Does the AT exhaust setup fit the MT version of the car?

[dogunbound]

One thing that would be nice is a louder exhaust. As y'all already know, the MT variant has a muffler the size of Texas because why not and this causes the car to be quite silent. I don't want to spend a lot on something purely performative, so something cheap like a muffler delete is an option. Another option that I just thought of is to take someone else's stock AT exhaust setup and bolt it onto my car. To my knowledge, the AT setup is a bit louder and more importantly, cheap as it is used.

Pretty sure it'll be an easy bolt on. What do y'all think?

 

[FSUZ33]

AT axleback on an MT is an option people have been happy with.

 

[KrackaC8]

Yup, direct bolt-on. 4 nuts + 2 hangers; super easy. Check performance/exhaust shops that specialize in the Z and they'd probably give you one for free/cheap. You're in Houston so I'd suggest swinging by RaceBox.

 

[HuskeRZ34]

I have a 2024 performance and I have the AT catback on mine and it sounds about perfect for what I want! I started with just the axle back and didn’t care for the drone cruising and volume as it’s pretty much straight pipes with how the rear resonator is set up. Once I added the mid section it was perfect! Eventually I may add the NISMO street but I really like the tips look on the OEM option! Depending on your goals the cat or axle back option is a great choice for a fraction of the money compared to other choices out there!

 

[dogunbound]

Yeah I'm thinking this is the way, and if I really want to level up the noise, I can do a poor man's cat delete for the lower downpipes. Pretty sure the O2 sensor is above the cat, so it isn't monitoring the performance of the second cat. Don't need to worry about hacking the secondary O2 sensor.

Thanks for the responses.

 

[KrackaC8]

Yeah I'm thinking this is the way, and if I really want to level up the noise, I can do a poor man's cat delete for the lower downpipes. Pretty sure the O2 sensor is above the cat, so it isn't monitoring the performance of the second cat. Don't need to worry about hacking the secondary O2 sensor.

Thanks for the responses.

Correct regarding the o2 sensors.

 

[FSUZ33]

Yeah I'm thinking this is the way, and if I really want to level up the noise, I can do a poor man's cat delete for the lower downpipes. Pretty sure the O2 sensor is above the cat, so it isn't monitoring the performance of the second cat. Don't need to worry about hacking the secondary O2 sensor.

Thanks for the responses.

Correct. The lower O2 sensors are pre-cat, mounted in between the inlet flange and catalyst.

 

[thesilverbullet]

I have the A/T muffler on an otherwise stock M/T. Definitely an increase in volume and still looks stock. not bad overall.

But they are a couple of quirks…

when cruising and light acceleration at 3K+ the tone is not that pleasing. Also, the exhaust makes a single thumping sound “thump’ with you let off while cruising at highway speeds.

otherwise - full acceleration and cruising around town is fine with more volume over stock.

but if you are planning on lowers, i would recommend a used full catback for a better tone…

 

[AlanZ]

This might be one of my favorite mods.

 

[HuskeRZ34]

I have the A/T muffler on an otherwise stock M/T. Definitely an increase in volume and still looks stock. not bad overall.

But they are a couple of quirks…

when cruising and light acceleration at 3K+ the tone is not that pleasing. Also, the exhaust makes a single thumping sound “thump’ with you let off while cruising at highway speeds.

otherwise - full acceleration and cruising around town is fine with more volume over stock.

but if you are planning on lowers, i would recommend a used full catback for a better tone…

I had the exact same problem with just the AT axleback, once I added the resonated mid pipes it sounded like a lot throatier version of the MT exhaust. Maybe 20% louder, noticeable but not harsh on the ears.

 

[trackratZ]

Just curious, why so much difference in design of the AT vs MT OEM catback and sound quality? Shift rpms, gearing?

 

[dogunbound]

Just curious, why so much difference in design of the AT vs MT OEM catback and sound quality? Shift rpms, gearing?

iirc it's due to testing requirements for sound levels. In California, manual has to pass the 92 db limit in 2nd or 3rd gear WOT the entire time. Autos only have to pass the 92 db limit with as much throttle needed without the car shifting down a gear for more power at some speed, so you are like in 4th gear or something like that.

 

[trackratZ]

iirc it's due to testing requirements for sound levels. In California, manual has to pass the 92 db limit in 2nd or 3rd gear WOT the entire time. Autos only have to pass the 92 db limit with as much throttle needed without the car shifting down a gear for more power at some speed, so you are like in 4th gear or something like that.

It's California driving the entire US design variations of exhausts on the Z?! Ouch!!

 

[dogunbound]

Kind of a nerdy question, but anyone know the torque ratings for the bolts that attach the flanges between the muffler and the midpipe, and the midpipe to the Y pipe?

Of course if no one knows, then I'll just eye ball it as it's prolly not serious as long as there isn't a leak.

As a side note, how tf do people normally get torque specs for their engine rebuilds and stuff? Like in this case, a quick google search isn't enough, nor will "AI" be enough. This is stuff locked behind some manual nissan secretly keeps behind closed doors.

 

[Who.Am.Eye.2716]

There is a link to the service manual in this forum. I dont remember where, otherwise, I would share it. Here is a screenshot of the torque specs of the axle back and hangers.

Yeah I'm thinking this is the way, and if I really want to level up the noise, I can do a poor man's cat delete for the lower downpipes. Pretty sure the O2 sensor is above the cat, so it isn't monitoring the performance of the second cat. Don't need to worry about hacking the secondary O2 sensor.

Thanks for the responses.

Modifying or swapping out the LDP recommends a tune. You can over spin your turbo with no back pressure, and prematurely ruin your turbo's when at WOT