Ok i have a 2001 Rx7

The car start and run perfect cold and hot, no flooding problem and other stuff

When i push gas around 3000-3500 rpm i ear a big "Bwhoooooom" for around 1/2 second (half) after this nothing strange happen.

Previous owned (in japan) istall a damn Big exaust (i can make photo if you need).

Do you have any idea to remove or reduce intensity of this noise? A silencer in terminal? other stuff? (withoud buy a new exaust)

Thank you.


PS Engine is stock except for aftermarket filters

 

sure, put the stock airbox back in. the sound is probably your smog pump venting into the open intake just before it shuts down at 3k.

a less likely issue is within the turbos themselves, a stuck open charge pipe butterfly will force secondary turbo pressure out the primary turbo and out the intake before the twins actuate together at 3500-4k.

but the smog pump is quite noisy on open intake cars. generally the smog pump sounds like a "moooo"(cow).

 

Yeah it's like a Cow....

ATM i don't have original filter...

Can this create other problem or it's only a matter of acoustic confort?