When do you need to get a tune?

[intoflatlines]

Tomorrow I'm getting a custom axle-back exhaust built. I'm debating having him build an x-pipe (with resonator) as well. But I'm worried about SES lights or losing power. It is my understanding that a tune is not necessary when just replacing the mufflers. Would a tune be required with an aftermarket x-pipe to ensure that I don't lose power?

[mfanatic325]

If your headers and section 1 (s-pipe) are both OEM, you won't need a tune even when modifying section 2 (x-pipe) or the muffler cannisters.

To put it simply, once you start removing any of your O2 sensors (whether it's the two in the OE headers or the two in the OE section 1), you should get a tune. Getting the tune not only can take care of SES light, but can also tie in your bolt-on mods for more power rather than less. Tunes, as you may already know, are for helping to utilize everything you have. Headers are best bang for the buck in terms of yielding more power, but ultimately it'll depend on what setup you choose. Do keep in mind your state's emissions laws in regards to removing any oxygen sensors.

[gferil]

^ yep, what mfanatic said.

I had intake and exhaust before my tune, and my dyno results showed that I lost a bit of power and smoothness but to be honest I could barely feel the power loss and the sound the mods made more than made up for any minor losses. But once I added the tune in, I gained back the smoothness and gained even more power, so I say if you plan on doing more mods later, then it will be helpful. Like mfanatic said, definitely needed once you put in headers (which I'm doing on Saturday!)

Keep us posted on your custom setup! I did one with mine with Aero Turbine cans and resonators in the Xpipe and am happy with it so far. On a side note it's funny to hear "axle back" on our cars...cause that literally means about 1" of piping, the mufflers, and then tips cause there is just no room back there!

[intoflatlines]

Thanks.

Haha regarding axle-back... imagine my surprise when I found out that the tiny axleback sections cost $1000-$3000+

I'll probably just do the muffler replacement for now, and see how that sounds to start. I just don't want to lose power by doing the X pipe with no tune

GoPro videos will come

[DRedman45]

Gferil, what aero cans are you using, 2525's?

[RobMCoupe]

People change out X-Pipe to delete resonator. Why are you building a custom X-Pipe with resonator that is same as stock?

[intoflatlines]

It was my understanding that a muffler replacement will make the exhaust sound very raspy, so I was considering switching out the tiny resonator in the x-pipe to a Magnaflow for more volume, but less rasp. If that's not how it works, let me know!

[mfanatic325]

Originally Posted by intoflatlines

It was my understanding that a muffler replacement will make the exhaust sound very raspy, so I was considering switching out the tiny resonator in the x-pipe to a Magnaflow for more volume, but less rasp. If that's not how it works, let me know!

Rasp will only come when you remove any of the catalytic converters. As I mentioned above, there are two "cats" in the headers, and two "cats" in the section 1 (S-Pipe). Removal of any of those will yield more rasp.

Changing out just the muffler cannisters will yield higher volume and change the characteristic of the sound of the car, and I recommend it to most people. However, I don't recommend people change out headers and/or section 1 IF they need to worry about emissions/smog/visual inspection, etc. etc.

Same thing goes for the section 2 (X-Pipe): changing that out will not necessarily yield much more rasp. In fact, X-Pipe from what I remember, only increased volume by a tad bit. It is good for very slight power increase as well if you couple everything with a tune.

[gferil]

OP, that's exactly why I started going custom route, the cost of "axle back" for our cars was ridiculous. In fact, I'm on my second custom system now and I've still spent less than $1K combined.

DRedman45, I'm using the AT2525's. My original plan was to also use AR25's in the Xpipe but there just wasn't enough room.

