jeff5347

I havent posted in a bit but i have a question hopefully someone wil be able to answer that has been in the same boat. I just had my stock exhaust from the catback replaced with 2.5 inch all the way. I have a 15 inch resonator after the cat and a flowmaster super 40 muffler. Previously it was gutted pre cats, test pipe, no res and a super 50 muffler. I liked the sound from before but had to ditch the super 50 due to it splitting. So now my problem i still have the gutted precats, cat converter, 15 inch res and the super 40 muffler. The volume is insane at least to me. With the previous exhasut i got pulled over for noise and this one is much louder. What im trying t ofigure out is how to drop the volume. I want to have some volume but not what i have. I have read adding a second resonator will drop it and have also read it will only kill the raspiness which i dont have. The only other option and replacing the muffler but thats more money. Has anyone encxountered this and what did you do to reduce the noise level. Oh also with the previous exhaust i had very little drone in the cabin. Now really anywhere i get the drone. So my main goals are volume reduction and reduction of the in cabin drone. Any thoughts on fixing this

cjandura

iTrader: (3)

magnaflow 10436 for a resonator and a 3 chamber muffler

ShocknAwe

iTrader: (3)

Yea if you dont like the volume then I would ditch the Flowmaster. THey are known for good sound but it is loud. Magnaflow is more middle of the road

TallTom

Look into the Dynomax VT muffler.

http://www.dynomax.com/mufflers.php?muffler=vt

jeff5347

Ok this is gonna sound weird but here goes. My tips off the muffler is a dual tip. Its oval amd is 3.5x2.5. So I was looking about tips and if they make a diff and it was 50/50. So I had 2 inch diam exhaust pipe so I cut them alittle shorter than the tips inside. Just to see I banged them in and took it for a drive. Ya know what....the low drone and loudness is gone. It still is very noticeable just more sport sound than muscle. I think the. Acted as a mrgaphone and really amped the volune so now havinfmg 2 2 inch straight pipes was the ticket to quiet to a more sporty sound. Thank u to all that replied...

mrjasonlyrics

I had the exact same problem. I first had a ebay N1 catback and magnaflow mufflers but I wanted power so I added the altima headers and that's when it all started. The noise was loud enough to wake a dead man and the polution was too much.

I added a huge magnaflow resonator and it reduced it a lot but the polution was still there so I addeda a high flow cat and not only it reduced the noise but it also reduce the polution. Check out my thread maybe you might get an idea. There's vidoes posted too.

Altima headers on 6thgen maxima pt 2

Ghost_54

iTrader: (13)

15" resonator is to short ... look into something that 28-29" long that will assist to quiet things down.

this what I had on my car but I wanted more volumn so I removed it for a straight pipe

Rods03Max619

iTrader: (5)

But most are like highest 22'' maybe 24'', I always see people say there exhaust is to loud, people should just get Ebay Cannon Laucher 2.5 and use stock muffler...I have Full Exhaust, not to bearing, and dont get the Cops attention....

LI_Max_WOT

iTrader: (9)

If you want to improve in-cabin acoustics and also block out most of the road noise, then Dynamat all 4 doors and use floor mats if you don't have them in currently. It's of minimal cost and with the "mega pack" of Dynamat you can hit the rear deck completely, too. All of this is a must if you have a powerful system or just want to improve ride quality, in my opinion. The only downside is weight. Dynamat extreme weighs 1.5lbs/ft^2, but they have a lightweight version that at 1/3 the weight which should work excellent as well. You will need about 36ft^2 to hit all the doors completely and the rear deck. This is one of my favorite modifications to my max.

mrjasonlyrics

Actually I have one that's about 26-28" from magnaflow. Can't remember. It reduced it around 35% then I added a high flow cat and it reduced anot 10-15%. Now I have a great sounding exhaust don't won't wake the dead and alert cops when I pass by

ShocknAwe

iTrader: (3)

35% lol how did you get that figure? I have a HFC as well but they add some rasp and don't really do anything for sound. If anything it makes it louder being that it flows more freely than a stock cat. I don't understand super long resonators. Most add an exhaust for noise anyways. I have a 16" Magnaflow resonator. The best resonator as far as being quiet is going to be the stocker

mrjasonlyrics

That's like putting water paint over rust. That's an expensive mod that will cost you an arm and a leg. Think about it, your exhaust is loud in the cabin and you dynomat ever where then you decide to roll your window down to save some fuel. It's right there. They don't make see through dynomat for the windows.

To the poster of this add. Take my advice and get the biggest and longest resonator you can find, and if that don't work add the highflow cataylic converter. I made a thread in the 6tg gen with a before and after video clip. Check it out. Good luck mang...

mrjasonlyrics

I don't mean remove the stock cat, I mean add another. I spent a ton of $$$ trying to get a sound that I can tolerate for daily driving so I added the resonator and cat and it's perfect now. 16"? Lol that small man. You should of gone bigger.

