the car ran perfect for about 2 weeks,the only thing i changed was my bov.
when i go into boost now it starts poping in the ex system,after about 4-5 pops it will backfire threw the intake.ive checked to make sure no wires were arcing,ive dbl checked afr with a wideband and its between 11.0-1 to 12.0-1.
the car was running very high boost but since this problem has started i had to drop boost to 9psi.but it still does it,if i stay uinder 6 psi its fine.The car dosent throw any codes,and it runs fine,any iudeas on what could be doing this,or any ideas on things to check out,was told by one person that the coil could possibly be weak,and that as the boosdt preasure comes up it cant light the mixture in the cyl,does this sound right?

 

Well I'm no expert on boosting but it sounds like an ignition problem or a tuning issue. I think when it comes to ignition alot of the problems people have is either the gap they use on the sparkplugs is too big for the ignition system they're using, or parts are beginning to fail. You can try running a smaller gap on the sparkplugs and see if that makes a difference, would give you an indication if thats the problem you're having. Or its possible parts are beginning to fail, I'm sure there are ways to test the coil and other parts, might have to try a search on that one. But you know the issue could also be tuning related. What octane fuel are you using? How are you controlling timing?

 

well i swaped out the coil and it got alot better.no more backfiring threw the intake,only pops out the ex still occiasonally.so next is to change the pickup in the dizzy,
heres 2 clips that i took this moring with the boost backed down to 7 psi
opens with realplayer or quicktime
15-120ish mph with 7 pounds of boost
http://lethal.ics-il.com/road2.3gp
and 0-80ish @ 7psi with a ****ed up shift (must get a ractheting shifter)
http://lethal.ics-il.com/road1.3gp
the quality sux took them with my cellphone was trying to get a shot of the speedo climbing

 

Just to throw something in this. Could you be holding the valves open at higher boost? That happened to me with my old heads at 13psi of boost until it got bad enought that it would do it at any amount of boost.