i beg to differ.....a little^
my buddy had a GSR like me and we both had same CAI, MUFFLER, SK2 IMO but he had DC 4-2-1 2pc. and I had DC4-1 1pc. We would be the same until 2nd and thats when i pulled. It was the driving skills of one another becuae this happened ALL THE TIME and we even swithced cars. I then read an article in import tuner discussing this with pics and dynos. 4-1 1 pc were the best. pain to put on, but better.

but im sure the gain is small