Alright, i'm normally over in the skyroadster forums but i havn't been active much since i havn't done much with the car.
so when cold and a few occasions when warm but really cold outside (specifically on my drive back from oregon to tennessee... 8F outside) it makes this sound approximately between 2k-2.5k rpm that sounds a lot like a sportbike chain that is loose and over lubricated.
now i'm sure this is partly due to a hole in the tune file i used for a while... my mistake for not looking over the work before using it... i've since fixed it but i did beat on it a good bit with two cells in the high 5800rpm range of cam timing going from -11 to 10 to -9 over about 300 rpm... i'm sure that's likely the cause. i've since retuned the car myself... other than the boost of power from properly tuning it and such... no more hole in the tune.
the car has aftermarket bov, i made a new charge pipe for the turbo side of the intercooler and it's re-circ (i didn't have the ability to remake the other side at the time... and no definitely don't or i'd move the maf). cat-back exhaust. and tune... that's it.
i know i'm likely in need of new valve springs and i intend to upgrade the cam when i do. running 20psi around 60 degrees f at 30% humidity.
i'm mostly trying to figure out if i need to replace more parts... and about how long before it likely starts damaging other components...
