350Z_LMS

Hi, I am currently running a stock Z with Crawford HFCs and a NISMO catback exhaust and I am not a happy guy. I use my car on the highway almost all the time and I am getting SERIOUS drone peaking around 3k rpm under load (of course it gets even worse at WOT). I have searched and read other threads and I get opposite reviews on the loudness of this very setup. Now, I have a few questions:
1. can others confirm that the droning is so loud it actually gets painful during long journeys at 140kph in 6th under load?
2. anyone managed to remove the resonance with this setup? If so, please tell me how they did it!
3. I have Strup headers waiting to be installed: say I removed the NISMO cat back and went "headers+HFCs+stock cat back"...would the drone go away?
4. Say I kept the NISMO cat back, installed the headers and removed the HFCs to get "headers+stock cats+NISMO", would it go then?
In other words, is the drone in the exhaust or is it down to the HFCs? Anyone any advice on the best setup for minimal or no resonance? Suggestions also welcome as to a different cat back system altogether...

davidv

iTrader: (2)

With intake mods and high-flow cats, you are pushing a lot of exhaust gas through the cat-back exhaust. Generally it is louder than stock and you will get some drone sound. Add headers (I did) and exhaust gasses move more efficiently through the cat-back exhaust. The exhaust gets a bit more noisy, and the drone increases a couple of decibels.

Members with dual exhaust have welded a H-pipe and say that it decreases drone. I don't know. As you mentioned, noise is so subjective. You can let two people drive the same car. One will say that they hear a little drone. Another will say that the drone is intolerable.

HyperSprite

iTrader: (6)

The Nismo with stock cats and exhaust manifolds is almost at the verge of drone. I would think adding HFCs would put it over the top. If drone is a biggest concern and you want to keep the Nismo, you probably need to ditch the HFC and Headers.

One of the members in NorCal with a ZR has Crawford's HFC and plenum with a Popcharger and he took his Nismo off and replaced it with the Stillen TD and is happier with it.

Chris

Beeker

iTrader: (5)

This is the exact reason why I went with the Borla TD.

I was going to get the Nismo because it looks and sounds awesome but the drone I read about changed my mind. I had a 1999 SH Prelude back in the day. I installed a Greddy cat back and after one weekend I removed it. The drone while cruising on the highway was unbearable!

I have the Borla with Strup headers and stock cats and there is no drone. In fact it is fairly quiet. It balances out the sound of the Popcharger and plenum spacer very well. With the stock exhaust all I could hear was the engine compartment.

I may add hiflow cats one day but for now I am content. You could always sell the Nismo and buy the Borla. You will probably get enough for the Nismo to cover the cost of a new Borla TD.

jovasi

How many miles do you have on your Nismo? I have this exhaust & Crawford cats & had some droan between 2500-3000 rpm's. I put a couple thousand miles on this set up & the droan is almost gone.

Some peop[le hate the droan & some like it. I originally hated it, but it doesn't bother me anymore.

Mr_pharmD

iTrader: (48)

get the borla exhaust. No drone in the +3K rpm where as every other exhaust gets louder as u climb the rpms.

suprpwr

iTrader: (7)

for me, I had just the Injen straight tip (everything else stock) and the drone was INSANE.

switched to a Stillen and am VERY VERY happy (think it has an X pipe)

350Z_LMS

thanks all, I must admit it does get loud...I'll install the Strup headers, test again (I know the sound won't change much) and then I'll take a decision...one of the owners of our italian club is interested in my NISMO...we'll see. Borla seems to have build problems...I'll look into Stillen

amsweigart@hotm

iTrader: (1)

I have Stillens Silver Series Cat Back exhaust. It sounds very noyce. It's the same set up as your NISMO but a much deeper pronounced tone. It has a slight drone at 2k rpm's but nothing unberable at all for me. It may be for you though considering the exhaust alone already drones a bit. But, at WOT it screams with zero dronning. I think I will get Helix HFC's pretty soon. Those will add some more drone prolly but I do not care. Good luck!

