The TRUTH about aftermarket exhaust drone

F.I. Inc. · 09-20-2013, 12:48 AM

Quote:

Originally Posted by ped

Other manufacturers are probably guilty of this as well, but FI is the one I (now) have experience with, so unfortunately I have to pick on them. I just had a FI catback with 18" resonators installed two days ago. Despite claims all over this forum this system has drone and a lot of it. 7AT drivers who leave it in D will find themselves in the tallest gear most of time - pressing the accelerator in this situation (but not enough to force a downshift) will bring on drone like crazy, turning the interior of the car into a low-frequency resonance chamber! Some people may not care about this, but the fact remains that all the claims of "no drone" are not true, and I wish someone had made this more clear around this forum - it would have saved me a lot of wasted money. So new people researching an exhaust for your 370Z and considering Fast Intentions consider yourselves warned.

For those who care or later find themselves in the same position, I want to let you know the answer to this problem is that Fast Intentions (and possibly other manufacturers) are building their exhausts minus a very important item - a Helmholtz resonator. This type of resonator attaches to the main pipes at a 90-degree angle, and is capped on the end. The shape doesn't matter (J shaped, etc) as long as it's the proper length - basically what you need is to know the frequency of greatest drone (say 120 Hz for example) and then shoot for a resonator that is 1100 feet / frequency / 4 in length which gets you a tube length which will have a natural resonance 1/4 of the wavelength of the worst drone. Since this tube is closed on the end that doesn't attach to the exhaust pipe no exhaust really flows into/through it, rather a standing wave is established (like when you blow over the top of a Coke bottle) which cancels much (or all) of the drone. Similar to noise-canceling headphones in concept.

Why FI and possibly others are leaving this out? I'd guess it's the inability to determine the proper frequencies needed since the catback may eventually be combined with other items like an HFC, different exhaust header, etc. Thus what would work with stock cats and headers wouldn't necessarily work (at least as well) with aftermarket replacements of these items.

My beef isn't so much that they leave them out, it is that so many fans of FI in this forum make FI exhausts out to have NO DRONE which is absolutely nonsense as I can tell from having it installed two days ago. At a minimum people need to have REAL information before blowing 1100-1200 dollars on an exhaust that can induce headaches or at a minimum be highly annoying. I'll probably get flamed for this since FI seems to be so well regarded here but I wish someone would have warned me before I wasted money having this installed and now will be paying labor charges again to have the stock system put back on (or to have Helmholtz resonators welded on) plus loss for restocking fee since the exhaust can't be sold as new anymore.

For the curious who want to see the outcome of the calculation above, for a drone that is worst at 120 Hz here is how to get the length resonator needed to counteract it:

1100 / 120 / 4

= 9.16667 / 4

= 2.29167 feet

(times 12 for inches)

= 27.5 inches for the length of he Helmholtz resonator tubes

Ped,

First and foremost let me be the first to apologize if you are unhappy with the result of your purchase. That being said I feel that the tittle of your thread is misleading and unfair. You need to understand that sound is subjective and everyone perceives it differently. What may be loud and have drone to one person may not be loud nor have drone to another! Not anywhere on my website page do I state the exhaust system has NO DRONE. I state that it has no rasp and that may actually be a little misleading. I should state that certain combinations have no rasp! I will be sure to change that shortly.

Now let it be known to everyone who reads this that you DID NOT purchase our exhaust through us. You purchased it through a third party vendor and I have no control how the purchasing process took place. I have no control how you were informed or educated on the options available.

I can tell you that every single one of my systems that I sell, I take the time to go over every option with each individual customer. I have been doing this a long time and have sold nearly 900 units for this car. For you come up with a thread like this now is a little unwarranted and ridiculous in my opinion. You are clearly have a bad taste in your mouth over your buying experience with the vendor and are directing it at us, NOT COOL! You should of resolved this with them in a private manner opposed to attacking us on a subject where subjectiveness of sound plays the main factor.

There are 100's of reviews out there. Here on the forum, on our website, YouTube, ect... I have hundreds of satisfied customers running different combinations for this car. Are there unhappy people out there who may have buyers remorse, sure but that has happened to all of us at one point or anther in life. You cannot make every single person happy however we try. At the end of the day I know our satisfaction rate is in the high 90 percentile.

