To "delete" or not to "delete"

srt20 wrote:


I am only looking to learn something here.

I thought that the in cylinder egr (3rd injection event) actually raised in cylinder temps due to more fuel being burned. This is why EGTs on 04.5-07 is higher than engines without the 3rd injection event.

Is this incorrect?
Thanks

P.s. I am only referring to Cummins engines.

Higher temperatures actually contribute to NOx formation, along with areas that can act as a heat island within the combustion chamber. Lots of science goes into NOx formation, that's why combustion chamber geometries (the piston bowl itself and ring land sizes and location, etc) are continually tweaked with each iteration.

And just for reference, here's how diesel emissions regulation evolved over the years. A very dramatic decrease since 1994. This is why even if you're deleted and getting 5 mpg better (which you won't against a 2010+ DEF equipped truck), you are still emitting at minimum 12.5x more NOx or worse depending on your tune (and I'm assuming that you're only as bad off as 2004 emissions at this point, but I bet most tuners are around the 1998 or 1994 emissions levels). So in order to match the NOx output of a truck with emissions, you would need to achieve a fuel burn rate equivalent to being 12.5 times better than the emissions truck. Not going to happen. You would need 10 time better mpg than the emissions equipped truck to spew out the same particulate matter. The only thing you improve when you delete is your carbon footprint because you are burning less fuel.