Sporty exhaust sound

Forum for Infiniti M35 and M45, and Nissan Fuga owners.
Dxta
Posts: 108
Joined: Sat Feb 22, 2020 5:52 pm
Car: Infiniti M45 sedan base sport

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Hi everyone! Pls is there away i could make my m45 exhaust or engine to sound more kike a sport's car, or like a powerbike sounds? I like tht BUUUUUUJ sounds sport's cars or motorbikes make.

Has anyone tried modifying their exhause systems to that effect, and what part of the syatem did you delete, to achieve that sound?

Thanks


EniGmA1987
Posts: 2257
Joined: Tue Apr 28, 2009 5:13 am
Car: '06 Infiniti M35 Sport

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Yep, of course. I dont have time now since I am about done with my break at work, but ill try to provide different info on the different types of mufflers, resonators, and piping diameters and how they affect your sound later today. It can be quite extensive.

EniGmA1987
Posts: 2257
Joined: Tue Apr 28, 2009 5:13 am
Car: '06 Infiniti M35 Sport

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Mufflers:
Glasspacks are the typical aftermarket universal mufflers you see. They tend to have a deep sound at idle and low RPM, and can get that higher frequency pop and a bit raspy sounding at higher RPM as the exhaust pressure builds.

Chambered mufflers dont sound as raspy at higher RPM like glasspacks do, but also don't sound as deep at lower RPM compared to glasspacks. These often have resonance drone though, even the dual-chambered models that are supposed to reduce the drone.

Then you have turbo mufflers which I have not had personal experience with but can sound nice from the youtube clips I have heard. They seem to sound too high frequency and "ricey" on 4 cylinder engines, but on 6 and 8 cylinders (like we have) to me they seem like the smoothest sound when compared to glasspack or chambered types.

Lastly, you have turbine mufflers which seem very cool to me. I really want to try one but as of yet I have no experience with them personally. These seem to have a deep sound like glasspack since the main bore of the muffler is straight through in the same manner, but also seem to have a deep throatiness as you rev. The design of a turbine muffler in a way is a combination of glasspack and chambered. It is straight through like glasspack, but instead of fiberglass material on the outside it has a chambered design directing gas flow around and then back to the center flow path.

edit: I forgot about another category that is an offshoot of glasspacks. The "Laminar flow" muffler from Flowmaster. These are very similar to a glasspack and they do have fiberglass outer shell in the same way, but do not offer a straight-through design like a glasspack does. Instead, there is a baffle inside that allows about half the exhaust gas to go straight through some small holes while the rest slows down and is forced around the muffler design, and the sound waves going through hit the baffle and are bounced in other directions into the fiberglass. I cant really decide what this sounds like (I do have one of my exhaust setups with them so have heard them in person). I guess it is sort of like a glasspack deep sound, but also a little bit like a chambered sound as well. So I guess it would sound similar(ish) to a turbine muffler.



Resonators:
A resonator in the car changes the sound of the exhaust and lowers the volume by 2-3db. The purpose is usually to remove some high frequencies to produce a more pleasant sound, and this also tends to smooth out the sound somewhat. People often delete their resonators to make the engine sound "throatier" and/or more "raspy" when you really hit on the gas.
The length of a resonator is directly proportional to the frequency of sound it allows to pass. The longer the resonator, the deeper the exhaust note.

You have all the main types of mufflers as resonators as well. They do very similar things. The most common aftermarket resonator is a glasspack.



Pipe size:
The size of your exhaust pipes should be directly proportional to the amount of power your engine makes. Too small exhaust pipes will restrict power by adding too much resistance to the air trying to flow through the engine, but you should not just throw on the largest size you can fit under the car. Too large of exhaust pipes with not enough air/exhaust flowing through will create a loud "drone" sound. You need a balance of restrictiveness to negate the drone, but size to allow the air to flow. Stock size is 2.25", and if you have a completely stock engine you may want to stick with this size. The largest I would ever recommend going without a turbo charger on the car is 2.5".

The larger your pipe diameter, the deeper your exhaust will sound. It allows the sound waves to bounce around more and cancel out higher frequencies, and by being so large as to not maintain enough back pressure it will create "pressure waves" as each cylinder hits in the engine and will sound more "boomy" at idle.



