ChopperDoc

I agree 100%. It's just a much different approach to achieve the same thing. Timing used to be done on the distributor, and advance was handled by vacuum. I used to work on and build cars with my dad growing up, so I am fairly good at setting up a carb. It's just a different animal now, which requires an even firmer understanding of why you need to advance or retard the engine, where, and when...

I'll tell you that of all the things that helped me learn the most was learning how to tune, and what all the tables actually do, what they reference, and so on. It's much, much more involved than grabbing the old bent 9/16" and adjusting the distributor a little one way or the other. That was easier, in my opinion. You either made more power, or you didn't, and vacuum took care of the rest for you.

The biggest advantage of EFI is you can control so much more on your engine. The best part is you don't even have to get out of the car. I love the new stuff.... now. I used to hate it because it seemed so hard to learn (and it is). It takes a good while to get comfortable with what you're doing and understand it. My dad is one of the best examples of the old timers hating new technology. He doesn't give a flying f**k about learning EFI anything. It's pretty funny, but I guess he always can give me a call if he needs a car tuned. He still drives cars from the 70's and 80's, so until now he hasn't needed me lol.

flipsta510fazn

iTrader: (1)

so i copied from 4.8 pcm the idle air tables under idle tab the following areas are idle airflow; under general-IAC steps vs effective area; base running airflow-idle airflow; adaptive idle airflow-st adaptive airflow max; throttle follower-airflow, airflow mult; and throttle cracker -airflow tables... also in the idle tab under rpm i copied the base idle speed table
also copied under general tab engine type from 5.7 to 4.8 the cylinder volume to .060079, under airflow tab; airflow vs frequency and main ve.
under spark copied main spark advance tables high and low octane

is that all good ??? loaded the info from my 4.8 pcm tune into the 5.7 pcm.

so ive done that and started the car drove it 2 miles car runs a little slower and less aggressive idle also a little lower i'll try this out and let you know if i get better mpg from the 13-16 mpg

RPM WS6

iTrader: (3)

I definitely agree that it's a different approach, though I wouldn't necessarily say it's a different animal; the IC engine is still just a big air pump and the same general principles apply in terms of making power and improving driveability - though obviously the adjustment process is quite different and most of the necessary tools are quite different as well.

On the surface and at the beginners level, I'd agree that carb/distributor tuning is easier since the basics of this can be handled with much more rudimentary (and affordable) equipment that's simpler to learn, but that will only get you so far. I consider myself fairly competent with carbs/distributors as well, but I'm not at the point of custom machining my own metering blocks nor do I have a functioning distributor machine in my garage. At the advanced level, both carb and EFI tuning are challenging and will require patience and practice. With good software and a laptop, one can make things happen with EFI which would require machining skill and extremely advanced knowledge with a carb. Overall, I definitely agree that you will never get quite the same level of precision (especially across a wide range of ambient conditions) out of a carbed setup, but a lot of folks make the mistake of considering carb tuning to be a matter of "hitting the side of a barn - if it works, then you're done." Much is left on the table in many of these cases, things that an advanced carb tuner could still improve. There are multiple circuits in a carb and multiple aspects of a distributor to be addressed for best performance and driveability.

One thing that carbs and EFI have in common is that tuning the factory pieces (such as a Q-Jet and factory HEI, or a stock PCM) for a highly modified setup is usually more difficult than comparable aftermarket pieces (carb/distributor, or aftermarket EFI system) which are designed to be more user friendly for the modifying enthusiast.

I learned basic and intermediate EFI tuning with LS1 Edit in the early days of these cars; got my setups running pretty well during a time when the software was much more limited, and collective experience was still in its infancy compared to today. Ultimately, I still prefer working on a Holley and MSD Pro Billet.

stockA4

Really all I did was dial the maf and ve with a wide band. did you at least keep the stock timing table? It Should be fine for a stock or mildly cammed 4.8 on 87 octane. I'm just running the stock 02 LS1 table but I've heard the 99-00 table is a little more aggressive still.

my gas mileage sucks right now too because it's so cold here we idle the car all the time to stay warm

SouthernRex

If I plan on getting the 92MM FAST intake + throttle body, should I wait to get the mail order tune until after I install that?

ChopperDoc

I don't see why you should wait considering it's a mail order tune. Obviously don't load the tune until you actually install the parts, but since they won't have any other data to go off of other than your mods, I don't see why you can't start the process. That is so long as you actually install those exact mods that you tell them you have.

SouthernRex

Makes sense, but don't I have to mail the PCM itself?

ChopperDoc

Well yes, normally. I forgot about that part lol. If you had a way to flash it, everything can be done via email, but if you could do that then you wouldn't need the mail order tune in the first place lol. I have other cars I drive during mods, and I do my own tuning... Just make sure you get it retuned before driving with new mods because you're playing with airflow.

ChopperDoc

Are you changing the MAF too? It will probably run okay without a tune if you are keeping the stock MAF.