If GT4 is going to be a better simulator than GT3 engine modifications and turbo upgrades to racecars should be banned. the idea of having a HP limmit in race cars is the main reason for categories. i understand that in GT3 the there was a smaller number of race cars and by increasing HP in some of they competition availability was increase. in the best interest of becaming a real simulator that practice should stop. for example: a suzuki escudo is a 2500 cc v6 engine twin turbo @ 900plus HP, the turbos in this kind of engine must be the size of a basketball each. then a turbo 4 upgrade that increase the engine output as much as 90% must be the size of a 20in tv set each at least, and dont forget the amount of boost needed. in the case of a nissan r390 the whole vehicle is designed to handle the amount of HP that the engine originaly came with. an increase in HP to 1100 or more means that in real simutation the parts wont hold and the vehicule wont perform at its best. if iam going to boost an engine to that limmits at least i should have better brakes and suspension parts available too. personaly i dont like 1000HP lmp cars racing versus F1 cars because in real life that wont happend. same goes for 1000HP jgtc cars racing versus lmp or gtr cars, it doesnt make any sense. in the case that modification remains it should be for cars that are restricted in real life to be part of a category example: mclaren f1 in jgtc and saleem s7 in gtr.