can someone take a look at my tune and tell me what i am doing wrong?
i have two big things going on and no matter what i change they stay the same.
1. RPM's are slow to go back down to idle. (looks like the timing is slow to drop back down)
2. when driving as soon as i get in to get a little the timing drops like hell and there is no power.
any help would be appreciated.
03 Silverado SS lq9, xr275hr cam, 243 heads with dual spring, E-fans, built 4l65e with a 2600 stall.
Do you have a wideband o2 sensor?
You are commanding a far too lean air fuel ratio under power enrichment, 13.25 is not a good idea. Stick to 12.5ish for a NA engine. You also left cat over temp protection on and that is causing the EQ ratio to drop while in PE. You are out of fuel injector anyway, so no real sense in tuning much more when you can't even supply enough fuel to the engine as it is.
There is lots of knock retard, so it's pulling a ton of power away. Getting the airflow model for BOTH the MAF and VE need to be done. In the mean time drop the timing way back to like 18 degrees at higher loads/rpm while you work on the MAF/VE. I'd disable burst knock too, just so that isn't causing any weird knock readings or pulling timing.
So if it was me, I'd get some larger injectors. Stick a wideband in the exhaust and get it data logging in HP Tuners. Calibrate the MAF in open loop with no fuel trims/closed loop for idle/part throttle. Then calibrate the VE the same way for part throttle/idle. Then work on getting into full throttle fueling later on. Often times once the MAF/VE are good for idle, it will make idle airflow changes and idle timing changes much faster. Going for power with timing can be worked on once fueling is all there.
Make sure to be running good fuel too, 91+ octane for the mods you have.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
thanks.
I had a feeling it was to small of injector and/or fuel pump. I was making wild changes. trying to see if it was the tune or something wrong.
I am running alcohol free 93 octane. what is a good fuel pump to run? will the Delphi 8.1l marine fuel injectors be a good fit?
Last edited by thebob232; 10-10-2019 at 07:37 PM.
Most use a walbro pump but you may be okay on pump still.
Injectors are for sure too small for a cammed 6.0. I don't trust the marine 8.1 injectors because of data issues I've seen. The regular gas 8.1 injectors are 31lb/hr, which should be just fine if you don't add anymore power. That's 6lb/hr more than the current 25lb/hr and the data is plug and play with those because the stock files are out there. Or just go with stock flex fuel injectors from a silverado/surburban of that same era, those are 33lb/hr.
The wideband is the key here.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
Reply With Quote