Carb VS EFI
- Thread starter 98dango
- Start date
98dango
Expedition Leader
Hear is my thoughts
I prefer efi over carb.
In my life I have had more good experiance with efi over carbs. Just on road a good carb will do. Yes you can tune them to run just as efficaint as efi but never off road. I do know some carbs can be made to work off road Q-jest being the best. In mu opinion tho the float bounce of every other carb is there and your not getting rid of it. Now Efi is good to go at all angles and compinsates for altitude. Also no fuel slosh as its sprayed and kept under pressure.
Yes you can dink with a carb for days to get the right tune and the right set up for you but for most Efi in my opinion is the way to go. I know how to tune a carb do it all the time for any thing from a 800hp chevell to a 46cc chain saw. But i fell for most efi is the best way to go.
I prefer efi over carb.
In my life I have had more good experiance with efi over carbs. Just on road a good carb will do. Yes you can tune them to run just as efficaint as efi but never off road. I do know some carbs can be made to work off road Q-jest being the best. In mu opinion tho the float bounce of every other carb is there and your not getting rid of it. Now Efi is good to go at all angles and compinsates for altitude. Also no fuel slosh as its sprayed and kept under pressure.
Yes you can dink with a carb for days to get the right tune and the right set up for you but for most Efi in my opinion is the way to go. I know how to tune a carb do it all the time for any thing from a 800hp chevell to a 46cc chain saw. But i fell for most efi is the best way to go.
Erik N
Adventurer
My '88 Suburban 5.7 is the first year of EFI, I think. The truck sits for 51 weeks a year, and sees about 350 miles in that single week. It has started every single time without fail, last year on the first crank!
It has an annoying off-idle hesitation, but the fact that it starts every time means a lot to me- more time fishing, less time farting around!
It has an annoying off-idle hesitation, but the fact that it starts every time means a lot to me- more time fishing, less time farting around!
1911
Expedition Leader
EFI: More efficient (better mileage), works at any altitude or inclination, easier cold starts, difficult to work on without diagnostic tools, subject to ECM, etc.
Carb: less efficient, does not like large changes in altitude, easier to work on/repair in the field, no ECM to fail.
I have two 4WD trucks with carbs and one with EFI; I like them all. Toyota EFI is stone reliable and foolproof (as long as you don't mess with the stock air cleaner); always works and never have to think about. On the other hand, I just like the carbed trucks, they're more fun to drive (have more character) and easier and more fun to work on. The stock carbs (Aisan) work very well at different altitudes and any inclination, just not quite as good as EFI. If I could only have one or the other for some reason, it would probably be EFI.
Erik N
Adventurer
Which passages? Just the regular air intake port?
Larry
Bigassgas Explorer
Obviously, computer controlled EFI engines are my preference. I too grew up with Q-jets, Edelbrock, Carter AFB’s, Holley’s, Thermoquads, Motorcraft’s, breaker point ignition, etc. and I don’t miss any of that. I remember when swapping HEI onto older vehicles was like a huge technology upgrade. WOW, no more points to fiddle with!
- Drivability. EFI starts easy in all weather conditions, provides a smooth and instant throttle response through all power ranges. EFI always maintains stoichiometric air fuel ratio of 14.7:1 to optimize performance, fuel economy and emissions. Tune your carburetor in your driveway and it is already out of tune by the time you change elevations when you drive over the curb. I suppose if you live in the Midwest where the altitude is about 500-800 ft. everywhere this isn't much as an issue. But here in the West we could traverse over 7,000 ft. in a few hours. I live at 5,000 ft. but we often pass over peaks that are in the 12,000 ft. range. Or if we head to AZ we could drop a few thousand feet in elevation. How many times do you want to get out to adjust or re-jet your carburetor in a day? Carburetors don’t like altitude changes, extreme heat, extreme cold, bouncing or running off camber. When my truck about rolled several hundred feet off the cliff side of the Grizzly Lake trail in Chaffee County, CO because the engine would not stay running at the altitude and died every time it hit a bump or stepped on the clutch I vowed to myself to rid my life of carburetors. Have never regretted the upgrade to EFI.
- Reliability. EFI regardless if it is TBI or MPFI, GM, Ford, Chrysler, Toyota, etc. Gasoline EFI is very reliable with few durability issues. About the only thing that will really stop the vehicle dead in its tracks is a failed fuel pump or failed pick-up coil on those older engines still running distributors. Carry a spare if one is worried about a breakdown. I carry a spare fuel pump. Failed MAP, 02, CKT, or even a MAF are not going to stop the engine although it won’t run that great but at least it will limp you home or to the next part store. ECM failures are practically unheard of and are more times than not misdiagnosed as a failed than they actually do fail.
