Marco exhaust system

[Andy0625]

Anyone got idea what piping size should a Waja 1.6 auto transmission use? Currently on 4-2-1, 1 midbox, 1 bullet and 1 sflow muffler running on 2". Before change to 1 midbox and 1 bullet, it's 2 bullet setting and my torque is lost. When replaced with one midbox, it feels better but my topspeed seems to end at 170 which is quite sad. Will a "weak" fuel pump causes that too? :(

 

[quicksilver7]

you took that picture especially for me? :P Thanks mADmAN!!