This is an archive of the post and files from the original post, just incase it disappears.
Second, I want to thank all of you who have dug through the interesting fan options available, so that we can alter the fan curves, rather than just throttling the fans to a potentially unsafe level.
Also, the steps are much easier than last time around. Now, you just need to turn off your iLO security protection and flash the new ROM locally. This is how I accomplished it on two DL380P Gen8’s via Ubuntu…
1. CP027911.scexe We’ll use this for flashing the hacked firmware
2. Download the custom 2.73 ROM We’ll swap out the original firmware in the 2.50 iLO4.
3. Disable iLO security by way of the system maintenance switch on your motherboard
4. Disable the HP Lights-Out Driver
Here’s the error message you might see if you don’t.
ERROR: hp Lights-Out driver "hpilo" is loaded.
Run commands “/etc/init.d/hp-snmp-agents stop”, “/etc/init.d/hp-health stop”, “/etc/init.d/hp-ams stop” and “rmmod hpilo” to unload it and retry. 
For Ubuntu, I had to do the following:
sudo modprobe -r hpilo
5. Replace the 2.50 ROM with the 2.73 ROM and flash
sh ./CP027911.scexe --unpack=ilo_250 cd ilo_250 cp /path/to/ilo4_273.bin.fancommands ilo4_250.bin sudo ./flash_ilo4 --direct
6. Start using it!
In order to use this mod, you will need to SSH in to your web server. Note that you can only see the results of your commands the first time after iLO has been reset (no need to reset the rest of your box), and I don’t know yet how the fan tables can be permanently applied (yet).
Here are some useful things people have found:
- Turn your fans down the lazy way
fan p XX max YY (XX=fan #; ranges 0-5, YY=fan speed; ranges 0-255)
- Looking at all the settings in one swell swoop. Pay attention to the PID algorithms section and the GROUPINGS section (look for the stars).
- Tweak the lower PID value of your system, especially for things that are causing your fans to go faster.
fan pid XX lo YYZZ
There’s a good writeup on what you can do to set up your system; I would suggest reading this post to get some nuances for what to do with those values.