- Performance. Throttle response of EFI is unmatched by carburation. The engines will run upside down on a shaker machine until all of the oil drains out if you want them to. Even a severely modified gas engine can run extremely well with EFI when properly calibrated.
- Fuel economy. Fuel economy is always a moving target but on average you will see a significant gain in fuel economy with EFI over carburation. My personal experience has been the fuel injected big block delivers about 2 more MPG than the carbureted small block before it (adding an OD trans later added more). Something to be said for an engine running at stoichiometry air fuel ratio with the ignition timing computer controlled to keep everything running spot on. Did a TBI swap on a ’72 C20 a few years ago with very noticeable difference in fuel economy as well.
Computer controlled fuel injected gas engines are not an automotive industry conspiracy as some have alluded. It is a system designed to maximize performance, fuel economy, durability and reduce emissions and does a fine job of doing all of that. The jury is still out to see what fuel delivery will be like in a couple more years. We are in a transition time now where every manufacturer has at least 1 direct injected engine in their lineup. In a couple more years direct injection will be as common and port injection is today. The industry change from port injection to direct injection is huge. This is like watching carbureted engine go the way of the dodo bird in late 80’s as EFI took over. The next few years will be interesting. Hope this new technology doesn’t do to gas engines as what happened with new diesel engine technology. 2014 will be a big year for GM trucks. Like 1987 (First TBI) and 1996 (first OBDII SFI) all over again.
- Drivability. EFI starts easy in all weather conditions, provides a smooth and instant throttle response through all power ranges. EFI always maintains stoichiometric air fuel ratio of 14.7:1 to optimize performance, fuel economy and emissions. Tune your carburetor in your driveway and it is already out of tune by the time you change elevations when you drive over the curb. I suppose if you live in the Midwest where the altitude is about 500-800 ft. everywhere this isn't much as an issue. But here in the West we could traverse over 7,000 ft. in a few hours. I live at 5,000 ft. but we often pass over peaks that are in the 12,000 ft. range. Or if we head to AZ we could drop a few thousand feet in elevation. How many times do you want to get out to adjust or re-jet your carburetor in a day? Carburetors don’t like altitude changes, extreme heat, extreme cold, bouncing or running off camber. When my truck about rolled several hundred feet off the cliff side of the Grizzly Lake trail in Chaffee County, CO because the engine would not stay running at the altitude and died every time it hit a bump or stepped on the clutch I vowed to myself to rid my life of carburetors. Have never regretted the upgrade to EFI.
- Reliability. EFI regardless if it is TBI or MPFI, GM, Ford, Chrysler, Toyota, etc. Gasoline EFI is very reliable with few durability issues. About the only thing that will really stop the vehicle dead in its tracks is a failed fuel pump or failed pick-up coil on those older engines still running distributors. Carry a spare if one is worried about a breakdown. I carry a spare fuel pump. Failed MAP, 02, CKT, or even a MAF are not going to stop the engine although it won’t run that great but at least it will limp you home or to the next part store. ECM failures are practically unheard of and are more times than not misdiagnosed as a failed than they actually do fail.
- Performance. Throttle response of EFI is unmatched by carburation. The engines will run upside down on a shaker machine until all of the oil drains out if you want them to. Even a severely modified gas engine can run extremely well with EFI when properly calibrated.
- Fuel economy. Fuel economy is always a moving target but on average you will see a significant gain in fuel economy with EFI over carburation. My personal experience has been the fuel injected big block delivers about 2 more MPG than the carbureted small block before it (adding an OD trans later added more). Something to be said for an engine running at stoichiometry air fuel ratio with the ignition timing computer controlled to keep everything running spot on. Did a TBI swap on a ’72 C20 a few years ago with very noticeable difference in fuel economy as well.
Computer controlled fuel injected gas engines are not an automotive industry conspiracy as some have alluded. It is a system designed to maximize performance, fuel economy, durability and reduce emissions and does a fine job of doing all of that. The jury is still out to see what fuel delivery will be like in a couple more years. We are in a transition time now where every manufacturer has at least 1 direct injected engine in their lineup. In a couple more years direct injection will be as common and port injection is today. The industry change from port injection to direct injection is huge. This is like watching carbureted engine go the way of the dodo bird in late 80’s as EFI took over. The next few years will be interesting. Hope this new technology doesn’t do to gas engines as what happened with new diesel engine technology. 2014 will be a big year for GM trucks. Like 1987 (First TBI) and 1996 (first OBDII SFI) all over again.
