Looking at converting to a simple EFI kit!

[drobertson]

So... I did the math. My 1973 Charger gets about 12-15 mpg overall w/ a combined 14 mpg.

Engine cid: 318 bored .040 to exactly 327 cid
cam spec.. summit cam .454 lift and 272 duration
stock 8.7:1 compression
340 valve springs
summit long tube headers and dual exhaust
Eddy intake and 1404 (600 cfm performer) carburetor
727 trans and 2.71 rear diff gears.

On average I drive about 36.5k miles per year...

with 14 mpg that comes down to 2,607 gallons of gasoline... and at an estimated 2016 average of $2.38 per gallon, I figure I'll be paying $6,204.66 for gasoline in 1 years driving.

If I can get at least 19 mpg combined with an efi kit, I'd save just under $1,700 estimated!

Do you guys think at least 19 mpg combined can be done with an efi-installed 318 w/ 2.71 gears? I sure think so. If I can, then I'm open to kit recommendations.

I also love the idea of not having to tune the engine all the time... and better cold starts... So the real question is whether It's possible to get 19 mpg combined with this combo, and if so, what kit's do yall recommend? I'd prefer an easy to install kit that's less than $1,500... because it'd pay for itself over time.

 

[mopar 3 B]

You should be getting that now. I would start looking for the existing problem before spending more on a new fuel and ignition system.
If I can obtain a consistent 16 mpg with a 4000 lb. Vehicle with 383 and 3:54 gears there has to be something wrong with your combination.

 

[drobertson]

You should be getting that now. I would start looking for the existing problem before spending more on a new fuel and ignition system.
If I can obtain a consistent 16 mpg with a 4000 lb. Vehicle with 383 and 3:54 gears there has to be something wrong with your combination.

Well I figured out why I was only getting 14 mpg... my carburetor was too big. an eddy 1405 600cfm. This afternoon I just rebuilt a 1403 Eddy 500cfm carburetor. Now I should get 19 mpg... but what could I get with efi?

 

[Dennis H]

efi and simple can be used in the same sentence? I agree with post 2.

 

[mopar 3 B]

Personally would not expect more than the 19 mpg.
You answered the rest in your original post.

 

[drobertson]

efi and simple can be used in the same sentence? I agree with post 2.

yeah I think so... after doing hours of research. I'll draw a picture of an idea on how I'd route the fuel system... but the rest shouldn't be too hard since I'm not running electric fans or a fancy ignition system.

 

[drobertson]

Alright I drew this and scanned it w/ my printer machine thing.

 

[5.7 hemi]

EFI will get better mileage overall as it can compensate for altitude, load, gas octane rating, engine temp and so on. No carb in the world can do that on the fly. So with that said, you need to decide what you want to run and you can get an efi kit for 1500 bucks with a 5 wire hook up.

 

[Mike67]

Just my thought...if your looking for mileage do like 3 B said....tune, tune, tune... With you changing the carb that's a great start. I've seen the fast/msd/ holley kits on places like cl & rj go for pennies on the dollar $1200-1500 and be new. Matter of fact I saw a new holley commander efi with everything on RJ for $975, that kit a couple of years ago was like $2300...or you could always buy a modern hemi set up for around $2500 and have the tunibility, reliability and a OD trans...

 

[drobertson]

So what are your guy's thoughts on FiTech EFI? Brand new on summit racing for less than 1k. http://www.summitracing.com/parts/fif-30002

 

[Mike67]

I've heard nothing but good things about it...now that is just the ecu.& tb... I think you can get the one that has the reservoir kit for a $200-300 more and if I'm not mistaken you can use you existing fuel pump & lines to feed it and the pump in the resv will feed the tb...might save a few bucks..

 

[drobertson]

I've heard nothing but good things about it...now that is just the ecu.& tb... I think you can get the one that has the reservoir kit for a $200-300 more and if I'm not mistaken you can use you existing fuel pump & lines to feed it and the pump in the resv will feed the tb...might save a few bucks..

I believe this is what you're talking about, and yes I'd use it. http://www.summitracing.com/parts/fif-40003

 

[Mike67]

If you're sticking with the 318 you could use the 400 model and save a $200....
http://fitechefi.com/default.asp.pg-GoStreetEFI

 

[5.7 hemi]

Fitech is a good system, affordable, and user friendly since it will learn to tune as you drive and very easy to hook up.

 

[drobertson]

If you're sticking with the 318 you could use the 400 model and save a $200....
http://fitechefi.com/default.asp.pg-GoStreetEFI

i do plan on swapping in a 500 hp 440 in sometime next year... so id get the 600hp efi so i dont have to buy two.

 

[furryfrog]

Although you have a "mild" cam, it could be even more so if fuel economy is your primary goal. I think these summit cams have very gentle slope rates, which I am assuming worsen the mileage compared to a steeper grind with similar @ .050 specs. I like the thought of a gentle cam on the valve train though. I have a summit cam in my 440 and my mileage is way worse than I expected, my double pumper holley is also to blame but I am thinking of swapping to a steeper grind with a little less duration to see if I can reach 12 mpg.

Strong ignition system helps, Vacume advance?

Awesome you drive the car as much as you do.

 

[watermelon]

looking at your sketch i would say add a fuel return line to the tank and fo with an in-tank fuel pump.

most of the issues that i have read about with these efis were pump overheating issues running a supply line only. returns lines usually fixed the problem.



edit: oops, i missed that mini fuel tank/pump unit in your drawing. that should be good

 

[jeepers007]

You'll need an o2 sensor for fuel injection. But you can also use those sensors to tune your CARB and timing.

 

[drobertson]

You'll need an o2 sensor for fuel injection. But you can also use those sensors to tune your CARB and timing.

the kit comes with an o2 sensor...

 

[drobertson]

Hey guys, I was wrong about my current MPG. When I had an edelbrock 600 cfm, I was getting 2.5 miles per gallon, and with the 500cfm edelbrock carburetor I'm getting 5-10 mpg. Part of why I really want to convert to EFI