View Full Version : Fuel Injected vs. Carburetor?

04-25-2009, 08:00 AM
So, I know this thread may and can cause a lot of controversy, and I know I will get MANY different responses, so I will try to clarify myself as much as possible.

My father and I are currently running a 350 SB in our '73 El Camino. My dad and I are planning on pulling it out to drop in a fuel injected 350 from a donor. He is using it as a daily driver in "nicer" weather, so he wants something a little more compatible.

This leaves me with the old 350, and it got me thinking further about fuel injection versus a carbureted engine. If I was to rebuild the engine, i.e. new heads, new cam, valves , etc., and simply had an Edelbrock Performer RPM intake with a 750 CFM carb versus an Edelbrock LS style EFI intake with a 90mm throttle body, where would I get more power?

I know this leaves the question: What is your main use of the car?
The answer is that I would like a car that can hit the track, hit the strip, and be a driver. This leaves me thinking that having and EFI setup with a laptop to change air/fuel ratios would be nice and convenient.

I know I may sound ignorant, but no one has ever had a real answer for me!

What are your thoughts? I trust all you guys out there!!

04-25-2009, 08:45 AM
i'm no expert, but i've read up on it a bit. there is no real power difference between a properly tuned carb and an EFI. but for multi-use, yes the EFI is much better. plus if you were to drive through the rockies (just an example)it will automatically adjust for the air pressure change, and any temp changes.

04-26-2009, 09:16 AM
Only advantage of the carb is lower cost, and less time for set-up.

EFI gives better gas mileage, better throttle response and same top end. It's also easier to start, both hot and cold, because of electronic controlled spark advance. Also safer--i run knock sensors to protect my engine in case of problems. This allows you to run a little higher static ratio for higher efficiency and more power (like cake and eat it too!)

My '68 Camaro with full interior gets nearly 20 MPG out of a 355 sbc and runs 0-60 in 4.9 seconds with the shocks and suspension set up for autocrossing. I've never had it dyno-tuned so i'm sure there's lots more in it both for fuel economy and power as well.

EFI is more cost and more time, but for me is so worth it!

Good luck,

04-26-2009, 04:02 PM
Wow Paul! I may need to get back in touch with you once I get this set up and going! I have my build sheet getting put together, and I am thinking this may be the worth it way to go. If you are getting 20 MPG, the the money is worth it since you get it back in fuel!

Curious--what EFI are you running? I was looking to do the LS style, but I think I am going to go with the Pro-Flo2. I will admit, I was originally going with the LS style for the looks :)

04-27-2009, 02:59 PM
I'm running Holley Stealth Ram, with a comp cams EFI cam and roller lifters and rockers (1.6). I purchased the entire HSR used on eBay for $1700 with a laptop to tune it included. Heads are AFR 180s, purchased these used on eBay for $1100, had a set of 186 chevy heads that flow nearly as well but wanted to get rid of the forward and high mass since i autocross. Block is a stock 2 bolt main bored to 355, nothing special at all. Compression is only about 9.5 to one, could be a point higher with Al heads, EFI, wideband O2 and knock sensor.

To be honest, it may be capable of 25+ MPG on the highway, i have done no tuning at all except a little work around idle to smooth it out. I just downloaded what looked like the closest tune to my set-up off the of the website at Holley and ran with it!! I have the air/fuel ratio set a bit on the rich side to be safe, so it's not tuned for economy at all. I'll get around to tuning it sometime...but right now i'm too busy racing and having fun!

The Comp Cams software Camquest estimates the HP topping out at 406 at 5500 RPM and the torque coming in at 435 at 4000 RPM. Of course these are just computer similations, i haven't had it dynoed or anything.

I'd be happy to help you with your project if i can. You may also check out my website (link in sig) for some blog action of my build.

Good luck!