Stay with a carburetor or go EFI

Stay with a carburetor or go EFI

  • EFI

    Votes: 18 48.6%

  • Carburetor

    Votes: 19 51.4%
  • Total voters
    37
-
OK, so this isn't necessarily about what's going to break down on the side of the road. My Duster is a street machine so for the most part, I'm not going to be straying too far from home. But that's besides the point because generally, unless something is completely screwed up mechanically or improperly installed, this stuff does not suddenly "stop working" for no reason. I've had enough professional level training and personal projects to know how to wire stuff and make sure it works as designed. I've also done my share of carb tuning from trying to get a heavy, low performance big block truck to accelerate properly and get better mileage to tuning my Duster to get it down to 12.0 @ 111 with a stock stroke 340 running on 7 cylinders. So there.

Plus, I'll even admit that with my Coronet, there have been instances where the EFI mysteriously stalled the car on the road and it wouldn't start. But, it always starts back up after letting it sit for a little while. I don't necessarily blame the EFI, it's really more about the person tuning the car and how well the systems are understood. Stalling can reveal things that you had overlooked so it's all a learning experience. Any obstacle that comes up can generally be tuned out so it doesn't happen anymore, you just have to dig into it to find the answers and know how to manipulate things. I'm not there yet but the more I mess with it, the better I get.

This is more about whether I want to get involved with adding more work to something I've already done a ton of work to. I apologize for not making that clearer at the start. But, that internal argument does manifest itself into an EFI vs. carb. discussion.

If you go to a really fast doorslammer race, most every single car is tuned with a laptop. Those cars have as many sensors as your garden variety Toyota - wheel speed, MAP, CTS, etc. It;'s just tools to measure and compare information. The throttle body does the same thing as a carb - it mixes air and fuel, it's just controlled electronically. You can tune stuff by ear all you want but you will never be as precise as with EFI.

And OK, so for whatever reason, it's generally accepted that EFI gives up some HP to a carb. But, the EFI will provide more opportunity to get the rest of the fuel curve more precise which can only benefit the overall tuneup. On my car will I notice a 10-15 hp difference at 6,300 rpm? I don't know. Conversely, if the carb is not tuned right then you could be in the same situation. I'm not Bob Book so I can't say I can look at a time slip and know what to do inside my carb. But, with the EFI, I can at least see things a little more clearly.
 
yellow rose said:
It has nothing to do with fear.

OEM EFI is about emissions and junk like that. It damn sure isn’t about maximum power.

If a carb can’t be made drivable that’s on the tuner.

If you are willing to spend the timing learning EFI, why not spend the time to learn carburation?

If your goal is to be able to turn the key and have it idle than EFI is what you want. Any half assed tuned carb will start and run with a turn of the key, and it takes about 1 minute for the car to sit and idle on its own. If that.
Click to expand...

Untill u drive it from 600 ft to 6000 ft altitude , the carb set up will run like boiled s--- .
 
DionR said:
FYI, all the new Challengers and Chargers have their battery in the trunk, and they seem to work fine. So it appears to me that it works.

Best guess, if you have good grounds and large enough power leads, probably works fine.

But just a guess.
Click to expand...

I have had my battery in the trunk for 9ish yrs. w/ fuel inj. , ----------??
Only problems I`ve had were created by me to start with .
 
DionR said:
I kind of wonder if an 485 HP motor could be run on a carb and still be grandmother approved to drive and return 22+ mpg. I am sure a 750 DP would work fine, but I bet it would be hard to get it to run clean all the time, slightly finicky when cold and return (at best) 18 mpg. Now take that same motor and carb and sell it in all 50 states and see how well it works when the climates are so radically different.

I don't think we would have Scat Packs and Hellcats if the OEM's had stayed with carbs. I agree they moved that way due to emissions, but I think it opened whole new chapter in performance in the end.
Click to expand...


My wife drives my car so how hard can it be?

If the carb is close it will self adjust for barometric pressure.

Kind of a straw man argument comparing new engine architecture to old stuff. I could easily build 500 HP with W2 heads that would be very, very docile.

And 485 HP is 485 HP. It takes the same fuel to make that power.