HA I guess since I am the one who ranted about modern tech I will chime in.
BUT first I would like to point ou that I did NOT say fuel injection was part of some sort of conspiracy. Fuel injection alone without all the emissions BS is a great thing in the automotive industry.
Now as far as the question at hand. For me its all about bang for the buck. My 94 is running a 1976 350 with lots of upgrades to make about 450hp. needless to say the stock TBI just WILL NOT SUPPLY THAT KIND OF HP. Stock TBI from 87-95 is meant for 220hp The TBI can be modified to run up to about 300HP with some time and money. Next option is aftermarket EFI such as products from holley, edelbrock, accel, howe ect. Any one of these options is going to be upwards of $1200 PLUS a bunch of other needed expences. Next option was to buy and tune a q-jet carb for under $300. I am perfectly comfortable with q-jet carbs I know them inside and out and I know how to build and modify them for my needs. So thats what I went with for my high performance engine. My truck starts in less than 1 revolution of the engine in any weather. Stock EFI will NEVER start as fast as my truck because it has to revolve enough to sence that everything is ok and ready to start including oil pressure. My truck does not flood out or stall or hicup spit or sputter off road because I have modified and tuned the carb to do exactly what I want from it. It gets 14-16MPG (not bad for a fullsize truck with 450hp and 33" tires)
On the other hand. If I was to go out and buy a truck with NEWER EFI such as a vortec truck which has PLENTY of potenial for fuel delivery, I would not change it. Going further up the scale into LS engines has even more potential in the fuel injection.
So it really depends on the actual EFI and what you plan on doing with it. I mean a honda motorcycle has fuel injection but the fuel injection off a honda motorcycle is going to be a big hairy cat turd on a big chevy V8.(Hi Larry) Same can be said about stock 87-95 GM TBI, it is EFI, however its a very poor example of EFI.
SO if I had all the money I could ever want would I ever run a carb on a vehicle? Hell yes I would! If I had all the money I wanted, I would have some pretty awesome old classic cars and trucks and I am old school at heart. But I would have some fun Fuel injected vehicles as well.
Maybe I am nostalgic, but I dread the day that carborators become extinct, I also dread the day when internal combustion engines and TIRES become extinct. I truely FEAR that some day (possibly in my lifetime) that "hot rodding" or any modification, such as a 8.1 swapped into a 78 chevy, becomes illeagle. (Hi again Larry) Allowing or even sugesting that something such as a carborator should be illeagle is just asking for communist/socalist goverment to step in. First its carbs, then its engine swaps, then its ANY modification at all.
BUT first I would like to point ou that I did NOT say fuel injection was part of some sort of conspiracy. Fuel injection alone without all the emissions BS is a great thing in the automotive industry.
Now as far as the question at hand. For me its all about bang for the buck. My 94 is running a 1976 350 with lots of upgrades to make about 450hp. needless to say the stock TBI just WILL NOT SUPPLY THAT KIND OF HP. Stock TBI from 87-95 is meant for 220hp The TBI can be modified to run up to about 300HP with some time and money. Next option is aftermarket EFI such as products from holley, edelbrock, accel, howe ect. Any one of these options is going to be upwards of $1200 PLUS a bunch of other needed expences. Next option was to buy and tune a q-jet carb for under $300. I am perfectly comfortable with q-jet carbs I know them inside and out and I know how to build and modify them for my needs. So thats what I went with for my high performance engine. My truck starts in less than 1 revolution of the engine in any weather. Stock EFI will NEVER start as fast as my truck because it has to revolve enough to sence that everything is ok and ready to start including oil pressure. My truck does not flood out or stall or hicup spit or sputter off road because I have modified and tuned the carb to do exactly what I want from it. It gets 14-16MPG (not bad for a fullsize truck with 450hp and 33" tires)
On the other hand. If I was to go out and buy a truck with NEWER EFI such as a vortec truck which has PLENTY of potenial for fuel delivery, I would not change it. Going further up the scale into LS engines has even more potential in the fuel injection.
So it really depends on the actual EFI and what you plan on doing with it. I mean a honda motorcycle has fuel injection but the fuel injection off a honda motorcycle is going to be a big hairy cat turd on a big chevy V8.(Hi Larry) Same can be said about stock 87-95 GM TBI, it is EFI, however its a very poor example of EFI.
