N1 Invidia Catback install for 3.6R

I wanted to install an N1 Invidia Catback exhaust on my 3.6R because I loved how it sounds and crackles from some YouTube videos I recently saw.

For example this video:

I purchased a N1 catback system from the follow Legacy GT dark side.

I noticed it was around 7 inches too long behind the 3.6R headers and cats.

I decided to cut near the end of the flexible coupling to use the existing weld flange to mount a donut gasket.

Now I needed to figure out a solution to mount the catback to the existing pipe coming from the cats. I decided to make some hardware that will close onto the catback system and simulate a exhaust flange.

And now the last step was to bolt everything up.

The alignment in the rear is not perfect but I was too excited to put these on. I will try to figure out a way to adjust them further. It seems like the mid pipe is going too far to the right, and pushing the mufflers and tips to the right. Need to figure out a way to lower them, and push them toward the left.

Anyways, what does the community thing of the install? Any recommendation of what I should've done? I know I could have just cut it and welded it shorter but I didn't have the proper equipment to weld stainless steel at the time.

Do you have any pics from the back of the car? I need to adjust mine as well, want to compare how yours look to mine..

Thanks

I have heard of people using hose clamps to help align the mufflers perfectly. Just put the clamp around the rubber hanger and tighten it where it needs it.

I did exactly that. Thanks for the idea.

Do you have any pics from the back of the car? I need to adjust mine as well, want to compare how yours look to mine..

 

Thanks

Sure I can take some later today. But so far off the top of my head they are too far to the right and the left side sticks out more than the right.

Here are some pictures of the stock fitment and alignment in the rear. I am also going to make a short video of the exhaust sound.

Sent from my SM-G950U using Tapatalk

Here is a driving video I did with the N1 Invidia Catback:

Here is my previous which was the Nameless 5" Mufflers with stock mid-pipe.

Thoughts?

After a week of driving, I am really loving the exhaust. Unfortunately, I am extremely annoyed with the drone when driving on the highway. That small band of 2,300RPM - 2,800RPM is the worst, and sadly that is where the engine sits when driving on the highway.

I am highly debating whether to switch to the INVIDIA Q300s. The mid pipe is the same so only the rear y-pipe is different along with the mufflers.

I have still one last hope to see if the silencers included with the N1s would do any help.

I can not tell if the exhaust is new or not. If it is new, drive it around for a couple thousand miles before making a decision. I had read that the Q300 has a bit of resonance for the 1st couple thousand miles as well.

Yeah, mufflers tend to change sound pretty drastically as they get a bit of carbon buildup in them. Another option would be to add a j-pipe (Helmholtz resonator) tuned for about the middle of that range to cancel out the drone, but I'd give it a bit and see how the sound changes over time.

The exhaust is brand new. I didn't know that they change sound that drastically. I hope it happens soon.

The exhaust is brand new. I didn't know that they change sound that drastically. I hope it happens soon.

The pipes soot up and that quiets things down. The resonator on that exhaust is made for a 4cyl with a turbo. Swapping resonators would help. I hear the Vibrant one works well. The Tip insets would help some too but not like a resonator for a 6cyl would.

I'd love to hear the q300 on a 3.6r, people have done it but no sound clips.

From your videos it sounds like the Nameless was the more quiet of the two. How were they in the cabin noise wise?

Vibrant ultra quiet resonator will solve your drone. Add it in line with the q300 resonator.

You think it would be a good idea to add it in line with the N1 resonator or even in-place of the N1 resonator? I love the exhaust I just wish there was less drone.

I heard some good reviews and opinions about this X-Pipe/Resonator from Magnaflow

https://www.magnaflow.com/products?partNumber=11386

People said it dramatically reduces the drone and makes the exhaust more raspy. Unfortunately, putting in an x-pipe into a single pipe mid-pipe is probably a messy idea.

The exhaust needs to be redesigned for true dual exhausts in order to use that properly.

I should've put more thought into this before purchasing a catback automatically. I feel like the 3.6 needs a dual exhaust setup.

You think it would be a good idea to add it in line with the N1 resonator or even in-place of the N1 resonator? I love the exhaust I just wish there was less drone.

I should've put more thought into this before purchasing a catback automatically. I feel like the 3.6 needs a dual exhaust setup.

It caused all kinds of issues that could not be tuned out, from excessive FKC/FLKC (likely as a function of knock sensor calibration no longer applying with the change in engine/exhaust sound profile), IAM stability issues, fueling issues (given AF sensor placement).