Rob, yep, I was just experimenting (you know me), The little resonator in the OEM Xpipe is actually a straight through design, pretty much the same thing as the AR25's from Aero (at least that's what it looked like when I cut mine open). For now I just have some simple resonators in there to cut down on overall noise, I'm guessing my current Xpipe setup is a tad quieter than OEM since the resonators I put in are larger, but it's still a straight through design so hopefully little to no loss in performance. I'm also guessing that is why most people don't see much of a change in performance or sound when they swap out Xpipes, cause the stock resonator in there didn't really look like it did much anyway. Oh well, now I know.

Again, OP, I second what mfanatic says in the post above. I'm curious to see how much more rasp I have once I get my headers put in. My first custom setup was just a muffler delete and replace with generic resonators. My second custom setup is the Aero Turbines as mufflers with the OEM resonator in the Xpipe replaced with some slightly larger resonators. The sound of my second system is much less "boomy" than my first, not as loud, not as much drone, and much more "exotic" sounding, but also now has rasp, whereas my first system didn't have any rasp at all.

[mfanatic325]

I would recommend for anyone looking to upgrade headers and/or section 1 (S-Pipe) to do one OR the other, and NOT both. Because I've removed all four catalytic converters before and the rasp drove me insane. So unless you're into rasp, I'd say just do headers only, and leave section 1 stock. Unless of course you want to put in some kind of resonators or high-flow cat in the section 1 or something. That is more than okay

[Rated M Roadster]

Originally Posted by mfanatic325

I would recommend for anyone looking to upgrade headers and/or section 1 (S-Pipe) to do one OR the other, and NOT both. Because I've removed all four catalytic converters before and the rasp drove me insane. So unless you're into rasp, I'd say just do headers only, and leave section 1 stock. Unless of course you want to put in some kind of resonators or high-flow cat in the section 1 or something. That is more than okay

I removed all my cats and put in AR20 resonators and there's no rasp.

[mfanatic325]

Originally Posted by Rated M Roadster

I removed all my cats and put in AR20 resonators and there's no rasp.

golf clap for you my friend!

Wish you were local so I could try on your custom section 1

[intoflatlines]

OK, I did just the axle back today. It drones so incredibly loud from 1000-3500RPM. It sounds fine from the outside though. After 3500RPM it sounds great both inside and out.

[JeffchaPz]

Hummmm I have euro headers, OEM sect 1, OEM Sec 2 and magnaflows.... right now the car sound nice, loud with no rasp unless I step on and go over 6k I get a little rasp.

However, the drone in 5-6th gear around 2k rpm make it impossible to have a normal conversation in the car. SO, I was planning to get rid of the OEM resonator and see if could get two AR20 squeezed in there to tone it down a little and hope to also help with the drone.... I still like the high-flow mufflers and kind want to keep it as straight through if possible.

Does anyone have resonators after sec1 and the mufflers? if so, where did you put them?

Or should I go for a quieter exhaust after getting rid of the OEM resonator?

thoughts?

[intoflatlines]

Quick pic and video of the new setup. I think I need to add a helmholtz resonator or something because the drone is honestly terrible. A GoPro video will be added later.

[gferil]

Originally Posted by intoflatlines

OK, I did just the axle back today. It drones so incredibly loud from 1000-3500RPM. It sounds fine from the outside though. After 3500RPM it sounds great both inside and out.

Looks great! And that sounds exactly like my first custom setup since I did pretty much the same thing as you. Mine only droned between 2200-3500K though, so I'm guessing that's attributed to just different types of resonators but we both had the same tips (love that style).

So, it won't help get rid of the drone, but it tames it down to a level that is, for the most part, acceptable if you Dynamat the trunk and back trunk wall area, which is what I did. Dynamat is fairly cheap, easy to apply, and the weight it adds is negligible compared to the weight you saved by taking out the stock mufflers.

[gferil]

Originally Posted by JeffchaPz

Hummmm I have euro headers, OEM sect 1, OEM Sec 2 and magnaflows.... right now the car sound nice, loud with no rasp unless I step on and go over 6k I get a little rasp.

