I recently added a set of berk HFCs to my xo2 exhaust. Let me begin by saying what a performance difference it made especially in midrange torque and lowering the tone of the exhaust. The fit was dead on and only took ~ 1 hour to install the cats with a lift. The only set back is that it has increased the Db level and I am hoping, with the break-in period after installation, it quiets down some. If not, Can I modify the exhaust to reduce the sound level without affecting the performance gain? I hope I don't have to remove the HFCs but the exhaust is too loud at this point for my taste.

 

the X02 exhaust is a very loud exhaust. Adding test pipes or in your case HFC's to your set up increased the exhaust flow significantly. I doubt it will get any queiter. When i had my Borla installed it was almost too quiet, when i put my HFC's on it made it perfect. If you had an exhaust that is border line too loud, HFC's will definatly put you over the edge. No point in waiting for the "break in" period, it's not going to quieter, if anything it will get louder. Sorry abotu yoru luck mang, should have done more research when selecting an exhaust. Who knows, maybe in a few weeks it will grow on you.

 

i have hks and hfc and i love the LOUNDNESS ; )

 

Add X Pipes

 

mmmm loudddd

 

I'm running an HKS exhaust with APS test pipes and it gets ridiculously loud after 4k. The HFCs are probably a little quieter, but give the car some break in time and the note will get lower.

 

+1

 

so a custom x pipe willl be better then the h pipe it has now?

 

definately. Itll kill the sound.

 

if you have space on your exhaust just throw on some resonators. any exhaust shop should have some they can weld on for you. but remember you will be cutting up the xo2 to add the resonators. it will quiet down the exhaust though.

 

This is what I did to my XO2, and I'm very pleased with the results. I have test pipes, not hfc's, but this was a huge improvement. And besides, it's just an XO2, not the HKS, so I did'nt even cringe when they started chopping.

 

I have just installed my xo2 exhaust with test pipes, and it is way too loud inside the car for my taste. So, I have been to two different exhaust shops to have them install resonators and have been told their isn't enough room, or that it wouldn't help. Which I think is b/s. Would you please take a post a pic of where you installed your resonators, so that I can show these morons it can be done.

 

I'll get a pic up here asap dude...

 

ya i have hks with test pipes and i just got a mufler ticket........and i deserve it it is unacceptibliy loud.....

 

The XO2 exhaust is most likely louder then the HKS cause its has larger piping. 2.36in vs the 2.5in on the Xo2. My exhaust gets crazy loud after 4k as well, but I have headers too.