Why Carbs over EFI?
12-03-2008, 06:42 AM
#2
Preference. Allot of people dont really know about carbs... But did you know that just by adding dual carbs to a stock d16a6 engine you will see gains up to 25% across the board... There was a Company back in the 80's and early 90's LightSpeed that showed documentation.. Carbs are a great source for real power. They are also very simple to use and tune.
12-03-2008, 07:03 AM
#3
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Preference. Allot of people dont really know about carbs... But did you know that just by adding dual carbs to a stock d16a6 engine you will see gains up to 25% across the board... There was a Company back in the 80's and early 90's LightSpeed that showed documentation.. Carbs are a great source for real power. They are also very simple to use and tune.
12-03-2008, 07:22 AM
#5
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Not always true. Todays fuel injectors have a wide array of spray patterns and are always getting better. I cant think of one reason to use carbs over efi. Other than not knowing how to tune your fuel injectors properly. In the world of mechanical VS electrical. electrical is almost always faster and more precise and more adjustable.
12-03-2008, 07:25 AM
#6
They are not really more efficient.. Carbs dont have the tunability that injection does. Idle, part throttle, full throttle, etc. Carbs are kind of one dimensional. As for all out power though, carbs are the way to go. If you ask Bisi today, he will tell you that carbs are the way to go for N/A for all out power. That is unless you have DEEP pockets and can afford Kinsler injection, and the AEM ecu... The Kinsler injection isnt really your normal fuel injection setup. Its actually a Low pressure system. It manipulates carbs.
12-03-2008, 07:43 AM
#7
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you have to realize that when bisi first started running carbs in the 90's, the tuning options werent as plentiful and advanced as they are today. that may have had a little influence on it. also he liked their atomization characteristics. they are simple once you understand them.
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12-03-2008, 07:48 AM
#8
you have to realize that when bisi first started running carbs in the 90's, the tuning options werent as plentiful and advanced as they are today. that may have had a little influence on it. also he liked their atomization characteristics. they are simple once you understand them.
12-03-2008, 08:47 AM
#10
FSAE
Just think of a good carburetor setup as a good ITB setup without the part throttle control. Good DCOE carbs have separate idle jets.
Plus side to carbs is the same expected power delivery for a fraction of the money spent.
There was a guy I met in Japan with 48mm DCOE Webbers on his B20Z CRX making over 230whp.
Plus side to carbs is the same expected power delivery for a fraction of the money spent.
There was a guy I met in Japan with 48mm DCOE Webbers on his B20Z CRX making over 230whp.
12-03-2008, 09:02 AM
#11
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Injected cars typically have the fuel atomised right behind the valves and the heat from the intake valves, piston tops and the added heat from the compression stroke to vaporise the fuel. This cools the mixture. Cooler intake charges reduce nitrogen emissions. The intake charge is slightly more dense since the bulk of the volume is air and liquid fuel instead of a vaporised mixture of fuel and air. So there's a slight increase in power potential but mixture suffers. This is why Honda works so hard to get swirl and turbulance at low rpms to compensate for poor mixture/atomisation.
With carbs the fuel typically has a longer path from the venturi to the combustion chamber. Better mixture gives a better burn and you get more power. Carbs are harder to tune for all types of throttle positions and atmosphereic conditions as it's mechanical and not very dynamic.
Fuel injection generally has better throttle response since there's no restriction between the throttle plate and the intake valve head. By definition carbs have a restriction for the air to pass through to create the pressure drop across the venturi that atomises the fuel. The restriction causes a slight lag between opening the throttle and the engine reacting to more fuel.
Of course a lot of it also has to do with placement of the injector/carb too. Either one will work but you'll get better economy with FI and lower emissions.
If you wanted to you could rig a double set of injectors to emulate a carburator by having a set just off the backs of the intake valves and then have another set way upstream for WOT throttle application. The closer set will aid throttle response and "throttle pump" and farther set will allow more time for the fuel to mix with the intake charge at higher manifold pressures. High-end motorcycles are doing a lot of this for throttle response reasons.
If you're always doing drastic changes to your engine and you have a complicated engine then setting the jets and needles on carbs are faster to tune (cheaper) on a dyno than something like iVTEC that has about 27 different load maps.
With carbs the fuel typically has a longer path from the venturi to the combustion chamber. Better mixture gives a better burn and you get more power. Carbs are harder to tune for all types of throttle positions and atmosphereic conditions as it's mechanical and not very dynamic.
Fuel injection generally has better throttle response since there's no restriction between the throttle plate and the intake valve head. By definition carbs have a restriction for the air to pass through to create the pressure drop across the venturi that atomises the fuel. The restriction causes a slight lag between opening the throttle and the engine reacting to more fuel.
Of course a lot of it also has to do with placement of the injector/carb too. Either one will work but you'll get better economy with FI and lower emissions.
If you wanted to you could rig a double set of injectors to emulate a carburator by having a set just off the backs of the intake valves and then have another set way upstream for WOT throttle application. The closer set will aid throttle response and "throttle pump" and farther set will allow more time for the fuel to mix with the intake charge at higher manifold pressures. High-end motorcycles are doing a lot of this for throttle response reasons.
If you're always doing drastic changes to your engine and you have a complicated engine then setting the jets and needles on carbs are faster to tune (cheaper) on a dyno than something like iVTEC that has about 27 different load maps.
12-03-2008, 06:21 PM
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Last edited by Team Evol Tyrone; 12-03-2008 at 06:32 PM.
12-03-2008, 06:46 PM
#16
Think foot in mouth and head in *** in the same sentence.. But thanks
12-03-2008, 07:39 PM
#17
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Ouch, Mr. I know everything. The big question Is why, sure it is very different, and Those gave got to be some damn good carbs, not like old school Holleys, but Hater-tech continues.
12-03-2008, 08:01 PM
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carbs def atomize fuel better and like everyone else said that is the advantage to the kinsler setup. However its going to be hard to have a carb dialed in 100% all the time since conditions change consistently. However many tuners want their tune run in open loop so i guess its kind of the same thing.
Couldnt we just run regular injectors at low rpm and part throttle and then at high rpms and WOT cut the fuel from the port injectors and run another set further up in the runners to better atomize fuel. I think this has been done before, doesnt one of the edelbrock manifolds have something similar ? and then theirs kinslers setup which is like this i believe.
I mean look at the setup in F1 cars, although they are seeing 14-18k all day they are not running regular carbs or a port injection setup.
Couldnt we just run regular injectors at low rpm and part throttle and then at high rpms and WOT cut the fuel from the port injectors and run another set further up in the runners to better atomize fuel. I think this has been done before, doesnt one of the edelbrock manifolds have something similar ? and then theirs kinslers setup which is like this i believe.
I mean look at the setup in F1 cars, although they are seeing 14-18k all day they are not running regular carbs or a port injection setup.
Last edited by lude98SH; 12-03-2008 at 08:07 PM.
12-03-2008, 08:05 PM
#21
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12-03-2008, 08:41 PM
#24
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Hey its the offseason, give me a break haha. I forget all the rules and regulations and they constently change.
I actually found a post on the injector/efi debate.
https://honda-tech.com/forums/showth...highlight=dyno
I actually found a post on the injector/efi debate.
https://honda-tech.com/forums/showth...highlight=dyno
