Which is faster carb or Fuel injection?

[Ed Wright]

But, if carbs are flowed at 12", that makes the LT1 throttle body smaller. Quadrants are 750 & 800 at 12", right? That throttle body won't be that at 12".

[rawhide]

Originally Posted by Ed Wright

But, if carbs are flowed at 12", that makes the LT1 throttle body smaller. Quadrants are 750 & 800 at 12", right? That throttle body won't be that at 12".

Holley four barrel carbs are flowed at 1 1/2" of mercury which is a little more than 20" of water. I don't know what others are tested at. The two barrel carbs from Holley are tested at 3" of mercury from what I have read.
Roland

[Ed Wright]

Originally Posted by rawhide

Holley four barrel carbs are flowed at 1 1/2" of mercury which is a little more than 20" of water. I don't know what others are tested at. The two barrel carbs from Holley are tested at 3" of mercury from what I have read.
Roland

That would make it 660 cfm, which about what I was told. Dave Layer told me my LT2 SS engine would be done about 8200 due to the throttle body restriction. It falls off a cliff about 8300 on the dyno. The 305" TPI cars have the same size, if I remember correctly (been a couple of years now.) Dave said the 305"s run right up to 8800/9000. Hope I remember the numbers correctly.

[Adger Smith]

Joe ask the question: All things being equal in a stocker, lift, valve, piston, head, etc.. what would be faster a carb or fuel injection?

The question has not been answered, yet, and probably will never be because of those first 4 words in his question. I'll add 3 more words that will always keep them unequal... Wet & Dry flow.

[Billy Nees]

Originally Posted by Adger Smith

Wet & Dry flow.

Finally, the magic words!

[Joe DeMarzo]

Billy, I thought the magic words were "I love you or is it please and thank you"?

So the CFM of a FI and carb are currently not even if someone was to swap it out at the track? Also I presume the manifolds would not be an even swap????

When looking for an advantage in my original question how would you measure which would be faster or make more power theoretically? By CFM and or air volume?

By the by I have no idea what you FI guys are talking about with all that mojo but it sure is an education. Thank you!

[Jeff Teuton]

I got a pretty good example. We ran Top Stock with a 360 w/ported Edlebrocks, an 850 good carb and it performed well. When the DP's came along, we added FI bungs on the manifold, changed from an QAF 850 to a 1000 CFM throttle body and we were now fuel injected. Same motor, same cam, same everything. It made about 10 or 15 less peak hp, which surprised us. Spoke to Wilson Manifolds. They said quite normal because the fuel starts atomizing in the carb, and the injector is down in the runner. Also said the total management with the FI system makes it better overall, but more technical. Then when NASCAR got FI, the injectors are in the top of the runner, which I think would be legal in NHRA SS. We will get around to trying that someday. My 2 cents

[Adger Smith]

Joe,
I know this doesn't answer you question in a direct manner, but......
Take a look at The Engine Masters Challenge rules for last few years.
When Wesley and I were doing the rules we made some slight differences between FI and Carbs to try to keep them as equal as we could. The differences are not all in the sizing, it is in the total induction package. Study that and you might be able to get a handle on what/where the difference really is.
Billy,
Another magic word to add to the discussion: Atomization
That word adresses the wet flow and the quality of the A/F mixture in the chamber before the combustion process. (touched on earlier)

Jeff, wow! I see we were typing at about the same time, but your got there first. (RT) Great minds must ...well

[Billy Nees]

Originally Posted by Joe DeMarzo

So the CFM of a FI and carb are currently not even if someone was to swap it out at the track? Also I presume the manifolds would not be an even swap????
When looking for an advantage in my original question how would you measure which would be faster or make more power theoretically?

These are just my opinions, I'm not looking for any arguments here.
Joe, you are trying to find an answer that I don't think anyone can give you(I know I can't) because you are trying to compare carb and FI combos based on the restrictions of Stock Eliminator. Adger just brought up atomization, the biggest barriers to keeping fuel suspended are throttlebody(carb)size, manifold and port shape, how fast you can get velocity in both AND the intake valve. If you've got a carb 305 over here, it's got a really good intake and head, a big carb that has to mix fuel and air in itself and send this wet mixture through a runner at a speed that will keep all of those little droplets of fuel from falling out of suspension in the air while it travels through the carb, intake(lots of sharp turns, not good) and intake runner which takes velocity. So at low RPM you will have poor velocity but at high RPM you may be able to sustain a higher HP number(RPM potential). With a TPI 305, you have a dry throttlebody and intake that don't need to suspend those little droplets of fuel through all of those twists and turns BUT that nifty little intake is reasonably small and can't be easily "enhanced" like a regular Q-Jet manifold. It wasn't built to make HP at high RPM. Also, in a carb combo you don't gererally get any puddleing(sp?) at the intake valve like you would in a batch fire port injection combo. Sequential FI wouldn't have this problem.
I don't know where else to go with this Joe. I've tried to explain the differences in how these two combos work and why as simply as I can. That 305FI intake only gets worse on a 350. The LT-1s and LS motors don't have as much of a problem as they have better intakes. Remember, you were talking Stockers here.
And I won't even go into carb vs. FI headers.