which tables / constants are commonly modified for fuel/timming ? building a 383,ported heads, ligenfelter cam, dual exhuast, have software to edit program, and have datalogging software, just dont know what tables do what !

 

what year? MAF or SD?

 

hhhaaa hhaaaa i had that same question i was about to post maybe we can get both our questions answered...

I have a 91 vette and i am using tunercats and my ECM definition per tuner cants i am able to open it up and read everything i just don’t know what to change and how much...for example i have pretty much the same set as GLEN29 91 vette 383ci 10:8:1 compresh with 218/230 @.050 cam from crane and stock heads and injection but 30# injectors , oh and full length headers and exhaust no cat or muffs…I do have a ed wright chip in it now but of course I cant see nothing when I pulled down the data
So i didn’t know what to modify as well?

 

ttt

I did a search and could not come up with nothing can some other forum members help out?

 

oops, got too exited !! It's an 88 with a 165 ecm, Will stay with maf set up, also what about the ninth injector , can i program that out, or will a super ram use that whenever I make the swap ?

 

I doubt the SR has the ninth injector, not sure how to handle that, but someone on here will know. There is a common ECM swap to a later one that does not use the ninth inj., maybe even just a prom id change.

Everyone has their own ideas and ways of going about it, but I would start with some datalogs at idle and part throttle to see if you are rich or lean, then change injector constant until you get around the 128 target for BLM. With a MAF setup, this should not be to hard for quite a good range of RPM and load (LV8).

The Injector PW table is not used unless you change the flag for the BPW Calc method, otherwise it uses MAF for calibration.

If you have stumble on throttle tip in, work with the Acceleration Enrichment (AE) factor vs. Load table.

I have no major mods to mine and I don't drag race, so I have not touched the MAF tables, but that may be your next step, again, I'll let some of the other guys who know more about that chime in.

Don't go WOT until you have al the part throttle stuff in order and little or no knock retard. Then you can work on a little more or less timing in the timing table and go for WOT A/F tuning.

The key is to start slow and take you time, document each change and do a datalog to see what affect it had on the engine. I have burned over 30 chips just getting it right for the larger injectors I had and to correct the timing which got advanced a couple of degree's when I had my intake gasket replaced.

Good Luck and Enjoy the ride!

 

thank for the reply, every bit of info helps

 

Yeah i heard tuning in SD is harder then MAF?

 

Typically yes, SD uses a look up table based on MAP for corresponding fuel trim, MAF uses actual airflow as measured at the MAF sensor for fueling.

 

Glenn29-

Assuming you are going to use the current mask your 88 has (I believe it is the 32b), after modifying the constants for fan on and off temps, your first task will be to sort out your part throttle fuel map. 32b has the option of turning off the injector constant and generating your fuel map by inputting pulse width values(Base Pulsewidth Calc). You will need to get that all sorted out first. You will be working with everything ranging from idle thru part-throttle. You may need to adjust the Accel Enrich vs LV8 table for tip in(ie "Pump Shot" for the old carb tuners) Make sure you are not detonating while doing this- you may need to retard spark in areas while you still sort the fuel. Use your BLM values to help you.

Next, concentrate on the timing table. You are looking to produce max torque with least throttle, and no knock.

Recheck fuel map before moving to wide open throttle.

The 89 mask (6e) does away with the need for the 9th injector. If you do not have a provision for it in your new intake set-up, you might want to consider the change.