Is modifing the stock air box bad?

[httrdd]

I was on rs25 with my swap thread and found that one of the guys had something to say about the eg33 AFR at WOT. He also says I need to run 93 octane. Not saying he is wrong just need more clairification. Thanks. TJ


Him: Don't dick with the filter or airbox, run 93 and you should be fine.
My stock ecu ran 15.4 AFR at WOT at 6000.. that's STUPID lean

Me: I am actually running a k&n cone since the air/filter box did not fit where the ABS pump was. Run 93 for the track you mean?

Him: no, run 93 all the time.
You are playing with fire having a non-stock filtering system on the stock maf on the stock tune.
You will for sure be more than 15.5 AFR at WOT. That means bad bad things for a 10:1 compression motor that likes to eat up 40+ degrees of timing

Me: Alright I will run 93 to be safe, but how does modifing the air box change the air/fuel mix?

Him: the maf is metering MORE air moving at a faster rate. The stock maf is maxed out at stock power levels.