disabling CSMA/CA protocol in esp8266 or any other wifi ic
There is a way to disable it using rom_chip_v5_disable_cca() function defined at address 0x400060d0 in the boot ROM of esp8266 (/tools/sdk/ld/eagle.rom.addr.v6.ld file in esp8266 Arduino core gives idea about it ).  

Although option to disable CCA is provided by some 802.11 chipsets and some operating systems, I would recommend not to disable it. It's one of the most important feature of WiFi protocol and disabling it just increases the number of packet drops as experiments suggest. The other functionalities of the wifi also become unpredictable.