Stillen Catback

[Big_Tone]

So, I found someone selling a used Stillen Catback, but it isn't stainless steel. Wondering if this is really a Stillen product? Anyone have any insight?

[beachbum718]

Post pictures

[Big_Tone]

I just took another look at it and realized its not Stillen. It's an OEM catback that came off of an M56. Grrrr!

[Ilya]

I just took another look at it and realized its not Stillen. It's an OEM catback that came off of an M56. Grrrr!

Good you saw it early and didn't buy a stock exhaust lol. I'd be pissed lol.

[Big_Tone]

I just took another look at it and realized its not Stillen. It's an OEM catback that came off of an M56. Grrrr!

Good you saw it early and didn't buy a stock exhaust lol. I'd be pissed lol.

Right! It clearly says OEM in the description, but I didn't pay attention to it, because i did a search for Stillen. I've read people in other threads say you can get a deal on them online, but everything I see is $1,026, which is about the same price as buying directly from Stillen. I won't be able to spend that kind of cash for a while.

[walt1227]

glad you looked again. I would of been pissed.

I just took another look at it and realized its not Stillen. It's an OEM catback that came off of an M56. Grrrr!

[armybrat]

I would also check the classified section here on the NICO site.

[Big_Tone]

I would also check the classified section here on the NICO site.

Good idea. I'm also checking with local shops to see how much an x-pipe will cost me. From what I've been reading it looks like it sounds better and adds power. And cheaper!

[armybrat]

I would also check the classified section here on the NICO site.

Good idea. I'm also checking with local shops to see how much an x-pipe will cost me. From what I've been reading it looks like it sounds better and adds power. And cheaper!

I had $300 in mine - post cats and Y-pipe/resonators removed and replaced with test pipes and handmade X pipe and welded to the stock piping and mufflers. OEM flanges were left intact, and I left the flex connectors. You can see the newer piping vs the original. I had stayed with the 2" size because with a stock tune this set up is plenty big enough. Might pay $200 - $250 if you delete the Y-pipe only (not the post cats) and go with just an X-pipe.

[walt1227]

Armybrat that stock exhaust looks like it is heavy. I def plan to get rid of mine and put a custom exhaust that weighs less.

[DFW2011M56S]

Good idea. I'm also checking with local shops to see how much an x-pipe will cost me. From what I've been reading it looks like it sounds better and adds power. And cheaper!

I had $300 in mine - post cats and Y-pipe/resonators removed and replaced with test pipes and handmade X pipe and welded to the stock piping and mufflers. OEM flanges were left intact, and I left the flex connectors. You can see the newer piping vs the original. I had stayed with the 2" size because with a stock tune this set up is plenty big enough. Might pay $200 - $250 if you delete the Y-pipe only (not the post cats) and go with just an X-pipe.

2" is too small for our cars stock tune or not! Stock 317 hp Titan has 2 1/8" pipes and they are still restrictive. We have factory widebands and a mass air based system. The ECU will easily pickup on the extra airflow and keep us from running lean. If anything my car still runs too rich at wide open throttle. I am still running a performance tune based on a stock car.

If you really want the flex joints you can buy them universal 2.25 or 2.5". They tend to be somewhat restrictive in flow and over time develop leaks in them. We just put a new OEM Y-pipe on a used G37 at work that had developed a leak in one.

[armybrat]

Armybrat that stock exhaust looks like it is heavy. I def plan to get rid of mine and put a custom exhaust that weighs less.

Yeah with the post cats and Y-pipe/resonators it is heavy. Getting rid of those two items definitely lightened the load. The OEM mufflers are pretty heavy too.

My new 2-1/2" set up with the sport mufflers probably weighs less than the 2" OEM factory set up.

[Big_Tone]

Found a shop by my house and am having a 2 1/2" x-pipe installed for $180!

