Funny sound...

[SupraSith]

Ever since I updated my car, I've noticed an odd sound every time I let up on the accelerator. Its kind of like a ringing sound. Almost a harmonic squeal.

The engine mods I did before this happened are as follows: K&N Air Filter, 3 inch straight thru exhaust, ACT Street clutch, Clutch Masters flywheel, upgraded turbo and oil lines, 550cc injectors, Super AFC II.

At first I thought maybe it was the clutch breaking in, but these mods were done over a year ago. Any ideas?

 

[SupraMario]

u got LSD on it?
could be that whining.

 

[bcg04]

Maybe BOV flutter if you are still running stock BOV? Since it occurs when letting off throttle if it is starting to fail... and with K&N filter you'll hear it well...

 

[SupraSith]

Maybe BOV flutter if you are still running stock BOV? Since it occurs when letting off throttle if it is starting to fail... and with K&N filter you'll hear it well...

...oh yeah, I installed a greddy bov. So now what?