JB4 Sound Question

applecst · 10-22-2023, 02:26 PM

Been living with the jb4 for a while now. Performance was expected so no surprise there. What surprised me was the increase in exhaust volume. The car growls way more than before jb4, even when in idle.

The unusual part is the volume gets louder a few seconds after start up. Especially in warm start. I would hear the normal not so loud warm start up exhaust first and the jb4 effect seems to kick in a few seconds later. I'm a little OCD and it's driving me crazy lolll. Any one has the same experience?

mike@x-ph.com · 10-23-2023, 11:51 AM

Are we talking about the real sound of the exhaust or the active sound from the speakers?

applecst · 10-23-2023, 11:57 AM

Quote:

Originally Posted by mike@x-ph.com

Are we talking about the real sound of the exhaust or the active sound from the speakers?

It's the real sound lol. It takes a few seconds after start up for the exhaust to pick up.

PNTDG42 · 10-23-2023, 01:00 PM

Placebo or something else changed unrelated. There’s no explanation for it to make audible changes at idle

applecst · 10-23-2023, 01:31 PM

Quote:

Originally Posted by PNTDG42

Placebo or something else changed unrelated. There’s no explanation for it to make audible changes at idle

Maybe it didn’t come across clear lol. Let me clarify. Not that it changes when idle. it’s when I start up the car (jb4 active) the exhaust note comes on a few seconds after start up. Meaning there will be a few relatively quieter seconds after start up before it gets loud. Nothing i did there so could only assume the loud jb4 noise kicked in later. Kinda curious.

BG42 · 10-23-2023, 05:43 PM

Could be that its communicating with the jb4 and the delay is that, the communication time. Hard to say though video maybe so we can hear?

PNTDG42 · 10-24-2023, 04:06 PM

Quote:

Originally Posted by applecst

Maybe it didn’t come across clear lol. Let me clarify. Not that it changes when idle. it’s when I start up the car (jb4 active) the exhaust note comes on a few seconds after start up. Meaning there will be a few relatively quieter seconds after start up before it gets loud. Nothing i did there so could only assume the loud jb4 noise kicked in later. Kinda curious.

The JB4 isn’t involved there.

Rdurty2 · 10-24-2023, 05:26 PM

At idle the JB4 isn’t doing anything. It definitely would not be affect exhaust.

ryo- · 10-24-2023, 07:33 PM

maybe it takes a second for the exhaust flaps to open after you start the car?

10-22-2023, 02:26 PM	#1
applecst First Lieutenant 257 Rep 317 Posts Drives: G42 M240i Join Date: Jan 2022 Location: LA iTrader: (0)	JB4 Sound Question Been living with the jb4 for a while now. Performance was expected so no surprise there. What surprised me was the increase in exhaust volume. The car growls way more than before jb4, even when in idle. The unusual part is the volume gets louder a few seconds after start up. Especially in warm start. I would hear the normal not so loud warm start up exhaust first and the jb4 effect seems to kick in a few seconds later. I'm a little OCD and it's driving me crazy lolll. Any one has the same experience? __________________ I doubt, therefore I might be.
	Appreciate 0 Tweet Quote

10-23-2023, 11:51 AM	#2
mike@x-ph.com Joint Chiefs of Staff 27133 Rep 196,286 Posts Drives: 07-335/12-328/18-M4/21-M4CP Join Date: Sep 2013 Location: Las Vegas iTrader: (23)	Are we talking about the real sound of the exhaust or the active sound from the speakers? __________________ Check out our current sale by clicking on this link! https://x-ph.com/sale/ Phone number 702-494-9435
	Appreciate 0 Quote

10-23-2023, 01:00 PM	#4
PNTDG42 Lieutenant 506 Rep 447 Posts Drives: G42, F97 LCI, EBA R35, Z34 Join Date: Nov 2022 Location: Illinois iTrader: (0)	Placebo or something else changed unrelated. There’s no explanation for it to make audible changes at idle
	Appreciate 0 Quote

10-23-2023, 05:43 PM	#6
BG42 Captain 419 Rep 611 Posts Drives: M240ix Join Date: Dec 2022 Location: ATL iTrader: (0)	Could be that its communicating with the jb4 and the delay is that, the communication time. Hard to say though video maybe so we can hear?
	Appreciate 0 Quote

10-24-2023, 05:26 PM	#8
Rdurty2 Captain 856 Rep 795 Posts Drives: 2022 M240i Join Date: Feb 2019 Location: NY iTrader: (0)	At idle the JB4 isn’t doing anything. It definitely would not be affect exhaust.
	Appreciate 0 Quote

10-24-2023, 07:33 PM	#9
ryo- First Lieutenant 269 Rep 373 Posts Drives: '22 MWM M240i Join Date: Feb 2022 Location: Central California iTrader: (0)	maybe it takes a second for the exhaust flaps to open after you start the car?
	Appreciate 0 Quote