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Discussion Starter #1 (Edited)
Due to popular demand from others looking for a more tame exhaust, I wrote a review with videos of the Milltek catback for the Subaru Impreza GR generation STi hatchback.

I had read a lot of the reviews on the Corsa exhaust and bought one trying to find a catback with more flow than stock, but sadly I was disappointed by the loudness of this cat back, more importantly by all the flak I caught from my wife. I did not want a cat back that was boomingly loud, a lot louder than stock. From my experience at local Subaru meets, autocrosses and track days, I would say anyone in this predicament who is looking for an exhaust that is not much louder than stock is going to be disappointed with most Subaru exhausts. I have heard from more than one mechanic as well as tuners (plural) that the Subaru crowd generally tends to favor very loud exhausts, perhaps almost as loud as the Civic ricers with all their fart cans; for the most part the ULH rumble design with exhaust pulses crashing into one another does a lot of muffling before the resonator and muffler, almost letS us get away with it.

But what about those of us whose preferences or life position (or both) would have us rather avoid failing inspection, upsetting the wife, waking up your entire neighborhood, attracting police or street racing negative attentions alike? What are the options in terms of a 3" cat back if a Subaru STi owner would like the flow such an exhaust allows, but none of the noise?

In my search for a quiet, free-er flowing catback, I was recommended the Milltek exhaust by several other drivers who not only owned it, but combined it with other mods like a downpipe or the header to end all Subaru headers, the Killer B manifold. This latter beast is truly wonderous but because it works magic for flow, spool, power and responsiveness, the tidal wave of exhaust so good for your turbo and right foot also gives it so many resonations at many never before heard frequencies making for fartiness, drone and rasp. Granted most of the Subaru exhausts are very loud, but these mods here do increase the noise even on the stock catback to levels that are generally still not over the top, but about as loud as one could get away with cranky cops, restrictive laws regarding aftermarket exhausts as well as the wife & neighbor factors.

I am very happy with the Milltek catback but I won't get into how it sounds so much as how loud it is not because this is a catback for those seeking the latter. Sure it sounds like a Porsche, sure it sounds like an exotic, if that's what you want to hear. Everyone says that about their exhaust because everyone thinks it. Opinions are like assholes, everybody's got one. My opinion is that I like the sound enough to make it worthwhile, but what I really like about this exhaust is the fact that it is about as loud as stock. It is in the same hunt of noise as stock, but a bit more aggressive. Factually speaking, it is slightly louder than stock on the outside, but slightly quieter than stock on the inside. Lowering the windows increases the tonality and makes it more fun to listen so down with the glass if you want to up the fun factor with this one. If anything at certain throttle positions it is a little too benign; you almost want to remove the main resonator, but not always because it delivers enough satisfaction. Certainly there are no sins of omission, it is never unliveable or obnoxious, not even close. I'd rather want 10% more noise than 75% less and if this is how you feel about most Subaru catbacks, then Milltek is for you.

The overlying theme is that there is a bit of a growl, some muted rumble, it sounds kind of mean but at the same time muted. Unlike say the Corsa exhaust whose noise level is logarithmic, with every little bit of engine load and pedal giving explosively more and more booming assault on your ears, the Milltek seems to have a glass ceiling past which there is little extra loudness with increasing load or throttle. Sure, giving it more pedal or more engine load makes it a bit louder, but it seems that past a certain point it doesn't want to get louder and louder so the booming and drone and rasp and farting if you hate all that is well contained. The wife, the neighbors and your inner ear will all thank you.

As far as the exhaust itself, it is a bit more expensive than most, but it is a quality piece. It bolted on by a mechanic who had never seen it in less than 30 minutes. It is solid, with high quality welds, and has a large muffler at the end, but the effect of extra packing on flow seems mitigated because the midpipe flows straight directly into the rear muffler and not curving around like so many GR hatch exhausts. You will also notice that each of the 4 quad tailpipes has little holes throughout its cicrumference because there are 4 extra resonators there to keep noise level down no matter what your mod set is.

