What's up guys ! I'm thinking of upgrading cats to either HFC or Test Pipes. Only looking at fast intentions for now, i was wondering whay you would recommend HFC, RHFC, TP, or RTP ? I'm stock for now aside for k&n intakes (came with car ) i want to have a pretty loud car ! I'm looking at the non resonated Test pipes but wondering how they will sound with stock exhaust ? Also what's the order of loudness ? Is the non resonated HFC louder than a resonated Test pipe ? Let me know your input guys !

Also for those in cali, anyone running test pipes or HFC ? Run into issues ?

 

FI Resonated Test Pipes FTW!

HFC= Catted but less cells than OEM set
Test pipes= Straight through pipe no cat cells at all
Resonated= Quiets down some sound and basically eliminates rasp.
Unresonated= Raspy and loud, given on certain exhaust setups unresonated can still sound good.
Loudest to Quietest Order: Unresonated test pipes, resonated test pipes, unresonated HFC, resonated HFC, OEM cat.

 

I might sell my Fast Intentions resonated test pipes. PM me if you are interested.

 

resonated test pipes with oem exhaust will not loud by any means. You would need to pair it up with the FI exhaust as well.
going non resonated will give you a lot of drone and rasp and eventually you will get tired of it.

 

I missed the part where you said OEM exhaust. I would not pair any test pipes with the OEM exhaust as it will still my quiet and just basically add rasp. Get the resonated test pipes and add a catback or axleback.

 

Resonated test pipes > all.

 

I also have the FI resonated Test pipes. I have it paired with an Ark exhaust and it sounds great ! No check engine light either !

 

It really boils down to what you want out of the exhaust, what you use the car for, and what catback you'll be pairing them with.

We always start with Resonated HFCs. Why? They're the best of both worlds.

#1) 300 cell cat will give you almost the same performance result as a test pipe minus the unwanted rasp and raw fuel smell.
2) the add'l 8" resonator paired w/ the 300 cell cat is both filtering yet avoiding in cabin drone.

Now, if adding resonators in the mid-pipe of an aftermarket catback, then you may get away from RHFCs and stick with HFCs.

I personally have ran RTP's, LTH's, RHFCs, and HFCs. End result, been running Resonated HFCs for the past 4 years straight and wouldn't think twice about swapping them out with anything else. Keep in mind I previously had a G37 coupe and now I use my currently 370z Nismo souly for getting to the track, on the track and back.

Tuning, HFCs(300cell core) will net you within 3whp of Test Pipes. Is a 1% gain/decrease worth the sound/drone/raw fuel smell? Again, depends what you're looking for out of the car as a driver.

 

Vote for the HFC. Why? As previously mentioned, pretty much the same thing as test pipes for performance. In addition, your car won't smell like a damn go-kart.