i have tried both OS Speed & T. Shimo pipe. heres the result

OS Speed, the best is it save fuel so much even compared to 2630. but top end losses some power.

T. Shimo, overall was satisfactory, the reason for buying this pipe is because its stinger is only 5mm, which i assume plenty of back pressure. i still prefer this pipe over OS Speed, since T. Shimo is a little bit cheaper.