My Camaro has the Holley Avenger 700cfm TBI and I have it controlling the timing. I have it on the stock settings which is 25 @ idle, 41 @ cruise, and 35 @ wot. Do these settings sound good? Engine is a mild 350, Dart aluminum 180 heads, Vortec cam, 1.65 rockers... CR is about 9.3:1. I only run 93 octane E10 from Costco.

 

Sounds good for a start. Need to log it and use factory knock detection to see if it wants those timing values but thats good ballpark for now.

 

I'm also working on my timing map (Accel Gen 7 ECU).

I know you can use the knock sensor to dial in WOT timing, but how do you dial in part throttle timing? Right now I'm only running about 34 degrees at part throttle and my fuel economy is horrible.

 

Can still run off knock sensor and give it more advance til you see spark retard. More spark generally means more cylinder pressure and more torque, so maintaining the same vehicle speed will require less throttle. If its a map car, you can also try advancing timing and watch map value. Want to see lowest map at a constant throttle position or speed. Maf car might want to look at LV8 values and try for the lowest value at constant throttle. Just some ideas to try.

Theres been some discussions i have read where more EGR effects from EGR system or cam overlap can help increase mileage by recyling exhaust gas amd reburning, which will end up having slightly greater throttle opening than with no EGR effect. That can be more efficient.

In the end you have to find what the motor wants as far as timing and air fuel for part throttle. Closed loop systems tend to target stoich or some offset value near stoich depending on throttle position or load. You can adjust these targets in most bins. O2 settings and stoich settings, rich lean offsets etc

 

I have a wideband 02 system so I may try running it down the freeway at constant load and adjust the timing until I have the shortest injector PWM (using the least fuel).

I'm looking at some .bin files with TunerPro. The loads go from 32 to 208. How do I translate that into kPA? Which is WOT, 32 or 208??

 

I dont believe you can. Would have to hook up a vacuum gauge and monitor that

Dont always need leanest mixture for best economy. It may want to be closer to stoich rather than very lean

 

Good advice. Keep it coming. I guess I should also not my A/F. Stock Avenger settings are 14.0 @ idle, 14.0 @ cruise, and 12.5 @ wot. I leaned mine a bit to 14.3 @ idle, 14.2 @ cruise, and 12.6 @ wot. BTW, I do not have a knock sensor. The Avenger does not even have a provision for it.

 

May have to go to good ol' spark plug reading

 

Are you running hyway mode? My wide band goes from 14.1(stoich) to 16.0/1 when I cruise over 50 mph. Likewise I have DFCO enabled to turn off injectors at any 0%TPS.

 

I have the Holley Avenger.

 

That seems a bit much at idle. Remember, just because you can adjust the spark curve to whatever you want that doesn't mean that's what the motor really wants or needs.

 

For reference, stock L98 will have 20-21 deg at idle. 20-25 should be plenty. Shouldnt need more either.