exactly, they were ES100s which suck for drifting. they are poorly made and fall apart easily. so that situation was explained because of the poor tire choice.
and for 245 on a 8" wide rim, no wonder you get so much sidewall flex. the max i would run would be 235 on an 8" wide rim. try running a 215 or even 225 on the rears, and 215 for the front. 205 is a perfect FIT (not stretch) on a 7" wide rim on my s14 rims. i’ve learned that if you want grip, don’t up the size of the tire on that same rim. you gotta get wider rims and wider larger tires so you don’t sacrifice handling. i use to run 225 on my 7" wide rim and it was crap, so i got myself 17x9 rims and now running 225, but i would like to run 215 wide tires.
but 245 are monster tires and are not necessary unless you are running 12-13" WIDE rims (for drifting), or have 400hp +. OR are drag racing.
i can guarnatee you that is why you are feeling so much slop. i can bet any money 215 would be perfect for your 8" wide rims. 225 would be alright, but not perfect. 245 is just out of the question. trust me on this one david, i know my tire setups =D
and yes, even if it came like that OEM setup, that setup isn’t meant for drifting.
PS: the reason why you like overinflated tires is because the tires you are running on your 8" wide rims are too big for the rim, and that factor is directly related to why you like running higher psi. if you had the proper setup with less slop, you would enjoy the lower psi. i can bet any money that you have a good 1-2" tire slop hanging from your rims. the tire and rim should be completely flush if you want AVERAGE handling.
all i can say is, stretch tires ftw!