Thanks to my buddy who helped me post these long videos of me just driving around town, traffic and highway, they should give you a really good idea if this exhaust is for you. But take it from me, fact is that it's about as loud as stock and in some situations marginally more, fewer still marginally less. If this is the kind of noise level you are looking for because maybe other exhaust mods are keeping the loudness about as much as you dare, then you'll love the Milltek, it does the job of keeping noise levels more than reasonably fun but above all reasonably inoffensive.

Without further ado, here are the videos long in the making. What I found is that the exhaust is louder, not softer than life. So you get a really good idea for what it sounds like though realize it is a bit tamer. It's because I have full bushings so the driveline whine kind of joins the exhaust note. But pay attention to my speech, my radar detector chirps, and background noise for a comparison and you'll see that the Milltek exhaust is not meaningfully louder than any of those. So in the search to find an exhaust that works well with ELH that doesn't rasp, drone or fart, Milltek does a really nice job.

Milltek Catback on a Subaru GR WRX STi - YouTube

Milltek Catback on a Subaru GR WRX STi (2) - YouTube
 

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Discussion Starter #3 (Edited)
Thanks for your informative review and the videos
The sound is take it or leave it. It's basically OEM like but more of a refined, "tuned" sort of sound. One can argue about whether one likes it or not but I can say for sure that Milltek is in the hunt with OEM for loudness. I think it does a better job with the ELH than OEM actually in filtering out sounds that are unpleasant.

A lot of people say "this is what I think it should have sounded like from the factory". Again one can agree about which exhaust fits this bill, but this is definitely an exhaust that could have come from the factory in terms of its loudness. People who have not hear an OEM STi before will not think it "has a catback". On the other hand it has a tuned feel to it as well so it does well in both regards.

The best recommendation for Milltek is for people who don't want something meaningfully louder than OEM. So if your state, like Massachusetts has laws prohibiting "any exhaust that is louder than OEM", Milltek will work well.

EDIT: from my experience, I have heard the following catbacks in person mostly at autocrosses or local meets and will range them in loudness:

1- Stock or Milltek are more or less equivalent, maybe the Milltek is 1.1 outisde but 0.9 inside with ELH.
2 would be slightly louder than stock, Cobb/SPT. Cobb better at quieting down more mods, SPT quieter bone stock but then goes to a 3 or 4 with more mods. I wouldn't go with SPT and ELH, bad combo, that one probably scores in the 4 territory.
3. Intermediate, somewhat louder than stock. Invidia Q300 and Nameless (fairly loud, some drone but less than others, with ELH starts going 3.5, Nameless better at muffling more mods so maybe 2.7).
4. Much louder than stock, start risking inspection and things like that Corsa/Invidia N1 (N1 probably a bit louder w/ other mods like DP)
5. (EXTREMELY loud, felony loudness) Tomei Expreme/Tanabe Concept G/Invidia Race. Tomei probably takes the cake in absolute loudness.
 

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NIce review. Yea I run the Cobb and I like it. Its not loud at all and yet it gives a deep enough tone that I feel like it brings the car to life a bit (epseicially with the Killer B header).

I have said this many times - as far as exhausts are concerned - the only one you could argue and prove that gives an ACTUAL performance boost over all the others is the Tomei Extreme Ti and thats because of its reduced weight and it has the least bends possible as its a single exit exhaust. However its loud as hell and sounds annoying. Exhausts boil down to noise and sound preference as all are going to perform really close to the same if they are a 3" construction. The performance benefits each one has over the other are going to practically be negligible.

I like the sound of this one though for sure too.
 

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I'm going to give this a try if the nameless 5" muffler is too loud.. I have killerb,1.5 and catless . Right now its through a invidia n1 and its ridiculous.
 

