ZL1 Colorado: take 2
06-19-2018, 04:59 AM
#24
Well...it sounds less terrible. Couple drone resonant peaks and some pipe-induced rasp that is likely due to my shoddy deburring efforts...but it sounds drivable now. It's all v-banded so I'll probably take some sections out at some point and pull the burrs out at the v-bands as well as drop in some quarter wave resonators. Has the tiniest bit of lope which is perfect. Also seems like as my phone gets older, the video quality gets worse... 
06-26-2018, 06:01 AM
#25
Shitty video for a shitty truck. Mostly 3rd gear stuff, the 4.10s prevent it from kicking into 2nd at highway speed.
This transient fueling calibration has been a pain in the ***. With the blower adapters the port surface is so weird that it's difficult to really make the model follow what is physically happening in the port. I almost need a **** to control evaporation factor as a function of the modeled puddle mass. Pretty sure fuel is filling some port crevices and the evap rate isn't linear with puddle mass. Makes things difficult for sure. May also be hitting some puddle mass clips, which will really hamper any proper calibration. I'm close to just ripping the 5.3 out and replacing it with something rectangle port
I've also noticed that with the lower compression and chamber design from these heads, pulling out a degree of spark seems to have many times the effect that it used to. With my ******* 87 octane calibration, it's actually super close to combustion instability even at the knock limit, numerically speaking. If I'm at 16 degrees of spark advance at an off-idle throttle stab, burst knock pulling spark down to 10 degrees will show up as lean misfire on the wideband lol. Pretty wild. So that's why it isn't blowing the tires off from idle. Got some burst knock changes to try out later and soften up the impact in those critical areas.
This transient fueling calibration has been a pain in the ***. With the blower adapters the port surface is so weird that it's difficult to really make the model follow what is physically happening in the port. I almost need a **** to control evaporation factor as a function of the modeled puddle mass. Pretty sure fuel is filling some port crevices and the evap rate isn't linear with puddle mass. Makes things difficult for sure. May also be hitting some puddle mass clips, which will really hamper any proper calibration. I'm close to just ripping the 5.3 out and replacing it with something rectangle port
I've also noticed that with the lower compression and chamber design from these heads, pulling out a degree of spark seems to have many times the effect that it used to. With my ******* 87 octane calibration, it's actually super close to combustion instability even at the knock limit, numerically speaking. If I'm at 16 degrees of spark advance at an off-idle throttle stab, burst knock pulling spark down to 10 degrees will show up as lean misfire on the wideband lol. Pretty wild. So that's why it isn't blowing the tires off from idle. Got some burst knock changes to try out later and soften up the impact in those critical areas.
06-27-2018, 05:27 AM
#26
Here's my fun little problem in action. The most common scenario happens to be the worst case scenario...waiting at a stop light in gear for a long period of time so that the transient fuel puddle model has had time to build up puddle mass. The calibration hard-limits calculated puddle mass at 2048mg of fuel. The modeled mass gets closer to that number as I sit and wait. Then stabbing the throttle to launch, transient fuel will only inject additional fuel until it hits that 2048 clip. Then boom, no more transient fuel compensation. I've even raped the PE table to add as much fuel as possible below 2000rpm (9.79 commanded AFR) and best case, it's rich enough to not knock but still too lean to make decent torque off idle. Notice the inflection in the RPM trace and the mix goes sufficiently rich and really starts making torque. These cathedral ports and port adapters have got this truck by the hamstrings... At this point I am tempted to grab an LY6 for the rectangle ports so I can at least have some hope of getting transient fuel dialed in.
06-27-2018, 06:50 AM
#28
A couple seconds, depending on the MAP/decel beforehand. There are some stabilization ***** to turn to help a tiny bit but its still the wrong way to approach the problem. I don't know how the aftermarket LSA crowd is putting up with this lol.
06-27-2018, 09:46 PM
#29
Like you know anything about transient fuel models... 
Actually, I wonder if there are any missing tables from the OEM software that might help with the issue?
Frankly, I have never liked the adapter set up and always kind of figured It would be an issue. I see some different heads in your future.
Actually, I wonder if there are any missing tables from the OEM software that might help with the issue?
Frankly, I have never liked the adapter set up and always kind of figured It would be an issue. I see some different heads in your future.
06-28-2018, 04:06 AM
#30
Like you know anything about transient fuel models...
Actually, I wonder if there are any missing tables from the OEM software that might help with the issue?
Frankly, I have never liked the adapter set up and always kind of figured It would be an issue. I see some different heads in your future.
Actually, I wonder if there are any missing tables from the OEM software that might help with the issue?
Frankly, I have never liked the adapter set up and always kind of figured It would be an issue. I see some different heads in your future.
Last edited by 1FastBrick; 06-30-2018 at 06:59 PM.