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I finally got around to putting in a delete pipe. It's a 4" exhaust and already had the muffler deleted. Doing this for EGTs which seems to have made an appreciable impact.

During normal driving, it sounds fine. Even part acceleration is sounds great (that point where boost kicks in hard without going full throttle). However, as soon as I go beyond this (say 3/4 throttle) the sound is garbage. It sounds like a wannabe ricer. Full, ratty, tinny sound. Like an amplified 4 banger without a muffler. I've rechecked all my connections and hangers. Everything is solid. I used those wide band clamps instead of the crimping style clamps.

I've read plenty of people saying they love the sound with full delete (and it is great up until that point). I found one post where a guy said he had the same problem and someone responded and said to take the old cat, knock it out and put that back on. His claim is that acts as a resonator and mellows that stupid ratty sound back out.

Anyone else have experience with this? I had hoped to keep my cat incase I needed to throw it back on for any reason but am willing to knock it out and do that if it's the real solution. Is this really the fix? I also wondered about these wide band clamps - maybe I need to go to the crimping style?

I'll add, I have a friend with a 6.7 straight piped. It sounds friggin amazing. That super nice low big block gurgle sound. I know it's a different beast but no ratty sound from that at full throttle.
 

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All 6.0s sound like a teen age kid with a Carolina squatted 1500 chevy with an instagram tag on the window below the locally hated sticker when you pin it.

 

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Discussion Starter #3
Haha. Nice.
Yeah, that's the sound I'm talking about when he hits the high roms at full throttle. Ok, didn't have that until I dropped the cat.

Is there any truth to a gutted cat will mellow that ratty sound?
 

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Haha. Nice.
Yeah, that's the sound I'm talking about when he hits the high roms at full throttle. Ok, didn't have that until I dropped the cat.

Is there any truth to a gutted cat will mellow that ratty sound?
Yup. I cut the taper to work for 4鈥 pipe. My cat puked it鈥檚 guts out, just about the size of the 4鈥 pipe I shoved thru to gut it. And even though I already had a muffler, it made it quieter for sure.


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I love the way my 6.0 sounds...until it starts that raspy bull****. I try to never go over 3/4 throttle and it sounds amazing. Nice rumble / growl to it.

Full-throttle? I slump down into my seat and try not to be seen. BRRRRRAAAAAAPPPPPP!!!!!!! I have friends that love it though. Go figure.

Full 5" MBRP. I haven't gotten annoyed enough to actually do anything about it, yet, since I keep it under 3/4 throttle 98% of the time.

I bought everything when I migrated from the 6.4 world (5" Flo-Pro on that) and didn't realize it until all was welded and done.
 
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Discussion Starter #6
Alright. Well at least I'm not alone. Thought maybe it was just something with my setup. Agreed though - up to that 3/4 mark, I love that sound.
 

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When I threw it all together and did the first rev in the yard I was in Heaven. My first WOT pull...not so much.

This is from a few years ago: 2006 - 6.0 - 5" MBRP
 

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Discussion Starter #8
Im sure it's in my head but it also feels like I lost power. I think it's just cause I'm more reluctant to get into the throttle now. Probably good for my mpgs though.

I'm really tempted to try gutting my cat instead of using the delete pipe to see if it mellows any.
 

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I have a 4" turbo back (actual 4" down pipe). Mine sounds good all the way through the throttle, better at full throttle. Maybe the 5" is resonating and causing the problem.
As far as power.... Yes, mine felt down on power, so I put a tune on it

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All 6.0s sound like a teen age kid with a Carolina squatted 1500 chevy with an instagram tag on the window below the locally hated sticker when you pin it.

馃ぃ馃ぃ馃ぃ I'm dying!!! Grest analogy!
 

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Discussion Starter #11
I have a 4" turbo back (actual 4" down pipe). Mine sounds good all the way through the throttle, better at full throttle. Maybe the 5" is resonating and causing the problem.
As far as power.... Yes, mine felt down on power, so I put a tune on it

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I'm 4 inch down but exit duals. It splits right before the axle. I'm also on a Looney PCT and an Atlas 40. I was wondering if I should try a different tune that likes the catless better.

