Hi-Flow Cats too loud!

Modshack · 08-21-2009, 03:53 PM

Quote:

Originally Posted by 2fast4thelaw

I loved the sound of the Stillen exhaust from the clips I heard. The HFC's radically change the exhaust note. I am not changing out my exhaust system, thats like throwing the baby out with the bath water. I am just not happy with the HFC's It makes the car sound ricy. Plus I doubt I will pass emissions when I have to test car in the next 3 years with the HFC's. Plus I dont like the hiss the HFC's make. It makes it sound like I have an exhaust leak. I think my HFC's need to go.

Yours and similar posts have pretty much convinced me to leave the CATS alone. I think the Stillen is a tad quiet, but is a comfortable system when traveling with no bad characteristics. I'd be kicking myself if I made the change and then did not like it...

WShade · 08-21-2009, 03:54 PM

"mattkim85" in CA already got pulled over for his being to loud. Check the classifieds.

JB1 · 08-21-2009, 04:32 PM

What about stock exhaust en HFC's? That is the setup I am going for. From the video's DDM posted, it sounds good, not too loud and it should yield nice performance gains.

6MT · 08-21-2009, 04:56 PM

Quote:

Originally Posted by Modshack

Yours and similar posts have pretty much convinced me to leave the CATS alone. I think the Stillen is a tad quiet, but is a comfortable system when traveling with no bad characteristics. I'd be kicking myself if I made the change and then did not like it...

I must say by reading all the negative posts here, that I'm kind of disappointed. A lot of people (by far the majority) talk about "modding" their cars. With just a little (and I mean a small amount) of research, one can find out loads about what the different mods will accomplish.

I was the same way. Some pointed questions, a little research, and finally... the big decision was made.

Nah, I've decided not to continue. I'll get flamed too hard.

So people..... my experience was to do the Stillen HFC's, CBE, Gen II intake system, and sway bars. I was surprised with the sound's "loudness". Yes, it's not quiet. But the performance gained far out weighs the "inconvenience" of the sound. I really like it. For those of you who are having trouble with the authorities, all I can say is I feel for you. Where I live, there's no such bother when we've got Harley's and the like driving around with what sounds like no exhaust at all.... the 370 sounds as quiet as a Honda Fit.

The HFC's (and the whole exhaust system) "resonate" at different revs. Cold starts are LOUD. Some speeds (read: revs) are uncomfortable (read: droning). But, I took a four day trip with the car and was very surprised at the level of comfort (sound wise). The audio system would generally cover up any exhaust notes when I wanted it to. After that, the rolled-up windows did wonders.

blackbird · 08-21-2009, 06:55 PM

I have the Stillen CBE, HFC, Headers, Gen 3 intake. car sounds like a Z. Cruising at 3000-3500 RPMS, sound is not harsh. Easy having conversations etc. In the hurry-up mode, it has a distinct throaty sound. Course this is comparing to just the Stillen exhaust since I had them install on day 3 of owning the car. Happy driver and local Law types have not stopped me. But this is Live Free or Die country. Or it could be I'm losing my hearing, but who cares.

Minicobra1 · 08-21-2009, 09:32 PM

Quote:

Originally Posted by CrownR426

I wonder if cops look at these launches and try to find out where it is.
lol, hope none of us get caught!

Hope not

That was in a very deserted industrial business park on a Sunday, I looked for a place with no cross streets and on a cul-de-sac. Not saying that this is a safe thing to do on the street, but I did put some thought into it.
I've seen others shooting video, and it looks like there right in front of their house in a residential section

Try and be as safe as possible out there and use discretion.

Minicobra1 · 08-21-2009, 09:39 PM

I think the Berks sound great, probably not quite as loud as the Stillen/Berk combo.
I've got Nismo/Berk at the moment, and it's a little too mild for me. Sounds great when you get on it, but I don't want to have to drive my car fast all the time to get the enjoyment of the engine growl. On the other hand, I don't want something that is going to drone or attract too much negative attention. Hoping the Berks CBE will be the solution.

I don't want to give up my Berk HFC's they have definitely made the biggest difference in performance gains so far.

One_Quick_Z · 08-21-2009, 11:31 PM

I like the loudness under WOT that is why Im going to get Test Pipes when I get Exhaust

I loved the sound of my Borla With APS test pipes, Megan Racing Headers on my 06 350Z

DAN

tstrick9 · 08-21-2009, 11:37 PM

I thought it was against federal law to removing functioning cats even if they were replaced with other cats.

m4a1mustang · 08-21-2009, 11:37 PM

Quote:

Originally Posted by Modshack

Yours and similar posts have pretty much convinced me to leave the CATS alone. I think the Stillen is a tad quiet, but is a comfortable system when traveling with no bad characteristics. I'd be kicking myself if I made the change and then did not like it...

