a properly tuned length extractor does not compress the exhuast gas from 4 pipes into 1 pipe... the length of primary and secondary pipes are tuned so that the exhaust gas pulse can travel one by one into the pipes according to ur engine firing order...
hehehe.at last.after all hardwork,sweatness & patience I would like to share with CS3A owner on my upgrade.sikit2 saja only not that much.hehehehehe:_: