Hey guys, I recently purchased an M56 through a dealer auction(without ever test driving one) and when I took delivery I was disappointed with the(lack of) exhaust note!!! The reason I got an m56 is because I love the V8 purr, but in the cabin it feels like you're driving a tesla. Can anyone recommend a good exhaust upgrade which sounds cool, yet is inoffensive to law enforcement????

I just bought mine as well, and was in the same position. Initially, I did straight pipes, but it was too much. I took it into the dealer and got a Stillen cat back and love it! Purrs at idle and sounds throaty when you get on it. I paid 1k out the door, and lifetime warranty because it was from an authorized dealer. I'm sure the warranty doesn't matter, but it should add value since it was done by Infiniti.

It's not a cop magnet, is it?

The Stillen exhaust in my todo list as soon as I can align it with my budget...stupid VA property tax delaying my plans.

Can you hear it well in the cabin??? I really don't care if its that loud outside. And it doesn't sound like an old El Camino, does it?

You can hear it in the cabin and it is not a cop magnet. I think it is the perfect tone, low and mean, not a "ricey" high pitched sound. You may like the straight pipes (all the 14 year old boys turn their heads when I take a corner), but I really like the Stillen sound that resonates when the valet pulls up my car. When you get on it, it truly sounds like a v8.

Until you get the stillen exhaust, just do the "washer mod". Some people call it ghetto but I loved it and got LOTS of compliments on it. It takes 5 minutes to do it.

You basically just put either a big nut or a few washers between the muffler flange. Costs $2.

TheMajesticKing wrote:Until you get the stillen exhaust, just do the "washer mod". Some people call it ghetto but I loved it and got LOTS of compliments on it. It takes 5 minutes to do it.

You basically just put either a big nut or a few washers between the muffler flange. Costs $2.

Does it cause any damage?

Not at all. As long as you have all of the OEM piping at the front, the exhaust is not hot enough to cause any damage. I drove around like that for a long time before I got my custom exhaust done. Also, the OEM resonators are very quiet as well so they do most of the quieting.

CaliSpeed wrote:You can hear it in the cabin and it is not a cop magnet. I think it is the perfect tone, low and mean, not a "ricey" high pitched sound. You may like the straight pipes (all the 14 year old boys turn their heads when I take a corner), but I really like the Stillen sound that resonates when the valet pulls up my car. When you get on it, it truly sounds like a v8.

So stillen's the way to go??

I think the stillen is overpriced. I went custom and spent $700 for the ypipe and midepipe. The stillen does NOT replace the y-pipe, which is very restrictive so you don't get much HP gain from it, if any. But if you only want sound, it would be fine.

TheMajesticKing wrote:I think the stillen is overpriced. I went custom and spent $700 for the ypipe and midepipe. The stillen does NOT replace the y-pipe, which is very restrictive so you don't get much HP gain from it, if any. But if you only want sound, it would be fine.

and the car will still pass smog checks???

https://www.youtube.com/watch?v=0nV47lV ... lewOLgWnNA
This was with custom ypipe, stock midpipe, and washer mod (muffler delete). So it's even quieter with the stock ypipe. This shows you just how quiet the stock resonators are.

Yes. You're not interfering with the emissions system by doing a muffler delete. However, the stock ypipe has cats built into it so technically a custom ypipe would not be smog compliant. BUT I just recently went through emissions here in MD and passed with no problems. There are 2 sets of cats (4 total) on the M56. The precats are located in the exhaust manifolds and they are VERY restrictive. So I couldn't see failing a smog check as long as those are still installed.
I have the custom ypipe now and there is no smoke or smell from my exhaust at all, and most importantly, no check engine light.

TheMajesticKing wrote:https://www.youtube.com/watch?v=0nV47lV ... lewOLgWnNA
This was with custom ypipe, stock midpipe, and washer mod (muffler delete). So it's even quieter with the stock ypipe. This shows you just how quiet the stock resonators are.

I just watched that video a few hours ago!! That's yours???? hahaha! Nice. So that's $700??? Will it void warranty?? I like the stock look too.

TheMajesticKing wrote:I think the stillen is overpriced. I went custom and spent $700 for the ypipe and midepipe. The stillen does NOT replace the y-pipe, which is very restrictive so you don't get much HP gain from it, if any. But if you only want sound, it would be fine.

Or you both Stillen AND custom Y pipe.

