im pretty sure the supra is 400whp. just because the race was against a civic doesnt mean that the other car is not as it says it is.
power to weight ratio. it is possible for the k swap ek to do that. and it is possible to run it with stock parts.
it is possible to run that fast with those mods. ive seen many other swaps with just intake and custom exhaust + a full tune (kpro) run that fast.
i think wayyy too many people underestimate civics