injector timing

[Carl Porter]

Put a decent cam and ported heads on the LS3 and I'm getting rich fumes at idle. It was tuned on a dyno but we didn't adjust the injector timing.

Don't have the cam card for the stock or new cam so made some assumptions. Stock cam 204/211 duration 117 lsa. New cam 231/245 duration 112 lsa. I assumed both cams degreed with the intake lobe center at 106 degrees ATDC.
Old IVC 205 ATDC 568
New IVC 220 ATDC 580
Old IVO 4 ATDC 364
New IVO 10.5 BTDC 349.5
Old EVC 19.5 BTDC 340.5
New EVC 3.5 ATDC 363.5
Old EVO 233.5 BTDC 126.5
New EVO 241.5 BTDC 118.5

Using a posted Formula for timing Boundary - ECT - RPM = EOIT
520-245-93=182
520-110-0=410
On the injector timing, the boundary is 520, Norm ECT runs from 245 to 110, so end of inject pulse is anywhere from 50 deg ATDC to 85 deg BTDC (410 to 275 on 720 scale). With the engine cold the injector pulse at idle is 2.6ms or 13 degrees at 850 rpm and start of pulse runs 37 degrees ATDC when warm to 98 Deg BTDC when cold. That's 14 degrees both valves are open unless ECT is over 111 degrees at idle



Do you change the ECT values so much that the B-E-R formula yields ~350 to 410 degrees?

2015 Camaro 2SS 1LE LMR tune.hpt
2015 Camaro 2SS 1LE LMR tune idle -12_6 morn.hpl