exhaust sound change

Bucks SS · 05-19-2018, 12:56 PM

I have 2SS with A8,NPP and love to drive using paddles for shifting. I also run exhaust in track mode so you get that throaty sound when shifting and running with revs up a bit. Today I was driving in 3rd gear and lost that nice exhaust sound almost like I had switched to stealth mode, I checked flappers in exhaust and they were wide open but now I don't have any sound coming from car. Anybody have any ideas what the problem could be?

Gen6_1Le · 05-19-2018, 01:39 PM

Quote:

Originally Posted by Bucks SS

I have 2SS with A8,NPP and love to drive using paddles for shifting. I also run exhaust in track mode so you get that throaty sound when shifting and running with revs up a bit. Today I was driving in 3rd gear and lost that nice exhaust sound almost like I had switched to stealth mode, I checked flappers in exhaust and they were wide open but now I don't have any sound coming from car. Anybody have any ideas what the problem could be?

May have something to do with the AFM valves kicking in .

Drags1998 · 05-19-2018, 06:49 PM

Its NOT a problem, That's the way it works. Next time it gets Quiet, Step on it, It WILL get LOUD again!!!!

misterjaayy · 05-20-2018, 02:17 AM

The valves automatically close at cruising speeds to prevent drone. Some people pull the fuse for the NPP valves so they stay open all the time. Can’t remember which fuse it is but you can search and find out.

mdhopt36 · 05-20-2018, 06:32 AM

I pulled what I thought was the fuse, and no difference. The diagram on the fuse cover was -NOT- consistent with the actual arrangement of the fuses either.
I guessed where the fuse was by what was ajacent preceding the actual amp fuse- 3-10 amp, 1-15 amp, followed by another 10 amp just before the 15 amp one you're supposed to pull.
I just shoved it back in- far as I know, nothing was deactivated.
I leave it in track mode right now.
What's wrong with drone?

Gen6_1Le · 05-20-2018, 10:01 AM

Quote:

Originally Posted by mdhopt36

I pulled what I thought was the fuse, and no difference. The diagram on the fuse cover was -NOT- consistent with the actual arrangement of the fuses either.
I guessed where the fuse was by what was ajacent preceding the actual amp fuse- 3-10 amp, 1-15 amp, followed by another 10 amp just before the 15 amp one you're supposed to pull.
I just shoved it back in- far as I know, nothing was deactivated.
I leave it in track mode right now.
What's wrong with drone?

I believe the AFM has another set of valves that is not effected buy the fuse pull , has to do with the need for back pressure .

craigss50 · 05-20-2018, 10:05 AM

Quote:

Originally Posted by mdhopt36

What's wrong with drone?

It gives you a headache after a few minutes.

Sev · 05-20-2018, 03:04 PM

Quote:

Originally Posted by misterjaayy

The valves automatically close at cruising speeds to prevent drone. Some people pull the fuse for the NPP valves so they stay open all the time. Can’t remember which fuse it is but you can search and find out.

Fuse 51

glenB · 05-20-2018, 06:36 PM

Quote:

Originally Posted by Gen6_1Le

I believe the AFM has another set of valves that is not effected buy the fuse pull , has to do with the need for back pressure .

Totally wrong

1. The engine doesn't need back pressure
2. Back pressure kills power
3. The AFM vales are to reduce the vibrations and the odd sound caused by the 4 cyl. operation only

mdhopt36 · 05-21-2018, 06:55 AM

"It gives you a headache after a few minutes."
****
?????
Ever been in a Cherokee, or Cessna? No problem---as long as you don't have much to say without the muffs!
Doesn't bother me one bit.

mdhopt36 · 05-21-2018, 07:02 AM

"Fuse 51"
In the fuse box, the cover on mine has the fuses numbered, but the fuse box itself, -NO- fuse is actually numbered, and the fuse schematic looks to me to be deliberately scrambled. I worked with an electrical engineer, and that would never have passed on his blueprints.
I'm wondering if it was a deliberate attempt to prevent the casual yanking of the fuse?
My car is only 2 months old.

