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[grunken]

Hi everyone,

Just wanted to share my experience as a 2009 STi hatch owner who recently installed an Invidia Q300 along with a catted Invidia DP. This post is also sparked by a 90 minute highway ride that has left my ears ringing.

Simply put, the exhaust is too loud for my taste. And to be honest I'm still a little baffled at all the research I did scouring the forums, hearing first hand anecdotal experiences and watching tons of videos (for what its worth) regarding the Q300 and its supposed QUIET exhaust. My biggest downfall perhaps is not actually meeting up with someone who had performed the exact same install. But even that, might not have proved useful. Let me explain.

For months now I have been eyeing the Q300 as the "civilized" choice for an exhaust upgrade. I was looking for a slightly louder than stock sound with an improved note under heavy throttle. This exhaust has often been clumped together with the likes of the Maddad Whisper and Borla Hush (among others). This is what I was told it would look like:



Dubbed the "kitchen sink exhaust", the pipe entry into the muffler has always been characterized as unusual and is often criticized. Regardless, I'm fairly certain all that I read and heard about this exhaust, was in regards to this particular design. Let's call it the Q300 v1.

This is what I got:



More photos here: Invidia Q300 Exhaust, new style, GR Hatch

The muffler is now on a slight angle and much closer to the rear of the car to allow the pipe to enter from the side. The adjustable tips (for length) are gone as well, and instead sit nearly flush with the diffuser. Overall, the Q300 v2 is a cleaner design and appears to be an improvement over the original. Looks awesome!

However, I have a hunch that this has also affected the acoustics of the exhaust. I was never expecting this exhaust to sound bass-ey in the cabin, but at anything between 1500 - 3000 rpm, it carries a nasty deep boom. At highways speeds, anything under load (going up hill or a car full of people), it is not just boomy but also pretty darn loud!

I set off car alarm warnings at low revs, and forget about going over 1500 rpm in a parking garage, unless you want to set off alarms 100 feet away. After about 3 months, I think it's actually getting louder too.

Only recently have I started coming across new style Q300 owners who seems to share my belief. There was a Maddad Whisper thread where 2 seperated Q300 spoke up about trading their exhaust for a Whisper (only to have tons of fitment issues). Another thread had someone's daughter complain about her "ears hurting".

Could a change in piping between v1 and v2 like that actually affect the sound so drastically? Or am I unreasonably expecting too little sound from a 3" design ?

I've been offered a few solutions. Obviously a full catback swap is one option, but I honestly can't seem to come across one that looks, sounds and installs as nicely as I would like it too.

I've also been told that equal length headers would reduce the boom. Is this true ?

I'm strongly considering going back to the stock catback, leave the Invidia DP, and perform another Protune, but I've been told that only the 2011 STi will put out good numbers with a stock catback, 3" DP and a CAI (approx. 300 whp / 345 wtq).

I'm also already in the process of performing a full QuietCar install. I've always wanted to do this for road noise reduction and a stereo install anyway, so maybe it will mute this exhaust as well. I can report back if people are interested.

I know this is all subjective, but I really feel like I didn't get what I thought I ordered. For people who are in the same boat as I was, let this be your warning.

I apologize for the long winded post. Feedback is always welcome. Thanks for reading!

Ken

[Redmed]

Well, don't hope on the sound deadener to do much to the bassy drone. The sound is resonating inside of the cabin because of the size of it, not because its vibrating against it. You'd have to fill your whole hatch with acoustic foam to get a measurable difference... if that.

Check for exhaust leaks! Those will make it drone so much more. I had exhaust leaks in my magnaflow before I got rid of it, in hindsight, if I would've fixed the leaks it would've been a DD exhaust. Waiting on my fujitsubo (supposed to be THE quietest exhaust).

[fromSVXtoSTi]

I'm speaking from experience with the Q300 on an '06, so not 100% the same situation, but I had the same result. Got the exhaust and immediately noticed the ear pummeling low frequency boom. I actually got dizzy on the ride home the first day because of the low low frequency content. So, my conclusion is that, while a VERY well built system, the Q300 lacks any real engineering or development of the sound.

[grunken]

The interesting thing I forgot to mention is that the drone/boom is much less prevalent in the rear seat. You certainly hear the exhaust, but you don't feel the ear-clogging boom.

In fact, the closer I place my head to the windshield, the louder it is. It must be the way the sound is collecting and bouncing off the windshield. For that reason, I'm hoping the QuiteCar might actually make a difference, in being able to defuse the resonating in the cabin and disturb whatever is happening near the front.

Originally Posted by Redmed

Check for exhaust leaks! Those will make it drone so much more. I had exhaust leaks in my magnaflow before I got rid of it, in hindsight, if I would've fixed the leaks it would've been a DD exhaust. Waiting on my fujitsubo (supposed to be THE quietest exhaust).

I didn't perform the install myself but I was there for it. No shortcuts were taken with gaskets and there were no issues with fitment whatsoever. And I 100% trust the mechanics work. So I'm fairly certain there are no leaks.

Originally Posted by fromSVXtoSTi

So, my conclusion is that, while a VERY well built system, the Q300 lacks any real engineering or development of the sound.

I totally agree with you ... I love the quality, build and look of this exhaust, it's just a shame about the intensity of the sound.

[DubyaSTi]

This throws a wrench in my plans. I was planning on ditching my Magnaflow in favor of the Q300 to tone down the sound level a bit.

[jjhoagland]

Yes, it is VERY bass-ey. It's not loud at all on the highway IMO (or anything over 3K rpm), but when it's warming up in my garage in the morning, it almost shakes things off the wall in bathroom above garage. People comment about the bass whenever it's their first time in my car, but like anything else, I've gotten used to it and plan on keeping it on long-term. Good luck, I've seen some people here on the forum go to a reputable muffler shop and have another resonator (ex: magnaflow hushpower resonator) welded into the mid-pipe to quiet things down... just fyi

[grunken]

Originally Posted by jjhoagland

... I've seen some people here on the forum go to a reputable muffler shop and have another resonator (ex: magnaflow hushpower resonator) welded into the mid-pipe to quiet things down... just fyi

This is another option I've given strong consideration for, but it seems like such a shame to start hacking up this well-built piping. I would expect the weld quality for the resonator to be on par with what Invidia provides.

Also, would this affect airflow at all, and as result, my Protune?

[mofoSTI]

Ill take it!

[blargle]

I'm not happy to see this as I had my eye on the Q300 as a quiet catback. Luckily, every tuner I've talked to has said that a catback won't add any power on a stage II setup, so you'll be fine going back to stock.

[tilem]

It's a bit quite for me...Depends on the person..!