[armybrat]

2" is too small for our cars stock tune or not! Stock 317 hp Titan has 2 1/8" pipes and they are still restrictive. We have factory widebands and a mass air based system. The ECU will easily pickup on the extra airflow and keep us from running lean. If anything my car still runs too rich at wide open throttle. I am still running a performance tune based on a stock car.

Yeah 2" is too small at WOT, but for normal driving across the overall RPM range with the stock tune, I will amend my statement to say that it is fine (as opposed to "plenty big enough"), especially when you delete the post cats and Y-pipe/resonators. It opens up the flow more than you think, even for the OEM 2" size. Ask a few of the other forum members about their loss of performance at the low end when they went with a larger size pipe and kept the stock tune, even with an ECU reset. Yes, the factory exhaust could've been designed a lot better performance-wise, but being a luxury sedan I guess Infiniti wanted a more subdued system. There are several articles about exhaust pipe sizing and the pros and cons of going bigger,especially regarding the scavenging effects. I am not familiar with the Titan 5.6 motor, other than it has different heads vs the Infiniti, but I can tell you based on my experience with my car that it ran great with the post cat/resonator delete OEM 2" size and stock tune. I would've put it up against any other M56x (the AWD is slightly slower off the line) that has the stock tune and a larger diameter aftermarket bolt on exhaust like a Stillen, etc., or a larger custom exhaust.

If you really want the flex joints you can buy them universal 2.25 or 2.5". They tend to be somewhat restrictive in flow and over time develop leaks in them. We just put a new OEM Y-pipe on a used G37 at work that had developed a leak in one.

Yes that is what I did when I went to the 2-1/2" size. I ordered mine from Bear River Converters. The ID was only 1/8" smaller due to the weld bead inside, so I am not worried about restricting flow. I am a firm believer that they do help with the sound inside the cabin. As far as developing leaks, yeah I agree they can...my original ones had 63,000 miles on them and they were fine, so I guess if I can get that much out of them I am good with that. Anyway just my $.02 give or take a penny.

[Big_Tone]

I'll post pics in a few. Nothing much to look at. I put in 2.25" pipes, but not all the way back to the muffler. I went back and forth with the guy at the shop about it, but I started to feel like he either wasn't comfortable doing it, or not comfortable doing it for the price he quoted lol. It's no big deal, though. I may go with the Stillen mufflers and if I do they'll replace the remaining 2" pipe that he didn't.

I'm very happy with the improved sound, BTW. As soon as I started the car my son asked if I didn't anything to the engine. He could hear the difference

[Big_Tone]

Here's what I had done...

[armybrat]

Cool...looks like you went with straight duals vs the X-pipe though, hence the cheaper price. I also noticed an improvement in gas mileage when I did mine.

[walt1227]

So how do we get HP gains out of this car using a custom exhaust if it is so restricted? Stillen sounds pointless from a financial standpoint if it doesn't add HP. I want more than just louder sound. I want added performance and at what $1200 or so for a Stillen exhaust and no added HP is foolish and not worth it imo. I remember adding flowmasters, borla, etc exhaust to other cars in the past and not only did it increase the sound it added a little bit of HP and performance. Maybe I'm not understanding this exhaust issue with the 56? Also can someone please explain the situation requiring a custom tune if doing an aftermarket exhaust?

[Big_Tone]

Cool...looks like you went with straight duals vs the X-pipe though, hence the cheaper price. I also noticed an improvement in gas mileage when I did mine.

Yep. I went straight pipe. I initially asked for an x-pipe, but he recommended the straight pipe. I'm very pleased with the sound. I haven't had a chance to get on the highway to see what the performance differences are. Nice to hear it improves gas mileage! Going forward I'm debating whether I should get the Stillen mufflers or the OEM sport mufflers, but this should hold me over for a bit.