OCG35Coupe

iTrader: (3)

Are FUjitsubo owners experiencing the same drone?

dingobiatch

iTrader: (3)

Ok, now I'm scared. This isn't meant as a thread hijack (kinda is, sorry!), but I thought NISMO was liked because it doesn't drone...
I was going to buy the NISMO exhaust in the next month but if it drones.. ahh! (I'm bone stock except for popcharger)

GMZ

iTrader: (6)

I just installed the Nismo catback + Popcharger this weekend. In 6th under load there is slight drone, but not bad at all, and I think it will mellow out over time. I also was very scared about drone/noise but after this weekend Im not! Even my Dad who is always skeptical likes it. Thats just my ears though, I shoot guns for a living

undrgnd

iTrader: (2)

Amuse R1 Titan + JIC y-pipe = no drone at all, but nothing in your wallet either. not sure if it's the titanium or the exhaust design, or maybe because the cats are still in there. could it be that eliminating the cats or installing hfc creates the drone?

dingobiatch

iTrader: (3)

What do you mean 'in 6th under load'? With throttle? If there's drone w/ almost no throttle, thats.. lame..

plumpzz

iTrader: (10)

drone usually happens under low throttle. i've heard that nismo drones a lot though. Anything w/ an H pipe or X pipe won't drone for sure..

GMZ

iTrader: (6)

In 6th under load, like when I have cruise on and I need to just give it a little gas to pass someone there is a slight drone to it. It "should" go away, at least thats what Ive heard, it doesnt really bother though.

350Z_LMS

I get this drone especially in 6th under load and from what other have written, I believe the loudness is down to the NISMO in combo with HFCs (I have Crawford). The sound gets LOUD in this condition especially in the rev range 2800-3500rpm...past 4k no problem at all. Now, that range in 6th coincides with motorway cruising speed (and the legal limit incidentally) of 140kph. I must say I am getting used to it and it is down to how open the throttle is. At WOT it's almost unbeareable (to my ears at least). I have been told I should tighten all bolts to eliminate some of this sould...I will do this week...

Z350Lover

iTrader: (2)

my nismo + HFC + headers setup is LOUDASS in the rev range 2500 to 3500rpm too... but at any higher rpm, the exhaust doesn't sound that loud anymore, more like engine sound from there and that's where I drive my car most of the time as well... I am also wondering to know if Fujitsubo exhaust gets loud at that rpm range? because my friend's fujitsubo Ti doesn't sound that loud even with HFC and header setup though... his car just sounds nice to me.... anyone really compared both setups before?

thanx!

cheers,

richie

Z1 Performance

iTrader: (564)

if you search, people have said since the beginning that the NISMO is one of the exhausts out there that is loud at cruising speed. It's just a function of it's a muffler design I suppose. Even with stock cats, the drone is there.

Some people do not mind it, others do. I love how the NISMO sounds under WOT, but at highway speeds its a bit annoying. Opinions vary alot though - I happen to think the Borla sounds like **** at pretty much any throttle input from any position except in the drivers seat - others say it sounds wonderful. Your opinion can vary widely on exhausts.

I've had both the Fujitsubo stainless and the ti, all the time with Ultimate Racing cats and Ultimate Racing Y pipe. Ask anyone who has ever heard or driven my car - there is zero drone to be heard, at any rpm. My Apexi Hybid Megaphone (essentially the World Sport 2) droned alot more than either Fuji, but not as much as NISMO

BrianV

Hmm. Check out g35driver.com's sedan section and read about the Borla (h-pipe) design and especially the Stillen (x-pipe) design. The Stillen especially drones REALLY bad and it has X-pipe. Droning is just a side effect of some exhausts. I'm not expert on what does and doesn't cause droning, but the more you free up your exhaust, the faster the exhaust exits the system. The faster it exits the system, the louder it gets.

That's what mufflers and resonators essentially do, they have resonators but they also work on slowing the velocity of the exhaust gases down, hence why 3-point mufflers and non-straight throughs work to quiet down cars even more.

Anything that slows the exhaust down is going to keep the car quieter. That's why changing to hfc cats or test pipes often adds more noise.