Procharged 6.2 silverado....false knock?

[GPGTP]

Stock 6.2, low pressure pump, headers and catback are the only mods. I leaned it out to lambda .85 and rail pressure is holding decent but i'm limited to single digit timing. Does this look like potentially false knock? what would one expect to be able to run as far as timing goes?12 degrees 2.hpl

[Higgs Boson]

check your torque tables. what is your injector pulse width?

[paulsmithsr]

U need to get tune help

[GPGTP]

U need to get tune help

what are you talking about? Isn't that what this is for?

[GPGTP]

check your torque tables. what is your injector pulse width?

pulse width hits 6.5 ish, it was logged in the scan I posted. What's wrong with the torque tables?

[Higgs Boson]

pulse width hits 6.5 ish, it was logged in the scan I posted. What's wrong with the torque tables?

pulse width over 4.8 means you are out of fuel for your window. 6.5 is way out.

[GPGTP]

pulse width over 4.8 means you are out of fuel for your window. 6.5 is way out.

Could this be causing knock?

[Higgs Boson]

Could this be causing knock?

false knock, yes. it will retard spark to try to make more room for injection so you don't spray through the spark.

[GPGTP]

false knock, yes. it will retard spark to try to make more room for injection so you don't spray through the spark.

What if set soi earlier? I read where you said don?t put it past 359. I?ve had it as far as 400 and still same issue. I remember someone saying 5.5 is the limit on pulse width or was that found to not be the case anymore? I can?t view my log right now but eoi was at about 150 ish is that too late of a close? Still gives about 140 degrees before spark lights off.

[Higgs Boson]

What if set soi earlier? I read where you said don?t put it past 359. I?ve had it as far as 400 and still same issue. I remember someone saying 5.5 is the limit on pulse width or was that found to not be the case anymore? I can?t view my log right now but eoi was at about 150 ish is that too late of a close? Still gives about 140 degrees before spark lights off.

i said 5.5 which is still a good rule, but stock is 4.8 and now when it goes over that I am ready to add supplemental fueling, meth but preferably a port injection system.

you might also try increasing the max angle from 350.

[GPGTP]

Hey thanks for the info. I?m a little confused though. Wouldn?t changing the max angle deliver fuel even closer to spark timing? Also, in the description of what the tables is, it describes EOI. It would seem it actually refers more to injector duration? Or am I way off?

My duration is only 230% currently.

truck scan.PNG

[Higgs Boson]

EOI only applies to split pulse which is only active during cranking on some cars.

Also, I would check your Virtual Torque Tables in that area and raise them up, it could be pulling timing to reduce delivered torque.

[GPGTP]

EOI only applies to split pulse which is only active during cranking on some cars.

Also, I would check your Virtual Torque Tables in that area and raise them up, it could be pulling timing to reduce delivered torque.

I get it now. The 350 is the limit on duration. Strange, when I had stock soi and commanding richer mixture .79 lambda, the ecu automatically pushed soi earlier to prevent eoi from going past 13-14 degrees. Oddly enough it didn?t have any effect on knock tendencies.

Can I ask why you chose 359 as the earliest we should open the injector? Is this based on exhaust valve opening?

Also why does injector pulse width matter as long as soi and eoi is within acceptable range?

[GPGTP]

Also, I would check your Virtual Torque Tables in that area and raise them up, it could be pulling timing to reduce delivered torque.[/QUOTE]

I will bump this table up a bit to see if it helps

[Higgs Boson]

I get it now. The 350 is the limit on duration. Strange, when I had stock soi and commanding richer mixture .79 lambda, the ecu automatically pushed soi earlier to prevent eoi from going past 13-14 degrees. Oddly enough it didn?t have any effect on knock tendencies.

Can I ask why you chose 359 as the earliest we should open the injector? Is this based on exhaust valve opening?

Also why does injector pulse width matter as long as soi and eoi is within acceptable range?

yes I try to stay away from spraying with the exhaust valve open and if it's necessary at least do it while the piston is pulling rather than pushing....at least unless we have the ability to measure how much mixture can be pulled back into the cylinder from the exhaust port for combustion. bigger cams reduce the time to fuel but also require more fuel, catch-22 there.

injector pulse width indicates when you are starting to run out of fuel, you will see pressure drop in the rail and on the low side as the injector runs out of time. the 4 cylinder guys got DI first and say there is potential for fuel puddling over 6, I think it was.

[paulsmithsr]

Two ways to add fuel - pulse time And fuel pressure.
U can add more fuel pressure if u are maxed out on pulse

[GPGTP]

EOI only applies to split pulse which is only active during cranking on some cars.

Also, I would check your Virtual Torque Tables in that area and raise them up, it could be pulling timing to reduce delivered torque.

yes I try to stay away from spraying with the exhaust valve open and if it's necessary at least do it while the piston is pulling rather than pushing....at least unless we have the ability to measure how much mixture can be pulled back into the cylinder from the exhaust port for combustion. bigger cams reduce the time to fuel but also require more fuel, catch-22 there.

injector pulse width indicates when you are starting to run out of fuel, you will see pressure drop in the rail and on the low side as the injector runs out of time. the 4 cylinder guys got DI first and say there is potential for fuel puddling over 6, I think it was.

Yes yes, later exhaust closing means less window. I wonder what the stock cam exhaust valve closing is.

I?m guessing puddling comes from lack of rail pressure? If that?s the case I wonder at what psi this starts to happen? Correct me if I?m wrong, but it would seem it?s more of a function of rail psi than injector duty cycle right? I can see they would kinda go hand and hand though.

[Maxspeed96ct]

bump, have you gotten this figured out?

everyone always mentions the torque management and Virtual Torque Tables being very critical on these but i cant seem to wrap my head around it

[GPGTP]

bump, have you gotten this figured out?

everyone always mentions the torque management and Virtual Torque Tables being very critical on these but i cant seem to wrap my head around it

yes i did, it was false knock