DFI and EFI are 2 different animals, I can see a DFI set-up doing as well as a carb and even better in the mid range. I can't see a factory fuel injected car (even with GM's computer being tweaked by the best tuner) running as good as a DFI equipped machine.

If it (GM efi) was that good you would see it in a NHRA stocker or superstocker and not everybody elses DFI set-up.

 

I am not sure what you mean by "DFI and EFI are 2 different animals". They are two words for the same thing. There are no "analog" fuel injection systems that I am aware of. That aside, the stock PCM is quite sophisticated. It does have some limitations that high end aftermarket systems do not. But if we are talking about WOT hp, if the limits of the factory PCM are not exceeded (primarily the 7,000rpm limit and the 1bar map sensor) hp/torque is basically a matter of getting the correct AF ratio and timing. The stock PCM with reprogramming is quite capable of doing this every bit as accurately as an aftermarket unit. The much maligned Opti, when it is working right, is an extremely accurate/high resolution distributor. The MAF may be an inlet restriction, but it is very easy to program the stock PCM in "speed/density" mode and eliminate it.

Rich

 

No, we are talking (in my case, if that is what you are referring to) is a Super Vic in both cases. The latter case being converted to use electronic injectors.

Rich

 

Rich, with everything you said above, aren't there enough differences especially for a performance application to call them two different animals? I'm seeing signifigant pitfalls in the factory EFI system especially the 7000rpm limit and its hosting of boosted power adders, sure you can bandaid the factory EFI but why would you when after market DFI exists?

 

Sure, I see your point. Just saying that w/in its' limitations the stock system will produce as much hp as any other system.

Rich

 

Ive never seen a test performed on the same engine that went from carb to FI that made more power. And from what I remember,that power they made was 11-12 HP (at the crank) which there is now F'in way I'd pay all that money to gain that little of power just so I wouldnt have to push the go peddle 2-3 times before I started it.

I wanna say HOT ROD did the test but im not sure

Not tryin to bust anyones nads,just my opinion.

 

Do any of you suppose that there is a reason that in EVERY professional class where the rules allow FI that it is used? EVERY time by EVERY competitor. Must be that these pro teams like to waste their sponsors money. A carb is an amazing device that has been supplanted by FI. It lives on where the rules require it or where the budget precludes fuel injection. Nothing to be ashamed of, just outmoded.

Rich

 

Rich, your right again, however I don't see them using a factory GM factory based computer to drive anything, they would be really throwing the sponsors money down the toilet trying to go that route.

 

Your right, wih the new split dom style TB's and big intakes and 16 96# injectors....the difference is they know what the hell they are doing with it or they have money to learn....I don't

I'm not even sure if I will do this or not, the car is up and running as it is. I can't say 100% its not a mechanical issue now...I just don't know

 

I may be able to help you. I am going to do some reading on your EFI system over the weekend. I don't have any experience with your particular EFI, but they basically all work the same. It sounds to me as though you have a problem with the base fuel & spark tables. Don't ditch the EFI, you will regret it. I have some experience with AFB & Holley 4150 carbs, and you don't want to get into all of the jets, metering rods, pump cams, power valves and so on. It's just a big hassle, plus you have to do it frequently. Don't get me wrong, carbs work well. When properly sized and tuned, they are very effective. However, you do have the better system.

 

It does not take money to learn, just time

 

I don't have the facility, the dyno, a wide band, not much data logging.....no money to make a bunch of test, track rentals etc. Its not like you just learn it and go run. Those guys constanly test that stuff