CPE full system and noise.

Gandalf said:
105 seriously? Those are ridiculously high Db levels...

Yup, and I'm too old for that noise, I really hope the 12" Oval Muffler will help. Drone is there as well, truthfully, it gets to the point of giving me a headache.

Full plan is, 12" Oval addition on the right side. If that Doesn't help enough, maybe another 12" Oval on the left side with custom "Y" pipe to make the system a dual exhaust. Then lastly, I plan to add Dynamat or Dynashield.

I will have the first 12" Oval on Monday or Tuesday and have it installed immediately. I'll keep you posted.

Jim
 
I feel the need to clarify myself here. I don't want this post to, in any way, bash CPE. The truth is, the exhaust sounds amazing and is built with the highest quality. But, with my work, I drive people around for lunch/dinner meetings and they are an older crowd. To respect them I am trying to decrease the sound a bit.

Some might ask, why would I even buy the CAI, DP and Exhaust then. As I said above, I drive a lot and I want something fun and fast to drive. Secondly, I'm a performance freak, I've owned Mustang Cobra's and Ford Lightning's... none were close to stock when they left my garage. I and, I'm sure my customers, could deal with a little sound. I just can't help myself.

My goal, in all this, is to keep most of the performance, while getting Exhaust Idle down to around 85 dps and interior to 86-88 dps in normal driving. And maybe show others how to keep performance while keeping the sound down to comfortable. Thanks for listening.

Jim
 
I am, once again, in the same boat as mustangman. As I went to the weld/body shop this morning to do some more precise measurements for my muffler addition/rearrrangment, the fellas at the body shop even commented on the craftmanship of the CP-E system. And they were shaking their head with the thoughts of me adding an additional muffler. (As they thought it sounded great). I am a student doctor and am trying to maintain some degree professionalism while driving around town to meet patients and such. Five years ago I would have given my right arm for a system that sounded this good.

D
 
So here is a little representation of a good way to waste time in Huntington, WV. This is gonna be a good little experiment to see if I can quiet down my exhaust. So I've found a company in Florida that makes a 24" long, 4" round muffler. It is 28" in length and is what they fabricated for a dodge viper side exhaust system. I've made some meaurements and it looks like it will be a good fit in the middle section of my current setup. I currently have two matching 14" mufflers (one in the middle and one at the end) of which I still want to utilize. So, I have decided to go back to a dual system and throw those mufflers on the end section of each side. It's gonna take a little bending, tweaking, welding and probably a helluva lot of patience.

Also, please note that these a photos were copied and pasted from the CP-E website, and it is not a current photo of my car. It is only for representative purposes.

243711660.jpg


243711680.jpg


243711668.jpg
 
So here's todays results of my db readings.

outside drivers window at 2,000rpm: 89db
outside drivers window at 3,000rpm: 98db
outside drivers window at 4,000rpm: 95db
exhaust at idle: 107db (6" away from pipe)
cabin at idle: 74db, but decreased to 67db after car warmed up
cabin at 40mph: 90db (6th gear)
cabin at 70mph: 88db (6th gear)
cabin at 4,000rpm: 90db (1st gear)
cabin at 4,000rpm: 93db (2nd gear)
cabin at 4,000rpm: 88db (3rd gear)
cabin at 4,000rpm: 95db (4th gear)
cabin at 4,000rpm: 94db (5th gear)
cabin under hard accel: consistently above 100db, peak at 108db

Also, something I noticed, the drone seems a more significant under deceleration that acceleration. For example, when I let off of the acclerator, my readings were about 5db more than under steady accleration, while staying in the same gear.

I have two of the 14" muffler/resonators currently, so this should give mustangman an idea of what to expect after the addition of another 14" muffler. Hope this helps.

D
 
MUSOM said:
So here's todays results of my db readings.

outside drivers window at 2,000rpm: 89db
outside drivers window at 3,000rpm: 98db
outside drivers window at 4,000rpm: 95db
exhaust at idle: 107db (6" away from pipe)
cabin at idle: 74db, but decreased to 67db after car warmed up
cabin at 40mph: 90db (6th gear)
cabin at 70mph: 88db (6th gear)
cabin at 4,000rpm: 90db (1st gear)
cabin at 4,000rpm: 93db (2nd gear)
cabin at 4,000rpm: 88db (3rd gear)
cabin at 4,000rpm: 95db (4th gear)
cabin at 4,000rpm: 94db (5th gear)
cabin under hard accel: consistently above 100db, peak at 108db

Also, something I noticed, the drone seems a more significant under deceleration that acceleration. For example, when I let off of the acclerator, my readings were about 5db more than under steady accleration, while staying in the same gear.

I have two of the 14" muffler/resonators currently, so this should give mustangman an idea of what to expect after the addition of another 14" muffler. Hope this helps.

D


Hope I'm not telling you guys what you already know, but I find a lot of people don't understand how the dB scale works....

So just in case you didn't know, every 3dB increase means a doubling of the sound level.
 
MUSOM said:
So here's todays results of my db readings.

outside drivers window at 2,000rpm: 89db
outside drivers window at 3,000rpm: 98db
outside drivers window at 4,000rpm: 95db
exhaust at idle: 107db (6" away from pipe)
cabin at idle: 74db, but decreased to 67db after car warmed up
cabin at 40mph: 90db (6th gear)
cabin at 70mph: 88db (6th gear)
cabin at 4,000rpm: 90db (1st gear)
cabin at 4,000rpm: 93db (2nd gear)
cabin at 4,000rpm: 88db (3rd gear)
cabin at 4,000rpm: 95db (4th gear)
cabin at 4,000rpm: 94db (5th gear)
cabin under hard accel: consistently above 100db, peak at 108db

Also, something I noticed, the drone seems a more significant under deceleration that acceleration. For example, when I let off of the acclerator, my readings were about 5db more than under steady accleration, while staying in the same gear.

