Exhaust System Questions...

[Pwnin O'Brien]

I plan on getting a new exhaust system installed in the next few weeks and I just have a few questions that I was hoping you guys could help me with so I know exactly what to say when I go to a shop to get some estimates.

My Plan: Remove everything after the downstream O2 sensors back (remove the resonators, muffler and post muffler) and replace with stainless tubing. I want a double-in and double-out muffler (in the factory muffler location) so I can have true dual exhaust.

I want to go with an all-stainless system so I don't have any rusting issues for a very long time. I like the Flowmaster Super 40, but they are only aluminized steel, which I feel will rust within a few years. The warranty on the Flowmaster Super 40 is only 3 years, which is a bit shorter than I want. Magnaflow has some nice stainless dual-in/dual-out mufflers which I think would work well. I'm just not sure how the Magnaflows sound. If anybody has any first-hand experience with Magnaflow mufflers, are they quality and will it sound nice (as nice as the Super 40)?

Also, I am unsure as to the factory pipe diameter. What is the factory diameter of the exhaust piping (I thought it was 2.5")? I'm also assuming it's the same diameter throughout the entire system.

I saw a post on the forums previously about enlarging the pipe diameter to something like 3"; will increasing the pipe diameter significantly increase flow? What are the advantages to increasing the pipe diameter?

One last question, what should I expect to pay for a complete exhaust system fab? I figure the installer will have to custom bend some piping and whatnot.

I apologize for all of the questions, but this is one thing that I can't do myself since I don't have a mandrel bender or welder. I appreciate any input and/or suggestions!!!

[KyooX4]

I'm glad you're asking these questions, as I'd like to replace my exhaust system soon also.

[Mikey178]

Hey there,

I have done a complete exhaust system from behind the cats back.

Going stainless steel is a good idea. I've got a magnaflow dual in - dual out and I'll tell you, im not sure how the flowmaster sounds but the magnaflow on mine sounds awesome. Gives the truck a whole new sounds which turns heads for sure. Under hard acceleration its even better.

Not sure of the oem pipe diameter but I've gone 2.5" all the way.

Increasing the diameter, from the fab guys who did mine, they said that increasing the size will give you more sound and increase flow, but not to sure of the performance gains, if any.

Not sure what setup you plan to go with out the back (exhaust exit), out on the sides, out the back together on the right side, 1 out on each side, out the middle?? That is up to you. I did mine 1 out one each side, a lot of bending and fab work was required for mine, plus I took out my spare tire, save some gas as I reduced the weight by a tire, lol.

I paid $1400 CDN. Its a lot but I've got a custom exhaust that not only sounds and looks good but I don't have to worry about for the rest of the vehicles life IMO. I also went with some nice polished chrome tips that are like 12" - 14" long that finish off the look.

Hey Slickroger or Qxxx4, how was the sound to you guys as you've both heard it in person?

I've got some pics out the setup on my cardomain page, see my sig for the link


Modified by Mikey178 at 9:37 PM 9/5/2009

[Pwnin O'Brien]

Mikey,

What size oval Magnaflow muffler did you go with (4"x9", 5"x11", 5"x8", etc.)?

Thanks for all the info! I do like your system a lot and it looks really great (definitely one of the nicest exhausts on NICO) and the tips look awesome and they are perfect placement. I plan on going with a more stealth install; I want to have the dual pipes split the same distance apart as yours, but I want them up behind the bumper pointed towards the ground so you can't see the pipes when you're looking at the vehicle from behind (also this will help maximize ground clearance, I already have my spare mounted in my cargo basket).
Modified by Pwnin O'Brien at 1:30 AM 9/6/2009

[slickroger]

Magnaflow

[REZN]

i had no idea an exhaust system cost so much...

[KyooX4]

I thought they were in the $100-$300 range.

[Pwnin O'Brien]

What kind of shops are good to go get this done at? I've been told to go to a small shop (1-4 mechanics) to get this done. What kind of shops are best to get a new exhaust installed (1-4 mechs, 5-9 mechs, 10+ mechs)? Who will be able to do a quality job for cheapest? My budget for this project is roughly $300 ($1400 is waaaaaayyyy out of my price range).

Also, would it be better if I bought the muffler online and then took it to the shop to have it installed, or can the shop get it for the cheapest price?

[JonathanPrem]

I replaced mine from catback(under passenger seat). My total came up to 700 give or take 10. It's expensive cause my tips came up to 180 and my muffler was 200 and the rest for custom piping.

Go to a shop where there 1-3 guys. They tend to do a better job.

