Thread: Hissing noise
View Single Post
Old 09-12-2020, 11:51 AM   #3
p1l0t
Senior Member
 
p1l0t's Avatar
 
Join Date: Jan 2016
Drives: 2016 Subaru BRZ Hyperblue
Location: West Hartford, CT
Posts: 8,478
Thanks: 22,741
Thanked 9,438 Times in 4,847 Posts
Mentioned: 58 Post(s)
Tagged: 1 Thread(s)
If you are at max boost it is probably relieving excess pressure. I have a twin scroll in my JDM STi swap (not a BRZ) and it makes all kinds of noises at many different throttle pressures/rpms. The only time it's not dumping pressure is on the inital acceleration but as soon as the first stage spools up it hisses a little and then when the second stage kicks in it makes a fluttering sound and the when I back out of the gas to shift it dumps even louder. So yeah it's probably normal. If you have a boost gauge you probably notice the noise starts around your max boost point (although there are many varibles).

Sent from my SM-G975U using Tapatalk
p1l0t is offline   Reply With Quote