Same for me... for now, anyways. I ordered the FI CBE with 18" resonators, which I'm thinking will be loud enough for me. If not, maybe I'll add HFCs... but only if I'm sure it won't be obnoxious.

2fast4thelaw · 08-22-2009, 11:57 AM

HFC will not make it obnoxiously loud unless you are WOT all the time. If you drive normal speed limit and keep your revs under 3k it's not that loud.

The HFC definitly make the car sound modified and that is what I didnt really want. Its not a bad sound by any means, it just isnt refined like the exhaust note of like a Porche or something. It sounds like a tuner.

Now I would tell anyone who is considering test pipes it will border on the obnoxious loud side and will sound raspy. Even with the HFC's there is a little rasp at WOT but test pipes would amplify this.

john370z · 08-22-2009, 09:30 PM

OK OK OK.. I did it today! I took off the Berk HFC's!

Oh my God!

I love my car again!!!!!

It sounds about 75% less noisy.
100% less raspy!
100% less drone!
and still has a sporty sound at the upper rpm range.

To be honest, I drove home with a smile on my face the entire drive home from the exhaust shop, and that's the first time that's happened.

If anyone is one the fence on this one. I hope this pushes you in one way.

Good luck to all!

2fast4thelaw · 08-29-2009, 11:50 PM

I havent pulled my cats yet and I may not. I just got my car back from the car audio shop and they put 120 sq ft of sound deadning in the car and it is sooo quiet inside. I can't hear the anoying drone anymore. Its a night and day difference not to mention hardly any road noise now.

I can live with HFC now. Without the sound deadning, I was ready to yank them like "John370z"

MacDaddy · 08-30-2009, 01:07 AM

2Fast, not to get off thread but other than the doors, where did the shop install the material...I'm guessing dynamat??? Fixin to do mine

thanks

mac

2fast4thelaw · 08-30-2009, 02:54 AM

Actually I used Rammat. Its not only cheaper but its better. I bought 2 rolls which are 62.5 sqft for about a $100.00 a roll. Plus I bought 6 yards of ensolite foam barrier that is glued to the Rammat.

RAAMaudio

I had it applied double layer in the trunk floor and wheel wells and yes, both doors. It was very well worth it as the car is amazingly quiet inside.

I had the entire interior of the car removed. I am adding pictures of the process on the Audio thread but there are a few there already.

08-21-2009, 03:54 PM	#17 (permalink)
WShade Track Member Join Date: Jan 2009 Location: San Antonio, TX Posts: 765 Drives: 09 370Z T/S/N Rep Power: 187	"mattkim85" in CA already got pulled over for his being to loud. Check the classifieds. __________________ Q50S Q60 RS400

08-21-2009, 09:39 PM	#22 (permalink)
Minicobra1 A True Z Fanatic Join Date: Nov 2008 Location: Orange County, CA. Posts: 1,205 Drives: 370Z Tour, Spt, 6mt Rep Power: 644	I think the Berks sound great, probably not quite as loud as the Stillen/Berk combo. I've got Nismo/Berk at the moment, and it's a little too mild for me. Sounds great when you get on it, but I don't want to have to drive my car fast all the time to get the enjoyment of the engine growl. On the other hand, I don't want something that is going to drone or attract too much negative attention. Hoping the Berks CBE will be the solution. I don't want to give up my Berk HFC's they have definitely made the biggest difference in performance gains so far. __________________ 370z Tour\| Spt Pack\|Navi\|BERK CBE\|Berk HFC's\| Eibach Springs\| Hotchkis Sway Bars\|SPC Camber Arms\|15mm Ichiba Wheel Spacers\| 19"Factory Nismo Wheels-Matt Black\|Stop Tech Rotors\|TWM Shifter\|3M Tint\|Black Fangs\|Black Rear Valance\|JDM Fog Light\| MY BAND-www.myspace.com/petroleum Last edited by Minicobra1; 08-21-2009 at 09:42 PM.

