pilot timing and poping under accel

[MAIDENCR]

Hi,....someone can explain to me how all pilot event timing table and correction work together....for now my tune is really cool but I have the poping that 03-04 have when they are tuned

at idle my main inj timing is 6 deg and pilot around 40.....and on hard acceleration can go up to 60-70 deg while main is 26
and tune pilot timing is no more than 25-26 deg...

[Jim P]

Not 100% what you mean by popping but I?m assuming you are describing pre-detonation. Without actually seeing your tune it?s hard to say but your pilot timing, holy sh*t that is some high numbers! Your main injection timing, all depends on where the highest is occurring and with how much duration and pressure to say if that?s ok or not and other engine mods. Even 6 degrees on main at idle seems a little more than necessary.

If you are getting pre-detonation you are tuning a recipe for a blown engine if you keep running it that way and tuning it that way. Do some research on pilot injection.

[MAIDENCR]

My truck did this kind of popping with smarty and sometimes with tune from big named shop

Sure i want to remove some pilot timing...but i need to know how table work together to pin point where to change things

[MAIDENCR]

I have 60% over injector maybe i should drop pilot pw a little bit

[Jim P]

Pinpoint where is easy. Your pilot timing itself is high, your main timing may be high in the area where you are getting popping as well but can?t say without seeing your tune.

Pilot has major affects on your main injection combustion, I would really do some research on the affects of pilot and main injection to get a good understanding of what they do and how timing and quantity affects things.

And remember your 40 degrees of pilot timing is 40 degrees ahead of your main start of injection. So if you are running 6 degrees main at idle your pilot is really 46 degrees start of injection. If your highest main injection timing is 26 degrees and your pilot is 70 degrees at that same rpm and quantity, your pilot is really 96 degrees start of injection. Depending on how much pilot shot is injected at that point, that can turn out to be some high stress on the motor way to early in the cycle. But again, without seeing what you?ve done in the tune it?s hard to see exactly where everything is at at different points of operation. Whatever has been done though is a building recipe for engine damage if continued.