Exhaust Options

[D&Sadventure]

Shit, I don't have them anymore...if you're looking at them from this direction, I believe it's clockwise.
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OK, I looked under the truck again this morning and I do believe Mikey is correct. It would be clockwise. The butterfly valve shaft is offcenter to allow exhaust pressure to blow it open. They are mounted so that the shaft is horizontal with the ground and the larger potion of the plate is hanging down. This would allow gravity along with spring pressure to close off the pipe. Looks like the end of the spring should be straight down when at rest fully closed. Turn it 90° and it should be full open. It will turn past 90° so don’t go full lock. Going to try these 20 mm wide band clamps I found on Amazon . Ithink one should work. Looks like it’s about an 1.375” around so I ordered two sizes to see what fits best.

https://www.amazon.com/Stainless-Steel_304-Intercooler-Radiator-Adjustable/dp/B0DF7PKYFZ?tag=ramrho-20

 

[eltaco]

Didn’t Mikey say he got a quote for $100 to just remove the stock valves? That seems like a good way to go!

 

[eltaco]

This picture made me think it must be CCW for full open.

 

[D&Sadventure]

This picture made me think it must be CCW for full open.

No the valves are before the muffler. Those butterflies will be hanging straight down. The exhaust will blow them open. Clockwise when viewed from the spring end.

 

[D&Sadventure]

Didn’t Mikey say he got a quote for $100 to just remove the stock valves? That seems like a good way to go!

Agreed but I want to do a test to see what it sounds like with just a valve delete. I may decide to go full Mikey on it, and I want to only cut once.

 

[Mikey Swift]

Agreed but I want to do a test to see what it sounds like with just a valve delete. I may decide to go full Mikey on it, and I want to only cut once.

You never go Full Mikey!

 

[Silver RHO]

Keeping the valves all depends on how much room we have with the new muff. I'm contemplating keeping them if it fits. I think they'd help with highway drone. I suppose we will see. Also I ordered that muff from AmericanTrucks, they had a guaranteed delivery date of today, now it's saying tomorrow. They blamed it on FedEx, shitt customer service, don't bother doing business. Seems install will have to wait til tomorrow.

Would you have been able to keep the valves or did you need to take them out upon installation? I have a feeling keeping them would help with cold start not being so loud and like you said highway drone. What do you think?

 

[D&Sadventure]

Would you have been able to keep the valves or did you need to take them out upon installation? I have a feeling keeping them would help with cold start not being so loud and like you said highway drone. What do you think?

That’s exactly what they’re there for is to keep cold start quieter. The problem is you exchange a louder exhaust for the clattering of the valve. The clattering of the valve isn’t that loud, but it irritates the crap out of some of us. That’s why I’m going to test mine by clamping them open first just to see how much louder it really is on start up.

 

[Silver RHO]

That’s exactly what they’re there for is to keep cold start quieter. The problem is you exchange a louder exhaust for the clattering of the valve. The clattering of the valve isn’t that loud, but it irritates the crap out of some of us. That’s why I’m going to test mine by clamping them open first just to see how much louder it really is on start up.

I haven’t noticed clattering of the valves on mine. Maybe if I started it and got underneath it. I will check at lunch. I like the sound of the flow master but it does seem quite a bit louder and might keep the valves on first installation to see what it’s like before cutting them out.

 

[D&Sadventure]

I haven’t noticed clattering of the valves on mine. Maybe if I started it and got underneath it. I will check at lunch. I like the sound of the flow master but it does seem quite a bit louder and might keep the valves on first installation to see what it’s like before cutting them out.

Park it next to a curb or wall and start it up. You will hear the clatter valve

 

[NeuteredTRX]

I swear my stock exhaust has gotten louder over time… am I just going crazy or is that real? Either way, I like it…. Well, except that cold start but every aftermarket exhaust I’ve heard so far sounds even worse on cold start (according to me).

Same! I was almost embarrassed at how quiet it was but I have bout 7k miles on it and in sport mode it’s gotten louder and has a sick grunt / pop from the exhaust when I let her rip. Not bad for a neutered TRX

 

[Silver RHO]

Park it next to a curb or wall and start it up. You will hear the clatter valve

I started it up and climbed under the truck. I realized what you are talking about when I manually opened the valves by hand and a rattling disappeared. Mine must not be as rattly as y’all’s haha but I can hear it if I focus on it next to the truck. I’ll probably just remove them. I didn’t notice much of a difference in sound when I opened them.

