I'm contemplating the installation of a crankcase vacuum/pressure sensor (2 bar MAP sensor) for my Holley Dominator EFI system.NOS Launcher manual said:Once a dry run is performed, the system can be activated with the nitrous and fuel solenoids hooked up.
The following are some basic guidelines for tuning. Every engine will be slightly different:
• Nitrous typically should not be activated below 3000 RPM or possibly higher depending on the engine.
If activated below 3000 RPM, use the progressive controller to meter less amounts of nitrous/fuel
as to not create excessive cylinder pressure causing detonation.
• Nitrous should only be activated at wide open throttle (WOT).
• If using a wideband A/F sensor, use the lean cutoff feature.
A delay of approximately .5 seconds should be past the typical lean spikes seen from nitrous activation.
The leanest it is recommended to run an engine at with nitrous would be between a 12-12.5:1 A/F ratio.
A/F ratio’s in the 11’s are typical with nitrous when trying to get a safe tune.
• Use the RPM cutoff to help shut the nitrous off when using a manual transmission.
• On race engines that use a vacuum pump and sealed crankcase, connect the [Launcher's] vacuum port to the crankcase.
This can be used to monitor the vacuum and detect any detonation by showing vacuum fluctuations in the crankcase.
I found the blue quote above very interesting. What kind of vacuum fluctuations/changes (detonation) have you seen in your data logs?
Also, the Holley EFI software indicates there will be a stainless steel 3.5-bar MAP sensor/transducer available at some point.
I know I'm supposed to use a 2-bar MAP sensor, but the transducer would be a nice fit and look a lot better too.
(I don't run a vacuum pump.) Will it be sensitive enough around 100 kPa? If so, I'll just wait for it.