Why everyone carb swapping?

So I’m going to build a 5.7 vortec a bit do the heads, cam, lifters a lot. But why is no one using the spider injection like what’s wrong with it and it actually seems like a better option than carb like why, Other than I can’t seem to find any performance parts of them they seem like they will hold so I’ll try it.

I wouldn’t build or buy a vortec truck personally. They are a pain in the butt. The TBI is gutless but reliable. An aftermarket MPFI system is the pinnacle of performance if staying with a SBC.

Lots of people are comfortable with carbs, they are reliable and easy to calibrate for different combos. Many people enjoy not having a computer controlled vehicle.

Personally I go carbed on anything SBC and if I wanted fuel injection I would just swap in a LS engine.

Personally, aftermarket ECMs are JUNK and so are carbs on a factory EFI vehicle. I would also not waste my time on a POS gutless LS all noise dyno queen either that has a torque curve of a 2 stroke weed whacker. Jump straight to the 8100 or L8T if swapping.

Busters said:

So I’m going to build a 5.7 vortec a bit do the heads, cam, lifters a lot. But why is no one using the spider injection like what’s wrong with it and it actually seems like a better option than carb like why, Other than I can’t seem to find any performance parts of them they seem like they will hold so I’ll try it.

Click to expand...

To better answer you question you will hit a limit with the spider injector setup around 400-450 hp. AUS makes higher flowing spiders but they are $$$$.

L31MaxExpress said:

To better answer you question you will hit a limit with the spider injector setup around 400-450 hp. AUS makes higher flowing spiders but they are $$$$.

Click to expand...

what he said https://www.fiveomotorsport.com/1996-2014-v-8-cpi-sequential-units/

Busters said:

why is no one using the spider injection

Click to expand...

Mistake in logic. Heaps and piles of people still have the "spider" injection system.

Busters said:

So I’m going to build a 5.7 vortec a bit do the heads, cam, lifters a lot. But why is no one using the spider injection like what’s wrong with it and it actually seems like a better option than carb like why, Other than I can’t seem to find any performance parts of them they seem like they will hold so I’ll try it.

Click to expand...

Greetings Busters,

Good question!

Carburetor vs EFI on a SBC is often an apples vs oranges debate. But if you watch parts of the
following video, you can see a 383ci SBC that was built for torque was refusing to deliver
the expected power using the FITECH EFI. Temporarily substituting a known-good 'house dyno' carb
during the initial dyno session made all the power show up.

But what's really cool about this video is that they eventually returned the same motor
to the same dyno with the EFI setup in place, and got it to work almost identically/slightly better.
(See attached.)

And they take the time to explain what went wrong with the original EFI dyno run.

NOTE: The main focus of this video is troubleshooting/fixing a mysterious oil leak on their
brand new build, so if you want to focus on the EFI vs carb stuff, then after the first couple
of minutes of the intro skip to the following sections:

* ~12:40 to 16:10
* ~33:20 on.



Me? I've dabbled in both carbs & EFI. Each has their strengths & weaknesses. As evidenced by
this 500+ hp 383, they can both deliver on the promise. Or they each can make you miserable. You
just have to learn the relevant theory and pay close attention to the details.

Do whatever it takes for you to fully enjoy the old truck hobby. In the GMT400 ecosystem there is
obviously no 1 single best answer for true happiness behind the wheel. And to me that's part of
the fascination I have for all the various shared perspectives in this forum from all around the world.

:0)

Busters said:

So I’m going to build a 5.7 vortec a bit do the heads, cam, lifters a lot. But why is no one using the spider injection like what’s wrong with it and it actually seems like a better option than carb like why, Other than I can’t seem to find any performance parts of them they seem like they will hold so I’ll try it.

Click to expand...

There are so many options out there. The spider injector set up works just fine for up to 500hp from what I've read. I'm building a 450 HP 383 L31 and I plan to keep the spider injection for now. I've had an idea to switch to tpi or something else, but for now the spider set up works fine.

Why do all these yahoos go carb? Because they don't know how to tune the factory PCM and chalk all the shortcomings up to "emissions BS" that in their eyes can only be rectified with a calibrated air leak.

I love the idea of EFI, it's easy to tune and you can mix and match so many things.