I got around to installing a NeuSpeed Discharge pipe that I got off a fellow forum member who was parting out both, charge pipe and discharge pipe new.
I did the discharge fairly easily however ran into an issue trying to remove the T30 lower/upper screws holding the charge pipe. They are like machine drilled secured. I had zero chance on them. I noticed I began to wear the bolt down so I backed off of fear of stripping it. In the end I gave up on the charge pipe and then read some reviews and having second thoughts of attempting it again. It appears there isn't much of added performance with the charge pipe as there is with the discharge pipe. Worth it to try again?
With that said, I did finally notice a difference with the discharge pipe installed when on the highway. It definitely pulls a lot more smoothly and quicker. I'm not sure how much benefit you would notice with K03 but with K04, that increase in diameter definitely helps with pushing more air. If I was K03 though I think the OEM design is engineered better regarding that it's like pressuring the air into a funnel to give it more force.