Carb Vs EFI discussion
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From: Norn Iron
Originally Posted by white2001s10
Most of you guys are just proving your inexperience with running carburetors.
That is all.
That is all.
Show me a carburettor car that can make almost 300bhp per litre yet still be a daily driver...I know of a few turbocharged Subarus and Evos making around 600bhp on pump fuel, yet are driven daily.
Do you think fitting them with a carburettor will offer benefits ?? Not likely. Id say you would lose about 250-300bhp, and most of its driveabilty with carbs.
There are Supras and LS1's making around 1000bhp, again, still daily driveable. Do any of them have carbs ??? No.
trying to compare a stock efi system to an all out race carb setup, on maximum power only is stupid.
Compare like for like, if thats possible. Efi wins hands down.
with a carb, there are always compromises. with efi, there need be no compromises as far as obtaining optimum AFR are concerned.
No doubt some carb manufacturers and sellers will try and convince you otherwise, but fuel injection is simply better.
Here is a point no one thinks of. FI Tubos especially. Blow-through designs are VERY hard to tune. EFI make Turbos a very reliable system. Berfore they were almost RACE-ONLY. EFI and FI go hand and hand. For Racing only, I like carbs for the simplicity they offer. And the cost is really great. For the Street EFI is way more effiecient. It makes fast cars streetable.
9 Second Club
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From: Norn Iron
All the cars I have tuned with aftermarket ecu's have been turbocharged. I have never had too much of a problem with this. Yes a n/a car would be easier, but a turbocharged one still isnt that difficult, and thats mapping to as far as 21psi so far, all on the road, with excellent results.
Given turbocharged efi production cars have been around, certainly here in the UK from the mid 80's, I dont think that it is limited to race only cars.
In fact, we havent had a production car here with a carburettor since about 1992, which is all good.
Carbs are simple, but if you have ever tuned a car with a good user friendly efi system, you will see how easy they are to work with.
Given turbocharged efi production cars have been around, certainly here in the UK from the mid 80's, I dont think that it is limited to race only cars.
In fact, we havent had a production car here with a carburettor since about 1992, which is all good.
Carbs are simple, but if you have ever tuned a car with a good user friendly efi system, you will see how easy they are to work with.
Originally Posted by stevieturbo
A metal block with a few holes.... The operation of a carburettor is fairly simple.
But what they are to tune, is hassle, full of compromises.
But what they are to tune, is hassle, full of compromises.
you've never tuned one
you can't even spell carburetor
TECH Senior Member
Joined: Nov 2001
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From: Lake Zurich, IL
Originally Posted by white2001s10
Most of you guys are just proving your inexperience with running carburetors.
That is all.
That is all.
But... I do know I prefer sitting in my car on a hot summer day w/the A/C blasting looking at my latest logs and making changes... then 30 seconds to reflash 
Seems alot of it comes down to what you know... I know EFI systems but not Carb cars... Carb supporters generally seem to know Carbs very well but don't know EFI very well...
To me it just makes alot more sense changing numerical values in tables in the PCM... ideally a pretty exact science (unfortaunetly not the way it really works)
9 Second Club
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From: Norn Iron
http://dictionary.reference.com/search?q=carburettor
Perhaps there is more than one spelling then....
Perhaps there is more than one spelling then....
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We use carburetor here for spelling, same difference I guess..
May as well ask is better a manual trans or a auto, chevy or ford.
Some guys can do well with carbs and hate EFI.
Some guys can do great with EFI and hate carbs.
Some guys can do well with both.
Substitute manual/auto or chevy/ford for EFI/carb in the above 3 sentences and you have 3 true statements
May as well ask is better a manual trans or a auto, chevy or ford.
Some guys can do well with carbs and hate EFI.
Some guys can do great with EFI and hate carbs.
Some guys can do well with both.
Substitute manual/auto or chevy/ford for EFI/carb in the above 3 sentences and you have 3 true statements
I work with both.
There is one situation in which port injection does have a distinct advantage over carburetion, but nobody here has even touched on it.
This tells me that those involved only have a partial grasp on either concept.
What I said about carburetion is true.
If some EFI lovers get their feelings hurt when carburetion is brought up, then that's just a character flaw.
There is one situation in which port injection does have a distinct advantage over carburetion, but nobody here has even touched on it.
This tells me that those involved only have a partial grasp on either concept.
What I said about carburetion is true.
If some EFI lovers get their feelings hurt when carburetion is brought up, then that's just a character flaw.
9 Second Club
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From: Norn Iron
I am not a lover or hater of either, but recognise efi is better.
Im still waiting for any examples of 300bhp per litre carburettor powered engines ?? Or perhaps 250bhp/l or even 200bhp/l which still return good fuel economy, and total driveability on the road..
Are there any ???
Im still waiting for any examples of 300bhp per litre carburettor powered engines ?? Or perhaps 250bhp/l or even 200bhp/l which still return good fuel economy, and total driveability on the road..
Are there any ???
Adkoonerstrator
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From: Deep in the seedy underworld of Koonerville
white2001S10 - Instead of just saying carburetion is better at certain things why don't you try to explain why it's better. That's what these forums are for....discussion. ALOT of people, including myself, on this forum don't know much about carburetors because the vehicles talked about here come with EFI from the factory. I'm sure there are quite a few that do know about them here also though.
