FI 18" and RHFC or FI 12" and RHFC
 

I have churned the internet upside down looking at G35s and G37s but I can't find any actual comparison between these two! I ordered a FI CBE with 18'' resonators but I am possibly thinking of changing to the 12" resonators. With either setup, I would like to have the RHFC for power purposes and for tone improvement. Will the RHFC from FI reduce or increase the sound? Some videos that I have been watching make the sound appear more tamed down than with only the CBE installed and others make it appear as if it increases the sound. I cannot come to a conclusion...

Help people, please:)

My stats so far for 2008 G35Xs sedan: modified Weapon R Secret SRI with afepower dry filters, want to order RHFC, and can't decide which resonators to get on CBE(!!??).

Car will be a DD, looking to be able to have convos in the car, but don't want to be waking up the neighborhood nor do I want to get sick of the sound after a couple of years. However, I don't want either to be let down by the 18'' resonator combo. Kevin from FI, who was very helpful, recommended the 18'' for lowest noise which I understand. Most of the videos are terrible...how can you judge noise by sticking the phone right by the exhaust...

Does 18'' sound like this? https://www.myg37.com/forums/video-s...fc-and-cb.html

or this? https://www.myg37.com/forums/engine-...-and-rhfc.html

Doesn't it sound a little light?

Does the 12'' sound like this? https://www.myg37.com/forums/engine-...fc-12-cbe.html

It sounds wonderful!

Will the 12'' cause too much drone with the RHFC? I read that it creates some drone. What about rasp? Does the sound of a CBE in general increase as it breaks in?

I just don't want to sound like a teenager with a crazy exhaust, you know? Thanks!!

For starters the VQ37VHR found in the G37 sounds quite different compared to the VQ35HR that's in your vehicle so watching video's of a completely different motor doesn't do you much good.

Secondly, those cars sound COMPLETELY different in real life, the recording instrument didn't capture a quality sound, and likely your audio equipment isn't reproducing the sound image exactly as it was recorded. That's the biggest issue with trying to listen to video clips on the internet to see what something sounds like. Granted some companies do use professional equipment to record their exhaust clips but that will still be reliant on your speakers playing back a true sound. This isn't hollywood movies with perfectly sound matched Dolby recording and playback equipment. It's a guy with a go-pro and who knows what your speakers and EQ setup are that you're listening back on.

Resonators and resonated HFC's are used to get rid of rasp and make the exhaust sound deeper. In my opinion they are DEFINITELY the way to go unless you want a tinny high-pitched ricer sound, which some folks do.

The exhaust will DEFINITELY be louder with a HFC compared to the stock exhaust, less restriction means more noise. FI makes great equipment so I wouldn't hesitate to buy their stuff but it's all meant to work together as a package for optimal sound tuning, personally I'd go with the 18" resonator.

Yes the tone of the exhaust will change over the first 1000 miles as the components become covered with soot on the inside. I think they usually sound better after they're broke-in though.

Thanks a lot for the reply Cleric! You're the best. I know that the g37 is different but I was just trying to make an educated guess on what it could sound like.

I also know for sure that the cats will sound louder than the stock exhaust. My question has been whether the cats will increase a little bit the sound of the FI catback exhaust. I have read that for some, the resonated cats decreased the sound of their fast intentions exhaust -- this is the reason for my post and why I was debating between 12in. and 18in. resonators. I just don't want the 18in. resonated cats to take the life out of the catback exhaust. Does this comment change your answer to my post at all?

I'll trust you and the rest of the good comments about the 18in. resonated cbe and resonated cats combo. I just don't see much on here on the 12in. resonated cbe with resonated cats.

Thanks!!

It will reduce the higher tones created by the exhaust and replace them with lower tones. This will decrease the overall decibel level of the exhaust but it definitely won't make it sound mild.

Think of a garden hose, if you hold your thumb over the end you can spray a very far distance. If you remove your thumb it comes out in a short stream, Both deliver the same volume of water. Sound works the same way, the intensity of the sound is measured in decibels, the amount of sound coming out is measured in frequency, frequency is how fast the sound pulses are happening.

You are lowering the decibels by increasing the frequency, overall it's the same amount of total sound energy.

EDIT: it will definitely not sound tame, it's still a high performance exhaust system designed to flow a LOT more air and thus total sound coming out the tailpipe.

That makes sense. Thanks a lot for your help! I will put in an order tomorrow for RHFC with FI and finalize my purchase of the 18in. resonated CBE. I hope this post will be helpful to others as well.