Now you emailed me Tuesday 9/17 and stated that you were "regretting" your purchase. I took the time out of a courtesy to email you back in detail in response. Now I could of just told you to deal with the shop you purchased it through because you were not my customer. However, I took the time to go back and forth in emails with you answering all of the questions you had for me. After all, it is my product. I explained to you much of what I wrote above and that the interior sound should dissipate roughly 10% once the resonators broke in and had some mileage put on them. You emailed me back stating that the combination you purchased was our quietest however not quiet enough. You asked if I had a quieter muffler to interchange. I responded with saying that unfortunately we do not have a quieter option than what you purchased and every once and a while our quietest option is just not quiet enough for some. I closed by saying the best thing to do moving forward was to contact the shop you purchased our exhaust through. Again, I will state if you feel like you were mislead than I do apologize. Not at any point did it come from me nor anyone from Fast Intentions, Inc. You can ask anyone who has dealt with me or my company. We take the time to make sure every single customer is satisfied and comfortable with their purchase!

All of this being said, I am more than willing to take time out of my schedule to talk with you over the phone. Even though you are not directly my customer, I would like to hear your side of the issue one on one and see if there is anyway I can help.

Thank you for your time.

Tony

sparky · 09-20-2013, 12:49 AM

I can tell you there's no drone above 5000 rpm! Ya baby.

ped · 09-20-2013, 12:50 AM

Not to stir things up even farther (is that possible?) but you don't even have to look far to see hat I'm talking about in this thread. Right near the top of the intake/exhaust section is this thread. In it the OP is asking for a catback that has NO drone. He even emphasizes that he "hates drone with a passion".

CBE w/no or least drone?

The *very first poster to reply* proceeds to tell him that FI catbacks (in all their combinations) have "no drone" and are a perfect choice for him.

SS_Firehawk · 09-20-2013, 12:52 AM

There are already a number of threads about hemholtz resonators already, nothing new introduced. HKS, ARK Grip, and Motordynes exhausts use em, even maybe a few knock offs. I don't see a reason for F.I. to add it on their exhaust, or any other exhaust manufacturer to theirs if they don't use them. The stock exhaust doesn't have one, and guess what? No drone. It's not an oversight because it's not being used, it's just another option.

DEpointfive0 · 09-20-2013, 12:56 AM

Quote:

Originally Posted by ped

Not to stir things up even farther (is that possible?) but you don't even have to look far to see hat I'm talking about in this thread. Right near the top of the intake/exhaust section is this thread. In it the OP is asking for a catback that has NO drone. He even emphasizes that he "hates drone with a passion".

CBE w/no or least drone?

The *very first poster to reply* proceeds to tell him that FI catbacks (in all their combinations) have "no drone" and are a perfect choice for him.

He says drone is subjective and that it's perfect for HIM, it has nothing to do with what is advertised by Tony or anyone at FI

DEpointfive0 · 09-20-2013, 12:58 AM

OP, sell the exhaust, you'll get what you paid for it because people don't want to wait.
Now the install/removal cost, you're SOL.

And if you think the Hemholtz resonators will work, why don't you add them to the exhaust?

F.I. Inc. · 09-20-2013, 12:59 AM

Quote:

Originally Posted by ped

Not to stir things up even farther (is that possible?) but you don't even have to look far to see hat I'm talking about in this thread. Right near the top of the intake/exhaust section is this thread. In it the OP is asking for a catback that has NO drone. He even emphasizes that he "hates drone with a passion".

CBE w/no or least drone?

The *very first poster to reply* proceeds to tell him that FI catbacks (in all their combinations) have "no drone" and are a perfect choice for him.

Ok, you are failing to realize something. First off, a consumer posted that. Second, he clearly feels the combinations do not drone. This is a case of subjectiveness just at the other end of the spectrum. Now as you are doing your research in the pre buying process it is your obligation as a consumer to read through what is accurate, what may be accurate and what is not accurate. If the general consensus is satisfied with their purchase however you are still not convinced, than don't buy the product. Wait until you can hear the combination you want in person before jumping in.

Thanks, Tony

DEpointfive0 · 09-20-2013, 01:02 AM

Btw, there are enough members in Dallas with the FI exhaust, so you should've gone for a ride. And I know one has an auto too, although I'm not sure if he'd give you or anyone a ride.

I suggest FI products not for sound because that's subjective, but I recommend their products for Tony, and FI's relentless pursuit of perfection when it comes to build quality.

ped · 09-20-2013, 01:05 AM

Thanks for replying Tony. If you acknowledge (as I do) that you make no claim that your exhausts have no drone, then I'm not sure why the thread title is an insult or a problem. But I can change it if that's possible to something else.

The main issue is with the misinformation so prevalent on here. After chats with you I knew what your quietest option was. After that the rest of the info necessarily comes from videos, reviews, general posts on here, and finding people's systems to listen to (something I already acknowledge I didn't go enough of). The fact I can look two threads below this one and find someone blatantly suggesting FI exhaust have "no drone" whatsoever to a guy specifically stating he wants none and "hates drone with a passion" speaks pretty loudly to what I'm referring to. I know you don't have control over what others say on here, but you are pretty active. I'd think if you really wanted to quell that type of thing that a few visits from you into threads like that, to set people straight, would have people producing more accurate information. So you should accept some responsibility for allowing this type of misrepresentation to go on. Maybe it's been good for business and you looked the other way, but it's not accurate. And you shouldn't cry foul when I start a thread calling out bad info that you (presumably) agree is incorrect.