Run EFI if you want. Just don’t tell me how great it is when the premise of your argument is so skewed.
 
rmchrgr said:
OK, so this isn't necessarily about what's going to break down on the side of the road. My Duster is a street machine so for the most part, I'm not going to be straying too far from home. But that's besides the point because generally, unless something is completely screwed up mechanically or improperly installed, this stuff does not suddenly "stop working" for no reason. I've had enough professional level training and personal projects to know how to wire stuff and make sure it works as designed. I've also done my share of carb tuning from trying to get a heavy, low performance big block truck to accelerate properly and get better mileage to tuning my Duster to get it down to 12.0 @ 111 with a stock stroke 340 running on 7 cylinders. So there.

Plus, I'll even admit that with my Coronet, there have been instances where the EFI mysteriously stalled the car on the road and it wouldn't start. But, it always starts back up after letting it sit for a little while. I don't necessarily blame the EFI, it's really more about the person tuning the car and how well the systems are understood. Stalling can reveal things that you had overlooked so it's all a learning experience. Any obstacle that comes up can generally be tuned out so it doesn't happen anymore, you just have to dig into it to find the answers and know how to manipulate things. I'm not there yet but the more I mess with it, the better I get.

This is more about whether I want to get involved with adding more work to something I've already done a ton of work to. I apologize for not making that clearer at the start. But, that internal argument does manifest itself into an EFI vs. carb. discussion.

If you go to a really fast doorslammer race, most every single car is tuned with a laptop. Those cars have as many sensors as your garden variety Toyota - wheel speed, MAP, CTS, etc. It;'s just tools to measure and compare information. The throttle body does the same thing as a carb - it mixes air and fuel, it's just controlled electronically. You can tune stuff by ear all you want but you will never be as precise as with EFI.

And OK, so for whatever reason, it's generally accepted that EFI gives up some HP to a carb. But, the EFI will provide more opportunity to get the rest of the fuel curve more precise which can only benefit the overall tuneup. On my car will I notice a 10-15 hp difference at 6,300 rpm? I don't know. Conversely, if the carb is not tuned right then you could be in the same situation. I'm not Bob Book so I can't say I can look at a time slip and know what to do inside my carb. But, with the EFI, I can at least see things a little more clearly.
Click to expand...


Then why come on here and ask? You’ve clearly made up your mind. It seems you want peer approval.

I say EFI is exactly what you need.
 
yellow rose said:
Then why come on here and ask? You’ve clearly made up your mind. It seems you want peer approval.

I say EFI is exactly what you need.
Click to expand...

Don't need peer approval but this is a forum. If we’re not bouncing these ideas off each other then what are forums for?

This is not an emotional decision, trust me. The car is apart. I can go one way or another. If I ever want to go EFI, now is the time.

Carburetors work, don’t have to make it seem like I believe they don’t. I also understand fuel injection is a better mousetrap. But, there are certain things that it can do that no mechanical fuel delivery system can which is datalog and tune itself of the fly. Obviously things need to be optimized for the self tuning aspect to bear fruit but again, EFI is all about real time evidence based off data. Not sure why that’s such a contentious point.

Despite what the marketing may lead you to believe, converting a car from carb to EFI is a lot of work and the initial money outlay is far greater than it would be if I just keep the carburetor.

The other idea the marketing promotes is that you just set it and forget it. That could not be further from the truth. Sure you can rely on a general base calibration to start but once you’re beyond that, things get pretty involved. The software provides the ability to fine tune every point within a range of data and then allows you to switch tunes with a few keystrokes for particular applications. Is that a bad thing? You’re on some sort of computer while you’re viewing this thread. Is that the only thing microchips and programming are good for? Its just another tool, thats all.

But to your point - carburetors can be tuned to a razor sharp edge but instead of software providing a visual representation of what the motor is seeing, you’d be relying on physical testing testing testing and more testing and if you kept notes, log books (aka data) for guidance. Nothing wrong with that at all, I’ve done it. I’m telling you that all the ideas to achieve your “tune” are the same, its just done with software.

The visual representation of the data is key.
 
I don’t know what to tell you except, for now put a carb on it until the funds and the whole entire F.I. system shows up to minimize down time. Looking forward to the tech!
 
Last edited:
rmchrgr said:
Don't need peer approval but this is a forum. If we’re not bouncing these ideas off each other then what are forums for?

This is not an emotional decision, trust me. The car is apart. I can go one way or another. If I ever want to go EFI, now is the time.

