This has probably been posted before so any links would be cool. But just to settle an arguement between a few friends and I. which is more cost efficient in producing horsepower a Carburated engine or FI. we'll set an example with 2 identical engines one with a carb one with FI. which is cheaper to build more horsepower?

 

This question should not even have to be asked.

I would find it almost impossible to build a FI setup from scratch for less than it would cost for a Carb and Intake Manifold combo that would yeild the same HP.

FI you need Intake, Injectors, Wiring harness, ECM, TPS, IAC, 02 Sensors, High Pressure Fuel pump, etc.

Its no contest.

 

See thats what i say. my friends keep saying FI is better and easier to make power out of then a carb would be.

 

In every single car i had ever worked on/owned, in order to make (alot) more power with FI you must swap injectors at the very least. Most of the time you must also swap manifolds to high performance ones, $350+ then you have to either do custom chip burning or a standalone ecm.

As you know just by looking at our TPI engines, aftermarket intakes are expensive, so are injectors and also a tuning solution is at least $200, ALOT more if you go standalone.

Ford guys have to worry about Aftermarket MAF sensors that cost upwards of $400

On the other hand, a good carb and intake setup can be easily had for under $800

 

Yea i'll have to make my friends read that cuz they are stubborn as hell...not that i care it's just annoying...lol

 

See, a carb is a nice cheap way for horsepower, and works just fine.

Until it doesn't. Ya see, Carbs like dying when you change temprature and altitude. On the track, that's expected. You set it every run, whenever you go to a new place, etc. For a DD, that's a b!tch. I dunno where you're from, but around here, less than a hundered miles of driving in just about any direction is enough to make you have to reset your chokes, your idle, and all of that. Fuel Injection does that for you.

Also, Carbs can have little flaws in the way they flow. This is an example, but I had a lawnmower that had a great little engine in it. Except if you revved it to fast, it'd fall on it's face. You revved it slow, it would work fine. I played with the idle screws on that thing forever, never got a happy mix. But the point is some parts of your powerband are going to be weaker with a carb, and there isn't a whole helluva lot you can do with it. With FI, you can balance out the fuel curve using tuning software, making up for the mechanical inadequacies of your parts, incresing overall performance, and gas mileage.

So yea, the carb is best for cheap horsepower. But FI is just so much more versatile. Especially in a StreetStrip car.

 

That's what I was going to comment on. Are we talking dollar for dollar, or just the final product? In the end you will be able to make more horsepower and have better drivability with fuel injection. Carbs are like my old girlfriend, cheap and easy. But ofcourse a lot of that also has to do with what car you are starting with. My car is TBI, I will leave it that way for simplicity sake and cost as well. My wife's car is carbuerted. It will stay that way, it's just easier than swapping a fuel injection setup in it.

 

(Basically repeating what was already stated, but want to drive the nail in even harder)

If your only concerns are cost and peak HP, yeah a carb is the best route.

If your gonna street drive it much at all, the headaches of a carb-system will rear it's ugly head. I think a good FI setup and tune would save you enough gas in the long run to pay for the setup if daily driven. With modern controls, you can even use FI with those huge-overlap cams.

In the end, I'd put my money on the FI making just a bit more peak power, and a lot flatter torque curve down low.

Now-a-days, I wouldn't even consider a carb for a street vehicle. The cost of gas is just too prohibitive, and it's only gonna go up. Besides, you can tune a FI setup without even getting dirty.

 

That's exactly it. Easy, and cheap. Maybe not the most efficient, but dollar for dollar (not including fuel mileage differences, which isn't THAT big of a difference realistically), carb is significantly cheaper.

Learning curve varies - if you're a computer nerd, not all that familiar with cars, tuning FI will be easy to pick up. Data logging, hooking up a laptop, piece of cake. Tuning jetting by ear would be hard to do.

If you've helped your daddy work on the 'ol farm truck since you were 11, then you know how an engine wants to run, how it'll sound when the timing is right, etc etc. A carb and a screwdriver is cheap, and easy to do the tuning with. A $2000 laptop, software, cables, sensors, IMMENSE computer learning curve, well, that's prohibitive.

Your call on the "easy" part then, that depends on the person. I'm more of a broke nerd, so learning to use the old school method was easier/better than spending top $ and going high tech.

Tell your buddy to go to a local race track, and see what they run. Top fuel, stock racing classes, whatever, carbs are more common. Out on the street - duh, grandma has FI in her Accord.

