Black dust out of my exhaust on start up?

[9240sx]

lately my car has been putting out looks like black dust or little black chunks.Only when i first start it up.I see it on the driveway.Car runs fine,I notice it started when i changed my spark plug gap from .30 to .28,Or maybe the new Profec B has something to do with it?Im running about 10psi.Im running a full 80mm exhaust with no cat.Is this normal?-Thanks,

[own3d]

your probably just running rich. carbon builds up on the inside of the pipes and every now and then breaks off and gets blown out

[9240sx]

So i souldnt worry about it then?Do alot of peoples car's with sr's do this?

[nismostate]

how much smoke is coming out? a small puff? i don't notice smoke on startup because i startup and then drive. if it's a constant smoke, you might wanna check your intercooler pipings. btw, i believe stock gap is at .029. mine is at .029-.030

[9240sx]

I wouldnt say its smoke,It just blows alittle black junk out when i first start it.Only if i havnt started up the car in a few days.

[9240sx]

so sould i move the gap back to .030 its at .028 right now.