open induction kits are the spawn of the devil!
cold air feeds are pointless. the filter is open, sat somewhere in the middle of a very hot engine bay. youve got all that filter exposed and a tiny little tube providing cold air, wheres the filter gonna draw all its air from? all around it, where theres barely any cool air at all, just all the hot stuff. you might drop the temperature a bit, but still nowhere near ambient, youre drawing in hotter air regardless. so youve already offset the "extra flow" the induction kit is providing with the lower density of the air
relocating the filter to the front of the engine bay helps, shielding it off from the engine bay helps even more, enclosing it is less effort and the ideal way though, so its £70 on something that will lose you power over the std airbox, or gain a little if the stock airbox was REALLY bad, or £150-300 on an enclosed kit that will definitely see gains, how large depends on how bad the stock airbox was though
there isnt a single application in the world though where an open IK is beneficial to power compared with mildly modifying the stock airbox to remove any major restrictions, and giving it a better air supply, or just biting the bullet and fitting an enclosed setup like a Maxogen or a Viper to start with