My options at this point are to live with it (not likely due to what I estimate to be 100 db+ of low-frequency harmonic resonance drone in the interior), pay someone a couple hundred to manufacture Helmholtz resonators, or return it and accept the loss of some money for trying out something that didn't work out. I would go with option 2 except for the unknown outcome of how much drone would actually be gotten rid of...

DIGItonium · 09-20-2013, 01:05 AM

I'm #1 on the list with the 12" resonators. Yes, there is some drone between 2-3k RPM, but I don't hold the pedal at 50% in 6th gear between those RPMs.

If it helps... turbo and test pipes seem to make it a quieter option.

NeverBoneStck · 09-20-2013, 01:05 AM

Quote:

Originally Posted by ped

Not to stir things up even farther (is that possible?) but you don't even have to look far to see hat I'm talking about in this thread. Right near the top of the intake/exhaust section is this thread. In it the OP is asking for a catback that has NO drone. He even emphasizes that he "hates drone with a passion".

CBE w/no or least drone?

The *very first poster to reply* proceeds to tell him that FI catbacks (in all their combinations) have "no drone" and are a perfect choice for him.

If you want a exhaust that has little to no drone and hiss the Invidia Gemini is the way to go . I have had every exhaust and combo there is . FastIntentions , HKS , ARK , MagnaFlow , Invidia Gemini , Motordyne and back to FastIntentions. I think Borla is also in there as well . Cant remember... The Invidia even with my ART pipes had very little hiss or drone. The sound was to tame for my taste . Motordyne was the loudest and the others except FastIntention rasped like no other . Give it a couple of months and make your decision ...

ped · 09-20-2013, 01:07 AM

Quote:

Originally Posted by DEpointfive0

He says drone is subjective and that it's perfect for HIM, it has nothing to do with what is advertised by Tony or anyone at FI

Not really. Here is what he said:

Quote:

Drone is subjective, some people say one exhaust gives it to you, another group will say another brand will give you drone.

Are you looking for just a CBE or a HFC/TP combo as well? I can tell you keeping the stock cats will remove any drone.

Fast Intentions gives you a multitude of options to look through:

Long Tube Headers
HFC's/(R)TP's
12" Resonators
18" Resonators
CF or SS Cans

All of which can be mixed and matched to produce exactly the performance/sound you want. With no drone.

If drone is so subjective why is he making claims about FI producing NONE?

DEpointfive0 · 09-20-2013, 01:08 AM

http://www.the370z.com/intake-exhaus...ml#post2496536

^ya, no...

His job is to make exhausts. Not moderate claims or suggestions made by customers. Especially on a SUBJECTIVE matter

DEpointfive0 · 09-20-2013, 01:10 AM

Quote:

Originally Posted by ped

Not really. Here is what he said:

If drone is so subjective why is he making claims about FI producing NONE?

You aren't getting it, HE is making the suggestion, based on what HE thinks

I like garlic, I think it tastes good in most everything, I put it in lots of things I cook, my dad would rather kill himself than eat it. It's subjective

ped · 09-20-2013, 01:10 AM

Quote:

Originally Posted by DEpointfive0

Btw, there are enough members in Dallas with the FI exhaust, so you should've gone for a ride. And I know one has an auto too, although I'm not sure if he'd give you or anyone a ride.

I suggest FI products not for sound because that's subjective, but I recommend their products for Tony, and FI's relentless pursuit of perfection when it comes to build quality.

I agree FI's build quality is amazingly good. The fit and finish are quite incredible.

09-20-2013, 12:49 AM	#32 (permalink)
sparky Track Member Join Date: Jul 2011 Location: Vancouver, BC Posts: 642 Drives: 12 370Z GM AT Rep Power: 15	I can tell you there's no drone above 5000 rpm! Ya baby. __________________ 2012 370Z GM 7AT/JWM LEDs / 3M clear bra / 35% tint / GTR start button / FI CBE SS 18" RES / Momo shift knob / K & N Typhoon / Z1 hood struts / H&R 20mm f/r / illuminated kickplates

09-20-2013, 12:50 AM	#33 (permalink)
ped Enthusiast Member Join Date: May 2013 Location: Dallas, Texas Posts: 258 Drives: 2013 370Z Rep Power: 12	Not to stir things up even farther (is that possible?) but you don't even have to look far to see hat I'm talking about in this thread. Right near the top of the intake/exhaust section is this thread. In it the OP is asking for a catback that has NO drone. He even emphasizes that he "hates drone with a passion". CBE w/no or least drone? The very first poster to reply proceeds to tell him that FI catbacks (in all their combinations) have "no drone" and are a perfect choice for him. Redglare likes this.

