CARB or EFI and WHY??????????

[85_SS_302_Coupe]

You get 16 mpg on the highway? Instead of comparing it to a Jeep (mine got less than that too with the AWD V8) compare it to my car. 27 mpg on the highway with EFI and mine probably weighed a LOT more. I do have 3.73s, not 4.10s, but it's a more fair comparison.

I only used that as a comparison because it's a modern EFI vehicle. Obviously there's more to mpg than just EFI, otherwise everything made today would have considerably better mpg than older carbed cars. Then again i also have my secondaries set to open at about half throttle so if i wanted better mpg i could have it. It's just not a big issue to me. Maybe if i drove my car as a DD or if i took it on long trips, but for just playing around town and driving to the track, i want the best WOT i can get.

 

[25thmustang]

That to me sounds like another reason the EFI might be considered slightly better, I dont have to go under the hood and play with things to get either 25 mpg, or 20 more hp, I have both all the time. Needless to say carbs are for those who want them, EFI for those that don't... different strokes.

 

[85_SS_302_Coupe]

That to me sounds like another reason the EFI might be considered slightly better, I dont have to go under the hood and play with things to get either 25 mpg, or 20 more hp, I have both all the time. Needless to say carbs are for those who want them, EFI for those that don't... different strokes.

Not quite...it's more of the equivalent of an aggressive EFI tune, which would give you worse mileage as well. Basically it just brings on the secondaries sooner into the throttle than having them open only at WOT. It's as simple as bending the linkage on the secondaries...it's a 10 second tune, i could have it done faster than it takes to check the oil.


Also how tall are those 18s? I got 16mpg with little 24 inch tires. If i ran taller tires, 3.73s and tuned my car for mpg there's no reason i wouldn't hit mid-low 20s.

 

[millhouse]

Not quite...it's more of the equivalent of an aggressive EFI tune, which would give you worse mileage as well. Basically it just brings on the secondaries sooner into the throttle than having them open only at WOT. It's as simple as bending the linkage on the secondaries...it's a 10 second tune, i could have it done faster than it takes to check the oil.


Also how tall are those 18s? I got 16mpg with little 24 inch tires. If i ran taller tires, 3.73s and tuned my car for mpg there's no reason i wouldn't hit mid-low 20s.

Not quite...your not understanding how EFI works. Even with an agressive tune, you can have equal fuel economy under low loads (i.e. freeway cruising). That's the beauty of it...you do not have to sacrifice driveability, fuel economy etc. to have a kick ass tune. I myself cruise with AFR's around 16:1 under low loads. 24mpg is not a problem on the freeway. My idle is at 14.7:1 and at 8psi I'm at 11.5:1. I have everything in between blended for different AFR's depending on load/RPM...so there is no need for me to tune "aggresively".

 

[85_SS_302_Coupe]

Not quite...your not understanding how EFI works. Even with an agressive tune, you can have equal fuel economy under low loads (i.e. freeway cruising). That's the beauty of it...you do not have to sacrifice driveability, fuel economy etc. to have a kick ass tune. I myself cruise with AFR's around 16:1 under low loads. 24mpg is not a problem on the freeway. My idle is at 14.7:1 and at 8psi I'm at 11.5:1. I have everything in between blended for different AFR's depending on load/RPM...so there is no need for me to tune "aggresively".

Geez. I give up. You guys are


Yeah, better mpg, better drivability, EFI even cures cancer i heard. But it's gonna cost you twice as much if not more if you have it tuned by a professional. That's my only point.

 

[25thmustang]

My tune is usually set up to make the bes timeslips, still gets middle to upper 20s on the highway. Thats my only argument, my 26 mpg over your 16, is a huge relief for me, especially with gas in CT being well over $3.00 a gallon. For what I would spend on a custom tune, I think could be made up in gas money after a logn season of driving.

I know it will cost more initially to buy the parts, there are more parts to purchase, and a tune might cost more if the car is to that point. I don't think anyone is denying that, I just think when all the factors are weighed in, the average person, even the average car guy, would stick with EFI, for ease of use, emissions, fuel mileage, and consistency.

I might have a different opinion after we get the 393 to the track. I have been helping a friend with his 352 carbed motor, but with my dads I will be under the hood anytime it is needed.

 

[Boss 351]

Ok man, i hate to do this, but this statement tells me you don't know all that much about carbs....so i'm sorry ahead of time but here's why. Just because a carb is a 'double pumper' doesn't mean it's going to have worse gas mileage than even an 850 with vacuum secondaries. What double pumper means is that the front and rear bowls have their own metering pates and fuel lines hence double pumper. Both carbs have secondaries and if they were both vacuum secondary they would operate the same way.

Here's another one for ya....my car has mechanical secondaries as opposed to vacuum secondaries. A lot of people think that means it's going to get worse mpg.....wrong again. The reason is, i can feel the secondaries through opening through the extra effort it takes to push the gas pedal, whereas a vacuum secondary carb will open any time the vacuum supplied to it exceeds the force of the spring that's holding the diaphram open....meaning every time you take off too quick or go up a hill, or pretty much all the damn time in an automatic. I could drive my car 100 miles and never open the secondaries, which basically means i'm only running on 2 barrels which gives me better (although admittedly still not fantastic) mpg.

