2019 ZL1 with Mag 2650, Stage 2 cam with 38% lobe maxing out injectors on pumpgas????

[Musky@RG]

Hey Guys I'm having an issue with a 2019 ZL1 nearly maxing out the direct injectors on 93 pumpgas. I have attached a log file of the dyno pull and you can see the injector PW is hitting 6.2ms which is no good because I'm planning to flex tune the car. It has all the supporting mods for flexfuel this which I will list below:

- Fore innovations twin walbro 450lph fuel pump setup (running 80psi on the low pressure side during boost)
- Stage 2 BTR Cam with 38% Fuel lobe and locked out the variable gear
- Johnson low lash lifters with DOD stuff removed and
- Magnuson 2650 Blower (18psi at redline)
- big gulp intake/headers/throttle body etc......... full boltons.

Firstly the car is showing false knock constantly anytime I go over 40ish% throttle. I've Confirmed that it is false knock with my knock detection equipment. So you will see knock being picked up on the log. My Equivalence Ratio Commanded is following my Power Enrichment commanded so it does not seem to be affecting my fueling. The high pressure fuel pump is showing 3200psi+ during the entire dyno pull also.
The car is only making around 715whp at 18psi and is nearly maxing out the DI injectors.....????? Anybody have any insight as to why? I have tuned many of these cars and for some reason this one is acting like the injectors are smaller. The log is attached below
Any insight will be greatly appreciated, Thanks
9 pump final pull.hpl

[TriPinTaZ]

What is your actual Lambda?

[ZLRob]

Your MAF is probably really off because of the new cam and big gulp. You need to get actual AFR readings from an AEM AFR gauge or similar then hook that up to your HP Tuners software and scale your MAF according to the new airflow values. That is just my super basic starting point for this issue.

[Musky@RG]

What is your actual Lambda?

Actual Lambda is: .816 on our dyno wideband which is accurate

[Musky@RG]

Your MAF is probably really off because of the new cam and big gulp. You need to get actual AFR readings from an AEM AFR gauge or similar then hook that up to your HP Tuners software and scale your MAF according to the new airflow values. That is just my super basic starting point for this issue.

MAF has been fully scaled and the Virtual VE has been scaled in SD mode. Actual Lambda under boost logged on the dyno is .816

[TriPinTaZ]

Actual Lambda is: .816 on our dyno wideband which is accurate

That is a little on the rich side but nothing major. If that is measured at the tailpipe it could be a little richer at the exhaust manifold. I know you said the Wideband is correct, but it could be calibrated a little off and showing leaner than actual which would mean you're definitely too rich.


But the reality is, if your fuel rail pressure is steady and your injectors are at max pulsewidth at redline then you are out of injection time. You're not logging SOI or EOI which are important as well. The only logical thing would be that the Wideband is off or the injectors are indeed smaller or maybe the dyno reads low. Could be a difference in Dyno types? Some read much higher like DynoJet vs Dynapak vs Mustang Dyno etc. Can't really see much else without the tune file and a log with additional PIDs.

[Musky@RG]

That is a little on the rich side but nothing major. If that is measured at the tailpipe it could be a little richer at the exhaust manifold. I know you said the Wideband is correct, but it could be calibrated a little off and showing leaner than actual which would mean you're definitely too rich.


But the reality is, if your fuel rail pressure is steady and your injectors are at max pulsewidth at redline then you are out of injection time. You're not logging SOI or EOI which are important as well. The only logical thing would be that the Wideband is off or the injectors are indeed smaller or maybe the dyno reads low. Could be a difference in Dyno types? Some read much higher like DynoJet vs Dynapak vs Mustang Dyno etc. Can't really see much else without the tune file and a log with additional PIDs.

Thanks for the reply. I've moved around the SOI up and down with no real change. The exhaust valve starts to open slightly before 360 so I have a lot of room for SOI. I have now ordered the 30% larger injectors so hopefully that takes care of it.