If you don't want to give away some secret to tuning a carburetor I can understand but, I doubt there are TOO many secrets left to them after all these years.
BTW, my feeling aren't hurt either. I've driven both and maybe because I was brought up with computers/electronics and things like that I'm more comfortable around the EFI stuff. I don't think anyone here is getting their feelings hurt talking about carburetors it's HOW some people are saying something and not presenting reasons for it that is getting people a little "upset".
If you don't want to give away some secret to tuning a carburetor I can understand but, I doubt there are TOO many secrets left to them after all these years.
BTW, my feeling aren't hurt either. I've driven both and maybe because I was brought up with computers/electronics and things like that I'm more comfortable around the EFI stuff. I don't think anyone here is getting their feelings hurt talking about carburetors it's HOW some people are saying something and not presenting reasons for it that is getting people a little "upset".
TECH Senior Member
Joined: Apr 2002
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From: So.Cal.
Originally Posted by white2001s10
...There is one situation in which port injection does have a distinct advantage over carburetion, but nobody here has even touched on it...
EFI does rule for big torque down low.
TECH Junkie
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From: Fresno/Chico
Ive been following this tread and I have to jump in. I have played a lot with both on a lot of different cars and there is NO clear answer. Is one better then the other? No.
Its like asking: Is Ketchup is better then Mustard?
One is not better then the other. They are just different.
Its like asking: Is Ketchup is better then Mustard?
One is not better then the other. They are just different.
With carburetion there is a very significant advantage to making power in the RPM range that the intake manifold runners are tuned at. This is due to a significantly higher mass or weight of intake charge. The more mass in the runner, the more effect pressure waves have on this mass. The end result is more cylinder filling during a limited range of engine speed.
Also, given the same average outside air temp, a carbureted system will always have a much cooler intake charge feeding into the head port. This temperature difference increases the density of the charge as would be measured on the top side of the intake valve. This increase, along with the increased density due to pulse tuning of a more massive charge adds up to a greater pressure differential when the intake valve opens... allowing the same head port & valve to flow a greater mass in the same given time duration.
Besides the obvious weight, reliability, and simplicity advantage a carburetor offers, you see there are times when they can produce more power as well.
During low-load high-vacuum driving, the fuel from a carburetor will be flash vaporized by the low pressure existing in the intake manifold, so there is really no problem with atomization or significant distribution problems in most manifolds. They can run very cleanly and return great mpg numbers when set up properly.
Also, given the same average outside air temp, a carbureted system will always have a much cooler intake charge feeding into the head port. This temperature difference increases the density of the charge as would be measured on the top side of the intake valve. This increase, along with the increased density due to pulse tuning of a more massive charge adds up to a greater pressure differential when the intake valve opens... allowing the same head port & valve to flow a greater mass in the same given time duration.
Besides the obvious weight, reliability, and simplicity advantage a carburetor offers, you see there are times when they can produce more power as well.
During low-load high-vacuum driving, the fuel from a carburetor will be flash vaporized by the low pressure existing in the intake manifold, so there is really no problem with atomization or significant distribution problems in most manifolds. They can run very cleanly and return great mpg numbers when set up properly.
As I hinted at earlier, the most significant real advantage that port injection has over carburetion (IMO) is that port injection does not require a high velocity in the intake manifold or head port in order to keep fuel in suspension. Fuel atomization and distribution will remain about the same for port injection no matter what happens with velocity in the intake runner.
This allows someone with port injection to use much larger intake ports without killing too much low-RPM power. This shows it's advantage at higher RPM once past the tuned RPM range of the intake runner itself. In other words you can get away with much slower velocity in the intake manifold and head port and reduce restriction at high RPM.
A carburetor requires you to maintain good velocity throughout the intake manifold and head port so that fuel doesn't drop out of suspension at lower engine speeds.
a sheetmetal intake and 240cc intake port heads is not a very streetable combination with carburetion unless you swap to a IR multiple carb set-up,
but would have no problem being streetable with port injection.
This allows someone with port injection to use much larger intake ports without killing too much low-RPM power. This shows it's advantage at higher RPM once past the tuned RPM range of the intake runner itself. In other words you can get away with much slower velocity in the intake manifold and head port and reduce restriction at high RPM.
A carburetor requires you to maintain good velocity throughout the intake manifold and head port so that fuel doesn't drop out of suspension at lower engine speeds.
a sheetmetal intake and 240cc intake port heads is not a very streetable combination with carburetion unless you swap to a IR multiple carb set-up,
but would have no problem being streetable with port injection.
Originally Posted by joecar
EFI is like a carb (they both do the same job) with dozens of jets instantly available as required for any vacuum/rpm/temperature condition encountered during driving.
In application there is also a big difference between a wet-flow induction and dry flow.
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From: Norn Iron
I would say most efi systems do not spray droplets. That is one of the benefits of fuel injection, its ability to fire a good spray at all times, not just when airspeed is high.
its the carb that is more likely to "spray droplets" of fuel.
That is another reason why efi cars produce much cleaner emissions.
its the carb that is more likely to "spray droplets" of fuel.
That is another reason why efi cars produce much cleaner emissions.