09-20-2013, 12:52 AM	#34 (permalink)
SS_Firehawk Premium Member Join Date: Oct 2011 Location: Tampa Posts: 4,142 Drives: 13' Magma Red Nismo Rep Power: 7335	There are already a number of threads about hemholtz resonators already, nothing new introduced. HKS, ARK Grip, and Motordynes exhausts use em, even maybe a few knock offs. I don't see a reason for F.I. to add it on their exhaust, or any other exhaust manufacturer to theirs if they don't use them. The stock exhaust doesn't have one, and guess what? No drone. It's not an oversight because it's not being used, it's just another option. F.I. Inc., XwChriswX and megalapagas like this. __________________ Old Car:GTM TSC'd 550whp / 410lbft tq @ 11.88PSI New Car: Under Construction

09-20-2013, 12:58 AM	#36 (permalink)
DEpointfive0 Premium Member Bitches Join Date: Jan 2012 Location: SoCal Posts: 14,824 Drives: a lot Rep Power: 17151	OP, sell the exhaust, you'll get what you paid for it because people don't want to wait. Now the install/removal cost, you're SOL. And if you think the Hemholtz resonators will work, why don't you add them to the exhaust? Felix 808 and ped like this. __________________ Do YOU want to know what/where I got my username from? ( Click to show/hide ) NSFW due to language:

09-20-2013, 01:02 AM	#38 (permalink)
DEpointfive0 Premium Member Bitches Join Date: Jan 2012 Location: SoCal Posts: 14,824 Drives: a lot Rep Power: 17151	Btw, there are enough members in Dallas with the FI exhaust, so you should've gone for a ride. And I know one has an auto too, although I'm not sure if he'd give you or anyone a ride. I suggest FI products not for sound because that's subjective, but I recommend their products for Tony, and FI's relentless pursuit of perfection when it comes to build quality. F.I. Inc., XwChriswX, Felix 808 and 1 others like this. __________________ Do YOU want to know what/where I got my username from? ( Click to show/hide ) NSFW due to language:

09-20-2013, 01:05 AM	#39 (permalink)
ped Enthusiast Member Join Date: May 2013 Location: Dallas, Texas Posts: 258 Drives: 2013 370Z Rep Power: 12	Thanks for replying Tony. If you acknowledge (as I do) that you make no claim that your exhausts have no drone, then I'm not sure why the thread title is an insult or a problem. But I can change it if that's possible to something else. The main issue is with the misinformation so prevalent on here. After chats with you I knew what your quietest option was. After that the rest of the info necessarily comes from videos, reviews, general posts on here, and finding people's systems to listen to (something I already acknowledge I didn't go enough of). The fact I can look two threads below this one and find someone blatantly suggesting FI exhaust have "no drone" whatsoever to a guy specifically stating he wants none and "hates drone with a passion" speaks pretty loudly to what I'm referring to. I know you don't have control over what others say on here, but you are pretty active. I'd think if you really wanted to quell that type of thing that a few visits from you into threads like that, to set people straight, would have people producing more accurate information. So you should accept some responsibility for allowing this type of misrepresentation to go on. Maybe it's been good for business and you looked the other way, but it's not accurate. And you shouldn't cry foul when I start a thread calling out bad info that you (presumably) agree is incorrect. My options at this point are to live with it (not likely due to what I estimate to be 100 db+ of low-frequency harmonic resonance drone in the interior), pay someone a couple hundred to manufacture Helmholtz resonators, or return it and accept the loss of some money for trying out something that didn't work out. I would go with option 2 except for the unknown outcome of how much drone would actually be gotten rid of...

09-20-2013, 01:05 AM	#40 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	I'm #1 on the list with the 12" resonators. Yes, there is some drone between 2-3k RPM, but I don't hold the pedal at 50% in 6th gear between those RPMs. If it helps... turbo and test pipes seem to make it a quieter option. XwChriswX, Mr&Mrs, megalapagas and 1 others like this. __________________

09-20-2013, 01:08 AM	#43 (permalink)
DEpointfive0 Premium Member Bitches Join Date: Jan 2012 Location: SoCal Posts: 14,824 Drives: a lot Rep Power: 17151	http://www.the370z.com/intake-exhaus...ml#post2496536 ^ya, no... His job is to make exhausts. Not moderate claims or suggestions made by customers. Especially on a SUBJECTIVE matter F.I. Inc., XwChriswX and Felix 808 like this. __________________ Do YOU want to know what/where I got my username from? ( Click to show/hide ) NSFW due to language: Last edited by DEpointfive0; 09-20-2013 at 01:11 AM.

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