Crossovers:
Inline engines all have exhaust coming out one side of the engine, so no crossover is needed. Our engines are a V though, which has two cylinder/exhaust banks in the engine. By using a crossover pipe, it merges the cylinder banks and allows for scavenging of one side of the engine to the other, increasing horsepower. You should always have a crossover of some kind on any V engine configuration or really any engine that has multiple cylinder banks.

An X pipe is the most efficient and produces the most power.
Our car comes with a Y pipe stock. This is fine, but it is more restrictive as it forces all exhaust into a single pipe for a couple of feet.



Tips and tricks:
Often the most pleasant exhaust sound comes from combining multiple types of muffler and resonators. Like using glasspack resonators and chambered muffler for example.

You can get a deeper exhaust sound like you would get from large pipe size by instead just upsizing the muffler and using large tips. Like if you keep 2.25" pipine, but have it go huge to a 3" right as it enters the muffler. Note that this will cause drone at the back of your car and be more noticeable in the back seat. You cant get fully around physics :/

You can smooth out your exhaust sound even more by using two crossovers, such as a dual x-pipe (sometimes called a helix). This doesnt increase horsepower by having more crossovers because the second one is usually too fart from the engine to make a noticeable difference.

If you want a higher-pitched growly sound similar to this: https://www.youtube.com/watch?v=n_n9vAw_6a0 Then you probably want to avoid glasspacks in both the muffler and resonators. Those will deepen your exhaust note which will keep it from sounding higher-pitched like this. You will most likely want to go with a "turbine" muffler style and possibly either no resonators or maybe a short length turbine type resonator to get this type of higher-pitched sound. See here for another example of the sound: https://www.youtube.com/watch?v=GPgmB73MD4Y



Product examples:
https://www.jegs.com/p/Cherry-Bomb/Cher ... 4/10002/-1
https://www.jegs.com/p/Flowmaster/Flowm ... 2/10002/-1
https://www.jegs.com/p/Dynomax/Thrush-T ... 6/10002/-1
https://www.jegs.com/p/Jones-Exhaust/Jo ... 5/10002/-1
https://www.jegs.com/p/Flowmaster/Flowm ... 4/10002/-1
https://www.jegs.com/p/Cherry-Bomb/Cher ... 2/10002/-1

I suggest breaking the exhaust into 2-3 sections so it can be removed easily without cutting or welding by using clamps:
https://www.amazon.com/EVIL-ENERGY-Stai ... 07D5V348W/
https://www.amazon.com/ESPEEDER-2-25Inc ... 07XYSYTGD/
Last edited by EniGmA1987 on Tue Jul 27, 2021 9:41 am, edited 1 time in total.

EniGmA1987
Posts: 2257
Joined: Tue Apr 28, 2009 5:13 am
Car: '06 Infiniti M35 Sport

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Personally, I would try this with your exhaust:

from the cats, bring the exhaust to the centerline of the car in a similar way it does now and go into an X pipe. Stay with 2.25" exhaust from the cats through the x pipe.
Once you leave the x pipe, upsize to 2.5" exhaust pipe.
Go into two glasspack resonators of 18" length.
From the resonators having the piping go down to the mufflers and go with Jones or Aero turbine style mufflers with a 2.5" center inlet and 2.5" center outlet
Use exhaust tips that go from a single 2.5" inlet to dual 3.5" outlets.

Insist on using V band clamps to break the exhaust into 3 sections held together with the clamps. That way you can drop the exhaust down if you need to in order to repair or replace your rear diff and also your driveshaft area and u-joints.

That setup should give you a deep exhaust note with some beefy throatiness when you step on it with minimal to no drone at cruising speed.

Full custom exhaust install at a good shop should only cost $300-400 in labor plus the cost of all the parts you want.

Dxta
Posts: 108
Joined: Sat Feb 22, 2020 5:52 pm
Car: Infiniti M45 sedan base sport

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EniGmA1987 wrote:
Mon Jul 26, 2021 9:15 am
Yep, of course. I dont have time now since I am about done with my break at work, but ill try to provide different info on the different types of mufflers, resonators, and piping diameters and how they affect your sound later today. It can be quite extensive.
Thanks so much. Id appreciate the feedback at your spare time.

