I was racing Motorkhana (tarmac) today and noticed my Throttle was very sluggish

My first thoughts are I didint had my pod filter on cause it a little dusty in the air, so I just had my standard air box in. What is happening is where starting off at the start line it was all ok, but when i am revsering into this box 'the garage' and staight away back in 1st (manual) and it wasnt pulling, like the car took a second to notice that i was pulling out of the 'garage; fast, like it didint feel like pulling out.

What would your thought about this? I need to tighten the throttle cabel if its possible, modify the air box so it almost acts like a pod filter... hard to explain even though it already acts like a pod filter, but not enough sucktion, or just chuck the pod filter back on next time..