Almost no performance gain, actually a loss given above, and a sound thats an acquired taste. Granted he did change his base timimg tables to produce pops & bangs (ugh) on throttle off or rev blips, but even without that it sounded like a bit much.

I did some writeups on the EZ36D exhaust setup in the 3.6R mod thread and a few other threads on here years ago. Likely tried the most setups and y/mid pipe modifications on here. Search for those to give you some ideas.

The H6, especially with headers is nearly impossible to tame in terms of either rasp or drone... unless running stock catback or narrow piping, resonators, high cell count cats, ideally 2 in line per bank like stock.

A flex pipe and helmholtz resonators go a long way too to banish the low RPM drone and help control high RPM rasp.

Before selling his 2013 3.6R, p1ckler ran a true dual setup.

It caused all kinds of issues that could not be tuned out, from excessive FKC/FLKC (likely as a function of knock sensor calibration no longer applying with the change in engine/exhaust sound profile), IAM stability issues, fueling issues (given AF sensor placement). Granted he did change his base timimg tables to produce pops & bangs (ugh) on throttle off or rev blips, but even without that it sounded like a bit much.

I have a hard time believing that the FKC and FLKC issue were cause by true dual exhaust and couldn't be tuned out. Quite a few time I have dealt with false knock it has been the exhaust hitting something making a seemingly inaudible metallic noise (With a louder exhaust, it is a lot harder to hear those noises as well) Perhaps the intentional backfiring by modifying the timing tables was the root cause. I just can't see dual exhaust not being able to be tuned out. With heated O2, one also should be tune the vehicle assuming the O2 are still mounted near the front of the motor, I don't imagine other 3.6R owner having issue with the headers.

I do think it is a lot work And expense to make dual exhaust just to put in x pipe resonator....

I heard some good reviews and opinions about this X-Pipe/Resonator from Magnaflow

https://www.magnaflow.com/products?partNumber=11386

 

People said it dramatically reduces the drone and makes the exhaust more raspy. Unfortunately, putting in an x-pipe into a single pipe mid-pipe is probably a messy idea.

 

The exhaust needs to be redesigned for true dual exhausts in order to use that properly.

 

I should've put more thought into this before purchasing a catback automatically. I feel like the 3.6 needs a dual exhaust setup.

Magnaflow sells a single, center 3" in and out muffler that splits into two tubes and reemerges before exit. Might look at that instead.

After a week of driving, I am really loving the exhaust. Unfortunately, I am extremely annoyed with the drone when driving on the highway. That small band of 2,300RPM - 2,800RPM is the worst, and sadly that is where the engine sits when driving on the highway.

 

I am highly debating whether to switch to the INVIDIA Q300s. The mid pipe is the same so only the rear y-pipe is different along with the mufflers.

 

I have still one last hope to see if the silencers included with the N1s would do any help.

I had the car at the shop on Monday and they aligned the exhaust for me. All they did was loosen and adjust the flanges from the Y to the mufflers and boom, perfect alignment. Here is the kicker all that annoying rattle I was getting in the interior is gone and the drone has actually subsided a bit. I know it sounds crazy and did not expect that to happen, but its substantially better now.

Any luck with the silencers?

I have a hard time believing that the FKC and FLKC issue were cause by true dual exhaust and couldn't be tuned out. Quite a few time I have dealt with false knock it has been the exhaust hitting something making a seemingly inaudible metallic noise (With a louder exhaust, it is a lot harder to hear those noises as well) Perhaps the intentional backfiring by modifying the timing tables was the root cause. I just can't see dual exhaust not being able to be tuned out. With heated O2, one also should be tune the vehicle assuming the O2 are still mounted near the front of the motor, I don't imagine other 3.6R owner having issue with the headers. I do think it is a lot work And expense to make dual exhaust just to put in x pipe resonator....

AF Sensor scaling or per injector comps don't really help and I believe (have no means or interest in testing/confirming) that with the headers and a full header-back in place, the stock knock sensor calibration for the H6 is no longer 'correct' or at least anywhere close to how its calibrated with the tiny stock (4-cylinder Honda Civic-like) header runners or the very restrictive back to back 800-1000 cell stock ceramic core cats. Especially the secondary cat on each bank is huge on the H6.

Headers themselves don't cause any issue, in fact they open the 3.6R up fairly nicely. Its how they interact with other changes and/or tune that can cause instability. BAU.