Why everyone carb swapping?

[99xcss4]

I like it all carb quadrajet or thermoquad tbi spider injector mpfi upgrade version not the csfi and aftermarket efi systems

 

[lbeninger]

I like it all carb quadrajet or thermoquad tbi spider injector mpfi upgrade version not the csfi and aftermarket efi systems

I don't dislike carbs. They have their place, it's just that ide rather upgrade to efi.

 

[Busters]

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.

I would like this idea, yet I would have to to change a lot of features on my current truck I have. My current set up it I have the 5.0 in my 1998 C1500 that has the 4L60e trans so ima try and pull a motor and than rebuild just a bit, in my head and opinion I feel it would be less to do.

And on another note I’m a 17 year old and my main goal is to build an engine as to understand the internals more on, with that I could do on hand work so I can learn and do have a budget. Yet I enjoy most of these OBS and had to ask my question cause I checked to see all peoples builds and discovered not many building kept it with spider injection. They just intake and carb swapped so it suprised me.

And my goal for my truck would be to daily and strip and little but thank you very much for your explanation, I would love to learn more about carb physics and how they can do more against a test. I do own one I should say my mom with a 1965 or 66 D100 carb 318 I believe could be wrong, but I do learn old stuff from it.

Definitely will check out the MFPI system thank you.

 

[Busters]

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.

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 $$$$.

Your saying 400 to 450 on stock injectors?? not the crap stock OEM ones but like the other ones?

 

[Busters]

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

Yeah I meant to say not many people, build there engines with them that I have seen.

 

[SAATR]

A great many of our trucks are carb swapped because the vast majority of people can't troubleshoot their way out of a wet paper bag. Either they take their truck to a clueless parts-changer of a mechanic that charges $$$$ to fire the parts cannon on the customer's dime, or the owner does it themself and hits nothing but their wallet. The blame for these failures is placed, inevitably, on "this fuel injection junk", and good money is thrown after bad while they source a new intake manifold, carb, and ignition system. Then the questions about fuel pressure regulators, sensors, transmission control, and the like flow onto places like this forum. How many of these projects end in a smooth driving truck with good power, fuel economy, and reliability is hard to say, as most vanish after the deed is done.

It is true that stock TBI and Vortec engines can pick up some power with carb swaps. I'm sure it's a combination of better air/fuel flow, a more aggressive timing curve, and a complete lack of the electronic nannies that keep our engines out of detonation and our transmissions from gaining extra neutrals. The increased power and relative ease of tuning is attractive to many, though I'm not sure of the power difference between a tuned factory Vortec and a carb swapped engine. What I AM sure of is that there are about as many people that can competently tune a carb as there are people that can competently tune an ECM; that is to say, not many at all. Lots of folks THINK that they can screwdriver a carb into submission, but it just ain't so. Most that I have seen just bolt on a parts store Edelbrock, twist the distributor until it sounds OK, and send it. The butt-dyno says it FEELS faster, so it must be! Right! Right? RIGHT?!?

 

[99xcss4]

Your saying 400 to 450 on stock injectors?? not the crap stock OEM ones but like the other ones?

the stock spider csfi or the mpfi replacement can support 400-450hp

 

[99xcss4]

this specs for the high psi spiders do not know how accurate they are

Stock OEM Unit - 24LB (csfi or mpfi upgrade) mpfi upgrade 429.95
UPGRADED Flow-Balanced & Matched, Complete Units:
500HP - 36LB 699.95
650HP - 48LB 799.95
800HP - 62LB 899.95

 

[Caman96]

I wonder if it would be worth having a new Acdelco MPFI tested for leaks and flow tested? Yeah, that shouldn’t even be in question but these days much is.
And then you need pcm reprogramming.

Edit: Actually pretty reasonable to do!

Flow Testing

Select this service if you just want to see if the injector is working properly. Our test service includes to following: Leak inspection: injectors are inspected for leaks both on the injector body and at the output nozzle. An injector that is leaking from the nozzle will require reconditioning...

www.fiveomotorsport.com

Then again maybe NOT.

• Price shown is per injector running gasoline and/or oxygenated fuels

 

[Komet]

In my opinion, the stock vortec intake with the internal poppet valves is a failed development pathway. It's a good performing intake for the application but it's also the last gasp of trying to shoehorn the sbc into the modern emissions era. It is also ugly. But I'd take it all day compared to a carb.

I prefer 8 full size fuel injectors on external rails. Cheap and plentiful to replace, o-rings on the performance wall at the parts store. There's a lot of induction options for the sbc still, you can pretty much have it however you want to tune it.