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Discussion Starter #7
It sounds freaking awesome. It does have that exotic tone to it. If only they made one for the gd.
They do:
Subaru Impreza 2.5 WRX and STi Milltek exhaust

The one thing is this, and I find myself in the same position of saying it because I am an asshole, or I have one just like everyone else. At least from what I can sniff, I can't smell shit from the distance my nose is to my rear end.

At any rate this is how I think the STi should have sounded from the factory. Almost everyone who is happy says that about their exhaust, but the reason I put a little extra feeling in this opinion of mine is because it has about the same noise level as stock, so it can pass for OEM like noise level. But within this universe, it sounds considerably more interesting than OEM while allowing for not just the same legality and noise level, but the noise level is not adversely affected should you want more mods downstream. In other words, whether you stay completely bone OEM stock otherwise or start slapping on downpipes, turbos and headers, the noise level won't grow to obnoxious or illegal levels.

I'll say at WOT the Corsa was more fun but the Milltek is a nice, mellow, better all around package. You can say that X exhaust works better than the Milltek in Y situation (WOT, with whatever kind of mods, you name it), but there really won't be a situation where the Milltek will fall short. The only way it might disappoint is the driver might want it slightly louder, but it's a small price to pay for the ability to hear yourself think.
NIce review. Yea I run the Cobb and I like it. Its not loud at all and yet it gives a deep enough tone that I feel like it brings the car to life a bit (epseicially with the Killer B header).

I have said this many times - as far as exhausts are concerned - the only one you could argue and prove that gives an ACTUAL performance boost over all the others is the Tomei Extreme Ti and thats because of its reduced weight and it has the least bends possible as its a single exit exhaust. However its loud as hell and sounds annoying. Exhausts boil down to noise and sound preference as all are going to perform really close to the same if they are a 3" construction. The performance benefits each one has over the other are going to practically be negligible.

I like the sound of this one though for sure too.
+1. Once you're 3" they all work more or less the same. I've heard from more than one reliable source past a certain power level you start to discern differences but that power level is very, very high, higher than most of us "stay stock", "stage 1/2" or even turbo upgrade people will do.
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I'm going to give this a try if the nameless 5" muffler is too loud.. I have killerb,1.5 and catless . Right now its through a invidia n1 and its ridiculous.
Some will argue but IMHO Killer B manifold is one of the best headers out there. But for the same reason it's so good, the flow, responsiveness and power, it was built for that purpose and introduces a lot of never before heard rasps, farts and drones. Many catbacks that would otherwise be well liked, even with other ELH setups sound awful with the Killer B header. Cobb and Milltek so far have been the only two I have heard that didn't sound tinny, raspy, ricey or farty in the negative stereotype of a 4-cyl kind of way. Not to degrade this wonderful header, but if it's not for a pure race car it's hard to find a catback that will mate well acoustically to attenuate all those extra noises.
 

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good review toivonen. good to put a voice to a screen name, too. i would've thought your voice was going to be deep and bassy like the corsa exhaust and not tinny and stock sounding like the milltek. ;) at least it wasn't farty.
 

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Discussion Starter #10
good review toivonen. good to put a voice to a screen name, too. i would've thought your voice was going to be deep and bassy like the corsa exhaust and not tinny and stock sounding like the milltek. ;) at least it wasn't farty.
:rofl:

Actually with the Killer B header the Corsa is very tinny and farty whereas the Milltek is more deep and bassy, it's the opposite....

As always love the friendship, camraderie, sense of humour and that you're still around!
 

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Toivonen, I've been following your search for the right exhaust (for you), and I'm glad you've found it! I haven't had anything to contribute to the conversation, but I wanted to say thank you for going out of your way to record these videos for us. The videos and your review are very helpful, and I think I'll have to add this exhaust to my shopping list now.
 

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Discussion Starter #13
Toivonen, I've been following your search for the right exhaust (for you), and I'm glad you've found it! I haven't had anything to contribute to the conversation, but I wanted to say thank you for going out of your way to record these videos for us. The videos and your review are very helpful, and I think I'll have to add this exhaust to my shopping list now.
I appreciate the kind words. I am trying to atone for how nasty I was with my reaction to the Corsa. Anger and hatred are the dark side of the force, but it was a lesson learned. So what do I have to offer?