 

I have ran a carb on evrything Ive built ( Holley's that is ) I have have never had to change the choke,floats ,jest due to climate change or altitude change. The only time I ever mess with my carb is at the track. I change jets and maybe float level to optimize it for racing. My 68 Nova I had I ran for several years on the street and track and it worked flawlessly, that was with a 850 DP. It always fired right up, never hesitated, boged or anything. I do not wish to make this into a argument or anything, Im just giving my expierence with carbs. They have been around along time and are still being made better than ever, Why? Because they work. To answer your question if you put a carb and a FI on the same motor, the carb will produce more HP almost everytime. I will say FI is more street friendly especially in the winter

 

I agree...each has it's own benifits. i'm just trying to prove a few idiots a good point about an old but awsome technology that can still run with todays vehicles.

 

It's doubtful that anything anyone SAYS is going to prove the point, unfortunately.
Put them in the driver seat of a car that has a carb that's been set up correctly by someone who knows what they're doing, and thier mind might be changed... maybe.
Honestly, a well set up carb that's right for the engine combo, and the rest of the driveline as well, can really amaze most FI diehards. And it will surprise a lot of carb enthusaists as well.
Either system requires a lot of trial and error, in addition to a lot of skill to get it right.
If you want a carb system that rivals FI in driveability, you have to do a lot of homework and tuning, but it can be done.
For driveability, the Qjet is tops.
Holley DPs will work great at the track with a minimum amount of specialized tuning.
But FI will always come out on top when compared to the DP in terms of driveability.
To be fair, compare a well tuned holley VS or a Qjet.

I don't think that carbs are a "headache" at all. Not if you know what you're doing with them.

 

Unfortunately most people don't these days. Amen on the QJet, I will hopefully end up putting one on my wife's Ford. Damnit if there won't be a bit of the General in that car!

 

Most cars at the track run carbs, because most of the people at the track fall into a few categories:
1. Retired with money. Used carbs growing up, sees no reason to change.
2. The college student drag car. Carbs are cheap. What can ya say?
3. Specialized in carbueration.

Although looking around I'm seeing more and more fuel-injected vehicles at the tracks. And whoever said $2k for a laptop is crazy. My old 233 laptop I got for a case of beer from a buddy can run almost all of the tuning software. Just can't have fancy graphs and stuff.

And to not having to change chokes or jets. You're lucky. Then again, around here we go from 3500 feet, to 7500 feet, down to like, 500 feet. With extreme temprature and air pressure changes.

 

The good news is that the knowledge hasn't been entirely lost. Guys who were truly Qjet saavy were few and far between to begin with. But the wisdom has been passed down to the next generation in some cases, and there are still guys out there who can meet the needs of the few remaining people who wish to have specialized work done.
It isn't magic. It's just the experience of having worked on a few hundred of them and having paid their dues to figure the stuff out.
A good experienced carb shop is capable of setting up a carb based on info that the engine builder gives them, without having to actually test it on the vehicle.
You send your carb in, and they'll rebuild it to the correct specs, and when you get it back it works like a dream.
There are hundreds of little Qjet tricks that tuners can use to make them work right for specific applications. But if you give it to someone who knows what he's doing and let the guy know how you want it to work, he can tweak it just right without any guesswork at all.

 

So, to put a lid on this...it's just personal opinion and skills. There are so many ways to purchase and put together a fuel-delivery system that it's quite plausable that they are equals.

It really is just going with what you know apparently. I know enough about modern computers to home-brew some expensive electronics, so that route would be easier(and maybe cheaper) than learning how to tweak a q-jet for me. Others can't even format a hard drive, but can adjust the secondarys and such on carbs like it's basic math.

I'll beat the FI drum all day long, and there are others on here that are the same way about carbs. You will always find an opinion for both sides,

At this point in time, I think there isn't a 'correct' answer for this question. But as time goes on, I think FI will put the carbs in the ground, at least for anything outside of NASCAR and restoration projects/classes.

 

Pizza Guy's right.
I have both systems and I like them both.
It's a question of whether you want to tune your car with hand tools or a computer.

 

My put: "Improve what you've got."

If you have a carb system, give it what it needs to work better.

If you have a FI system, give it what it needs to work better.

But, the guy who's going to get the most HP increase/$ is going to be the carb guy, every time. I don't consider 25/18 MPG with easy starting and good driveability while having 13-sec 1/4 mile capability a Hobson's choice. Certainly did that for a lot less than a bud who spent over $10 grand to make a TPI system do the same. With 4.10 gears. . .

 

Here is a link to some of the top engine builders in the country talking about the subject. Some of these guys have won the Engine Masters.

http://www.speedtalk.com/forum/viewtopic.php?t=4543