Hi all, I have done many searches but can't really find the answer I need - I have v5 type r which I have just changed the air intake from an apexi cone filter to the standard airbox with a green cotton panel filter (the apexi was too noisy for me!), with the apexi it would boost to 1.35bar but now with the airbox it is peaking at 1.5bar (mapped by Andy F to 345bhp at 1.35bar with the apexi, larger fuel pump, full decat, ported headers, v8 tmic).
My question is how can it be over boosting this much with the 'more restricted' airbox? Will this cause a lot of damage and knock, and what should I do (put the apexi back on, or get the map tweaked, or will it be OK as is)? Also, very occasionally it will lurch on full throttle like its cutting the fuel temporarily, this was both before and after the intake change. Thanks

 

Maybe the original air box wasn't as bad as you thought.
I would put cone back on.
Then get map tweaked for original.