all these fancy words and yet you still ake no sense. the weight i was actually reffering to is the 1999 si coupe not the new si wich weighs 2744lbs wich is still 4 lbs lighter than the stock 1999 si. i understand that its a cool swap (the k20 into si) but coolness doesnt make you any faster unless you on the set of fast and the furious, but in this case its real life and in real life its not and i repeat not possible for two equally skilled drivers driving those cars and the rsx comes out the victor its just not right. intake header and exhuast on the rsx maybe 30 whp and the mustang picked that up with just a chip.