However, the drone in 5-6th gear around 2k rpm make it impossible to have a normal conversation in the car. SO, I was planning to get rid of the OEM resonator and see if could get two AR20 squeezed in there to tone it down a little and hope to also help with the drone.... I still like the high-flow mufflers and kind want to keep it as straight through if possible.

Does anyone have resonators after sec1 and the mufflers? if so, where did you put them?

Or should I go for a quieter exhaust after getting rid of the OEM resonator?

thoughts?

So I had the same exact idea as you when I fabricated my second custom system. However, there was just no way to fit the AR20's after section 1 cause there is just no room under the car for them unless you completely remove that rigid plate under the X pipe. The only place that looked like they would fit is in the section 1 S pipe, which I didn't want to modify just yet.

So for now I have Aero AT2525's for mufflers, and then the smallest resonators that the shop could find in a custom X Pipe setup. However, even those small ones required crafty installation, we had to shim that rigid plate (use metal spacers to drop it down an inch or so) on the back. Sound is great, quieter than my first custom setup but still aggressive, and I like the sound much better since it is more exotic sounding.

There is more rasp in this setup though, and I'm thinking it has to do with the type of resonator. The AR20 is a straight through design with a perforated inner that has packing material in it. This is pretty much the same type that the OEM X Pipe has (I cut mine open just to see), and it actually is a straight through design with a perforated inner with packing material. The resonator I replaced it with is the type that uses "chambers" to resonate the sound waves, not packing material. So it seems that the packing material type helps cut down rasp, while the chamber type helps cut down noise better.

My advice to you, is same as my post above, try Dynamat in the trunk first to cut down on drone. As far as rasp, not sure what to say there, unless your shop can figure out a way to make the AR20's fit. Maybe a slightly larger muffler will help? But that will require you to cut into the OEM X Pipe...

[intoflatlines]

Thanks. After another drive today it seems like the drone is actually strongest at around 2300-2500RPM. I might see if I could add a helmholtz resonator pipe but I'm not sure if there's enough room. I'm going to give it a few hundred miles to possibly break it, then if that doesn't work I'll try the dynamat. I'm also going to test the dB with an SPL meter sometime this weekend.

[intoflatlines]

[kennyfrc]

Playing around with piping most often results in a LOSS of power.

[intoflatlines]

Are you referring to my earlier thoughts of adding a helmholtz resonator pipe?

[JeffchaPz]

Originally Posted by gferil

So I had the same exact idea as you when I fabricated my second custom system. However, there was just no way to fit the AR20's after section 1 cause there is just no room under the car for them unless you completely remove that rigid plate under the X pipe. The only place that looked like they would fit is in the section 1 S pipe, which I didn't want to modify just yet.

So for now I have Aero AT2525's for mufflers, and then the smallest resonators that the shop could find in a custom X Pipe setup. However, even those small ones required crafty installation, we had to shim that rigid plate (use metal spacers to drop it down an inch or so) on the back. Sound is great, quieter than my first custom setup but still aggressive, and I like the sound much better since it is more exotic sounding.

There is more rasp in this setup though, and I'm thinking it has to do with the type of resonator. The AR20 is a straight through design with a perforated inner that has packing material in it. This is pretty much the same type that the OEM X Pipe has (I cut mine open just to see), and it actually is a straight through design with a perforated inner with packing material. The resonator I replaced it with is the type that uses "chambers" to resonate the sound waves, not packing material. So it seems that the packing material type helps cut down rasp, while the chamber type helps cut down noise better.

My advice to you, is same as my post above, try Dynamat in the trunk first to cut down on drone. As far as rasp, not sure what to say there, unless your shop can figure out a way to make the AR20's fit. Maybe a slightly larger muffler will help? But that will require you to cut into the OEM X Pipe...

Thanks for the info - I'll look into the Dynamat. However, now that the weather is getting warmer, driving with the windows down is more fun.
With the top and windows up >> drone is bad.

Anyone ever tried the Dynomaz VT mufflers?

http://www.dynomax.com/mufflers.php