[Pwnin O'Brien]

I replaced mine from catback(under passenger seat). My total came up to 700 give or take 10. It's expensive cause my tips came up to 180 and my muffler was 200 and the rest for custom piping.

Go to a shop where there 1-3 guys. They tend to do a better job.

Did you remove the resonators from your system or did you leave them in? I definitely want to remove the resonators since the passenger side resonator is starting to fail and leak again. I want to remove the old system right between the downstream O2 sensors and resonators. The less weight the better (and one less part to fail, again).

Also, do you have any pics of your system I could look at?

[Mikey178]

Pwnin, thanks for the compliment. The Magnaflow I went with was 4"x9" dual in dual out. I went to a small shop, but very reputable in my city, they been here for like 40 years.

I spent 220 for the muffler, 250 for the tips and the rest is the custom pipe bending and stainless steel and labour.

Well sounds like you got a great idea with your setup you wanna go with. Don't forget to post pics when its complete.

[K03sport]

The Magnaflow I went with was 4"x9" dual in dual out. I went to a small shop, but very reputable in my city, they been here for like 40 years.

Isn't that kind of small considering the stock main muffler is 20" long.

I've thought about taking two 5" round, 14" long mufflers, welding them together with a brace, but keeping them about 1/2" from each other so the bodies aren't touching and using that at the main muffler replacement.

However, if you aren't dead set on Magnaflow or Borla, take a look at Spintech (no endorsement applied). They are about as straight flow as you get with no filler wadding. Check their Truck/RV section. Found several 2in/1out designs along with some 2in/2out.

Here is a Youtube vid with a V6 Tribute. Granted, most cars running a Spintech muffler(s) have V8s, but you get the idea.

[Mikey178]

Isn't that kind of small considering the stock main muffler is 20" long.

Thats what I said when the guy was putting together the setup. In actual fact, I have no idea where magnaflow came up with there measurements because the muffler I got said 4x9 but that is of the oval section. The true overall dimensions are 14" long x 9" wide on the body and from tip to tip its 20".

[K03sport]

right...I could see 4" high x 9" wide x 14" long. That does make sense.

[Pwnin O'Brien]

So I measured my exhaust pipe the other day while I was working on my rear bumper and I measured an outside diameter of 2.25". Does this sound right?

I also read somewhere that the Frontiers also use 2.25" OD pipes.

[Mikey178]

2.25" sounds right to me. I recall hearing that size was what it was originally.

[Pwnin O'Brien]

Ok, so I have more questions than before about a new exhaust system. I hope somebody out there can help me answer some of these...

So what I am looking to do is to keep the factory resonators (welding the seams on the side to prevent future failure) to reduce the raspiness of a new system. Now I know that the factory piping from the catalytic converters is 1.65" OD, however you cannot purchase an aftermarket muffler with an inlet/outlet smaller than 2" OD. Having said that, I think I want to go with a muffler with 2" inlets/outlets to preserve exhaust gas velocity. From what I've read going too large will kill my low end torque, so 2" (for each 3 cylinder bank) shouldn't be too bad.

I want to make a dual-exhaust system, so I originally wanted to use a Magnaflow dual-in/dual-out oval muffler. The problem: Magnaflow doesn't manufacture an oval muffler (dual-in/dual-out) with 2" inlets/outlets. My next idea was to go with two Magnaflow round mufflers in place of the single oval muffler. I was thinking of going with two 6" round mufflers but not sure if they will fit in the space where the stock muffler currently resides. I measured the stock muffler, it came in at a whopping 7.5" tall x 13.5" wide x 19.75" long! Going by those measurements it looks like the Magnaflow 6" round mufflers may just fit in. My first question is what kind of difference in sound will I see between a 6" round muffler and a 4" round muffler? Is a 6" deeper or louder than the 4"? Also, performance-wise, which is better?

If I were to scrap the idea of round mufflers and go with an oval muffler then the smallest piping size I could use is 2.25". How much low-end torque will I lose? Will it be noticeable?

I have watched countless videos on YouTube to try and see what each exhaust sounds like, but still can't figure out which would work best.

I guess the most important question is what would be the best setup in terms of performance and sound (while keeping the stock resonators)? Oval muffler? Round mufflers? Cherrybombs? Something I don't know about? Also, I'm not trying to build a loud exhaust, my main concern would be performance (highest CFM's).

[K03sport]

See my post several replies up. ^

My idea was to take two 5" round by (14" or 16" or 18"L long), weld them together with a 1/2" or 1" gap between them. This will require some braces to make the two round mufflers act as "one" piece.

My first question is what kind of difference in sound will I see between a 6" round muffler and a 4" round muffler? Is a 6" deeper or louder than the 4"? Also, performance-wise, which is better?

