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Discussion Starter · #1 · (Edited)
A few weeks ago I installed a 3" CNT catted downpipe and have been extremely happy with it. Fit perfectly and the catback flange did not pull the exhaust system to the passenger side like OBX owners are reporting. Also did not need to trim exhaust hanger like OBX owners report. Quality of the product is great as well, clean welds. I used an O2 spacer for the downstream but do not think I needed one because of the opposite-the-flow angled O2 port.

Just this week I finally got my custom catback installed. It is a 3" pipe which splits into 2 x 2.5" pipes via a y-pipe. Since 2 x 2.5" is equivalent to 4" round, this thing is very unrestrictive. To picture it, it looks just like the stock exhaust except for the diameter increase in all piping. The stock resonator was replaced with a Dynomax bullet and muffler was deleted. The tips are from cherrybomb, they are slanted tips just like stock but are dual 3" round as opposed to dual 2.5" round. The dual 3" look awesome the way they fill the bumper cutaway nice and snug compared to stock. I would be happy to share all my installation part numbers if anyone is interested. The total price after parts and installation was $400. Not bad right?

The exhaust tone is stunning, I love it. The dynomax bullet really makes this car sound like it has many more than 5 cylinders. However, and this is a BIG however, the drone is a mood killer. At cruising speeds (2000RPM) it hums like a mofo. I want to ask advice from fellow forum members; what is the best muffler to reduce this low-end RPM drone? I want to try the dynomax VT with valve technology but have heard alot of complaints about the valve rattling. For those that don't know the VT uses a butterfly valve to restrict a little bit of flow and idle and cruising to eliminate drone. Many people swear it is a perfect solution. Any ideas from you guys?

Video:

In the video, I am cruising around town with the windows up most of the time. While on the highway I was looking for a rattle in the cab that was caused by the bullet, lol figures.



Photos:
Coming Soon
 

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Discussion Starter · #3 · (Edited)
I see what you mean by that drone, btw have a part # for those tips?
2x CherryBomb 577572. They have multiple options though. I got 12" length but they also sell 18" and 22". I recommend 12" because any longer would contact the left rear wheel well. 3" tips is as large as you will want to go with the non-sport aero kit because 3.5" tips would be snug against the bumper. Yikes! They are 45 deg angle cut and I'm pretty sure our stock is around 40 deg. Can't really tell tho if you get them angled right. I got the angle I wanted and hot glued them, then asked the exhaust shop to drop a bead of weld in there for a permanent hold (I didn't trust they would get the angle right themselves). Then after first startup, the hot glue melted with the exhaust temp and dripped to the ground. Worked out alot better than planned.
 

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A few weeks ago I installed a 3" CNT catted downpipe and have been extremely happy with it. Fit perfectly and the catback flange did not pull the exhaust system to the passenger side like OBX owners are reporting. Also did not need to trim exhaust hanger like OBX owners report. Quality of the product is great as well, clean welds. I used an O2 spacer for the downstream but do not think I needed one because of the opposite-the-flow angled O2 port.

Just this week I finally got my custom catback installed. It is a 3" pipe which splits into 2 x 2.5" pipes via a y-pipe. Since 2 x 2.5" is equivalent to 4" round, this thing is very unrestrictive. To picture it, it looks just like the stock exhaust except for the diameter increase in all piping. The stock resonator was replaced with a Dynomax bullet and muffler was deleted. The tips are from cherrybomb, they are slanted tips just like stock but are dual 3" round as opposed to dual 2.5" round. The dual 3" look awesome the way they fill the bumper cutaway nice and snug compared to stock. I would be happy to share all my installation part numbers if anyone is interested. The total price after parts and installation was $400. Not bad right?

The exhaust tone is stunning, I love it. The dynomax bullet really makes this car sound like it has many more than 5 cylinders. However, and this is a BIG however, the drone is a mood killer. At cruising speeds (2000RPM) it hums like a mofo. I want to ask advice from fellow forum members; what is the best muffler to reduce this low-end RPM drone? I want to try the dynomax VT with valve technology but have heard alot of complaints about the valve rattling. For those that don't know the VT uses a butterfly valve to restrict a little bit of flow and idle and cruising to eliminate drone. Many people swear it is a perfect solution. Any ideas from you guys?
Click the "loud enough for ya" link in my sig. That's my stock exhaust with resonator AND muffler delete. It too drones a fair bit betweeen 2000-2500 RPM. My solution is just keep the REVs above or below that range. So yeah, if I'm cruising at 60MPH I'm in 5th not 6th gear and it's just fine, noise-wise.

You could also add sound deadening to the car. Start with a vibration dampener, then a foam layer (preferably closed-cell) and then finish up with a layer of Mass-Loaded Vinyl. If you're cheap, just do minimal VD material (Fatmat, Dynamat, RaamMat) and use cheap foam but you gotta do lots of MLV, that's what really blocks sound.
Just starting with some RaamMat will help though.
 

