I'm no mechanic or physicist, but if you have a larger snorkel and a freer flowing filter, I would assume that all that means is that the engine is working a little less harder in getting the same amount of air that it would normally use to operate.
I wouldnt think that the larger snorkel would mean that the air is being rammed straight into the engine as you have the filter and the mechanics behind still providing a damper/wall against the air flow speed.
I'm curious to know what the problem is as I've just got hold of the larger snorkel and am about to put in a K & N in my AUXR6 VCT. Perhaps one the more mechanically minded viewing this post can shed some light on what the problem may be.
By the way I've got 80k on the clock and at 75k I was having problems with slight surges (albeit at much lower speeds!), problem identified was that one of the leads had begun to perish, got it replaced, no more surges.