Finding the right catback is exhausting!

[smackrel]

I think that one of the things that make them better at not transferring sound/vibration is all the negative space in the middle.

[Spuds]

Originally Posted by smackrel

I think that one of the things that make them better at not transferring sound/vibration is all the negative space in the middle.

I have a feeling it has more to do with the elasticity and mass of the different sections but that's not my area of expertise.

[Spuds]

I did wind up getting all the tools I needed to analyze the exhaust resonance, but I got distracted and lost motivation lol. I kind of got my heart set on finding the holy grail of catbacks, a single-exit that sounds great but doesn't drone or break sound when you have headers... And there's a bunch of other criteria I have on top of that that would take too long to go through lol.

In the meantime, I found out a friend has a TRD catback in his spare parts closet. Probably gonna try that on and see if it will offer temporary relief. I'm not really a fan of the D shape tips, but if it is in better shape than my stock catback and sounds alright I might keep it for a bit.

Before I do that, I need to cut off the stupid flared donut gasket ring JDL welded on and get someone to weld on a simple, straight 65mm ring so I can use standard-sized donut gaskets like a sane person.

[vindiesel]

Cost effective would be uel catted and stock catback.

I’m going remark axle back with muffler should be minimal drone seems to be the quietest exhaust.

Technically the stock exhaust has drone just depends on your sensitivity.

[Muskoka800]

FYI, if the Crosstrek (FB20 or FB25) is like the FA20 in the FRS/BRZ axle backs make zero performance gain, only sound changes.
Only a header &/or performance front pipe add power while also increased sound.
I run a catless header and catted/resonated front pipe followed by stock mid-pipe and stock axle-back on my super-charged FRS. It growls plenty.

Whoops! Wrong forum. My bad.

[RToyo86]

Originally Posted by Spuds

I did wind up getting all the tools I needed to analyze the exhaust resonance, but I got distracted and lost motivation lol. I kind of got my heart set on finding the holy grail of catbacks, a single-exit that sounds great but doesn't drone or break sound when you have headers... And there's a bunch of other criteria I have on top of that that would take too long to go through lol.

In the meantime, I found out a friend has a TRD catback in his spare parts closet. Probably gonna try that on and see if it will offer temporary relief. I'm not really a fan of the D shape tips, but if it is in better shape than my stock catback and sounds alright I might keep it for a bit.

Before I do that, I need to cut off the stupid flared donut gasket ring JDL welded on and get someone to weld on a simple, straight 65mm ring so I can use standard-sized donut gaskets like a sane person.

I would be amazed if the TRD didn't drone worse than the HKS. I tried one for a week before uninstalled it and moved on. 3000rpm range was particularly bad, especially on decel.

Assuming your ears are as sensitive as mine most CBE hit a resonance once exhaust gets hot. I started taking allergy pills which helped with my sinuses which took the edge off ear pain and headaches from it.

Ultimately CSG touring is what fixed it for me. Greddy SP, and fujistubo Authorize S both had frequencies that bothered me, even though the authorize was actually quieter than the CSG or at least hid more rasp from the JDL EL.


For stock CBE I liked UEL header, ultra quiet FP and stick CBE for stealth. Never tried the CSG with that, almost snagged a JDL uel cheap last year before the ACE header popped up from a friend and switched from the JDL EL.

Authorize S

Stock CBE

CSG touring

[NoHaveMSG]

Originally Posted by RToyo86

Assuming your ears are as sensitive as mine most CBE hit a resonance once exhaust gets hot. I started taking allergy pills which helped with my sinuses which took the edge off ear pain and headaches from

Hearing this makes me so glad I have zero sensitivity to this. Plus Im too busy listening to my IRP shifter rattle

[mrg666]

On my 2014 FRS (JR SC), I have the HKS Hi Power SpecL exhaust + HKS dual resonator front pipe (catless) + upgraded 2019 header (with cat). Drone is not that bad for me. There is some around 2000 and disappears after 2500 rpm. You could try the front pipe.

There are 4 resonator (2 mid pipe, 2 front pipe) + 2 separate straight-through mufflers in my configuration. And, the first resonator on the mid pipe is Helmholtz.

Of course, supercharged engine has different exhaust pressure. So, drone will also be different.

[Spuds]

I wound up trying out the Apexi N1 Evolution R. It still drones pretty bad, but the headache-inducing resonance is gone. Definitely a smaller RPM range of drone, and it can be minimized by using a light foot or driving around it, which I definitely couldn't do with the hks. Long story short, I can work with this.

Apexi is not as loud as I feared it would be for a straight through 2.5" single exit. Sounds a bit like stock higher up in the rev band actually, but deeper rumble lower. Can't really hear much in the middle other than drone lol. I do miss the somewhat wild musical note from the hks, but I guess the apexi sounds more... racecar?

Debating whether I will try to add a helmholtz resonator somewhere on it to reduce drone. Way more simple than the hks for that purpose if I decide to try it.

Little shout out to sales folks at Speed Industry (86 Speed) for the help getting this one.

Forgot to take a good picture while the car was on the ground, and now it's back on stands again because I just can't stop myself...

[spcmafia]

Originally Posted by Spuds

I wound up trying out the Apexi N1 Evolution R. It still drones pretty bad, but the headache-inducing resonance is gone. Definitely a smaller RPM range of drone, and it can be minimized by using a light foot or driving around it, which I definitely couldn't do with the hks. Long story short, I can work with this.

Apexi is not as loud as I feared it would be for a straight through 2.5" single exit. Sounds a bit like stock higher up in the rev band actually, but deeper rumble lower. Can't really hear much in the middle other than drone lol. I do miss the somewhat wild musical note from the hks, but I guess the apexi sounds more... racecar?

Debating whether I will try to add a helmholtz resonator somewhere on it to reduce drone. Way more simple than the hks for that purpose if I decide to try it.

Little shout out to sales folks at Speed Industry (86 Speed) for the help getting this one.

Forgot to take a good picture while the car was on the ground, and now it's back on stands again because I just can't stop myself...

Did you re-use the OEM hangers or got JDM ones.

JDL and Fujitsubo make double resonated Front Pipes but are pricey. Your best/cheaper chance is to go OEM Front Pipe to completely reduce drone.

[Spuds]

Originally Posted by spcmafia

Did you re-use the OEM hangers or got JDM ones.

JDL and Fujitsubo make double resonated Front Pipes but are pricey. Your best/cheaper chance is to go OEM Front Pipe to completely reduce drone.

I did get the JDM hangers for the hks, they helped, but not a lot. I am using 2 of the JDM hangers for the apexi, and had to go back to the original one in the way back because the angle between the hanger mounts caused the JDM to rub against the canister.