SO if I had all the money I could ever want would I ever run a carb on a vehicle? Hell yes I would! If I had all the money I wanted, I would have some pretty awesome old classic cars and trucks and I am old school at heart. But I would have some fun Fuel injected vehicles as well.
Maybe I am nostalgic, but I dread the day that carborators become extinct, I also dread the day when internal combustion engines and TIRES become extinct. I truely FEAR that some day (possibly in my lifetime) that "hot rodding" or any modification, such as a 8.1 swapped into a 78 chevy, becomes illeagle. (Hi again Larry) Allowing or even sugesting that something such as a carborator should be illeagle is just asking for communist/socalist goverment to step in. First its carbs, then its engine swaps, then its ANY modification at all.
A bit more. I live in Utah so I see the elevation changes and cold winters and I dont have any problems with them and a carborator. Also I wont run any other carborator than a q-jet. Mainly because they are the next best thing to EFI and because they are the carbs I know best.
Bullseye240
Adventurer
Mechanical Diesel................done
would lone to go EFI, but only with enough budget to get an aftermarket MPFI. To me a TBI is just an electronic carb and not worth the effort most of the time. I have a Quadrajet 800CFM to feed my 496 and it does just fine, not to mention the awesome sound it makes when you stomp it and the toilet bowl sized secondaries open up and try to suck the hood down the intake!
Larry
Bigassgas Explorer
Yeah, TBI is pretty terrible. Here is a TBI project I’ve been working on for the past few weekends. 1993 C1500 Sportside. Yanked a 4.3L and replaced it with a 454HO with L29 Vortec heads topped with a stock 7.4L TBI unit. Runs horrible from what short distance I drove it around the block with open manifolds. :elkgrin: Hoping to button it up and have the tow truck pick it up for an appointment with the exhaust shop Monday. Howell Engine Developments did the ECM tuning. More in this ride later.
4.3L coming out
Family reunion. Freshly pruned 4.3L on Left, 7.4L right and 8.1L in the back ground
As it looks as of about an hour ago.
4.3L coming out
Family reunion. Freshly pruned 4.3L on Left, 7.4L right and 8.1L in the back ground
As it looks as of about an hour ago.
To be fair TBI is fine for a stock, or under 300hp engine (possibly a bit more for a big block). After that its really hard to get any more out of it without a TON of time and money. When this engine was in the 91 suburban my brother owned, he and I did a lot of research and he spent near $1000 and a lot of time trying to get more out of the TBI. In the end it still wasnt enough.
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There are a lot of ways to get a good seat of the pants power upgrade to a stock 87-95 TBI truck. However TBI heads and cam profile are simply the worst ever put out by GM for a V8 truck. Then once you replace those with better versions the TBI simply will not keep up.
You know what I would love to see for TBI? A ready made way of running dual TBI or even a bigger throttle body for more air and provisions for 4 injectors. Either way you would have a fairly cheap way to make real HP with cheap and easy to find TBI parts. Another downfall to TBI trucks is the OBDI computer system, It really only allows a little room for improvement.
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If it will help anyone with stock TBI truck OR even a TBI retrofit to and older engine such as Larry has done and mentioned, this is a really good web site to help you achive the max potential of a TBI EFI system. http://marine-performance-parts.com/gmtbiperformance.aspx
Also a great way to rid yourself of OBDI. http://www.megasquirt.info/
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-*NOTE* I just noticed they now have a ported 7.4L Throttlebody that flows up to 720CFM! Man if they would have had that just a few short years ago maybe I would sing a different tune about TBI.
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There are a lot of ways to get a good seat of the pants power upgrade to a stock 87-95 TBI truck. However TBI heads and cam profile are simply the worst ever put out by GM for a V8 truck. Then once you replace those with better versions the TBI simply will not keep up.
You know what I would love to see for TBI? A ready made way of running dual TBI or even a bigger throttle body for more air and provisions for 4 injectors. Either way you would have a fairly cheap way to make real HP with cheap and easy to find TBI parts. Another downfall to TBI trucks is the OBDI computer system, It really only allows a little room for improvement.
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If it will help anyone with stock TBI truck OR even a TBI retrofit to and older engine such as Larry has done and mentioned, this is a really good web site to help you achive the max potential of a TBI EFI system. http://marine-performance-parts.com/gmtbiperformance.aspx
Also a great way to rid yourself of OBDI. http://www.megasquirt.info/
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-*NOTE* I just noticed they now have a ported 7.4L Throttlebody that flows up to 720CFM! Man if they would have had that just a few short years ago maybe I would sing a different tune about TBI.
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