Do you have Delete pipe clamped in, a true welded straight, or a gutted cat?
 

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I'm 4 inch down but exit duals. It splits right before the axle. I'm also on a Looney PCT and an Atlas 40. I was wondering if I should try a different tune that likes the catless better.

Do you have Delete pipe clamped in, a true welded straight, or a gutted cat?
Im running a diamond eye straight pipe setup, no "nothing" on it.

Since your running duals, you should probably have a muffler.... Or, if you are running a muffler, try removing it. I'd think a baffled muffler would be necessary to keep the throatiness when you have that much flow space.

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Discussion Starter #13
The whole reason I did this was for cooler egt and it made a huge difference there. I'm hesitant to put something back in that would restrict flow again.

Never thought I'd be opening it up too much to where I have power loss. I hear stories of people dumping right where the cat used to be. Or see the dual stacks. Surely my dual exit doesn't flow that much. But I guess I missed or overlooked the part where they had power loss.
 

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The whole reason I did this was for cooler egt and it made a huge difference there. I'm hesitant to put something back in that would restrict flow again.

Never thought I'd be opening it up too much to where I have power loss. I hear stories of people dumping right where the cat used to be. Or see the dual stacks. Surely my dual exit doesn't flow that much. But I guess I missed or overlooked the part where they had power loss.
Those guys are running tunes.
I don't think a muffler is going to create very much back pressure on a big exhaust like that. IMO, going to a 5" was a mistake, as the 4" is plenty big to keep the egts down.

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I have a 4" turbo back and deleted the cat. I added a straight through Magnaflow 4" muffler (more of a resonator in reality) and it sounds great. Deep tone, beefy midrange and no rasp at high RPM.
 

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Discussion Starter #16
Those guys are running tunes.
I don't think a muffler is going to create very much back pressure on a big exhaust like that. IMO, going to a 5" was a mistake, as the 4" is plenty big to keep the egts down.

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I have a 4" with dual exit (goes to dual at axle after what would have been the muffler). It was already muffler deleted. I just deleted the cat. I'm also tuned. Running altas 40 and a Looney Tune right now. Removing the cat made a pretty big difference on egt. I have a steep hill I run on the way into town. Before I had to be careful to keep it out of the danger zone but it pulled like a beast. Now, I'd have to be really trying to get into it. Course, loss of power is probably having an impact to that too. It doesn't give you that, put you in the back of your seat, feel anymore.


I have a 4" turbo back and deleted the cat. I added a straight through Magnaflow 4" muffler (more of a resonator in reality) and it sounds great. Deep tone, beefy midrange and no rasp at high RPM.
I might try this or the baffle muffler 6rider is suggesting. I think I need to add a bit of backpressure back and bonus if it gets rid of the braaap sound. When you did this with the straight through muffler, did you notice a power drop from before/after?
 

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I might try this or the baffle muffler 6rider is suggesting. I think I need to add a bit of backpressure back and bonus if it gets rid of the braaap sound. When you did this with the straight through muffler, did you notice a power drop from before/after?
I deleted the cat after putting the muffler on because I wanted to avoid the rasp in the first place so I can't say. My EGTs definitely dropped though which is all I was really after in the first place.
 

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I have the stock exhaust system but I deleted the muffler and I have a hollow kitty. Sounds awesome. Still has the bbrrraapp at full throttle. Can be a bit annoying. But it doesn鈥檛 have any annoying drone on the highway.
 
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Discussion Starter #19
Yeah, I don't really get a drone. At least not enough to care. Just the rasp when I get on it.

Side note, I put the atlas80 on and my power is back. I love how much my egts dropped. So, I'll just deal with the rasp.
 

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Discussion Starter #20
Hey, do the tips effect the rasp/sound at all? I've got 5" (I think) welded on tips. Are these things just for looks or actually do anything to tune the sound?
 
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