Well, I've been engaged in a (friendly) year long battle with a friend of mine on the merrits of fuel injection vs. carburators. So I pose the question to you all, wich is better, when, and why? I present some of the claims from both sides. Mind you we are speaking strictly from a performance car type standpoint. We are both in agreement that for an every day "get it and forget it" driver FI is the better choice. Anyway as follows:

FI- (me)

1: Econemy and efficiency

2: Perfect stoichiometric ratios from idle to redline with no power or efficency gaps.

3: Tuning can be done in the car, almost instantly, and very precicsely.

4: FI cars have sensors that can help you tune without external equipment.

5: Feedback to changes are instant, not the next change of plugs away.

6: Better fuel atomization and more precise with MPI systems timed to the valves.

7: More adaptable and tunable to dynamic forced induction, like turbochargers and centrifugal superchargers.

Carburators: (him)

1: Better throttle response.

2: Better fuel atomization.

3: Better for forced induction, particularly linear boost like Roots type blowers.

4: Easier to tune, especially since modern Holley style carbs have provisions for external jet changes without removing bowls.

5: More reliable.

6: Easier to troubleshoot.

7: Makes more power than FI.

I'm sure there are more things that I can't think of right now, but those are some of the biggest issues of contention between us.

So what do you all think? Who's right, or should I say who's "more" right than the other? Is modern FI really as good or better than carburators, or do they still have an advantage on a performance car?

Discuss

 

I'm interested in this. I LOVE playing with my FI car. Haven't gotten into tuning yet, but I'll be there eventually. On the other hand, my dad wants to get an old 60's vette or some other old school carburated muscle car and I'm sure i'll have my share of working on one of those too.

 

I disagree with all 7 points of his.

 

I will disagree with him in your order.
1. The throttle response on a LS1 Sequntial Fuel injection system is much better then that of a Carberated car. U se to run the Dominator Holleys (which I love) and the smaller Holleys and there is no comparisons to the fuel injection. Not to mention, hot days and cold days you can always start the car through the window.

2. A LS1 fuel injection system beats a carberated system hands down on atomization issues. The fuel is spayed from a high pressure to a low pressure to creat the better mist. The Delta P (pressure drop across two points) is greater on a fuel injected system. A carberated systems delta p is going from around 15apsi (atmospher pressur) to a pressure of about 7 apsi. Thats a 8psi drop. A fuel injection system like the LS1 goes from 65 apsi to 7 apsi which is a pressure drop of 58 psi. Which makes the fuel Atomize that much better. Not only that but have you ever wondered why if you put a 1050 Dominator on a stock 350 it will stumble on the line but a fuel injection system like the LS1 does not even though they have close to the same CFM cappacity? Because the carberator is relying on the air flow across the Venturies to draw the fuel out. At low RPM and a small CI engine, there might not be enough air flow to make it draw the fuel right. But on a FI system, the fuel is always under pressure so the system does not need airflow to creat the fuel flow. Besides that FI just smokes a carb when you look at pecise fuel delivery. In other words each cylender will get the exact, proper amount of fuel. Which means more power. But a carb some cylinders get more fuel then others. Carbs are just inefficent dinosours. Things of the past. They can not come close to a good FI System.
3. Well, I do not know enough about Forced induction fuel injection systems to coment on that one. But I would bet that statement is absolutly false.
4. Now what can a carb be as easy to tune as a fuel injection system. Hell, I sit in the seat with the AC on and can tune everything about my car. Never get dirty. Never get a back ack. Plus I can change more then just my fuel settings. Timing, trany shift points, speedo correction, tire size correction, fan off on temps, egr system, air system, when the ac shuts off. how hard the tranny shifts. Lets see how long it takes him to tune all these things. Lets see how dirty and how bad his back hurts afterwords. While we sit on our buts in the cool air and tune it all in minutes. Never getting dirty.
5. Yeh carbs are more reliable. Thats why you have to tune at every track. Every altitude and ambiant temp change. While the Fuel injection system does all that for me. Heck while I am running down the rode. Reliable my ***.
6. How can troubleshooting a fuel system get any easier then plugging up some kind of computer and letting it tell me exactly what is wrong? Don't get that one. You have to know how to trouble shoot in order to troubleshoot a carbed engine. But anyone with half a brain can troubleshoot a computer controled car.
7.No way can it make more power. Hell when Chevy went from Carberated Vettes to Fuel Injected Vettes they gained 40% more power without even changing the engine! That was in the begining of the computer fuel injection. Now, hell, I have 320 rear wheel horspower, I get 24 mpg at 80 mph. How can a carbed system do bothe?

To end, it sounds like to me, the gentelman you are arguing about is just symply scared of new technoligy. He probly haits to even use a computer at home. Doesn't understand them. If he understood the potential of a good computer controled fuel injection system, he would never mess with dirty carbs again.

Now for those that think I am bashing, no I am not. I am just stating a few points as to why I think the "friend" is wrong. But remember, different strokes for different folks. I just hope some day he will see the light and come over to our side .

Great post for a million different opinions. Keep them coming!!!!

 

Thanks for the replies.

Actually he's an excellent tech, was a Corvette Specialist back in the 80's early 90's, and loves the internet. He may be a few years behind the curve on FI technology but he's far from a fool, in fact he probably knows FI better than most of us in some aspects. And he is THE best carburator tuner I've ever met. That's how this argument has lasted over a year.

But I agee with you on most points, fo shizzle

1: Modern FI has excellent throttle respone, but my experience with FI bikes is carbs still hold the advantage on throttle response. They're also very SMALL carburators that react quickly to vaccuum signals. Accellerator pumps work pretty quick! But how an inexpensive motorcycle FI system compares to something complex like our LS1 system I don't know. There's one point I may just have to agree with him on.

5: Sorry, to clarify he doesn't mean "reliable" in a sense that it's going to run the same time every week with no tuning, he meant reliable as in you'll never get half way down the track and have the engine die because the carburator blew a fuse or something. But modern FI is just as reliable IMO, although more complex and more potential for failure it just doesn't happen.

7: I think a big reason FI cars started making more power in the 80's over carbed cars was emissions. Carburators just couldn't match the precision (there's that efficieny thing again ) that FI could match, and simultanious control over fuel AND emissions controls. I have seen carbed cars with similar setups make, for all intents and purposes, equal power than FI. But not as flat a torque curve and not every day when you get in int

Thanks for the replies everyone, keep 'em coming!