Exhaust "rasp" or "tick"?

[teeje]

Well, drove to work today. Very hard to notice now even against a sound barrier or median. Ive heard that its a by-product of scavenging basically meaning when the valves close it creates a vacuum and when the valve opens it in turns make a tick type noise. Also the thinner material for the cat deletes prolly makes it louder also. I guess thats just unfiltered bald eagles comin out of the exhaust!

 

[teeje]

Well, drove it today and didnt hear it on the highway. Got off into city driving and when driving normally and shifting 1-2 or 2-3 you can hear that sort of ticking noise around 3000rpm but goes away as soon as you pass it. If I hold the brake pedal down and hold that rpm I can hear it. Could this be too much timing?