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thanks for the info I see you ended up using 2 tips to instead of 1 cleaver to get the slant to match the lines. thanks.
 

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Discussion Starter · #6 ·
Click the "loud enough for ya" link in my sig. That's my stock exhaust with resonator AND muffler delete. It too drones a fair bit betweeen 2000-2500 RPM. My solution is just keep the REVs above or below that range. So yeah, if I'm cruising at 60MPH I'm in 5th not 6th gear and it's just fine, noise-wise.
Holy piss that sounds familiar. I don't want to have to adjust my driving all the time to keep the sound levels down. I have to do something about this.
 

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Holy piss that sounds familiar. I don't want to have to adjust my driving all the time to keep the sound levels down. I have to do something about this.
I notice in the video a familiar JVC double-din logo at boot up, which HU do you have? Mine in sig.
 

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Holy piss that sounds familiar. I don't want to have to adjust my driving all the time to keep the sound levels down. I have to do something about this.
Can always run two resonators.
 

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Discussion Starter · #9 ·
I notice in the video a familiar JVC double-din logo at boot up, which HU do you have? Mine in sig.
It is the AVX-640 which is now been replaced with the AV-50. I really like the button color customization and the fact you can load any .jpg as a background.
 

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Discussion Starter · #10 ·
Can always run two resonators.
The race bullet has the muffling capability of -4 db. Whopty-doo lol. Unless I bought a different resonator, I dont think a second would do much.

I am exploring resonator chambers. Check it out on google. Pretty cool and cheap solution. Uses good old physics. Instead of muffling noise it actually works to cancel unwanted frequencies.
 

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The race bullet has the muffling capability of -4 db. Whopty-doo lol. Unless I bought a different resonator, I dont think a second would do much.

I am exploring resonator chambers. Check it out on google. Pretty cool and cheap solution. Uses good old physics. Instead of muffling noise it actually works to cancel unwanted frequencies.
Yep, anything that is "straight through" is not going to reduce drone, it will just make everything a tiny bit quieter. You need a chambered muffler OR a quarter-wave "resonator" (google that) installed in the correct place and made the correct length.
 

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I also run the cnt catted down pipe. I love it so far. You do need that spacer on there. Mine throws a code for the rear o2. What spacer did you order? I head some are too short for the sensor tip.
 

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Discussion Starter · #13 ·
Yep, anything that is "straight through" is not going to reduce drone, it will just make everything a tiny bit quieter. You need a chambered muffler OR a quarter-wave "resonator" (google that) installed in the correct place and made the correct length.
A quarter wave resonator is what I was talking about. Should I install two on the dual 2.5" pipes or one on the 3" by the downpipe? It is so tight down there, there is really no convenient place. I was thinking of installing right after the bullet which is right after my downpipe. This would allow me to make a longer resonator due to space. Also, I was going to create a slip joint so it can be properly tuned to my exact drone.
 

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I experimented with a VT. Didn't help much. I found that there was enough pressure under anything above vacuum to open the valve. Basically, the good sound at idle remained, and the drone when cruising with anything but your foot off the gas pedal was ok. If you have to touch the pedal....just to keep it moving, the valve opened and the sound came back. I ended up going back to the stock muffler with the resonator delete and some very custom tips. Sounds a little throatier than stock...and the breathing upgrade is really from the DP anyways. Couldn't deal with driving to daycare with a car that was that loud all the time.
 

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A quarter wave resonator is what I was talking about. Should I install two on the dual 2.5" pipes or one on the 3" by the downpipe? It is so tight down there, there is really no convenient place. I was thinking of installing right after the bullet which is right after my downpipe. This would allow me to make a longer resonator due to space. Also, I was going to create a slip joint so it can be properly tuned to my exact drone.
I think you just want to make sure that your QWR tubes don't connect to the exact center of the length of your exhaust system, they should be offset because at the center the the sound wave is neutral or whatever. I don't know the exact term.

If you google for "exhaust quarter wave resonator" you'll hit a ton of forum threads for all sorts of cars, you should be able to find one where they talk through the basics of determining both where to attach it and the appropriate length. Of course with a slip joint that second part is easy as you can do trial and error testing.
 

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Where did you get your custom exhaust done? Dd you provide the parts? I so where did you get them?
 

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Discussion Starter · #18 ·
Where did you get your custom exhaust done? Dd you provide the parts? I so where did you get them?
I got it done at a local exhaust shop, USA Muffler and Brakes. I bought a y-pipe from magnaflow, tips from CherryBomb, and a Dynomax Bullet. I also bought a flange to attach the catback to the downpipe from amazon.com along with a downpipe-to-catback gasket from IPD. I would not recommend reusing the stock gasket.

The exhaust shop supplied the labor and all the pipes. Jegs.com and summitracing.com had all the parts I needed minus the flange.
 
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