Check out the thread with the video I made before and after and you'll see exactly what I'm talking about

ShocknAwe

iTrader: (3)

I've seen it. Your's did seem loud but then again you have a different engine than I anyways. Really, a longer aftermarket resonator only changes the tone. If you want quiet you should of kept the stock resonator which is designed for low volume as opposed to the aftermarket which is designed for a specific tone quality. The muffler also has a lot to do with volume. Get a muffler with a silencer option and it will give you great tone at low volume levels

LI_Max_WOT

iTrader: (9)

Dynamat Xtreme Bulk = $120

You would be surprise by how much of that sound is transmitted through METAL doors and flimsy panels?! Windows up or windows down, that noise is traveling through the door panels in both scenarios. Also, if I may add.. what sort of alien sound waves are you dealing with? That come from underneath the car, turn up, and then turn into the window. Sound produced by an exhaust system is omnidirectional but travels in a straight line from the source. The ONLY way you would hear exhaust coming through your window is if it is refracted off of something. The overwhelming majority of in-cabin noise comes through the floor panels, the doors, the firewall, and wheel wells. It's not like I have personal experience with a before and after or anything like that . . . Dynamat doesn't rust, btw. The OP figured out the problem already, it was his exhaust tips... I was just offering a further option to increase functions of in-cabin acoustics and soundproofing. Personally, I think a quieter in-cabin ride is classier. Soundproofing is a great way to accomplish this. The ONLY cost is the added weight and about $120, some all-purpose cleaner and a few terry cloths. Meeting adjourned.

jeff5347

Ok so added the two pipies in the tips and re-added the test pipe. Sounds much better but just a smidge to loud. Not by much but just want to tone it down. If I put the cat back in its too quiet. So I'm wondering about adding a resonated test pipe. The sound should be more than the cat but less than the straight tp. Only thing I'm wondering is my exhaust is 2.5" and the resonated tp is a 240sx 3"....
Will the 3" resonated still help or will it do nothing. Anyone use the 240sx 3" resonated tp's? Did u like it or regret buying
Keep in mind I have a test pipe on now which is 2.5" so will having a 3" resonated help at all? I also years ago dynomated the car I'm my big stereo days so that's all in there. And the resonator already in the car is 15 inches so this would be like having a 27 inch resonator.

LI_Max_WOT

iTrader: (9)

I've had great success achieving the exhaust note I was looking for by tweaking the intake side as well. Just for kicks, can you tell us what sort of intake you have?? NWP spacers/BOP? Also, if you're capable and have the know-how, you could disconnect your y-pipe from the pre-cats and then port out the exit outlet from the bank 1 precat (firewall side) which is small (maybe 1.75" ID) compared to the bank 2 precat (radiator side) which is closer to 2" ID. This will increase smoothness in exhaust flow, and drop your exhaust note a few dB. Also, try different intake setups, like SRI or CAI, just try the opposite of what you have on now first and see what you think.

jeff5347

For the engine side I have:
Ssim
Sri w/ 3" id intake
No plenum spacers
Gutted precats

Thars something u shouldnt have told me on the firewall precat haha now I have something else Im thinking of doing lol. And its not I want the volume lessened I huess, I want more mid tone like a 350z or so. I can hear the mid tone but the low tone overpowers it. I know I wont get a 350z , exotic sound just want more mid. But the shaving of the precat is now a next todo. I may get the res tp just to see what it does

mrjasonlyrics

$120 plus a day of removing trims,seat,door panels,and carpet. Noise is noise man regardless if the window is up or down.

The resonator is about $100 and $40 installation. And if its loud inside it's loud outside chances are the cops will hear it too and give you a ticket for excessive noise. So you can cover up the noise from inside or get rid of it from inside and outside.

Good luck brutha

jeff5447

LI Max this is the OP under jeff5447, couldn't log on my comp. Have you tried porting the firewall side precat. If so have u noticed a diff in performance as well..

LI_Max_WOT

iTrader: (9)

Well, I went from fully functioning cats to gutted and ported front and rear cats and the difference is so much I can't even remember what my max used to drive like because it's so much better now. More responsive, more power everywhere, and smooth as butter acceleration. This is what you should see as well by porting out the exits of both cats (if you're able). But DO NOT port them while on the car if you don't have your secondary o2 sensors spaced out, as metal shavings might fly into there and you'll end up with blown sensors. The major difference between our setups is you have SSIM and I have stock with NWP spacers, which should just about level things out. The difference should be noticeable if you port out the radiator side precat as well (where the o2 sensor port is) where there is pinched pipe to direct the air through the sensor. But, if you have your sensors spaced out, you will also increase the smoothness of the exhaust flow. O2 spacers are a necessity if you are going to port the exits of both your cats (if you don't have these already).

I also have another trick up my sleeve. This one will cost you some $$ as I am always looking to make some. I try to offset the expense of being addicted to hooking up my max with some sort of profitability It will take 5 minutes to install, aid in giving you a more aggressive exhaust note (not a louder one) and will cost you $50 + $50 deposit (refundable).

Check out this vid:
http://www.youtube.com/watch?v=1lZeK...ature=youtu.be

Here is a straight shot after allowing the ecu to recalibrate after my gutted/ported cat install.. There are still a few kinks in my set up but it is on its way..

NmexMAX

iTrader: (22)

http://www.moroso.com/catalog/catego...?catcode=35054