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Nice look you got going there Army!

Glad this post came back. I am beginning to like the Race Pros a bit less than I did before. Last weekend was really the first time I've had my car out for some real miles since installing the shorty headers and getting the timing set right. While the Race Pros sounded great on my tired low HP 400 and seemed OK with the 461 with the stock cast manifolds, I've developed a pretty nasty drone between say 1900 and 2300 rpm. It's fine everywhere else. They are definitely not quiet by any stretch on my set up and the car sounds great outside (lots of thumbs up). Tough thing here is I have the 18 inch body mufflers and there is not much available that are the same size. I was thinking of maybe going with Dynomax turbos and with a shorter body and adding extension pipes but not sure yet. I may also just drive it for a while and see if the drone is a deal breaker.
 

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Cameo Ivory 1967
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As I suspected before I went down this road... the new system is still far too quiet, so I do stand by my initial statement in this thread, which is that; despite what Pypes says, the mufflers do not control the noise. At least, not as much as the exhaust. They also talked me out of the 3", which now Im REALLY regretting.

Even with the violators on, every Mustang, Camaro, Chevelle, and Dodge that I see, embarrasses me with their muscle car tone... even though my engine is bigger and often more aggressive.

Yes, adding the side tips fixes it, but it doesnt sound great... just like open manifolds... and did I really need to send $1000 on an exhaust that I have to bypass?

So................
I like the kit. It fits well... but in retrospect, I would do header mufflers and then have a shop finish the tail pipes.
 

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Cameo Ivory 1967
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Here's my update, for anyone who still cares.

Even with the loudest mufflers that Pypes has, which are 3", straight through chambered, with no baffles, the car is super quiet at start up and idle, to the point of embarrassment.

Pypes wouldnt sell me the 3" kit that I wanted, because they only recommend that for engines over 500 HP, for fear of losing too much bottom end.

That being said, on a car making 450 lb feet of torque, with a manual trans and 13.1 first gear ratio... I couldve easily given up some small torque to get that sound!

Fortunately, I bought the 2.5" x-pipe kit with the side dump provisions... and I put it to good use.

Uncapped, the dumps are loud, but sound like crap... so I welded up two homemade, removable baffles and I put them into 2.5"x17" straight pipe, welded to collectors, and bolted them in.

Now the car FINALLY sounds like a GTO!!! It made a huge difference in sound, and interestingly enough, the car revvs up much faster and pulls much harder. So... I essentially have four mufflers... wouldve preferred the 3" kit, but just goes to show, my car wanted more flow than 2.5 duals was allowing. Pypes may be the experts, but in the end, science and logic still reign supreme.

I am now getting afterfire when shifting, so I have to see if I can tune that out.
 

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Discussion Starter · #104 ·
Here's my update, for anyone who still cares.

Even with the loudest mufflers that Pypes has, which are 3", straight through chambered, with no baffles, the car is super quiet at start up and idle, to the point of embarrassment.

Pypes wouldnt sell me the 3" kit that I wanted, because they only recommend that for engines over 500 HP, for fear of losing too much bottom end.

That being said, on a car making 450 lb feet of torque, with a manual trans and 13.1 first gear ratio... I couldve easily given up some small torque to get that sound!

Fortunately, I bought the 2.5" x-pipe kit with the side dump provisions... and I put it to good use.

Uncapped, the dumps are loud, but sound like crap... so I welded up two homemade, removable baffles and I put them into 2.5"x17" straight pipe, welded to collectors, and bolted them in.

Now the car FINALLY sounds like a GTO!!! It made a huge difference in sound, and interestingly enough, the car revvs up much faster and pulls much harder. So... I essentially have four mufflers... wouldve preferred the 3" kit, but just goes to show, my car wanted more flow than 2.5 duals was allowing. Pypes may be the experts, but in the end, science and logic still reign supreme.

I am now getting afterfire when shifting, so I have to see if I can tune that out.
Thanks. Good information
 

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Here's my update, for anyone who still cares.

Even with the loudest mufflers that Pypes has, which are 3", straight through chambered, with no baffles, the car is super quiet at start up and idle, to the point of embarrassment.

Pypes wouldnt sell me the 3" kit that I wanted, because they only recommend that for engines over 500 HP, for fear of losing too much bottom end.

That being said, on a car making 450 lb feet of torque, with a manual trans and 13.1 first gear ratio... I couldve easily given up some small torque to get that sound!

Fortunately, I bought the 2.5" x-pipe kit with the side dump provisions... and I put it to good use.

Uncapped, the dumps are loud, but sound like crap... so I welded up two homemade, removable baffles and I put them into 2.5"x17" straight pipe, welded to collectors, and bolted them in.

Now the car FINALLY sounds like a GTO!!! It made a huge difference in sound, and interestingly enough, the car revvs up much faster and pulls much harder. So... I essentially have four mufflers... wouldve preferred the 3" kit, but just goes to show, my car wanted more flow than 2.5 duals was allowing. Pypes may be the experts, but in the end, science and logic still reign supreme.

I am now getting afterfire when shifting, so I have to see if I can tune that out.
Do you have video or it didn't happen ;)
 

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Cameo Ivory 1967
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Yes it comes out of four mufflers... thaanks to Pypes, who simply shoulve sold me the 3" that I wanted... regardless... no need for cutouts. Cant see any reason that Id ever close them. The car is fairly quiet inside, which you can hear in the video.

It's not ridiculously loud, at all. Still much quieter than a Mustange GT or Chevelle
 

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