The Milltek deserves credit because it is fun and rich enough on its subtle, refined sound considering how damn quiet it is. In other word what distinguishes the Milltek is its fun, sporty, aggressive yet subdued note that doesn't rely on loud volume to be fun combined with the possibility of 3" flow. There are other "fun" exhausts too but IMHO they all are more fun because they use loudness.

It may not be a big niche, but this is an exhaust that deserves consideration as it shows OEM like noise levels, with all their legal advantages, can actually be enjoyable if muffled properly into something aggressive yet subtle and still get the benefits of full turbo back flow.
 

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For fun one day I'll send you my catback. Just to see you go off on a longer than long rant on crap exhausts lol. Nice review btw. I'm looking at the blitz nur for my GR.
 

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I was actually thinking about this on my drive in to work this morning... your exhaust volume level sounds about as loud as my car, Corsa exhaust and all ;)
 

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Discussion Starter #17 (Edited)
For fun one day I'll send you my catback. Just to see you go off on a longer than long rant on crap exhausts lol. Nice review btw. I'm looking at the blitz nur for my GR.
No because from the sound of how you are implying your exhaust is, my expectation is that it would be very loud and likely met. While I dislike loud exhausts, since I would pay zero for it no harm no foul. I'd just say "fart can is as fart can does" or something like that!

I was actually thinking about this on my drive in to work this morning... your exhaust volume level sounds about as loud as my car, Corsa exhaust and all ;)
This is why videos are deceiving. There is a lot to say about this so let me try and be succinct.

First off I had mentioned in my review that the video is louder than what the exhaust sounds like in real life. Since the Milltek might appeal to people who want a less loud exhaust, I went out of my way to speak a lot as well as leave things on like the radar detector or to find other background noises for comparison, and it's not that loud.

So the video's loudness might be because you have to turn it up to hear it properly, and there are lots of other noises that blend in as one. This happens because a human has two ears so each side gets a little different interpretation with your head blocking more than some sound from the opposite side. Your brain puts it together so two microphones (ears) are better at picking up indvidual sounds particularly if there are different noises from each side than just one ear or microphone. Just put an earplug in one ear and walk around for a while, you'll see what I mean. With just one lousy, old 2008 era I-touch speaker microphone, all the NVH from fully stiffened driveline, chassis and suspension kind of meld in as one. It's a noisy car, and while those chassis, supension and driveline noises are much louder than your typical car, when you hear my speech or the radar detector they are still not super loud. But they are louder than the exhaust and instead of drowning it out, give it more perceived volume and "booming" than it really has because without two ears from listening in person, you can't tell the difference. This is why all recordings, even of your kid's voice, sound different than real life.

Lastly I kept the window open for most of the pulls and driving because under normal conditions you can hardly hear the exhaust windows up, and I wanted to accentuate this otherwise quiet exhaust as much as possible so the end user could use it to make the best decision knowing it would be softer in real life having been advised of such.

Do realize it is a bit louder than stock outside, but less loud than stock inside. At some speeds or engine loads the stock catback would not quite drone, but invade the passenger compartment with a bit of intrusive noise that if it was significantly louder, would be classified as "drone", particularly at engine speeds over 3000rpm or cruise speeds over 75mph. Milltek never does that. Any speed car or engine, any gear, it never even comes close to being intrusive so I feel it actually muffles more effectively while still making for a fun sound. Thus I give it credit because as you hear, it's a fun sounding exhaust but it accomplishes that through refinement abstaining from the easy way out, by making it louder.