 

[D&Sadventure]

I started it up and climbed under the truck. I realized what you are talking about when I manually opened the valves by hand and a rattling disappeared. Mine must not be as rattly as y’all’s haha but I can hear it if I focus on it next to the truck. I’ll probably just remove them. I didn’t notice much of a difference in sound when I opened them.

You’re probably not gonna hear much of a difference in sound when you’re holding them open unless your arms are long enough to hold them open while standing behind the truck.

 

[Silver RHO]

Alright boys, here it is. First thought, amazing...very deep, videos do no justice! Zero rasp, nice n deep through rev range, 50% louder at WOT, and mild drone 2000-2500 RPM. With all windows up maybe 20% louder at WOT. Very pleased for $330 installed. This is the Flowmaster FlowFX, XPipe muff #72469.
VIDS

20250717_145611_1_1.mp4

drive.google.com

20250717_150210_1.mp4

drive.google.com

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Just ordered mine from Summit. Will be installing this Saturday. Will see if I have the same thoughts as you. Thanks for sharing this!

 

[Mikey Swift]

Would you have been able to keep the valves or did you need to take them out upon installation? I have a feeling keeping them would help with cold start not being so loud and like you said highway drone. What do you think?

Cold start loud AF. As for the valves, length of muff was exactly the length of stock plus valves when cut at the stock weld points, there simply was no room to keep valves, I tried. Did a 5 hour trip yesterday, couple things. 65-75 - 8th gear 1500-1900rpm no drone. Once you hit 2k rpm, mild drone, maybe 1-2 out of 10...on freeway that was like 76-78mph. Once you creep into 2100-2600 drone is like 5 out of 10. If it downshifts and increases load, like uphill, it gets pretty loud but mellows once the RPM drops. Overall I stayed in the no drone zone for 90% of the trip...quite pleased actually, thought it'd be worse. I attribute this to the torque this engine makes, allows it to sit in 8th gear and not downshift alot.

 

[Silver RHO]

Cold start loud AF. As for the valves, length of muff was exactly the length of stock plus valves when cut at the stock weld points, there simply was no room to keep valves, I tried. Did a 5 hour trip yesterday, couple things. 65-75 - 8th gear 1500-1900rpm no drone. Once you hit 2k rpm, mild drone, maybe 1-2 out of 10...on freeway that was like 76-78mph. Once you creep into 2100-2600 drone is like 5 out of 10. If it downshifts and increases load, like uphill, it gets pretty loud but mellows once the RPM drops. Overall I stayed in the no drone zone for 90% of the trip...quite pleased actually, thought it'd be worse. I attribute this to the torque this engine makes, allows it to sit in 8th gear and not downshift alot.

Well shit. When you said WOT was 50% louder I assumed it wouldn’t be too loud on cold start. I ordered it last night haha. But I live in apartment complex and don’t want to piss all my neighbors off in the morning. Maybe I can cut further back from stock weld points to keep the valves idk. The drone and rpm ranges sounds fine to me thanks for sharing. Will see about the cold start and if I can keep it.

 

[Silver RHO]

I’m sitting here thinking there’s no way it could be as loud as the AFE or MRT extreme since it has a long muffler. Although maybe the straight through design just doesn’t muffle much idk.

 

[Mikey Swift]

Well shit. When you said WOT was 50% louder I assumed it wouldn’t be too loud on cold start. I ordered it last night haha. But I live in apartment complex and don’t want to piss all my neighbors off in the morning. Maybe I can cut further back from stock weld points to keep the valves idk. The drone and rpm ranges sounds fine to me thanks for sharing. Will see about the cold start and if I can keep it.

One caveat, I start in a garage...I'm sure it makes it seem louder. Also, just cut the valves off the stock muff and keep them...worst case, you can have them weld em in farther forward.

 

[Silver RHO]

One caveat, I start in a garage...I'm sure it makes it seem louder. Also, just cut the valves off the stock muff and keep them...worst case, you can have them weld em in farther forward.

That makes sense. Garage start definitely going to be louder. Excited for Saturday to see how it turns out.

 

[Mikey Swift]

That makes sense. Garage start definitely going to be louder. Excited for Saturday to see how it turns out.

I think you will be pleased!