Resonated X Pipe - Which One?

[Scootsmcgreggor]

So I'm gathering odds and ends for my coyote swap and want to keep the exhaust as quiet as I can while still maintaining decent flow. I drive the car to and from the track, and Laguna is 45 mins away so would like to be able to continue running there (preferably without laguna pipes, one less thing to worry about).

So I'm looking at resonated X pipes. There are two I've found. A number of people have done the Magnaflow and it seems to generally sound pretty good. But the "X" is not exactly an X, more like and H pipe with a little shape to it. Then there's the Dynomax which is a true X. Anyone run either of these? Anyone with knowledge of exhaust scavenging care to comment on whether I could expect any better performance with the true X pipe in the Dynomax or am I just overthinking this like I do every damn detail?

Magnaflow:


Dynomax:

 

[Mad Hatter]

Are you looking at performance first, DB level second?? Or the other way round?? The setups you have in the post look like they are very much for sound and not so much for HP.

 

[Scootsmcgreggor]

Good question. I want the quietest hp I can get. But unfortunately keeping sound down is #1 priority.

Prob looking at dual 2.5”

 

[Mad Hatter]

Good question. I want the quietest hp I can get. But unfortunately keeping sound down is #1 priority.

Prob looking at dual 2.5”

What is your DB limit for laguna?? 95? Down here we have a strict 90DB limit at 6000rpm in a sound boooth. its a biznitch...but can be done. My car has a custom 3" exhaust LTH and no cats with a decent 468rwh. With a bit of care you can do it and Its cheaper then you think.

If you have a a stock exhaust, I would imagine that either of those muffled suedo Xpipes will get you below 90Db.

A Camaro I ran against spent a fortune with a Borla setup with 4 glass packs and two mufflers...and it went from 110DB to 97DB.... car never got on the track again becuase of the new 90Db rules.

 

[xr7]

The DynoMax looks a little restrictive, both pipes merging into one before splitting back into two pipes.

 

[Scootsmcgreggor]

90db at Laguna.

I went back and re-read the other exhaust noise limit threads.

Looks like there are a number of ways to skin this cat but seems a bit of trial and error potentially. I’m also a bit afraid of making a system that works but also doesn’t sound that good. I guess I’m looking for a unicorn, a good flowing system that’s quiet but also sounds good, and while I’m at it how about cheap too?

Ok so back to reality. Was thinking to add an x pipe of some sort and a muffler replacement. Based off the stock 2.5” tubing as 3” will be heavier, louder, cost more money, and from what I’ve read maybe not make much more power than a 2.5” system. Not sure about the power, mostly anecdotes can’t find any dynos. Will do 3” if it clearly makes more power below 450whp.

Again maybe I’m making this way more complicated than it needs to be. But I sure know I’m not spending $2k on a catback when I’ve got this welder sitting in the garage begging to be used.

@xr7 thanks for the comment, I definitely see what you mean.

 

[JDee]

I replaced the resonator with an H pipe, the rest of my system is stock GT. No idea if it helps power or not, probably not, but it was a lot lighter and it does not add much, if any, noise. It passed sound at Mont Tremblant and they're very strict there. I think it came from Steeda but l doubt there's much if any difference between the different ones available.

I think this track's days are numbered, if it's on your bucket list better run it soon. It's 55 db, according to this:

Circuit Mont-Tremblant : victoire pour l’action collective | Tremblant Express

Les membres de l'action collective contre le Circuit Mont-Tremblant remportent une victoire en Cour supérieure. « On a gagné! Pas sur tout, mais sur l’essentiel, et dans un jugement fouillé et…

tremblantexpress.com

Edit: It's 92 dBA at the track, the 55 thing is at the place of whoever is complaining. I think. It's hard to know for sure, it's Quebec and they're kind of, well, different. Not that that's a bad thing or anything, hell no! Vive la diffference? I think? I dunno. Sorry for hijack.

 

[Champale]

Hey Scoots - I don't have any experience with noise meters but I can tell you about my experiments with mid pipes on my GT350R and how I was able to take the edge off the exhaust note with a couple of different versions. I bought Shifteck H and X 2.5" pipes and installed some resonators. The H pipe has Borla 10" resonators (about $100/each) and it really made the engine note a lot deeper and quieter (not quiet, though! It was still pretty loud!). With the X pipe, I installed some cheap Amazon 7" resonators and it also toned the exhaust down a bit and kept the characteristic GT350R roar/scream/yell. My final version (not pictured) uses the Shiftek X with the 7" resonators and 2.75" pipe on the back side to mate up to the OE 2.75" back section of the 350R exhaust.

Just FYI - I dyno'd the car with OE exhaust then we installed the H pipe (before adding the resonators) and the car picked up over 10whp. The guys at the shop were just as surprised as me! The runs were about an hour apart. I have not run it with the X.

 

[Mad Hatter]

We dropped 2Db by adding a Xpipe after the Hpipe. Or you could add two X pipes, anything that mixes the frequency and amplitude helps lower the sound level. We added a Dynomaz ultra flow muffler and a Dynomax Race Bullet after the H pipe.

 

[Scootsmcgreggor]

Really appreciate the insight guys. I didn’t know about the bottle resonators. Seems like the best option. While I’m not sure I’ll benefit from a 3” system I’d also prefer not to find out I’m wrong down the line and need to re-do things so I’ll probably build a 3” system from the get go. Last part is to figure out which mufflers.