How loud or not is an HKS catback with a catless downpipe on there? I know right now its really not loud at all with the stock cats, but I don't know how much louder it can get when thats all opened up

 

I ran that setup for a long time. It's not really loud when cruising but at WOT it gets very deep. I never got looked at twice tho from a cop nor have i been pulled over for the exhaust. *knocks on wood*...... I think if you had headers and such then it would be very loud, but this setup is nice and deep. hope that helps a little.

Wes

 

I have this set up now on my 06 STi. As mentioned above, when cruising, its not terribly loud. However, when you are at WOT, or whenever the RPMs are past 4k, You'll definitely hear it.

 

I had regular HSK Hi-Power (pretty much the same thing) with Invidia dp for a bit...and like everyone else said once you get on boost it really becomes noticeable because its just such a straight through design with no resonators.

However, IMHO it will also depends on a tune. For example, an ECU tuner has to tune for idle when putting together a map. Un-tuned my Borla Hush was almost loud as the HKS, so a proper tune made it much more quieter.

 

^The hks catback has a resonator in it.


Like everybody else said, if you're not on it, it's pretty tame. Sometimes it's louder on some days and sometimes it's quieter if you're just driving around normally. If you're going catless, it'll sound a bit louder, but not that much. If u can tolerate it now with your stock downpipe, then chances are u will be able to tolerate it going catless.

I had the catback before and after headers. Noisewise, the headers don't make a difference. But it will change the tone of the sound slightly.

Forgot to mention, since u have the carbon ti, it'll be a tad louder than the regular hi power since it's all stainless steel (the regular hi power with the black paint coating is quieter). Also, your after-fire popping will be much louder.

 

Hahaha I guess it does have a resonator...just looked up a pic of it Sorry for the misinformation.

I thought carbon ti only had the carbon fiber wrapping and burnt tip as the only difference with no design differences...why would it be louder?

 

The Carbon Ti is full stainless steel piping. The Hi Power is mild steel piping coated with black paint. The paint on the piping makes the noise a tad quieter than a full ss piping. It's kinda like how the original Greddy Evo1 catback (mild steel coated with ceramic paint) vs Greddy Evo2 (full ss piping). The Evo2 was a bit louder than the Evo1.

 

Ah bleep, no wonder I got surface rust all over my old Hi-Power back in Chicago I love realizing all the stupid n00b mistakes [and knowledge] from previous purchases, even though I would not make the same choice now. Thanks for the info.

 

where did the rust occur? It shouldn't occur on the canister or tip since it's stainless steel.

 

i've actually got a video on facebook when my car was getting tunned with carbon ti if you want to hear it pm me

 

Well everyone keeps saying "its not that loud," but i have to disagree. I had that exhaust when i first got my car and I liked it, but every cop would break their neck looking at my car as it passed. I got a noisy exhaust ticket and I swapped that bad boy out for the SPT cat back. Its natural for our cars to be loud because of the boxer rumble, but IMO that exhaust is way loud. Just my 0.02

 

i have an hks carbon/ti with less than 2k miles on it as well as a catless downpipe for sale very cheap if anyone here is interested

 

Was your car tuned? I had the SPT and Borla on my car before it was tuned and both were just as loud and drone-y as the HKS. Also, SPT is way more restrictive than many of the other exhausts...it is pretty much a shiny stock exhaust. It was designed with the same back pressure levels as the stoker because that's the only way Subaru would warranty it [keeps all the specs within factory norms]. At least that is what I remember reading and hearing.

 

I actually just put a catless downpipe on right now, and its pretty much the same sound level around crusing speeds, a bit louder, but not that much. However, when you rev it up, it is significantly louder, but way nicer sounding.

But that could change a little bit soon here, im going to fli for a tune in about an hour or so

 

it'll still sound the same for the most part. You probably won't notice any difference.