[Big_Tone]

So how do we get HP gains out of this car using a custom exhaust if it is so restricted? Stillen sounds pointless from a financial standpoint if it doesn't add HP. I want more than just louder sound. I want added performance and at what $1200 or so for a Stillen exhaust and no added HP is foolish and not worth it imo. I remember adding flowmasters, borla, etc exhaust to other cars in the past and not only did it increase the sound it added a little bit of HP and performance. Maybe I'm not understanding this exhaust issue with the 56? Also can someone please explain the situation requiring a custom tune if doing an aftermarket exhaust?

All good questions. I agree the Stillen catback is a waste if all it does is sound better, which is why I went with the straight pipe instead. Cost about 10% of what I would've paid for Stillen and (from what I understand) I will get better performance AND better sound. The resonators in our exhaust, along with the y-pipe restrict the system, slowing it down. Getting rid of those parts and increasing the pipe to anywhere from 2-2 1/2" allow the system to perform better.

Auto experts, did I get that right?

[armybrat]

Cool...looks like you went with straight duals vs the X-pipe though, hence the cheaper price. I also noticed an improvement in gas mileage when I did mine.

Yep. I went straight pipe. I initially asked for an x-pipe, but he recommended the straight pipe. I'm very pleased with the sound. I haven't had a chance to get on the highway to see what the performance differences are. Nice to hear it improves gas mileage! Going forward I'm debating whether I should get the Stillen mufflers or the OEM sport mufflers, but this should hold me over for a bit.

You'll want to add the X pipe eventually. With this motor being a DOHC V8, when you have two cylinders firing on the same side sequentially (in this case, #3 and #7 on one side and #2 and #4 on the other side) you're squeezing the exhaust gasses into a single pipe. The X-pipe allows gasses from each bank to exit through both pipes, thus balancing the exhaust pulses and makes for better performance. Oh yeah straight duals sound great but you're sacrificing a little HP and torque in the process.

[Big_Tone]

Yep. I went straight pipe. I initially asked for an x-pipe, but he recommended the straight pipe. I'm very pleased with the sound. I haven't had a chance to get on the highway to see what the performance differences are. Nice to hear it improves gas mileage! Going forward I'm debating whether I should get the Stillen mufflers or the OEM sport mufflers, but this should hold me over for a bit.

You'll want to add the X pipe eventually. With this motor being a DOHC V8, when you have two cylinders firing on the same side sequentially (in this case, #3 and #7 on one side and #2 and #4 on the other side) you're squeezing the exhaust gasses into a single pipe. The X-pipe allows gasses from each bank to exit through both pipes, thus balancing the exhaust pulses and makes for better performance. Oh yeah straight duals sound great but you're sacrificing a little HP and torque in the process.

Ah. Good to know!

[walt1227]

Will doing this type of setup work and add power? Delete resonators, remove post cats, add x pipe, and magna flow mufflers. Probably do 2.5" pipes all the way around with tips big enough to fill the wells of the bumper. I'm guessing 4.5" to 5" in circumference tips.

[armybrat]

So how do we get HP gains out of this car using a custom exhaust if it is so restricted? Stillen sounds pointless from a financial standpoint if it doesn't add HP. I want more than just louder sound. I want added performance and at what $1200 or so for a Stillen exhaust and no added HP is foolish and not worth it imo. I remember adding flowmasters, borla, etc exhaust to other cars in the past and not only did it increase the sound it added a little bit of HP and performance. Maybe I'm not understanding this exhaust issue with the 56? Also can someone please explain the situation requiring a custom tune if doing an aftermarket exhaust?

Will doing this type of setup work and add power? Delete resonators, remove post cats, add x pipe, and magna flow mufflers. Probably do 2.5" pipes all the way around with tips big enough to fill the wells of the bumper. I'm guessing 4.5" to 5" in circumference tips.

