a coil driver, so you can control timing without a big MSD ignition box as well. It also has a built in relay for the fuel pump.

I needed all new fuel system components...fuel tank, lines, etc. For me, EFI was a no brainer. The sniper, and other TB kits, still gives you the classic underhood look.
 
#38 ·
I think some of it is personal preference, and/or what you are used to.

For me, I grew up with fuel injection, however... Not on my Mustang, but when I built my Cobra kit, I initially used the stock Ford EFI and even went as far as putting a Vortech blower on it. Drove it for several years like that, then got the full vintage bug. Pulled the motor, swapped in a 331 with dual quad carbs and haven’t looked back. The sound, smell and look of a carb is pure vintage to me! I knew nothing about carbs and have learned to tweak it to run pretty well.

I’ve since rebuilt the Mustang carb as well and it runs pretty well too. I only put a few thousand miles at most on them annually, so I may not be the best data point. Good Luck!
 
#39 ·
Converted this engine from SEFI 5 years or better ago no changes but the induction. only issue was the foam floats went bad and installed brass ones 3 years ago no issues since. Winter only adjust the idle feed screws about a quarter turn. I drive it any nice day and take 1000 mile or better trips often as well as around town. gets 24 mpg

The injected version only got about 20 mpg after months of data logging and tuning didnt preform as the carbs

Now my truck a 86 dually with a 460 built for towing would get around 14 mpg until the inner pivots of the twin I beams screwed up the alignment. have thought about CFI on it from time to time
 

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