If not mistaken, original is 2" from the extractor to the muffler. But don't bother to alter it into bigger size as it will decrease your power, if you like to have a louder or more aggressive sound, change out the whole system. You can try PM "Semperfi" as he have the whole new complete set of HKS muffler original from Japan for GTT. This might help you to get better HP and more aggressive sound.
i wonder where can i buy back
1. arc manifold cover
2. ganador c/f or non c/r or mickey mouse one
3. hks 18k grounding
4. radiator colling plate evo 8/9
5. arc spliter
ANYBODY HERE KNOWS WHERE CAN I FIND ALTEZZA RS200 manual transmission??
i am intending to buy a altezza...went to Naza this morning ..but they only have AT transmission one..