New 2019 RST put up on the lift, several exhaust oddities...

[Blanz]

Finally had a chance to put my new 2019 Silverado RST, 5.3l DFM up on my lift to take a look at the new chassis and drivetrain and came across two items I felt would be worthy to share.

The first item is what I'll call typical GM compromise in design with the left side exhaust downpipe. As this pipe makes its transition across the transmission, they had to collapse the pipe for clearance issues (see pic). 

Nothing like a little extra back-pressure for the left bank. I wonder if the engineer that came up with that design did any calculation to ensure there was no decrease of internal area. I can see this will be a popular mod to eliminate this constriction point.

Second area of interest is what appears to be some sort of acoustic stainless steel mesh scabbed onto the tailpipe in two areas. I going to guess that this is some sort of attempt at tuning those ugly power pulses when the DFM kicks in and go's from 8 to 6 to 4 and 2 (see pics).

  

Not to limit the "WTF were they thinking" discussions simply to the exhaust area, how about those "Task Lights" in the outside mirrors that would have been better served as down-facing "puddle" lights instead of something I'll never use and will most likely leave on by accident.

Add to that the push-to-start button being placed low enough in the dash to be convenient only to people shorter than a midget.

But with that said, I do love the truck and the ability to turn off the auto stop-start.

Bill.     

 

UPDATE:

Learned something new every miunute. Here is the info on the resonance free pipe technology.

https://altairenlighten.com/wp-content/uploads/2018/07/Enlighten_award_slide_module_Faurecia.pdf

 

 

Edited February 12, 2019 by Blanz

[KozzyJr]

Gm has been using the crushed y pipe for over 20 years. Doubt they will change any time soon.

[Black02Silverado]

The screens on the exhaust I have seen before.  What gets me is why didn't they use them on all the Silverado's?  Mine has regular resonators.  As the link you posted stated, it is a weight savings which is always a good thing.  The only thing I can think of is they didn't work well on a 6.2 exhaust system.

 

As for the crushed pipe.  If you go over to the C5 Camaro forum, you will find that the pipe doesn't effect HP. Many have done dyno runs with theirs on and with regular pipe and it didn't change. 

[Rakkasan_Justin]

The crushed pipe does nothing in terms of added back pressure, as it doesn't restrict the movement of the air. In fact, Engine Masters did an entire episode special on power numbers for guys that are scared to bash headers for clearance issues, showing that even on severely mangled/dented headers, you might lose 1 HP/TQ.

 

Video here (actually quite an interesting test): 

 

[Grumpy Bear]

https://altairenlighten.com/wp-content/uploads/2018/07/Enlighten_award_slide_module_Faurecia.pdf

 

I note that placement in the system is critical. Interesting. 

[VdellaV]

On 12/2/2019 at 11:38 PM, KozzyJr said:

Gm has been using the crushed y pipe for over 20 years. Doubt they will change any time soon.

When putting my Longtubes, i chaged the pancake pipes place to behind the transmission (under the yoke)

 

I saw a great reduction on transmission temps and now it takes a much longer time for the transmission fluid to warm up. The stock pipe literally cooks the transmission pan.

[KozzyJr]

1 minute ago, VdellaV said:

When putting my Longtubes, i chaged the pancake pipes place to behind the transmission (under the yoke)

 

I saw a great reduction on transmission temps and now it takes a much longer time for the transmission fluid to warm up. The stock pipe literally cooks the transmission pan.

True. But think of the boys that live up north. That same effect will help heat the trans fluid when in -30.

[Sierra Dan]

On ‎2‎/‎12‎/‎2019 at 3:05 PM, Blanz said:

Second area of interest is what appears to be some sort of acoustic stainless steel mesh scabbed onto the tailpipe in two areas. I going to guess that this is some sort of attempt at tuning those ugly power pulses when the DFM kicks in and go's from 8 to 6 to 4 and 2 (see pics).

The Mesh basically replaces the old Can style Resonators that date back to GMT900 platform.

They are integrated now rather than an actual separate piece of the exhaust system.

Makes it much harder for a weekend warrior to eliminate it with a Sawzall. 

[KARNUT]

WOW, an exhaust leak. I’d rather have a glass pack.


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[Blanz]

6 hours ago, KARNUT said:

WOW, an exhaust leak. I’d rather have a glass pack.


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Ah, the good old days when a custom exhaust was only a hack saw and a cherry bomb muffler away. 

And don’t forget a set of Highjackers to get more room for those L60-15 rubbers. 

[KARNUT]

 
Ah, the good old days when a custom exhaust was only a hack saw and a cherry bomb muffler away. 
And don’t forget a set of Highjackers to get more room for those L60-15 rubbers. 

N-50s Mickey Thomson’s. 74 barracuda the pipes came together right under the floor board. Hack saw two glass packs. And of course high jackers air shocks. High rise, 780 Holley, memories.


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[ShamrockShooter]

Meanwhile somewhere in Michigan, a disgruntled wife or husband of a GM exhaust engineer is looking frantically through the kitchen drawers trying to find the missing cheese grater...

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[ShamrockShooter]

Is the 5.3 stock dual exhaust on the 19 louder than the stock 5.3 exhaust on the k2s with the resonator?

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