As far as perceived differences fro Corsa, I can give you objective evidence that it's a lot, lot, lot softer than the Corsa on all fronts, and I can use the following as impartial evidence in addition to the above:

1. Almost everyone in my life noticed a big difference right away and made comments noticing how much softer the Milltek is.
2. Wife in particular not only made very disparaging remarks about the Corsa when I had it but as per #1 when I got home with the Milltek she immediately greeted me with this phrase just about verbatim: "I don't know what you did to fix it but I am so glad your car doesn't have that noisy asshole exhaust anymore" (see my previous posts about her using 7 letter word that starts with the letter "A").
3. Mechanic who made unsolicited comments that I would be hard pressed to pass inspection with Corsa subsequently made comments "This one is a lot quieter" about Milltek after he installed it. This is why I keep mentioning "passing inspection" as a potential problem because had I kept the Corsa on, I would probably not have passed and had to take it off anyway.
4. Windows don't rattle any more if I have to go back in the house after first starting the car.
5. I don't have that "ear ringing" or "exposed to too much noise beat up" feeling after more extended drives any more.

So in summary seeing as how many of the below apply to me as well, I can report that Milltek is a good choice for those who:
-want a more fun sounding exhaust than stock that relies on refinement, not volume for this theatrical effect
-don't want to give up the quietness of a stock exhaust at all
-on that note desire a sleeper car
-on that note don't want to draw attention to themselves
-on that note don't want legal headaches such as LEO attention or failing inspection associated with louder than stock exhausts
-may need or desire 3" flow in their application
 

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This is why videos are deceiving. There is a lot to say about this so let me try and be succinct.

First off I had mentioned in my review that the video is louder than what the exhaust sounds like in real life. Since the Milltek might appeal to people who want a less loud exhaust, I went out of my way to speak a lot as well as leave things on like the radar detector or to find other background noises for comparison, and it's not that loud.

<snip>

So in summary seeing as how many of the below apply to me as well, I can report that Milltek is a good choice for those who:
-want a more fun sounding exhaust than stock that relies on refinement, not volume for this theatrical effect
-don't want to give up the quietness of a stock exhaust at all
-on that note desire a sleeper car
-on that note don't want to draw attention to themselves
-on that note don't want legal headaches such as LEO attention or failing inspection associated with louder than stock exhausts
-may need or desire 3" flow in their application
I wasn't attacking your position or trying to detract from your personal preferences or choices, just giving you a hard time is all :)

I had a Tanabe Medallion Touring -which is more quiet than stock-... not only did I feel like I spent money for nothing, it was so boring. If I'm spending big $$$ on a noise maker, it should at least make noise different enough from stock to justify the purchase. While I can appreciate the 3" diameter the Milltek offers, I can't for the life of me figure out why it costs an arm and a leg.

The other problem I have with too quiet of an exhaust is having to listen to the little shitty interior rattles that a higher volume exhaust covers up
 

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I wasn't attacking your position or trying to detract from your personal preferences or choices, just giving you a hard time is all :)

I had a Tanabe Medallion Touring -which is more quiet than stock-... not only did I feel like I spent money for nothing, it was so boring. If I'm spending big $$$ on a noise maker, it should at least make noise different enough from stock to justify the purchase. While I can appreciate the 3" diameter the Milltek offers, I can't for the life of me figure out why it costs an arm and a leg.

The other problem I have with too quiet of an exhaust is having to listen to the little shitty interior rattles that a higher volume exhaust covers up Image Link
I agree, I also had the Tanabe Medallion Touring and it was also too quiet. The Tanabe was definitely a welcomed downgrade from the 3" droney/loud Harman Motive exhaust but it was just too boring and the 2.75" was restrictive at my power levels. That's why I switched it out after 2 months for the Corsa due to the advertised zero drone and I haven't looked back since. The Corsa netted me 10 wtq and 250rpms of earlier spool over the loud 3" HM exhaust and it is very tolerable for all the daily driving I do, zero complaints from my passengers.
 