Yes it will, but you just won't realize it in a car that already has 420 hp...and most of that will be in the upper rpm range. The ECU will pick up on the extra airflow, but there are other settings that can be adjusted with a custom tune that will really make a difference. Here's a good thread on that:
trying-to-unleash-the-beast-tuning-my-m56s-t592787.html

As far a spending money on the Stillen, I can't say too much, as I spent $691 on the sport mufflers. Good thing about the Stillen cat back and axle back is that it is a bolt on system that you can install yourself, same as the sport mufflers. Yeah you can get the post cat/resonator delete and Magnaflow mufflers installed at a shop for about the same price, maybe less. You can run a custom exhaust with a stock tune no problem; just don't expect to feel any major difference in performance. The sport mufflers are 4" diameter, and they fill the bumper well pretty good.

[walt1227]

Cool.I just don't want it to be so loud the neighbors can hear it coming down the road. I use to drive a Firebird Formula 350 with two straight pipes in place of the cats and a Flow masters muffler out the back with two quad turbo tips on each side. You could hear it a mile away even just cruising. I'm looking for something around the sound of the cls55 amg that my cousin has. It has a nice deep rumble at idle and cruising but opens up when you get down on it. The sound of a challenger with just a cat back system is way to loud for me. These cars don't need to be very loud at all but enough to know it is a V8. Heck it is sad that a stock camaro, mustang, and charger come from the factory with more sound than the 56 did.

[armybrat]

Cool.I just don't want it to be so loud the neighbors can hear it coming down the road. I use to drive a Firebird Formula 350 with two straight pipes in place of the cats and a Flow masters muffler out the back with two quad turbo tips on each side. You could hear it a mile away even just cruising. I'm looking for something around the sound of the cls55 amg that my cousin has. It has a nice deep rumble at idle and cruising but opens up when you get down on it. The sound of a challenger with just a cat back system is way to loud for me. These cars don't need to be very loud at all but enough to know it is a V8. Heck it is sad that a stock camaro, mustang, and charger come from the factory with more sound than the 56 did.

I hear ya. Based on your preferences and how my current set up sounds, I would recommend that you delete just the Y-pipe/resonators and go with the X-pipe and Magnaflow or Flowmaster. Of course there are different model mufflers as well, so checkout their website and YouTube. Here's a good writeup on Magnaflow vs Flowmaster: http://exhaustsystemsguide.com/magnaflow-vs-flowmaster

Also, the M is technically a base model luxury sedan, hence the more mellow sound vs a Camaro, Mustang or Challenger which are sports cars. The Mercedes AMG cars are a whole different level of high performance in themselves; their engines and exhausts are not even stock. FYI, with the post cat/resonator delete, 2-1/2" X-pipe and performance mufflers and Uprev custom tune, the M56 can be a low 12 second or even a high 11 sec 1/4 mile car which beats the CLS55 AMG 1/4 mile times. The forum member who I bought the X-pipe set up from posted a 12.88 sec time @ 111.09 mph with the above mentioned mods which is close already. That was with no advanced timing change and 20" heavier wheels.

[walt1227]

Cool.I just don't want it to be so loud the neighbors can hear it coming down the road. I use to drive a Firebird Formula 350 with two straight pipes in place of the cats and a Flow masters muffler out the back with two quad turbo tips on each side. You could hear it a mile away even just cruising. I'm looking for something around the sound of the cls55 amg that my cousin has. It has a nice deep rumble at idle and cruising but opens up when you get down on it. The sound of a challenger with just a cat back system is way to loud for me. These cars don't need to be very loud at all but enough to know it is a V8. Heck it is sad that a stock camaro, mustang, and charger come from the factory with more sound than the 56 did.