Carburetors work, don’t have to make it seem like I believe they don’t. I also understand fuel injection is a better mousetrap. But, there are certain things that it can do that no mechanical fuel delivery system can which is datalog and tune itself of the fly. Obviously things need to be optimized for the self tuning aspect to bear fruit but again, EFI is all about real time evidence based off data. Not sure why that’s such a contentious point.

Despite what the marketing may lead you to believe, converting a car from carb to EFI is a lot of work and the initial money outlay is far greater than it would be if I just keep the carburetor.

The other idea the marketing promotes is that you just set it and forget it. That could not be further from the truth. Sure you can rely on a general base calibration to start but once you’re beyond that, things get pretty involved. The software provides the ability to fine tune every point within a range of data and then allows you to switch tunes with a few keystrokes for particular applications. Is that a bad thing? You’re on some sort of computer while you’re viewing this thread. Is that the only thing microchips and programming are good for? Its just another tool, thats all.

But to your point - carburetors can be tuned to a razor sharp edge but instead of software providing a visual representation of what the motor is seeing, you’d be relying on physical testing testing testing and more testing and if you kept notes, log books (aka data) for guidance. Nothing wrong with that at all, I’ve done it. I’m telling you that all the ideas to achieve your “tune” are the same, its just done with software.

The visual representation of the data is key.
Click to expand...

You just made my point. If you have to have a graphical representation to do your tuning then don’t waste time with a carb.

I’ll leave you with one last thought. For what you are going to spend on EFI, you could buy a QUALITY carb from some like BLP, Thumpr or Lightning carbs and then invest some money in a QUALITY O2 sensor that you can also log throttle position and MAP and you will be much less money in.

It just frustrates me that guys are willing to spend big money for EFI but they want to spend 600 bucks for a carb and then nothing else. The off the shelf carbs are just that. If you pay someone to build you are carb the results would be significantly different. Then add in the ability to log O2 verses RPM/throttle position and MAP and you can easily get a tune very close to EFI.

But again, I’m not trying to change your mind. I’m just explaining my position.
 
I have an A/F meter which if you squint hard enough is kind of EFI lite.

I dont need to have to have a graphical representation but its nice.

And sorry, $600 for a “built” carb? Eh, not really. Probably a LOT more.

Again, this is more about adding complexity and cost to a half-done project and whether its worth doing now or down the road.

There’s a strong argument for keeping the carb - I don’t need to buy anything and would ‘t have to undo some of the work I’ve done to get the car where it is now. But its been a number of years since I started on it and things have changed both in my own life and in the aftermarket world of go-fast trinkets.

Do I stay the course with the old school stuff or make a left turn at Albuquerque and embrace the new technology?
 
yellow rose said:
I could easily build 500 HP with W2 heads that would be very, very docile.
Click to expand...

And get 20+ mpg? :poke: :D

It should be pointed out thought that there is more to new muscle's efficiency than just EFI. Pretty nice to have 8 speeds and several overdrives.

yellow rose said:
And 485 HP is 485 HP. It takes the same fuel to make that power.
Click to expand...

Sure for ultimate power. But the difference is, how much gas does it use at part throttle?

No need to respond, I already grasp your opinion.
 
DionR said:
And get 20+ mpg? :poke: :D

It should be pointed out thought that there is more to new muscle's efficiency than just EFI. Pretty nice to have 8 speeds and several overdrives.



Sure for ultimate power. But the difference is, how much gas does it use at part throttle?

No need to respond, I already grasp your opinion.
Click to expand...


Don’t forget the aerodynamics of the newer cars as well.
 
rmchrgr said:
I have an A/F meter which if you squint hard enough is kind of EFI lite.

I dont need to have to have a graphical representation but its nice.

And sorry, $600 for a “built” carb? Eh, not really. Probably a LOT more.

Again, this is more about adding complexity and cost to a half-done project and whether its worth doing now or down the road.

There’s a strong argument for keeping the carb - I don’t need to buy anything and would ‘t have to undo some of the work I’ve done to get the car where it is now. But its been a number of years since I started on it and things have changed both in my own life and in the aftermarket world of go-fast trinkets.

Do I stay the course with the old school stuff or make a left turn at Albuquerque and embrace the new technology?
Click to expand...


I was saying you can’t spend 600 bucks on a carb and expect it to perform unless you are willing to really tune on it.

