NITROZ9
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Registered: 04-2010
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EFI vs DI
Can anyone give a good description of what the differences are in the injection systems?
I know this is going to be mostly opinions but can you list the pros and cons of why you would want either one.
Why not old school carbureted.
I know people that in the 200hp mercs they would rather build the EFI. they say they are faster than the DI.
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Aug/6/2010, 7:49 pm
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1Nightmare
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Re: EFI vs DI
I can tell ya "why not carbs"....efficiency.
Carb technology just don't compare, starting with atomization of fuel into the air charge. In a carb, fuel gets atomized by being drawn through an orfice into the airstream.
It gets the job done but FI pressurizes the fuel through the orfice which can be reshaped to do the job better under those circumstances. Plus injection can be applied directly to the cylinder to eliminate fuel falling out of suspension on it's way to the cylinder after the carbs - thru manifold, thru cankcase.
Since the FI is bangin' it in at up to a couple hundred psi at the cylinder, the cylinder can also be more efficiently scavenged of exhaust gases before the fuel enters, so you have a less diluted fuel/air mixture.
FI isn't subject to problems related to float/bowl problems.
These are a few things I can pull outta my.....ear, and I might be full a.....garbaage and Bullet can tell us better - I would hope.
Of course, the down side of FI is they're all electrically/electronically controlled which usually means they're not usually in the mood to put up with weak voltage. More expensive stuff to go wrong. When they're right, they're real right - but - when they're wrong, it's gonna be expensive to get'em right again.
--- Good things comin' outta Crap!
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Aug/7/2010, 12:00 pm
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NITROZ9
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Re: EFI vs DI
Correct me if I'm wrong but I think th DI does not mix the oil with the gas like thethe EFI and carb models do.The DI injects the oil directly where it is needed hence the NO smoke.I also think that the DI injects the fuel when the cylider is at TDC orwhen needed for optimum performance.I think the EFI mixes the oil and fuel and injects in the intake stroke.
I may be wrong and I'm sure that Bullet will let me know.
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Aug/7/2010, 12:33 pm
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Bullet20dc
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Registered: 09-2004
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Re: EFI vs DI
Give that man a cigar he's got it exactly right., In an efi and carbed for that matter the oil is mixed in the pre-staged area. before the carbs or injectors where as the DFI is where air oil and fuel is "directly injected" separately
--- Charlie B
Bullet20dc / 250XS
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Aug/8/2010, 7:46 am
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