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Discussion Starter #20
I wasn't attacking your position or trying to detract from your personal preferences or choices, just giving you a hard time is all :)

I had a Tanabe Medallion Touring -which is more quiet than stock-... not only did I feel like I spent money for nothing, it was so boring. If I'm spending big $$$ on a noise maker, it should at least make noise different enough from stock to justify the purchase. While I can appreciate the 3" diameter the Milltek offers, I can't for the life of me figure out why it costs an arm and a leg.

The other problem I have with too quiet of an exhaust is having to listen to the little shitty interior rattles that a higher volume exhaust covers up Image Link
No offense taken; this post is about a quieter exhaust and making sure the potential buyer knows what they are getting into.

I get your point about if you spend the money you want more noise, but IMHO the charm of the Milltek is that it sounds more fun than stock while maintaining the same noise level, so they have to work on the tone itself and not just making it noisy.

This is exactly why it's expensive, because a cheap(er) exhaust like the Corsa doesn't spend as much on the parts and quality control and can be tinny and thin walled which is why it's loud(er). You have to pay for thicker, better quality metals as well as more packing in terms of material cost.

But the overarching point of my essay, and the third big advantage of the Milltek, is that it gives 3" flow with stock like noise. It doesn't necessarily apply to me, but if you're extremely highly modded like User1029, you can have all those mods, all the flow you want, and still be quiet enough to pass inspection because all the other mods do a lot to make the car extra noisy which leads me to my next thought....

I agree, I also had the Tanabe Medallion Touring and it was also too quiet. The Tanabe was definitely a welcomed downgrade from the 3" droney/loud Harman Motive exhaust but it was just too boring and the 2.75" was restrictive at my power levels. That's why I switched it out after 2 months for the Corsa due to the advertised zero drone and I haven't looked back since. The Corsa netted me 10 wtq and 250rpms of earlier spool over the loud 3" HM exhaust and it is very tolerable for all the daily driving I do, zero complaints from my passengers.

I wonder about why someone with as much power as yourself would want such a loud exhaust though because everything from the DP to the headers, intakes, cams and just running 500+whp will be simply noisier. I mean, people want to "hear the rumble more" and do have mod plans to begin with, but no one realizes that for example, a DP will make the car both more deep and louder and more powerful all in one swoop without shelling out the big bucks for a full TBE.

Datalogs of my old Corsa were more or less identical to my Milltek. I don't know about dyno passes and wtq, but spool was identical. Actually Milltek spooled slightly sooner by a few rpm's but when I logged it was also a lot colder.

Again it's psychoacoustics, I think to call Corsa quiet is misleading. Your videos and those of others I have heard were not that different from my own experience with this exhaust yet our reactions to this exhaust are pretty much diametrically opposite. And in all truth, there are more than a few exhausts that are even louder. I am learning about terminology, to me "Drone" was basically any invasive noise into the cabin, not just low pitched ones. To me the stock STi with stock everything droned aplenty, it was "just right" in terms of loudness, at least from the exhaust anyway. But apparently "drone" is just low pitched noise. So what do you call invasive exhaust noise that the owner finds inhibits them from being able to think?

But even with a louder exhaust like the Corsa, when you run 8k/8k or 8k/9k springs, camber plates and full bushings everywhere and as much bracing as possible, there is no way you're not going to hear the body panels creak and the driveline whine and road noise. Hence why the Milltek sounds louder than it really is in the video because the recorder merges all those noises into one. But your ears appreciate it better individually. At least to me I like this way of exhibiting "tonality" much better.

I have to mention an aside now. I fired a ship's salute cannon last year. The day later I felt like I had huge pressure in one ear and much decreased hearing. I didn't know if it was noise exposure but I know healthcare wise if you have one sided hearing loss it's bad. So I went to the ENT who did a hearing test, told me it was either a cold or exposure to loud noise (probably both) and except for that slight tone deafness which went away, I was found to have much, much, much better than average hearing. So I am a hyperacoustic. I can pick up faint sounds, but I cannot hear (and get hugely vexed) in a loud room with loud noises.
 
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