I have two of the 14" muffler/resonators currently, so this should give mustangman an idea of what to expect after the addition of another 14" muffler. Hope this helps.

D

Thanks Musom, the more I look at this, the more I'm thinking the Dynashield/mat is going to be the way to go. Hopefully the 12" oval muffler will help a bit more than the two 14" resonator's you have. I still plan to have this done by Tuesday. LOL Whoever gets this car when I sell it in a few years is going to get one nice ride.

Jim
 
I hear ya. I sure hope that I won't have to install the dynoshield/mat. I'm banking that this 24" muffler will do some serious good, and hoping my expectations aren't too high. When I added my second 14" muffler, to be honest, it made only a slight difference. I could tell the difference myself, but noone else seemed to notice, including the guys who let me borrow their weld shop. Good luck to ya.
 
Stock with CPE CAI:

Cabin @ idle - 69 dbs
Cabin @ 40mph - 86 dbs
Cabin @ 70 mph - 96
CAI (measured outside the car) rev to 4k rpm - 92 dbs
Exhaust (Stock) @ idle - 79 dbs
Cabin rev to 4k RPM - 80 dbs


Test Conditions:
All windows up, car at 600-700 rpm Idle, Mild to no wind.



CPE CAI - CPE Exhaust w/14" resonator - CPE DP w/Cat
Cabin @ Idle - 80
Cabin @ 40 MPH - 90
Cabin @ 70 MPH - 98
Outside Driver window - Rev to 4,000 RPM - 99
Exhaust @ Idle - 105
Cabin Rev to 4,000 RPM - 93
Cabin @ hard accel - 1-2 Gear - 105

CPE CAI - CPE Exhaust w/14" resonator & 12" Oval muffler - CPE DP w/Cat
Cabin @ Idle - 72
Cabin @ 40 MPH - 86
Cabin @ 70 MPH - 94
Outside Driver winder rev to 4,000 RPM - 95
Exhaust @ Idle - 98
Cabin Rev to 4,000 RPM - 90
Cabin @ Hard Accel - 1-2 Gear - 102

This 12" Oval helped a ton, drone is way down, and as is shows above DBs are down very close to stock. Under hard accel and spirited driving the exhaust note is still there, albeit less noise. I am very pleased with the results and plan to still do Dynamat/Shield to make the cabin very quiet, that will also be followed with DB levels.

I am attaching pictures of the system, this will show others the quality I always speak of when it comes to CPE... I mean, look at the welds, those alone are beautiful. Josh, Jordan, and Anthony... thank you guys for all your help and always taking the time to talk with me.

Jim
 

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Last edited:
Mustangman, do you have the CP-E downpipe too? And is this 12 inch oval muffler from CP-E? Looks like you have found my solution also. I will have to give CP-E a call this week. Thanks a ton for all the testing.
I have the complete CP-E exhaust(DP & Catback w2/14 inch resonators).
 
Yes, I have the DP w/Cat. Also, please note these tests were taken directly after installation. Once the muffler has been on a week or so it should get quieter.

Lastly, I didn't notice any decrease in power, the 12" oval is straight through, so if anything it is very marginal.

Jim
 
One other thing I forgot to mention. To make the 12" Oval fit better and with no rubbing, the heat shield must be bent in a touch. The is plenty of room behind the heat shield, and all we are talking is a couple taps with a hammer to bring it in about 1/4"

Jim
 
Hey KLIP, i think we have the exact same setup. I'll be installing a 24" straight through muffler system within a week or 10 days. If you are looking for some serious sound dampening and can hold off for a couple of weeks, I'll be more than happy to let you know how this 24" additional muffler works for me. Stay tuned,

D




Klip said:
Mustangman, do you have the CP-E downpipe too? And is this 12 inch oval muffler from CP-E? Looks like you have found my solution also. I will have to give CP-E a call this week. Thanks a ton for all the testing.
I have the complete CP-E exhaust(DP & Catback w2/14 inch resonators).
 
Very nice - thanks for the leg work and all the measurements. I am very surprised though at the 98 dB at idle reading is that a correct measurement? Thats almost 20 dB higher then stopck while all the other measurements were much closer.
 
Gandalf said:
Very nice - thanks for the leg work and all the measurements. I am very surprised though at the 98 dB at idle reading is that a correct measurement? Thats almost 20 dB higher then stopck while all the other measurements were much closer.


Yes, that is a correct reading, but its also 7 DBs lower than original. It was also read, immediatley after installation, so it should go down a bit once the exhaust packing is set.

The drone is way down, if not very close to stock, there is a decel drone... but I think its expected with an aftermarket exhaust. Overall though, I'm extremely pleased with the results, and I'm a bit of a perfectionist... all I can say is trust me on this, you'll notice the difference immediatley.

Next step is still the Dynamat, and talking to them directly, I am to expect a 12 DBs decrease on the inside throughout the tests above.

Jim
 
mustangman said:
Lastly, I didn't notice any decrease in power, the 12" oval is straight through, so if anything it is very marginal.
How long did you have the CPE catback on the MS6 before modding it? Did you completely adjust to the power so that you would easily recognize any drop-off?

The only reason I ask is that the shape of the new 12" oval muffler seems to stick out quite a bit compared to the stock 14" on that 3rd section. Also, the ends are square instead of angled to allow for smoother airflow. I would be very interested if CPE could get some dyno runs with this new muffler before offering it. Yes, it might make things dramatically quieter, but silence comes at a cost. My guess is that with the square ends you are losing some of the power. Just my $0.02.
 
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