I've got a book that details exactly how to carb the LT1. It's called "How to rebuild a small-block Chevy LT1/LT4." I'm carbing my LT1 for one reason and one reason only. It's easier for me to work on and tune my carb than it is to fully understand how the h@ll the computer on these cars works (and I'm an electrical engineer). My car is a 93 and the wiring on the car is going to have to be replaced soon. When I do this, probably this summer, I'm going to carb the car. It's really not that hard to do. Just buy the book and it details exactly what you need to do.

There is no debate whatsoever over which produces more HP. Fuel injection wins EVERY time. That's why all cars switched to computer controlled fuel delivery systems. However, with that being said, carburated engines are MUCH easier to tune. I can tune a carb in under 5 minutes. If you add/remove a part or make a modification then you can tune the car INSTANTLY. I'm not looking for a 1000hp car. I can get 400-500hp out of my carburated LT1. That's all I'm looking to do.

 

It's all a learning curve. I think the 93's still have to have chips burned, but all the other cars can be connected to a computer and flashed very easily.

I'm pretty sure that the carb will make more power than the EFI, but it won't be as emission or gas mileage friendly. Also, less consistent.

I hope you really know what you're getting into, should be fun.

 

CRAP! I'm sorry guys. I thought I was responding to the "I'm carbing my LT1" thread. I didn't mean to start a whole new thread. Sorry.

 

EFI was actually switched to for emissions and driveability reasons. It had nothing to do with horsepower. AFAIK top fuel doesn't use EFI and theres a reason for that, carburetors are much easier to deliver the amount of fuel needed for a high horsepower application. but EFI is 1000x easier to tune than carburetors its just cheaper to tune a carb than EFI. but EFI is much easier to learn to tune.

 

Was there a question here?

Just about every statement you made is completely backwards. EFI is a heck of a lot easier to tune, and it stays in tune over a wide range of operating conditions and minor engine modifications. Carb usually makes more power. The primary reasons for EFI being on every new car today are emissions and lower maintenance not power.

I am also a EE and I've been working on carbed cars for 30+ years, and the LT1 is the first car where I've gotten into the EFI tuning.

If it's easier for you to carb and you have trouble understanding EFI, then more power to you. OTOH LT1 EFI tuning is extremely easy, so I wonder what kind of EE you are. Mail order degree?

Who needs a book that details "exactly how to carb" an engine? The less than one page in that book on carbs contains only common sense and common knowledge. Another black mark on your claim to be an engineer...

 

That's what I said, or at least that's what I meant. It's just easier for some to tune carbs because that's all they know.

Steve's revoking engineering quals, lookout. LOL.

 

Just adding my 2 cents to what you said, wasn't trying to refute anything. Though someone claimed to have seen something about top fuels using EFI I was kind of hoping someone might chime in and correct me about top fuel using only carburetors.

 

Wow! So steve9899 is calling me a liar. I graduated from UF in Dec. of 2003 . Where did you get your degree from? Your profile says your 37, so you've been working with carbs since you were 7?

YOUR car may be easy to tune, but in case you didn't know the 93s have chips that need to be reprogramed. I can't just plug a laptop into my car and make corrections on the fly. Carbing is the way to go for me because I know how to tune carbs.

 

Carbs are far harder to tune than EFI, IMHO. After giving up carbs, I never looked back.

Rich

 

Why not? I have.
Yours is even easier to tune than a 94+ all you need is a chip burner, you just swap the old chip out with a new one. 94+ if the laptop dies in the middle of a reflash, you're screwed. Yours you can set up a tune for the track and a tune for DD, then just swap out the chips when you feel like it.

 

to get a carb to run right and run in a car that will win round after round.......it is wayyy harder to tune


for just a street rod etc. either way will be fine and probly make close to the same hi h.p. numbers...its the mid and drivability where the fuel injection is better

 

I'm sorry you thought I was calling you a liar. I was not trying to do so.

You made several incorrect statements, but you probably believe them, so that doesn't make you a liar. And you claim to be an engineer, while the evidence points in a different direction, but you may have been misled by someone else to believe that you are, so again that doesn't make you a liar.


That's unfortunate. The best-case scenario was that you were an old-timer who just hadn't grown up in the computer era and refuses to learn new fangled things.

For a recent ECE grad to not be able to pick this up easily is pretty much the worst-case scenario.

I wasn't all that impressed with the quality of some of the ECE undergrads at UF when I was a grad student there, but apparently the standards have fallen even farther since then. Have they dropped the required microcontroller course? I guess you didn't take IMDL or any other hands-on electives, either?


Roughly. Dates get a little fuzzy that far back.



Can't make corrections on the fly in a 94. You actually can do that with a 93 with the right hardware.

As someone else mentioned, there are benefits to the earlier system, but for the actual job of tuning the spark and fuel there is no difference in difficulty.

Please tell me you didn't get an ECE degree from UF without learning how to burn a PROM?


Like I said, that's great. Go for it. Have fun.

Just don't post false information on the forum about carb vs. EFI in the process. And don't use "I am a EE" to try to provide weight to the false information.

 

I'm an "old timer" and I'll take fuel injection.

Sure, it's easy to adjust a carb, but two days later when the weather is 20° warmer, or it's more humid, or the barometric pressure is different, it won't run the same.

My LT1 runs good every day. My carbed engines had good days and bad days... and they could be hard to start in cold weather.

Maybe a carb is better on a race car (but you notice those guys at the track with the weather stations who re-tune their cars multiple times per day?)... but for a street-driven car, I'll take fuel injection every time.

 

How much of an "old timer"? Fuel injection has been in development for over 100 years. It has been available on commercial produced vehicles for over 50. My 1973 mercedes 450SL came with port EFI with a LS1 style intake (though made out of aluminum and not composite), exhaust (cast iron tubular manifold) and overhead cams (1 per head). I can't remember if it used O2 sensors, IIRC it did not. Thats 35 years old, and it was being manufactured as early as 1970, so the system itself was possibly older than steve here.
Perhaps one of the nicest things about the computers that are more modern is the computer controlled spark advance, how nice is it to be able to change your spark advance curves with a very fine degree of control and safety margin (such as pulling timing as coolant temperatures rise) without needing to fiddle with springs and weights in the distributor.
We have those weather stations as well and re-tune our cars multiple times per day with EFI, except we aren't aware of it because it is all handled automatically by the cars computer. The only real reason to choose carbureted over fuel injection is it costs about 20 bucks to tune a carburetor , although if you want a complete setup with all the instruments, jets and tools to properly tune a carburetor with the same degree that you can tune a modern or even semi-modern computer such as the LT1s you would pay well over the 200$ or so it costs to tune a LT1 and that still only gives you control over the fuel flow! you can't touch spark at all yet without further investment.

 

Well, I'm in my 50s and I owned a number of cars made in the 60's that had carbs... so that is why I consider myself an "old timer"

I guess when I say "easier to tune," I mean you can get it in the ballpark just using a screwdriver and some pliers...