1500 bucks and up is probably a good starting point for carb prices, depending on boosters and the tune up.
 
rumblefish360 said:
3hp per cubic inch, WHOA! Veeeeeeeeeeerry nice!
Click to expand...


And...if you read it all Strader was on the fence at the short deck and 400 CID. IMO I would have pulled some stroke out of it and spun it up a bit higher, which is kinda where he was going with his thinking. But I’ve always been an RPM guy.

Definitely impressive for sure. 10k is no big deal nowadays IF you plan for it. God knows I love RPM way more than sex or BBQ.
 
rmchrgr said:
This is the fuel tank I have. The sender is over there in the corner, not in the front like normal. Best thing would be to emulate how Tanks, Inc. does it and cut a recess in the front to make room for the top of the pump and outlets. I kind of don't want to have to do that to this thing but it seems like there isn't any other reasonable way to accomplish having an in-tank pump.

I could just buy a stock-style EFI ready tank but with a 3" exhaust and springs offset inward things will be tight.
View attachment 1715729073
Click to expand...

Aeromotive phantom kit, but you'll be cutting a hole in the top of the tank and making a relief in your trunk or spacing the tank down.

Did a whole multi-port EFI/Coil near plug setup with Megasquirt. If you can do the wiring and had any idea on what your engine needed with a carb (timing especially), you'll have an easy time with EFI. The most important other part is the fuel system but sounds like you are committed to do an in-tank pump with a return anyway.

My double pumper had great WOT performance but the street driving is better with the EFI. Been over 2 years now since I touched the tune. Starts up on ~5-6 month old gas exactly like it ran when I put it away. Idles smoother. It was kind of a fun project.
 
yellow rose said:
My wife drives my car so how hard can it be?

If the carb is close it will self adjust for barometric pressure.

Kind of a straw man argument comparing new engine architecture to old stuff. I could easily build 500 HP with W2 heads that would be very, very docile.

And 485 HP is 485 HP. It takes the same fuel to make that power.

Run EFI if you want. Just don’t tell me how great it is when the premise of your argument is so skewed.
Click to expand...
yellow rose said:
Warren Johnson once said he never changed a jet from Denver to Sonoma. Maybe his carb tuning skills were better than most.
Click to expand...

Yeah, chrysler said u didnt need to change jets untill u went over 4500 ft altitude once too , especially on the rat roaster intake .
I gotta disaggre with u on this one cars aint no diff. than 4 wheelers that ran like s--- in an altitude change .--.03% per 1000 ft.
 
famous bob said:
EVERY RACE I SAW W.J AND CURT AT THEY WERE CHANGING JETS ---------------
Click to expand...


You sure? I’ve never seen them change a jet. I watched Greg Anderson change emulsion at Woodburn and he said that’s about all he ever changed, other than the occasional high speed air bleed.

We didn’t have a long discussion about it, but he did let me look at his plugs and I’m not kidding when I say they were tuning so tight you couldn’t see anything without a very good magnifier.

He was looking at heat mostly and about a .030-.040 wide fuel ring.


Of course, that was probably 1995ish and I’m not sure if those were 4 circuit carbs. They could have been 5 circuit at that time.
 
Early on in this thread there was a post about a retrofit in-tank fuel pump that goes where your sender is in a stock tank. Seems like a decent enough idea but I don't have a stock tank anymore.

Holley offers another retrofit in-tank fuel pump module that is regulated for carburetor pressures. The internal regulator can be changed to accommodate EFI fuel pressure and can be used with a return. Cool!

I'd still have to make a recess in the top of the fuel tank but besides that, this could be a good option. It'd be great to have a quiet, in-tank electric pump and I could keep my nice tank.

It could also enable me to get the car running sooner because it would save having to to futz with the wiring or fuel system too much.

Sniper - 340 LPH In-Tank Retro Fuel Module Systen

Just so everyone knows, on my way home today I was thinking hard about staying with a carb.
 
I wish I had a dollar for every thread I saw where someone was having BIG problems with their FITEC or Holley EFI. Maybe some of it was installation error, but likely not all. I have come close to pulling the trigger on a Sniper a few times, but by the time I get a new tank and whatever else, it's over $2,000. My 340 runs great with a carb.
 
You must log in or register to reply here.
-

Back
Top