EGR and Timing

[Kaiserbailey]

I'm pretty sure EGR has the effect of retarding timing, so when you delete it should you lower timing around idle a little bit?

Stock 5.9 is in the -2* to -4* range, stock 6.7 is +1* (BTDC). I would think, after you delete EGR +1* would be a little much since the 5.9 is -3.

 

[Killerbee]

CARB requirements from platform to platform can change timing for emissions optimized ignition.

EGR on has the effect of reducing oxygen in the charge, but also of heating up the charge. Less O2 would suggest the need to advance, a hotter charge should be retarded. Final timing depends on a lot of other things as well.

 

[IdahoRob]

Interesting data is taken from a LB7 california model and the same year non-egr engine. This way the injectors are the same size and most everything is a constant so comparison is apples to apples.

Only the low altitude timing table is different, and just a couple degrees more advanced timing at very high rpm and load levels with the egr equiped engine.

 

[Kaiserbailey]

Ok, so I guess it would be best to leave idle at 1* then? Would I see a benefit of backing it off to 0*? Maybe better spool, or just leave it be?

Oh, and thanks for the help. :Cheer: