I have original fat ps3 40g, fan sounds like a jet taking off 
, any and all mods to get that as quiet as ps4 pro 7115 would be cool. I know ps3 uses crazy wattage too 
. Any steps to reduce that at same time would be awesome. 
Have you tried changing the thermal paste? This is probably the most effective way to do it. I have a few FAT PS3’s and they’re all mega loud.
No I haven’t yet it was on my list. I was hoping to gather many ideas and doing them all at the same time, maybe there is a better heat sink and fan as well as the liquid metal paste, maybe there is a chassis mod that allows for a radical layout but reduces energy while getting same performance. 
To fix the fan issue just put new thermal paste that happends on everything and is not way to make the ps3 use less watts is like a high end computer it requires of that energy if you are interested of playing ps3 with less watts get a slim version or just use an emulator
You also need to replace the thermal compound under the IHS specially on the CPU.
Found a youtube, this guy basically built a custom chassis, replaced HDD with SSD, swapped the BD for a more energy efficient one, removed the fan, built a console sized heatsink…fanless. Wow, admirable job. Reduced wattage dissipated to just 73 watts while CPU temp at 43 degrees C (I think) after running 3 hours on max load. 
That is quite a project. Literally thinking outside the box. Beyond the scope for most people. Very cool idea though.
I’ll stick with changing the thermal paste, pads, maybe SSD.
Thanks everyone for the input. 