racing soon..

[SilviaDriver]

well..from the topic u can see im racing soon..next weekend actualy..an di was wondering..if i can get ur input on it..

i know that there is a lot backpressure in play, but I would like your guys opinion on this subject.
I don't have a expensive exhaust system.  i plan to take my whole exhaust off from the headers, right before the cat. is there too much exhuast pressure lost. compared to as when, i would just take off my muffler from the rear axle back.
which would be better?
  and my intake system. i have an arm coming out of my headlight.
  shoud i run a air filter or not?  i know that without a filter would be faster but at the same time i don't want rocks going in. let me know wat i should do on both topics..thanks guys