Gen6_1Le · 05-21-2018, 08:12 AM

Quote:

Originally Posted by glenB

Totally wrong

1. The engine doesn't need back pressure
2. Back pressure kills power
3. The AFM vales are to reduce the vibrations and the odd sound caused by the 4 cyl. operation only

Don’t matter what back pressure does or don’t do ,it’s in the tune from the factory mess with it and it has its effect. Put long tube headers with straight 3 inch pipes on it without a tune and see if it was worth it .

mdhopt36 · 05-24-2018, 08:00 AM

Quote:

Originally Posted by mdhopt36

"Fuse 51"
In the fuse box, the cover on mine has the fuses numbered, but the fuse box itself, -NO- fuse is actually numbered, and the fuse schematic looks to me to be deliberately scrambled. I worked with an electrical engineer, and that would never have passed on his blueprints.
I'm wondering if it was a deliberate attempt to prevent the casual yanking of the fuse?
My car is only 2 months old.

**********
Well, went to the local dealer, and the salesman helped me locate the right fuse. Print on the cover was throwing me off.
Now, she purrs all the time!

mdhopt36 · 05-24-2018, 08:01 AM

(What I actually pulled before, was the HORN fuse!)

05-19-2018, 12:56 PM	#1
Bucks SS Drives: 2016 2SS Join Date: May 2016 Location: Millbrook Ontario Posts: 2	exhaust sound change I have 2SS with A8,NPP and love to drive using paddles for shifting. I also run exhaust in track mode so you get that throaty sound when shifting and running with revs up a bit. Today I was driving in 3rd gear and lost that nice exhaust sound almost like I had switched to stealth mode, I checked flappers in exhaust and they were wide open but now I don't have any sound coming from car. Anybody have any ideas what the problem could be?

05-19-2018, 06:49 PM	#3
Drags1998 Drives: 15 SilveradoLTZ,162SSVert BlazerRS Join Date: Dec 2015 Location: Minot,Maine Posts: 644	Its NOT a problem, That's the way it works. Next time it gets Quiet, Step on it, It WILL get LOUD again!!!!

05-20-2018, 02:17 AM	#4
misterjaayy Drives: 2019 CTS-V Join Date: Feb 2016 Location: San Diego Posts: 421	The valves automatically close at cruising speeds to prevent drone. Some people pull the fuse for the NPP valves so they stay open all the time. Can’t remember which fuse it is but you can search and find out.

05-20-2018, 06:32 AM	#5
mdhopt36 Drives: '17- 1ag37 V6 traded, for 1SS 2018! Join Date: Mar 2018 Location: MA Posts: 469	I pulled what I thought was the fuse, and no difference. The diagram on the fuse cover was -NOT- consistent with the actual arrangement of the fuses either. I guessed where the fuse was by what was ajacent preceding the actual amp fuse- 3-10 amp, 1-15 amp, followed by another 10 amp just before the 15 amp one you're supposed to pull. I just shoved it back in- far as I know, nothing was deactivated. I leave it in track mode right now. What's wrong with drone?

05-21-2018, 06:55 AM	#10
mdhopt36 Drives: '17- 1ag37 V6 traded, for 1SS 2018! Join Date: Mar 2018 Location: MA Posts: 469	"It gives you a headache after a few minutes." **** ????? Ever been in a Cherokee, or Cessna? No problem---as long as you don't have much to say without the muffs! Doesn't bother me one bit.

05-21-2018, 07:02 AM	#11
mdhopt36 Drives: '17- 1ag37 V6 traded, for 1SS 2018! Join Date: Mar 2018 Location: MA Posts: 469	"Fuse 51" In the fuse box, the cover on mine has the fuses numbered, but the fuse box itself, -NO- fuse is actually numbered, and the fuse schematic looks to me to be deliberately scrambled. I worked with an electrical engineer, and that would never have passed on his blueprints. I'm wondering if it was a deliberate attempt to prevent the casual yanking of the fuse? My car is only 2 months old.

05-24-2018, 08:01 AM	#14
mdhopt36 Drives: '17- 1ag37 V6 traded, for 1SS 2018! Join Date: Mar 2018 Location: MA Posts: 469	(What I actually pulled before, was the HORN fuse!)

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