What shop did your custom exhaust in MD? I'm in NOVA...did I ask this before...maybe get a discount for group buy if several folks want to do some exhaust work just a thought.

russianbear54 wrote:

CaliSpeed wrote:You can hear it in the cabin and it is not a cop magnet. I think it is the perfect tone, low and mean, not a "ricey" high pitched sound. You may like the straight pipes (all the 14 year old boys turn their heads when I take a corner), but I really like the Stillen sound that resonates when the valet pulls up my car. When you get on it, it truly sounds like a v8.

So stillen's the way to go??

IMHO, Stillen's the way to go. You can get a straight pipe done for $350 (I did), and there was just too much vibration in the cabin and an unrefined sound. I like the rip of a V8 as much as the next, but remember, you bought a sports sedan, not a sports car. You get both with the Stillen, loud when you want but low and powerful when you don't. It's worth the extra couple hundo. I got it done at a dealer, but I found the Stillen exhaust at many places for less. You could certainly find a local shop to install it and save some $$.

russianbear54 wrote:

TheMajesticKing wrote:https://www.youtube.com/watch?v=0nV47lV ... lewOLgWnNA
This was with custom ypipe, stock midpipe, and washer mod (muffler delete). So it's even quieter with the stock ypipe. This shows you just how quiet the stock resonators are.

I just watched that video a few hours ago!! That's yours???? hahaha! Nice. So that's $700??? Will it void warranty?? I like the stock look too.

Yes. That's my old M56.

The thing I don't like about the stillen is that the collector is too small for the M56. This motor needs to breathe! I went with a custom Xpipe and Ypipe. The stillen costs so much that you can just get a shop to do the same thing but they can customize it to your needs/wants.

I went to MBS (Mandrel Bending Solutions) in Pasadena, MD. They do amazing work. They did my old M56 and my current one.

Here's my exhaust thread:
m56-sport-custom-exhaust-t589893.html

What, if you don't mind me asking, happened to your old m56??

by adding washers between the exhaust flanges you are basically creating a small exhaust leak which adds noise because its not being muffled by the..... well.... muffler. Not the recommended route to go. Thats why you hear some slight rasp in themajesticking's exhaust.

Ordered the Stillen cat back system for my M56S today. Not that this matters for a 2+ ton car, but is the Stillen setup much lighter than OE?

russianbear54 wrote:What, if you don't mind me asking, happened to your old m56??

I wrecked it when my stretched tires popped off the bead at 55mph. Car spun out of control into a ditch and took out a light pole.

thisiswang wrote:by adding washers between the exhaust flanges you are basically creating a small exhaust leak which adds noise because its not being muffled by the..... well.... muffler. Not the recommended route to go. Thats why you hear some slight rasp in themajesticking's exhaust.

You only hear rasp because I got rid of the cats. If you do the washer mod with the rest of the exhaust completely stock there is ZERO rasp.

rjoe wrote:Ordered the Stillen cat back system for my M56S today. Not that this matters for a 2+ ton car, but is the Stillen setup much lighter than OE?

Can you please share your feedback on the Stillen cat back system on the M56S. I had it on my 06 M45 and loved it but obviously this is a different part number and different engine. I am looking for low and grumbly at idle/low rpm and loud at WOT but very quiet/no drone at cruise.

Also would be curious where people find the best prices on this. Any forum discounts anymore?

Apparently the exhaust from Stillen for M35, M45, M37 and M56 all fit one another.

Call Stillen to confirm, but the part number is the same last I checked. Hopefully you still have yours.

I have the Stillen exhaust on my 11M37s and love it, low rumble but when you mash on it, it comes to life, very good mod to do

Hmm, so I may need to tweak my setup a bit.

I had a local shop do the following;
Xpipe (or Ypipe, whatever that choke point is by the resonators) delete
Resonator delete
Stock mufflers still on

I kinda like the sound, but it doesn't sound quite V8... I'll see if I can post a video of it. I think I might like it better off putting the resonators back in, maybe changing or removing the mufflers.

I think the Stillen is crazy over priced for what you're getting. I can't imagine that I couldn't get the same sound out of magnaflo (which the shop carries) or something else. The only thing this shop won't pull is the part with the CAT's in it (from the manifold down)?

https://youtu.be/yosNqvlfIcw
Video of my setup... haven't gotten used to it yet.

Holy crap hah. Doesn't sound like a V8? That thing sounds like a Mustang lol. Pretty beastly/like a boss sound.

IlyaKol wrote:Holy crap hah. Doesn't sound like a V8? That thing sounds like a Mustang lol. Pretty beastly/like a boss sound.

Hehe, well it's growing on me. I think it's a little more 'poppy' than I expected. Every car has their own sound. I am going let it ride for a week or so and see how I feel. Thanks for your feedback.