has any one done or tried to do a carburetor conversion on a j-body motor. i was thinking about it because its overall simplicity and wouldn't the direct air flow characteristics resemble that of individual tb's for fuel injected engines. i know tuning is limited compared eclectronic fuel injection, but would the conversion be good for an all motor build?
Carburetors actually get worse performance over a properly setup efi system because the carb relies on a vacuum to pull gasoline into the intake. something the EFI system doesn't need.
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'96 Cavalier Good ol' Pushrod 2.2
-24X,000 miles on factory build
-Some oil loss between changes, me thinks it be rings.
thanks guys, your examples are simple but make it clear y efi is better
http://auto.howstuffworks.com/fuel-injection.htm That site tells you about carbs and EFI...I love that site
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'96 Cavalier Good ol' Pushrod 2.2
-24X,000 miles on factory build
-Some oil loss between changes, me thinks it be rings.
^^^I love that site as well!!!
NEW SIG COMING SOON FOR 07'!!!
Quote:
EFI engines were made to squeeze more power out of an engine. Look at the old 350's versus the new 350's, tons more power, same displacement.
I'd attribute the power difference to the vast improvements in the heads. Compare the ls1 and lt1, both efi yet the ls1 hands down blows away the lt1. Different camshaft profiles and intake design would also have played a role.
Then again I'm kinda biased...
Quote:
Carburetors actually get worse performance over a properly setup efi system because the carb relies on a vacuum to pull gasoline into the intake. something the EFI system doesn't need.
? that makes no sense.
2000 z24
1985 z28
http://www.cardomain.com/ride/825536
The venturi restricts air flow to create the required intake vacuum to pull the gasoline out of the resivor when the butterflys are open too much to create a strong vacuumin the intake manifold. It does have an accelerator pump but that is only used to give a boost in fuel when increasing throttle. A carburetor doesn't have a pressureized fuel system past the float. One of the reasons they tend to stall with a minor accident. A fuel injected car uses a pressureized fuel system meaning it doesn't need the restriction in the fuel system at wide open.
Yes I know there are huge engines making huge power with carbs but they wouldn't get better performance if they were fuel injected. I think the biggest benefits of fuel injection is:
-not having to rejet you car when moving from a place of high alt to low alt to avoid being rich or lean with different elevations.
-longer engine life due to much less fuel wash because of better atomization of fuel with efi spray and actual control over the mixture.
-increased mileage from better combustion from a stoichiometric burn wasting less fuel.
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'96 Cavalier Good ol' Pushrod 2.2
-24X,000 miles on factory build
-Some oil loss between changes, me thinks it be rings.
In fact, carburated engine can make same power as fuel injected engine (Chevy High Performance and Car Craft did the test on dyno).
Like David Jones said, if you want to keep your carb perfectly tuned, you have to readjust the idle mixture screw, rejet and so on each time the temperature, atm pressure or humidity change. Electronic fuel injection do it by itself (the ECM) by reading its sensor.
You have no advantage by replacing your EFI system by carbs. In my case, I would like to put my '70 Chevelle fuel injection but it's too expensive.
If you want to modify your car, just learn how EFI works or give the job to someone who knows.
Good luck!!
