i got a new y-pipe made for my headers a few days ago. the guy made the part where the pipes come together smaller than the stock one!(2" opposed to the stock 2.5") there is no increase in performance and i think there is a little less now. i'm hearing a clicking sound when i hit the gas after i advanced the timing a little there is a clicking sound. i don't know if this is just the headers causing this sound or detonation. i'm running 89octane right now so i'l try 93 and see what that does. it also does it in another car i have if the timing is advanced too much and that car has manifolds.
it sounds sort of like a rattling/knocking sound, sort of high pitched or squeeky. i don't know what the timing is at because the balancer is messed up.

 

Make sure your headers are sealed tight to the heads. Mine loosened up and the exhaust leak made sort of a ticking sound under acceleration. Just a thought.

 

First of all, get a larger y-pipe made. Having headers flowing through a 2 inch y isn't gonna help you at all. The ticking may just be an exhaust leak from crappy welds. Then again, it may be knocking. Replace the balancer and really set the timing. That's the only way you'll know.

 

i got it set ok, it dosn't tick and it gets pretty good performance. a new balancer is next on my list along with a better y-pipe. its not easy when you are 15 and spend your last $100 on a y-pipe that the guy says he can make a good performance one and makes it worse than the stock one. when i get the money i'm going to go to a shop i know of that builds race cars and have them just replace the 2" section after the Y that is restricting it a lot.