I will say this though....my 'stang still get around 16mph on the highway, and my '98 Cherokee gets exactly the same with an inline 6....and that's with 4.10s and low profile tires all around vs. an engine with less cylinders, less cubes, lower gear ratio and taller tires. It's just an example that EFI doesn't necessarily equal mpg either.


And btw if your carb motor is only getting 10mpg, you must be running 4.56 gears and an 1150cfm Holley Dominator

I agree, I don't know much about carbs... I know that my milkshake has 1100 carbs in it I'm all EFI now anyway, I'd rather change injectors and MAF calibration than jetting a carb My next adventure is learning to use a TweecerRT

 

[Modular2v]

you know i should do a stangnet experiment....... i still have ALL my EFI stuff for my car....who wants to make a bet that if i switch it back over this winter my car will run slower times? I would have to purchase a MAF conversion kit thought since the car was speed density

 

[25thmustang]

Id be willing to see that, run it on hot and cold days under the same tune, drive it 500 miles on the same tune for mpg, take it to a smog test, and such. I wouldn't mind seeing some real world results, if I had a carb set up for my car, I would do it and see what the difference was.

 

[85_SS_302_Coupe]

Id be willing to see that, run it on hot and cold days under the same tune, drive it 500 miles on the same tune for mpg, take it to a smog test, and such. I wouldn't mind seeing some real world results, if I had a carb set up for my car, I would do it and see what the difference was.

It's like i've been saying all this time....in most cases, like the mpg and such, EFI is going to be better, but a lot of the other issues can be dealt with by the user. The problem is that a lot of people are just too lazy to learn what to do and to get their hands dirty.


Personally, if i had cash to blow and had a choice, i wouldn't get either...i'd go with a Webber setup

Webbers IMO were the inspiration for EFI (although i think there may have been some crude EFI systems before Webbers). You can do almost anything with Webbers, they sort of walk the line between carb and EFI. The coolest part is that the same Webber setup will support a 300hp motor just as well as it'll support an 800hp motor, because the cfm is actually tunable as well. The only problem is that you're going to spend about twice what you might spend on a typical EFI system to get'em, and then talk about learning.....they're a SOB to tune, but it's like a fine art, and once they're dialed in they're pretty reliable.

 

[Boss 351]

if you were a fighter pilot back in WWII, you'd hate carbs

I think in 1957, Chevy had a mechanical fuel injection setup...

 

[85_SS_302_Coupe]

if you were a fighter pilot back in WWII, you'd hate carbs

I think in 1957, Chevy had a mechanical fuel injection setup...

Yeah, but Webers have been around since the 1920s....i'd say any EFI system before then was purely prototype.

Unfortunately i could buy myself a nice roots supercharger for the price of the 302 setup
http://www.webercarburetor.net/catalog/Weber-Conversion-for-351-Cleveland-FORD-p-16241.html

 

[Boss 351]

yeah that would make a nice Cleveland engine, not something we see everyday.

 

[85_SS_302_Coupe]

They came as original equipment on the GT40 351C

 

[Shamus O'toole]

I don't post up here very often but this thread caught my eye.
I run a 327 10.8-1 comp AFR 185 heads 2.02int 1.60 exh, big cam (won't reveal specs LOL) Victor 5.0 intake, 80MM TB,30lb INJ, Anderson PMS and a bunch of other related crap.
with this combo put 408hp 385 tq to the rear wheels. Runs 11.02@124 N/A
Switched over to Victor JR intake, Quick Fuel pseries 750, same ingition as before,no other changes.
With this setup put down 425hp and 420tq (have not been to the track yet, weather down here sucks!!)
This car sees street time but is mainly a track car. No real big diff in drivability.
Why did I do the switch to carb?
Well I grew up tuning carbs and it's what I know. The EFI was nice but I can feel the car pull harder up in the higher RPM range. I shift @ 7200.

Obviousley (sp) I don't care about mileage.
P.S. when it was EFI it was tuned by the leader in EFI tuning for NMRA. name withheld.

 

[Foxfan88]

i think we have all gathered and found how that each carb and EFI both have their pros and cons and neither one if better and depending on what you want to do with your car. like a pure track racer, a carb is a good choice, for a street car mustang making low power, efi works great!

just depends on what sort of car it is.

 

[Shamus O'toole]

/\/\ well said.....................

 

[25thmustang]

Its like the manual vs auto debate... hey work well for both, one does one thing better, one does another, but its all personal taste in the end.

For me: EFI with a manual all day, everyday!

 

[85_SS_302_Coupe]

I just feel like it's a lost art....like someone has to stick up for the old carb


Think about it though....EFI is definitely superior in many ways, i won't deny that. That's never what i was trying to get across. I'm just saying that for the money, a lot of people will be happy with a carb and they're not sacrificing SOOOO much. Think about all the old classics that are still out there cruising the streets with carbed engines. Plus why the hell hasn't NASCAR gone to EFI yet? We're talking state of the art race cars, yet they're still running a fuel system that some people consider out dated.

 

[millhouse]

Plus why the hell hasn't NASCAR gone to EFI yet? We're talking state of the art race cars, yet they're still running a fuel system that some people consider out dated.

Because they are at WOT for the entire race! Lol…seriously though, if they needed the extra control (cough..F1 racing…cough) you would see EFI setups in NASCAR. No, it's not the only reason…I'm sure cost too has a great deal to do with it.