Are you parked outside a brothel?
Forgive me - I couldn't resist that!
How many kms on the car? I don't follow your "as I speed up it becomes constant" as this suggest it is in fact variable.
Is it affected by variable road surface. Suspension noises will be worse over more variable surfaces and may subside on smooth surfaces.
Is it a knock or a click? CV joints should not be discounted, esp if you or a previous owner has launched hard.
The previous suggestion is also valid - check wheel nuts.
Good luck!
Last edited by Doug_MPS6; 31-03-2014 at 12:48 PM.
CP_e Standback & PNP; CP_e 3" SS Downpipe; Corksport FMIC with Top-mount K&N filter & OEM Ram CAI; Turbosmart BOV; Dashhawk; Prosport Boost Guage; JBR solid shift bushes; DBA 4000 Wiper-Slot front rotors; Hawk Ferro-Carbon HPS Street front brake pads (@ 69,000km); Sumitomo HTRZIII's in 225/45 x 18