Hi,
Recently I was checking my redtop swapped s13 and I found that my blow off valve has been leaking from the diaphragm. My motor was having a slight misfire at idle and i never thought much of it being that I'm a few degrees advanced in timing so I thought that was the cause until I covered my BOV with my hand and the miss dramatically reduced. Pissed at my eBay intercooler kit, I went covered the outlet with a condom and surely enough, it filled up with air in a matter of seconds.
Near the top of my rev band, the turbo (S15 spec R) starts to trail boost off. It'll hold 19 psi until about 6k and then fall to 15 until redline. I had a dyno pull done only reaching 280 peak RWHP, which is odd for an SR on 19 psi because I was expecting about 320-330 at the wheels.
So my question is, with the leaky blow off valve and the loss of about 4 psi, how much power would I be losing and could this be THE cause of the misfire at idle?
Any input helps, Thanks!