ECM 13338 (EOIT vs RPM) differences...same OEM engine!

[bmd2_colo]

Hi-

Just lookin at the 06 GTO's ECM 13338 vs the 07 TBSS's (my current rig), why would two LS2 engines require different injector timing vs RPM? I know the ECMs are different (40 vs 67) and the injectors are different, however the engines are the same, same cam. This makes no sense to me. Granted, the GTO's LS2 is 24x and the TBSS's is 58x, but they're both "gen 4". Has nothing to do with valve events and injector timing, as far as I know?? what is going on....gurus please chime in lol

Thanks
Mike

[bmd2_colo]

hmm I see. in the 07 they accounted for it by lowering the boundary table. hmm weird. had to be a reason. maybe more efficient on the computing side.

[5ft24]

Most likely because the cams are different. They are LS2's, but not identical in terms of the cam and valve timing, so the injector timing will be different. that and the TBSS has about 1500 pounds on the GTO as well.

[bmd2_colo]

Yah, for sure. Been reading a ton on this EOIT thing, lookin at c6 ls3 cars comparing stuff, seeing how gm does it (re inj timing on the same platform with the same engine across different years). Interesting. Plus im dropping a cam in the TBSS soon and obviously this needs to be right

-gonna use ls3 injectors with the new cam, should be good, maybe 90% max, plus we have known good data etc

[bmd2_colo]

interesting comparison of boundary degrees when at 180 ECT-
comparing the LS3 to the LS2(truck). 3 has 42 pph, 2 has 34 pph.
Cam is almost the same, with the only exception being .025 more lift on the intake valve.
Maybe the differences in injector size and cyl head+bore made the change in boundary time necessary?

timing.PNG

[bmd2_colo]

and then comparing the LS3 to the LS7 stock. LS7 with the oem 210/230 cam. seems EOIT is advanced, if the boundary-ECT-RPM is true, which it is, so interesting. Seems to have a pattern, advancing EOIT at low rpm and delaying it in the mid range, then advancing it again at high rpm. LS3 and LS7 have the same injectors, LS7 makes more power tho and has more defined injector timing. I forgot to carry on the RPM table for the LS3, sorry. changed



ls7 comparo.PNG