Okay, don't laugh but I have never touched the fuel part of ARAP. I have spent the summer perfecting the timing curve. I have reached a limit where I need to add fuel. How is the done in Tunercat? I looked through the tables but nothing jumps out. I don't want to funble through the tables and screw my motor. Please tell me what tables to alter. Thanks!

------------------
1988 L98
Vette Heads/no EGR
SLP Headers/Y-Pipe
ARAP bin

 

You need to modify the MAF 1 thru MAF 6 tables. I'm still learning it myself...

------------------
1991 Camaro Z28
5.7L 5-Speed (originally 305)
317 RWHP, 418 RWTQ
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Member: SoCal F-Bodies
-=ICON Motorsports=-

 

Where do you want to add or remove fuel?.

 

I found I needed to "globally" change the whole fuel curve first, as all my blms were low. Just change the injector constant up or down to change the whole fuel map to get it as close as you can. Get the blms as close to 128 as you can-a few above and below is Ok. Then go on to the maf tables.



------------------
86 406

 

What is the name of the constraint for the fuel?

------------------
1988 L98
Vette Heads/no EGR
SLP Headers/Y-Pipe
ARAP bin

 

ECM constant table; then scroll down to injector flow rate and adjust them. Then after getting the blms close go to the mas air flow 1 thru 6.



------------------
86 406

 

If you need more fuel while in Power Enrichment (higher throttle positions and WOT), then you'll need to work on the 2 tables for it. One is PE (or WOT) vs. coolant temp, the other is PE vs. RPM. I use the PE vs. RPM table to get a somewhat linear curve from the O2 sensor, then use the PE vs. coolant temp table to make a global change to the fuel curve, using more power or better mph as the judge for what works.

------------------
Greg Westphal
'87 IROC 355TPI/A4

 

Are you trying to add fuel for WOT or just normal driving. I went about it in a different manner than the others said if your just after normal driving.

If you need to richen (or lean) the entire curve adjust the injector constant as previously mentioned. After that though I used the Open Loop % Change Fuel vs. Load (not sure on actual name, TC isn't in front of me right now) table to add and remove fuel at specific points in the curve. Although the name says Open Loop this table actually affects both Open and Closed loop modes of the ECM, it was just incorrectly named by TC. Personally I have never touched the MAF tables as I saw those as simply calibrations for the MAF sensor. I figured those calibrations would be fairly close from the factory, and left them alone.

------------------
Black 88 GTA L98
261 RWHP, 345 RWTQ
13.406 @ 103.72 MPH
ZZ4 bottom end, Edelbrock 6085 heads, LT4 HOT cam, GMPP 1.6 RR's, ported stock TPI, SLP 1 3/4" headers, no cat, Dynomax cat-back, Stock PROM
E.T.F.A Member #11

 

Hey Scott, I am looking at that table you suggested. Open Loop fuel/air ratio %change vs. Load. So the lower the %change(number) the more fuel? Or is that backwards?

------------------
1988 L98
Vette Heads/no EGR
SLP Headers/Y-Pipe
ARAP bin

 

No, the higher the % change the more fuel is added. Basically the computer has a predetermined equation that determines the amount of fuel based on the amount of airflow into the engine as measured by the other sensors. This table then basically modifies that final answer before the PW is sent to the injectors. So after the ECM calculates the needed fuel it looks at this table and mulitplies it by 1.xx where the xx is the percent change listed in the table for the given load value. So if at some given load value you had a value of 5% change it would multiply it by 1.05 and then send this value out to the injectors. You can even put negative percentages in which would drop the change to below 1. I believe that this is the way GM intended for the ECM to be adjusted for the individual needs of each different engine.