Considering all of the things I spend money on for my C3's, the price of gasoline is just not a consideration or worry.

One thing about a carb. It's simple, at least compared to fuel injection. You can rebuild a carb yourself. I've already built a lot of extra complexity into my 68. Keeping the carb limits the gowth in complexity.

I would be happier to add fuel injection if it improves power. Also, I'm aware of the story that engines with fuel injection have less engine wear since optimal fuel/air ratios prevent excess gasoline washing oil off of engine cylinders. If this is true, this would be, to me, a favorable reason for going to fuel injection. I have a BB70 and I will look into a fuel injection for it.....for more power.

 

FI will not gain you any HP of a properly tuned carb, but as stated above it, once dialed in it will optimize the eng performance over w wider range of conditions and net better gas mileage

 

I agree. For absolute MAX-HP applications, a carb can exceed the capabilities of most EFI systems. Note, I say most, not all.

For real-world cars.....? Where you want a lot of horsepower, and yet STILL be able to drive it....? Sorry, carbs are a loser proposition, compared to EFI.

Ironically, I used to be on the other side of this debate.

With a wide-band 02 sensor feedback, EFI can and will beat carburators for average area under the HP curve, if the EFI is set up to maximize HP. It may or may not happen for peak HP, but the EFI really shines in a forced-induction setup, where a carb is basically using band-aid fixes, to accomplish what an EFI system can, by design, perform without blinking...

It's not unusual to see 500+ HP C-5 Vettes running around, normally-aspirated, that are quite tame in street manners. It's extremely rare, to find a 500HP 350 SBC (carbs) with the same streetable manners.

 

As far as the complexity goes, I find tinkering with fuel curves and burning new EPROMs far simpler than trying to tune a Q-jet.

 

With my old 350 and the stock Q-Jet and a 3.70 diff ratio I got 20 or better on the freeway. All in the gearing (T56).

But I'm sure this new motor won't come close to that. Does anyone know of any aftermarket fuel injection setups that are 50 state legal?

 

Why is everyone obsessed with aftermarket? Factory GM systems are well-built, versatile, and the parts are junkyard cheap. GM paid those engineers a lot of money to come up with those systems...a lot more R&D than the aftermarket, probably... Just my $.02.

 

One reason folks like them is that the aftermarket systems are user programmable while the GM ones are closed black boxes.

 

Ummm.......How times change Back when Zwede and I first took the plunge and installed our Holley Commander 950 MPFI's, It was a hard sell to get anyone on the forum to side with EFI. Now all we have to do is convince Dep and 427Hotrod I installed the Holley MPFI on my 69 427 back when they were first introduced and have never regreted it. With 12:1 compresion and 4:11's it wasn't for fuel economy

The 502 Ramjet I installed in the 70 coupe has the GM MEFI 3 ECU running speed density. Sorry Batman but that thing is a POS. I love the Ramjet FI system with that exception. I will upgrade to the FAST XFI or ACCEL Gen VII ECU as soon as I can

But, Even the POS MEFI 3 beats the hell out of a carb IMHO. I took it down to Eureka Springs Corvette weekend a couple of weeks ago and entered it into the fuel economy run. I got 20 mpg believe it or not I give most of the credit to the Tremec 5-speed though. After getting lost a couple of times I couldn't restrain myself from blowing by a couple of 40mpg C5's in a fit of anger, so it could have been better


Bullshark

 

Not true at all. All you need is some free (or cheap software) and an EPROM burner. Maybe not quite as easy as the aftermarket systems, but a whole helluva lot cheaper...and parts are readily available at your friendly neighborhood Chevy dealer or parts store.

 

Wish that were true for the MEFI series ecu's.......but ....unfortunatly it is not
And it is going to be next to impossible in the very near future as GM incorporates it's "hack proof security" with today's available technology.

Bullshark

 

I'm right in the middle of doing a swap on my 76 from the Qjet to EFI, I tried to rebuild my carb and tune it, but still no luck.

Could I have sent it out and paid for it to get tuned? Are there others out there (Lars) that are good at it? Yes.

I didn't buy a car made in 1976 to have someone else do the work for me.

Can carbs perform well? Yeah, they can go side to side with EFI, but you have to consider that EFI is more exact.

I'll be tuning without an O2 sensor at first, then I'll go to a narrow-band, then a wideband. And I could do the same with the carb.

I really think it comes down to folks being comfortable with computers and/or electronics. The carb is a mechanical device, and it's alot easier for me to change the fuel mixture (and relatively more precise) by clicking with a mouse then adjusting with a screwdriver.

Which if you really think about it is kinda sad because I think alot of guys are missing out by not trying out EFI. For example, I can setup my EFI at a shop with a sniffer, get it emissions checked, pull out of there and double click and get my old settings back. Really easy.

Now a guy with a carb could do the same thing, but I doubt it's as easy as clicking 'File -> load'. He'd have to have it written down how many screwdriver turns, etc etc.

I think it really is anymore a personal choice. But don't be scared off of EFI because it's something to learn.

Check out www.megasquirt.info if you're new to EFI, there's alot of good info out there.