View Full Version : how close can a carbs come to fuel injection
yellow1098Greg
02-28-2012, 10:57 PM
I hope i can get across exactly what i am trying to ask but i have been thinking about how nice it would be have fuel injection on my 77 trans am. It has a built 400 with eheads on it right now. I like to drive the car alot and was thinking about a new carb. I have a holley 650 on it now and i know its alittle small for my setup. I was wondering if there is newer carbs that come close to the same response and turn key feel of a fuel injected setup? If my carb is dialed in correctly how "good" can i expect it to perform compared to a Injection setup? Is there any new carbs that do the job much better than older ones? like expensive new holleys or something else. Just looking for some feedback on guys who have there carbs running perfect and how well the stack up to fuel injection. thanks guys, hope you know what i mean.
carb or fuel injection? sounds simple, I guess its what you want it for, mileage? looks? driveabilty? if you look at the fastest drag racers its carb, old school motor or even LS engines, the biggest power makers are carb and dizzy, an old school gen I block on the street with fuel injection runs good and gets better mileage than the same carb set up, but an LS engine with a carb runs well and gets 20+ miles to the gallon, and you will get 100 other opinions here
TheMeat
03-28-2012, 06:20 PM
I have a Holley DP 750 on my car with some Braswell parts thrown on it. It is nice and crisp but could probably get better fuel mileage with newer metering blocks.
If you take the time to tune a carb like you would with EFI, I think you would be surprised how good a carb can be. MPG wise, EFI will always win.
another69
04-07-2012, 06:51 AM
A properly built & tuned carb will have exellant throttle response & drivability. For me it came down to cost & simplicity, so I went with a Pro Systems built Holley, and I'm very happy overall with the carb. The cost was about $700.00. Its simple, clean, no electronics, and because the car is just a "toy" its fine. If you have the extra money, and drive your car more often in all kinds of weather, you might want to consider FI. Entry level fuel injection kits start at about $2000.00, and would be a better way to go if you can afford it. Look into the FAST easy efi kit, and there are a bunch of others like it.
Vegas69
04-07-2012, 06:53 AM
To answer your question. Not very close.
Shaker455
04-07-2012, 12:31 PM
Thats what we do here,
Custom hand built units from select part carbs tuned to your specs.
Live tested and wideband O2 sensor varify A/F ratio on my own Pontiac, then guide you thru final tune on your combo.
We also tune FI cars.
A well tuned carb can be very close to FI with the right features and having a wideband on your own car will help as well.
What dist you running & cam?
yellow1098Greg
04-10-2012, 02:02 PM
I'm just running an msd and a edlebrock performer rpm cam.....and I'm not to firmilar with wideband...what's that about and where are u guys located???
just food for thought,, I just put an LS6 with a carb(650 eddy) in my camaro, it is getting about 23 miles to the gallon, I just ran it at delmar goodguys autocross and it turned in times good enough for 5 place and there were a lot of injected motors there, the carb isnt better or worse injected, I did it because of the simplictity of the build, cost was about the same
Vegas69
04-10-2012, 06:10 PM
What about heat soak, cold idle, flooding on hard stops, and tuning every cylinder for max efficiency? Carbs work fine, injection is better.
Shaker455
04-10-2012, 07:38 PM
I'm just running an msd and a edlebrock performer rpm cam.....and I'm not to firmilar with wideband...what's that about and where are u guys located???
We are in Southern New Hampshire.
Wideband O2 sensor is a tuning tool.
It's is an O2 sensor in the exhaust like a modern car that you can read the Air/Fuel ratio realtime.
It gives you ability to balance all aspects of the carb thru out the entire rpm band.
yellow1098Greg
04-14-2012, 02:20 PM
Sounds awsome.....would I have to come up there from Florida to get you guys to do that?
funcars
04-14-2012, 09:15 PM
EFI lets you control ignition timing and gives more uniform mixtures in each cylinder. That makes a large difference for lower speed operation. WOT at elevated rpms not as much difference.
Shaker455
04-15-2012, 06:40 AM
Sounds awsome.....would I have to come up there from Florida to get you guys to do that?
Along with a new custom carb built to your specs we offer "Fly -n-Tune"
We would spend the weekend with you tuning with the wideband....then you can post your results!
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