HFC's and exhaust noise levels
 

I didn't see this being discussed so I feel I should bring it up. Simply put, I don't like my car being too loud. Don't get me wrong, I love the sound of this engine but I can only take so much. This car is my office 5 days out of the week and my only car. So obviously it being too loud would ruin the appeal for me.

Everyone has different tolerance levels when it comes to noise. So, the best option here would be to get a series of dB readings on stock(for a baseline) and modded exhaust. For example: I would like to know what the increase would be for a HFC+FI TDX+Intake system. Different variations using different products would also be good. Maybe a database could be created for us anal retentive people out there. :)

Just thought I would give this a shot as noise is a deal breaker for me when it comes to mods.

i think the dB reading on stick is in the low 70's at idle and around 83 or 84 in the cockpit while accelerating theres a review on the invidia gemini with HFC on youtube by a forum member and he gets readings on stock CBE, Invidia, and Invidia with HFC

To be honest, from your post, I'm going to guess that any HFC/CBE combo is going to be too loud for you.

While adding dB notes to each brand of exhaust in the sticky would be helpful, most of your questions can simply be asked or answered from videos.

My best guess for people that don't want a noisey exhaust, but want gains, is to go with the HFC first. They don't add a lot of volume at all, but can drastically improve the tone of the stock exhaust. Unfortunately, the CBE's I've heard in person (FI and BERK) both add quite a bit of volume (but sound glorious!!!!)

FI offers a resonated HFC.

if you want a good mellow sound i would prob go with stillen or invidia gemini and leave the stock cats but if you want it to sound bad A$$ go with F.I, Ark, or Agency Power

Right now, you have the 12" resonated version on order from me. I would recommend jumping to the 18" version to keep it as quiet as possible. I know that you already have another brand HFC but if you were coming to me with a clean slate, I would tell you only to go with just the CBE with the 18" resonator option. Leave the stock cats on the car and run a K&N drop in air filter. I feel that this combination will keep the noise level right where you want it and maximize your performance given the mods that will be on the car...

Thanks, Tony

Tony actually spoke with me at length on this subject on the phone. I totally wasn't expecting that! Basically he told me to hold off on the HFC's until I install the CBE and listen to how it sounds first and if it's acceptable to me THEN get an HFC.

Also Tony was misinformed, I currently do not have HFCs on my car. Another thing, I'm not looking for whisper quiet, I know it will be louder and that's fine for me. I've driven 4-cyl turbo engines with full TBE systems, so I can take a bit of noise. I just wanted to be able to carry on a conversion either with a passenger or on bluetooth whether at idle or at highway speeds without having to talk over my exhaust. Since I primarily work from my car it would be crippling if I had to do so. Imagine having to yell over the phone to a client over your droning exhaust. Wouldn't go over too well, lol.

Edit: BTW +1 rep to Tony for going above and beyond.

Been there, done that with the dB level thread. No one wanted to participate.

Not to completely derail the thread but....Tony, you've mentioned adding K&N drop ins in a few threads now. Have you dyno'd any gains with them? Many have said they don't add anything at all, but I've never seen data to back up claims either way.

Thanks, and back on track after Tony answers :)

That was my thread he was refuring too. Yes, the invidia gemini w/ HFC's is very livable. Check out my video db comparison - http://www.the370z.com/intake-exhaus...omparison.html

Buy a beater and turn the current office up!

My combo of a Berk CBE and stock cats would work for you. The only time it is loud is when you first turn on the engine. Once it warms up a little it settles into a nice mellow tone that is no louder than stock. When cruising, no drone, no loudness. Open up the throttle, and it sounds sweet with a (for lack of a better term) Euro tone. At WOT, it is loud, but then again, so is the stock exhaust.

i'm planning to track my car in July at Laguna Seca and they have a limitation of no more than 90db. I currently have the Stillen CBE with Berk HFC. Do you think I'll have an issue? I think the Stillen CBE has a resonator. But I have a feeling I'm screwed cuz I don't have the stock exhaust anymore.

I've got the resonated FI CBE and resonated 18" HFCs from FI. I'm in sales so I'm on the road a lot. Cruising at a constant speed (except 62-63 MPH) I can talk on the bluetooth. If it's under load, like going up a hill, it's impossible. I have to pick up the handset.