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Carburetor vs. EFI On An LS, Which Works Best? Westech Tests Both Of Them!

Carburetor vs. EFI On An LS, Which Works Best? Westech Tests Both Of Them!

It might be the best technical competition out there. On one hand, you have the modern fuel-injection systems, computer-controlled, well past the mystery days of early EFI systems. They are simple, tunable, and provide easy data acquisition via the computer systems. Over the last fifteen years, this has been easily adopted by the aftermarket and by builders big and small. Then, there’s Old Faithful, the four-barrel carburetor. About as technologically advanced as a brick and just as simple. One fuel line goes in, a link to the right foot is created, and as long as the carburetor is tuned properly, everything else should be happy and content. But which is actually better performance-wise? It’s a great question to ask, especially since in the BangShift Mid-West shop, this is a dilemma that I’m actually facing with the GT40P-headed 302 that is destined for the Great Pumpkin Mustang. The original fuel injection system was not saved when I pulled the engine from the Rollover Explorer, as at the time there were damaged components and I was planning on going to a simple four-barrel setup. But looking at systems like what Holley has that are more-or-less plug and play, would a fuel injection setup be beneficial?

In this test, a 6.0L LS is going to be the guinea pig of this comparison. A known runner that has served well for a multitude of tests, it’s a great baseline for both fuel systems. Obviously, the main question is going to be about what kind of power difference there is between the two systems, but that isn’t the only issue to look at. Air/fuel ratios and different styles of fuel injection patterns can affect the output of the engine, and in this test individual cylinder tuning was performed on the EFI systems to try to get the last little ounce of power out of the LS. You want in-depth testing? This is as in-depth as it gets!

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3 thoughts on “Carburetor vs. EFI On An LS, Which Works Best? Westech Tests Both Of Them!

  1. Chris ewrrs

    Great comparison. I am an old school motorcycle guy. I agree it is almost impossible to tweak a carb mixture at a specific rpm.
    This has shown me that I should have done fun with a fuel injection system on my cafe racer. Who knows might be worth it lol

  2. Gregory McGee

    Very interesting. I am building a 502 chevy big block 500HP marine application engine. Been debating the carburetor vs the new Holley efi system. Since most of our running power will be expected below 5000 rpms, your test would suggest the 750 Holley route may be an equal if not the better option, especially when using an Eldebrock air gap intake and the less aggressive HP500 Crane hydraulic roller cam to maximize low end torque. Thank for the valuable information. I hope I interpreted it correctly for my application.

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