I don't think you will notice too much of a difference. I would suspect the 4" to be louder considering there is less sound absorbing material/volume in a 4" can as compared to a 6" can. More volume, more absorption...does that make sense.

If I were to scrap the idea of round mufflers and go with an oval muffler then the smallest piping size I could use is 2.25". How much low-end torque will I lose? Will it be noticeable?

You can keep you 2" pipe from the resonators to the muffler. Any good muffler shop should be able to expand a 2" pipe to fit a 2.25" inlet or at least fab a coupler.

Also, I'm not trying to build a loud exhaust, my main concern would be performance (highest CFM's).

Two 2" pipes will have more total internal volume than a 2.5" pipe over the same distance. edit: to expand this idea, the two 2" pipes will have about 28% more volume than the same length 2.5" pipe. This is measuring absolute volumes, so actual volumes will differ slightly due to pipe wall thickness, but I hope you get the idea.
Modified by K03sport at 2:04 PM 10/1/2009

[Pwnin O'Brien]

Well I ordered two Magnaflow 6" round mufflers (#12644). My appointment to get the exhaust done is next Thursday. I'll post some pics and whatnot when I get it back.

[Empty V]

Well I ordered two Magnaflow 6" round mufflers (#12644). My appointment to get the exhaust done is next Thursday. I'll post some pics and whatnot when I get it back.

Congrats! So are you going to keep the resonators on?

Billy

[Pwnin O'Brien]

Yeah, the exhaust guy said I would probably get a lot of interior droning if I were to take them off. I'm just going to have him weld the seams on each side of the resonators.

[Empty V]

Yeah, the exhaust guy said I would probably get a lot of interior droning if I were to take them off. I'm just going to have him weld the seams on each side of the resonators.

Nice, what did he quote you for the work? When I go back next week to replace the flowmaster and do a dual out instead of the single I'm dropping another $225 which would bring it to a total of $510 and that's including both mufflers.

Billy

[Pwnin O'Brien]

I was quoted at $450 for the labor and piping, but that was to remove the resonators. I'm hoping it comes in around $350 without removing them.

[Pwnin O'Brien]

Got the mufflers today. Tomorrow they go on.



That's pretty high-flow.

[moseng]

Just curious... how did it go? Hows dos it sound?

[Pwnin O'Brien]

Just curious... how did it go? Hows dos it sound?

They go on the car tomorrow. I'll take some pics and a short video and post them up here on Friday probably.

[Empty V]

They go on the car tomorrow. I'll take some pics and a short video and post them up here on Friday probably.

Congrats dude! I'm having mine done on Friday with the dual-in dual-out Magnaflow you suggested. I'll take some before and after video too.

Billy

[Pwnin O'Brien]

So I got the system installed and I drove it a little bit yesterday, here are my first impressions...

From outside, the system sounds amazing. It isn't loud at all and it only emits the deep exhaust tones. When revving the engine, it will get somewhat louder, but not a lot. The tone changes to a more smooth and deep sound once you rev the engine up to 3000-4000 RPM's. It doesn't sound like a V8 but it's far from sounding like a 4-cylinder Honda or something. There is absolutely no raspiness and the sound is very clean and smooth.

The interior, now that's an entirely different story. At idle you can barely hear the exhaust system at all, there is a faint rumble but nothing noticeable (gets easily drowned out by the music). When the engine reaches 2000 RPM's, the rumble becomes very noticeable. Interior droning increases ten fold and without music, I could easily see the noise becoming very annoying. Under heavy acceleration, the noise becomes somewhat overbearing and it drowns out all interior noises. I could definitely see a long highway trip being very difficult with this noise coming from the back cargo area of the vehicle, especially for rear-seat passengers.

Would I change anything? Probably not, it sounds great from the outside, not too loud. The system is extremely high-flow and you can really feel the difference by the exhaust gas velocity at the tailpipes. If I were to change anything, I would remove the stock resonators and put in some higher-flowing resonators that would hopefully help the interior droning. Also, no, any gain in horsepower from the new system is not noticeable at the pedal.

I'm going to try to get some pictures and a short video once it stops raining here.

[fastpathy35]

WOT my intake is louder than my exhaust. under slightly heavy acceleration it is pretty loud in the cab. but on the interstate, its not really all that bad for any speeds under 80. but i have flowmaster super 40 series dual in dual out. you have a much different set up.

[Empty V]

Congrats bro! I just dropped mine off. Unfortunately I overslept and didn't have a chance for any before video. One solution to your issue is to dynamat the floor, doors and tailgate.

Billy