08-21-2009, 11:31 PM	#23 (permalink)
One_Quick_Z A True Z Fanatic Join Date: May 2009 Location: Seneca Il Posts: 1,374 Drives: 10 Civic EX Sedan Rep Power: 219	I like the loudness under WOT that is why Im going to get Test Pipes when I get Exhaust I loved the sound of my Borla With APS test pipes, Megan Racing Headers on my 06 350Z DAN __________________ -My BRZ with exhaust will decimate all if we overnight parts from Japan- 10 Civic EX Sedan- Current Daily

08-22-2009, 11:57 AM	#26 (permalink)
2fast4thelaw Enthusiast Member Join Date: Feb 2009 Location: Denver Co Age: 50 Posts: 403 Drives: 09 370Z Sport/MT6 Rep Power: 16	HFC will not make it obnoxiously loud unless you are WOT all the time. If you drive normal speed limit and keep your revs under 3k it's not that loud. The HFC definitly make the car sound modified and that is what I didnt really want. Its not a bad sound by any means, it just isnt refined like the exhaust note of like a Porche or something. It sounds like a tuner. Now I would tell anyone who is considering test pipes it will border on the obnoxious loud side and will sound raspy. Even with the HFC's there is a little rasp at WOT but test pipes would amplify this. Last edited by 2fast4thelaw; 08-22-2009 at 12:00 PM.

08-22-2009, 09:30 PM	#27 (permalink)
john370z Base Member Join Date: Jan 2009 Location: new mexico Posts: 141 Drives: 2007 335i coupe Rep Power: 283	OK OK OK.. I did it today! I took off the Berk HFC's! Oh my God! I love my car again!!!!! It sounds about 75% less noisy. 100% less raspy! 100% less drone! and still has a sporty sound at the upper rpm range. To be honest, I drove home with a smile on my face the entire drive home from the exhaust shop, and that's the first time that's happened. If anyone is one the fence on this one. I hope this pushes you in one way. Good luck to all! __________________ 2009 370Z, Had Berk HFC and un-installed them cuz too noisy!, Stillen CBE, 10mm rear wheel spacer, K&N drop in filters. Blower to come...

08-21-2009, 04:32 PM	#18 (permalink)
JB1 Track Member Join Date: Mar 2009 Location: Chicagoland Posts: 748 Drives: 09 Nissan 370Z sold Rep Power: 17	What about stock exhaust en HFC's? That is the setup I am going for. From the video's DDM posted, it sounds good, not too loud and it should yield nice performance gains.

08-21-2009, 06:55 PM	#20 (permalink)
blackbird Base Member Join Date: May 2009 Location: Nashua NH Posts: 179 Drives: 09 370Z BLk GTM TT Rep Power: 16	I have the Stillen CBE, HFC, Headers, Gen 3 intake. car sounds like a Z. Cruising at 3000-3500 RPMS, sound is not harsh. Easy having conversations etc. In the hurry-up mode, it has a distinct throaty sound. Course this is comparing to just the Stillen exhaust since I had them install on day 3 of owning the car. Happy driver and local Law types have not stopped me. But this is Live Free or Die country. Or it could be I'm losing my hearing, but who cares.

08-21-2009, 11:37 PM	#24 (permalink)
tstrick9 Base Member Join Date: Jun 2009 Location: north carolina Posts: 45 Drives: 2003 cobra, 2006 tb Rep Power: 16	I thought it was against federal law to removing functioning cats even if they were replaced with other cats.

08-29-2009, 11:50 PM	#28 (permalink)
2fast4thelaw Enthusiast Member Join Date: Feb 2009 Location: Denver Co Age: 50 Posts: 403 Drives: 09 370Z Sport/MT6 Rep Power: 16	I havent pulled my cats yet and I may not. I just got my car back from the car audio shop and they put 120 sq ft of sound deadning in the car and it is sooo quiet inside. I can't hear the anoying drone anymore. Its a night and day difference not to mention hardly any road noise now. I can live with HFC now. Without the sound deadning, I was ready to yank them like "John370z"

08-30-2009, 01:07 AM	#29 (permalink)
MacDaddy Base Member Join Date: May 2009 Location: NRH2O, Texas Posts: 32 Drives: 09 370Z MB 7AT Rep Power: 16	2Fast, not to get off thread but other than the doors, where did the shop install the material...I'm guessing dynamat??? Fixin to do mine thanks mac

08-30-2009, 02:54 AM	#30 (permalink)
2fast4thelaw Enthusiast Member Join Date: Feb 2009 Location: Denver Co Age: 50 Posts: 403 Drives: 09 370Z Sport/MT6 Rep Power: 16	Actually I used Rammat. Its not only cheaper but its better. I bought 2 rolls which are 62.5 sqft for about a $100.00 a roll. Plus I bought 6 yards of ensolite foam barrier that is glued to the Rammat. RAAMaudio I had it applied double layer in the trunk floor and wheel wells and yes, both doors. It was very well worth it as the car is amazingly quiet inside. I had the entire interior of the car removed. I am adding pictures of the process on the Audio thread but there are a few there already.

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