Flapper Question

[hihosilverado]

Can someone tell me how much tension should be on the flapper valve spring?  I can turn the flapper by hand with almost no resistance and its "resting" position with the engine off is not all the way closed.  Does this sound right?  

[pokismoki]

i bolted mine open on a k2 truck,  is this the t1 truck, I'm amaized they still use the flapper?

[Grumpy Bear]

6 hours ago, hihosilverado said:

Can someone tell me how much tension should be on the flapper valve spring?  I can turn the flapper by hand with almost no resistance and its "resting" position with the engine off is not all the way closed.  Does this sound right?  

 

You're good. 

 

5 hours ago, pokismoki said:

i bolted mine open on a k2 truck,  is this the t1 truck, I'm amaized they still use the flapper?

 

Because? 

 

I like quite and lots of it.  

 

 

Edited October 29, 2021 by Grumpy Bear

[pokismoki]

10 hours ago, Grumpy Bear said:

 

You're good. 

 

 

Because? 

 

I like quite and lots of it.  

 

 

 

 

it's not any louder, and it potentially can stick closed causing restriction.  though i'm sure it helps with other aspects like cat and o2 warm up, but i never noticed any issues with it being bolted open.

[Grumpy Bear]

5 hours ago, pokismoki said:

it's not any louder, and it potentially can stick closed causing restriction.  though i'm sure it helps with other aspects like cat and o2 warm up, but i never noticed any issues with it being bolted open.

 

Hum....

 

Potentially? 

 

So what do you do with parts that WILL wear out or fail with use?

"Will" seems much more threatening than "might".

Right? 

[pokismoki]

i think the potential to stick closed is higher if the truck sits for long periods of un-use,  if its a daily driver than it most likey continue functioning without any hang ups.  definatly add this to a lubrication point during service, shoot some silicone spray lube into the bearing surfaces

 

I only read of one report that the valve stuck closed and overheated the exhaust and caused a fire, but i dont have access to all the reports made to GM Legal department

[Grumpy Bear]

4 hours ago, pokismoki said:

i think the potential to stick closed is higher if the truck sits for long periods of un-use,  if its a daily driver than it most likey continue functioning without any hang ups.  definatly add this to a lubrication point during service, shoot some silicone spray lube into the bearing surfaces

 

I only read of one report that the valve stuck closed and overheated the exhaust and caused a fire, but i dont have access to all the reports made to GM Legal department

 

Solid logic me thinks. Lube is also good as you point out. I think we have all the nails in this coffin.  

 

[AJMBLAZER]

The flapper on my wife’s 2017 actually broke off and was stuck in the muffler causing intermittent issues. Luckily the muffler shop was able to shake it out after they took the muffler off. Welded the muffler back on and no issues since. No weird noises either and my wife would notice if there were any. 

Edited October 31, 2021 by AJMBLAZER

[JohnH4260]

After receiving my truck in March 2021, I cut the flapper spring and fixed the valve in the open position with 2 hose clamps. A few others have done the same and posed photos on the forum. I don’t know if it has done any good, but it won’t fail.

Edited December 28, 2021 by JohnH4260

[TNTSierra]

The flappers are junk!  They restrict the exhaust. Cut out the factory exhaust and install an aftermarket Catback system like Corsa, Borla, or Gibson. Zero drone, engine breathes like it should, and you pick up some freed up Horsepower and Torque. 
 

Have had the Gibson on my 2018 and now the Corsa on my 2019. Both are very good.  Borla teamed with GM and made the GM Performance package for the trucks. Many have it and like it. Do it right or not at all!