EdBwoy
Moderator
Posts: 3507
Joined: Tue Dec 25, 2012 12:47 am
Location: Indiana, USA
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This is why I love the forums, there's always something to learn here.
Enigma, thank you for sharing that knowledge. I am sure it will be helpful to both OP, as well as all the visitors who hit up our pages.

EniGmA1987
Posts: 2257
Joined: Tue Apr 28, 2009 5:13 am
Car: '06 Infiniti M35 Sport

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EdBwoy wrote:
Tue Jul 27, 2021 9:45 pm
This is why I love the forums, there's always something to learn here.
Enigma, thank you for sharing that knowledge. I am sure it will be helpful to both OP, as well as all the visitors who hit up our pages.
No problem :bigthumb:

Dxta wrote:
Tue Jul 27, 2021 2:58 pm
Thanks so much. Id appreciate the feedback at your spare time.
When you decide on some parts you want to try, let us know what you are going with here on the forums :)

Dxta
Posts: 108
Joined: Sat Feb 22, 2020 5:52 pm
Car: Infiniti M45 sedan base sport

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@Eni. I'm thinking of either welding a straight pipe into the rear muffler inside, or replacing the muffler entirely, with a straight pipe, from the Y catalyst's portion.

What do you think?

EniGmA1987
Posts: 2257
Joined: Tue Apr 28, 2009 5:13 am
Car: '06 Infiniti M35 Sport

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Dxta wrote:
Fri Jul 30, 2021 2:01 pm
@Eni. I'm thinking of either welding a straight pipe into the rear muffler inside, or replacing the muffler entirely, with a straight pipe, from the Y catalyst's portion.

What do you think?
If you simply delete your muffler you will most likely get a ticket for being too loud, or your neighbors may do things to get back at you:
https://driving.ca/auto-news/news/ford- ... -with-foam
It is also illegal to not have a muffler which means you will not pass a smog check if your state and county require it. Even modifying a muffler with a pipe welded into it may be noticed and fail you.


If you just delete your resonators, it may give you a sound in the direction of what you are looking for. I believe the stock resonators are a glasspack type, which means they will both lower the exhaust note, and they will be smoothing things out.
You can always start with replacing the resonators with straight pipe, and if you are still not happy with the sound then you could replace the muffler with another one.

EniGmA1987
Posts: 2257
Joined: Tue Apr 28, 2009 5:13 am
Car: '06 Infiniti M35 Sport

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One thing you could start with doing wont cost you anything and can be done on your own.

Remove the mufflers from the car, and then start it up yourself and rev it a few times and see how it sounds from inside the vehicle. Then have a friend be in the car and do some revs while you stand behind the car a dozen feet or so. See how loud it is, and what it sounds like. Maybe record a sound clip or two on your phone.

Then remove the midpipe with the resonators and repeat starting the car and revving it yourself and with a friend. Compare how it sounds and see what the difference is and whether you like it or not.

That will give you a good idea of what the engine itself sounds like, and what your "base sound" is. From there, you will only be able to take away various sound frequencies with the use of new resonators and/or mufflers in order to tune it to a sound you are going for.

Dxta
Posts: 108
Joined: Sat Feb 22, 2020 5:52 pm
Car: Infiniti M45 sedan base sport

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EniGmA1987 wrote:
Mon Aug 02, 2021 8:11 am
One thing you could start with doing wont cost you anything and can be done on your own.

Remove the mufflers from the car, and then start it up yourself and rev it a few times and see how it sounds from inside the vehicle. Then have a friend be in the car and do some revs while you stand behind the car a dozen feet or so. See how loud it is, and what it sounds like. Maybe record a sound clip or two on your phone.

Then remove the midpipe with the resonators and repeat starting the car and revving it yourself and with a friend. Compare how it sounds and see what the difference is and whether you like it or not.

That will give you a good idea of what the engine itself sounds like, and what your "base sound" is. From there, you will only be able to take away various sound frequencies with the use of new resonators and/or mufflers in order to tune it to a sound you are going for.
Hi Eni! Thanks for your replies. I think trying and erroring the sounds, would be a better option for me.
In Lagos, no one cares about how loud your exhaust system sounds, as long as does not make neighbours uncomfortable.


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