I hear ya. Based on your preferences and how my current set up sounds, I would recommend that you delete just the Y-pipe/resonators and go with the X-pipe and Magnaflow or Flowmaster. Of course there are different model mufflers as well, so checkout their website and YouTube. Here's a good writeup on Magnaflow vs Flowmaster: http://exhaustsystemsguide.com/magnaflow-vs-flowmaster

Also, the M is technically a base model luxury sedan, hence the more mellow sound vs a Camaro, Mustang or Challenger which are sports cars. The Mercedes AMG cars are a whole different level of high performance in themselves; their engines and exhausts are not even stock. FYI, with the post cat/resonator delete, 2-1/2" X-pipe and performance mufflers and Uprev custom tune, the M56 can be a low 12 second or even a high 11 sec 1/4 mile car which beats the CLS55 AMG 1/4 mile times. The forum member who I bought the X-pipe set up from posted a 12.88 sec time @ 111.09 mph with the above mentioned mods which is close already. That was with no advanced timing change and 20" heavier wheels.

Thanks again! Yeah I think I am going to do that setup with the resonator delete, cats delete, add x-pipe and magna flow or borla mufflers with 5 inch tips. I just love big tips on cars plus it gives that deeper sound over smaller tips. I want to make the car lighter versus making it heavier because reducing the weight will make it faster as well. I really love the sport rims but I may change them out next year for lighter 20's. I would love to do a two-tone black with high polish silver set of rims with a custom infiniti logo cap in the center to make it seem like factory wheels.

Something very similar to these wheels right here that I can't seem to find out who makes them.
https://www.youtube.com/watch?v=qNzsEcFbXDE

[Big_Tone]

I hear ya. Based on your preferences and how my current set up sounds, I would recommend that you delete just the Y-pipe/resonators and go with the X-pipe and Magnaflow or Flowmaster. Of course there are different model mufflers as well, so checkout their website and YouTube. Here's a good writeup on Magnaflow vs Flowmaster: http://exhaustsystemsguide.com/magnaflow-vs-flowmaster

Also, the M is technically a base model luxury sedan, hence the more mellow sound vs a Camaro, Mustang or Challenger which are sports cars. The Mercedes AMG cars are a whole different level of high performance in themselves; their engines and exhausts are not even stock. FYI, with the post cat/resonator delete, 2-1/2" X-pipe and performance mufflers and Uprev custom tune, the M56 can be a low 12 second or even a high 11 sec 1/4 mile car which beats the CLS55 AMG 1/4 mile times. The forum member who I bought the X-pipe set up from posted a 12.88 sec time @ 111.09 mph with the above mentioned mods which is close already. That was with no advanced timing change and 20" heavier wheels.

Thanks again! Yeah I think I am going to do that setup with the resonator delete, cats delete, add x-pipe and magna flow or borla mufflers with 5 inch tips. I just love big tips on cars plus it gives that deeper sound over smaller tips. I want to make the car lighter versus making it heavier because reducing the weight will make it faster as well. I really love the sport rims but I may change them out next year for lighter 20's. I would love to do a two-tone black with high polish silver set of rims with a custom infiniti logo cap in the center to make it seem like factory wheels.

Something very similar to these wheels right here that I can't seem to find out who makes them.
https://www.youtube.com/watch?v=qNzsEcFbXDE

Reading the comments people posted it says the wheels are made by a company called Savini. The video is about 5 years old though, so they may be discontinued.

[Big_Tone]

Sooo, I was able to get a great deal on some OEM M56s mufflers from a forum member and decided to have them installed along with an x-pipe today. I also added HPS intake tubes. These upsgrades along with the timing change work, I definitely feel more power. I'm very pleased! Here are a coupe pics of the updated exhaust work just before they finished. The tailpipes were a little off center, but they're good now.

[walt1227]

Sooo, I was able to get a great deal on some OEM M56s mufflers from a forum member and decided to have them installed along with an x-pipe today. I also added HPS intake tubes. These upsgrades along with the timing change work, I definitely feel more power. I'm very pleased! Here are a coupe pics of the updated exhaust work just before they finished. The tailpipes were a little off center, but they're good now.

Tone, that looks nice man. When you get a chance please make some video clips of it idling, revs, and driving. Did you get rid of the cats or are they still on the car. I see something that looks like cats up to the front but not sure if those are the first set that we can't remove or the second set we can remove. Never seen under the car before.