The Fan config block is signed. and you welcomed
Thanks ddxcb. Much appreciated. I tried 44speed and 70speed from Fantools.zip and both the dev and retail paths in FanSpeedFlash.rar and they all keep the system at about the same temp after 30 min in XeXMenu as Autospeed.xex or an unaltered config.
The 100speed.xex I created above using your excellent patch and the Autospeed.xex from fantools.zip worked perfectly. Also, the 00speed.xex included in FanSpeedFlash.rar (stopped fans dead).
Auto value as normally found in the config which can be checked against original nand by issuing command: "nandpro orig.bin: -R16 config.bin 3de 2" and then open config.bin in a hex editor and go to offset 0x4011 it should be 7F 7F
Auto speed is 7F 7F (I know I said that already.)
Fan speed fixed speed range is 80 to E4
After looking more closely it appears the reason is that 44speed and 70speed set the values without adding the 128 dec. A minor bug.
7F 7F for CPU and GPU fans - Autospeed.xex
80 80 for CPU and GPU fans - 00speed.xex
2C 2C for CPU and GPU fans - 44speed.xex - should have set to AC AC for 44% constant speed
46 46 for CPU and GPU fans - 70speed.xex - should have set to C6 C6 for 70% constant speed
E4 E4 for CPU and GPU fans - 100speed.xex as created using ddxcb's patch to autospeed.xex from fantools.zip