What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Robslost

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Sam Harris

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Yesterday, I capped off the cutout half of my exhaust since the valve fell apart. Now it's just running through the 40" of muffler and the 3" unmuffled part is acting like a Hemholtz chamber.


Beat a piece of cardboard on the tip to get a pattern:

View attachment 273370


Cut out the pattern, traced it on some 14 gauge sheet and cut it out:

View attachment 273372


Welded, primed and sprayed with high-temp paint:

View attachment 273371




It sounds LAME. But, it's really quiet inside. It's only slightly louder than when I had the 18" muffler and cats. Of course, at WOT and high RPM, it gets louder than it did back then. But at no point is it uncomfortably loud any more.
Nice work. I’ll bet it sounds hellova lot better than when that valve was falling apart!
 

Sparksalot

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89Suburban

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Yesterday, I capped off the cutout half of my exhaust since the valve fell apart. Now it's just running through the 40" of muffler and the 3" unmuffled part is acting like a Hemholtz chamber.


Beat a piece of cardboard on the tip to get a pattern:

View attachment 273370


Cut out the pattern, traced it on some 14 gauge sheet and cut it out:

View attachment 273372


Welded, primed and sprayed with high-temp paint:

View attachment 273371




It sounds LAME. But, it's really quiet inside. It's only slightly louder than when I had the 18" muffler and cats. Of course, at WOT and high RPM, it gets louder than it did back then. But at no point is it uncomfortably loud any more.


Very nice welding work there brother.
 

iamdub

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Nice work. I’ll bet it sounds hellova lot better than when that valve was falling apart!

Thank you.

It's really screwing with me, to be honest. It idles and lopes like it did before, but now that it's so quiet, it's like a stock vehicle with a misfire. The flapper fell out a month or so ago so it was always either 50/50 muffled and unmuffled (loud) or, with the cutout open, muffled side closed off and unmuffled side 100% open (loudER).

I'm just glad to be able to cruise and converse with the fam again. I'll probably have to design and make my own cutout to have what I want. I have many, much larger priorities at the moment.
 
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Routing wiring for my dashcam and radar detector a while back and found a foot pressure switch under the floor pad.
View attachment 273375
Did some searching and found out it was this...
https://www.tremcoemergencyproducts.com/anti-theft-system/
Shift lock pressure switch.
Our vehicles already have this ability, called "Immobilizer" and just needs a switch providing 12v to the tan/white wire from the BCM to the shift lock solenoid.
b65f3e8cfdd90e5f93f68fbf7e45185d.jpg

Sent from my SM-G930V using Tapatalk
 

Sam Harris

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Our vehicles already have this ability, called "Immobilizer" and just needs a switch providing 12v to the tan/white wire from the BCM to the shift lock solenoid.
b65f3e8cfdd90e5f93f68fbf7e45185d.jpg

Sent from my SM-G930V using Tapatalk
Yes, I suppose all you really need is a button to activate / deactivate it... [emoji3166]
 

Rocket Man

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Yesterday, I capped off the cutout half of my exhaust since the valve fell apart. Now it's just running through the 40" of muffler and the 3" unmuffled part is acting like a Hemholtz chamber.


Beat a piece of cardboard on the tip to get a pattern:

View attachment 273370


Cut out the pattern, traced it on some 14 gauge sheet and cut it out:

View attachment 273372


Welded, primed and sprayed with high-temp paint:

View attachment 273371




It sounds LAME. But, it's really quiet inside. It's only slightly louder than when I had the 18" muffler and cats. Of course, at WOT and high RPM, it gets louder than it did back then. But at no point is it uncomfortably loud any more.
No more cutout then? NVM, caught up in the thread.
 

Rocket Man

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Thank you.

It's really screwing with me, to be honest. It idles and lopes like it did before, but now that it's so quiet, it's like a stock vehicle with a misfire. The flapper fell out a month or so ago so it was always either 50/50 muffled and unmuffled (loud) or, with the cutout open, muffled side closed off and unmuffled side 100% open (loudER).

I'm just glad to be able to cruise and converse with the fam again. I'll probably have to design and make my own cutout to have what I want. I have many, much larger priorities at the moment.
Reminds me of my Silverado with it’s too quiet exhaust and the cam makes it lope hard. It just doesn’t seem right. Damn truck rocks a bit from the lope but it sounds weird.
 
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