Looking at purchasing the Stillen Catback exh. But I do not believe the "This Stainless Steel cat-back exhaust system will increase your Sedan's performance by 21-23 hp and 21-23-lbs ft. of torque - at the rear wheels!"....per Stillen's webpage. So I wanted to ask the board if anyone has a dyno of this on their car (with no other mods). Any info about this setup or any other catback is welcomed. Also let me apologize if this has already been posted before.

thank you

 

I can tell you in a couple weeks. I have the Stillen on order and plan to dyno before and after install. I won't be completely stock though. I have z-tube and pop charger. I would suggest doing a search over at my350z.com (or any of the other G35 boards) on Stillen. You will find lots of number discussions there. There are several on this board who have the Stillen. DaveO or GurgenPB have quite a bit of technical knowledge and have the Stillen installed IIRC. You might be able to coax them out.

03.5 5AT-S (Black-Willow-Premium-Sport-Aero-GroundingGear™-Silverstars-PIAA-PopCharger-Z Tube-Tint)

 

Might help...Dyno w/ Stillen x-pipe for sedan

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

thanks guys

geeman49 - please let us know the dyno when you get it installed

 

Big Money,

Looking forward to your experience with the Stillen package. I'm interested in getting one, but have a slight concern about the noise/droning problem that's allegedly associated with the system. Please keep us posted after install!

Thanks!

QR

 

DHolly,

Did you install a Stillen exhaust? If so, how do you like it and does it "drone?"

Thanks!

QR

 

Yes all with Stillens. I really would like to know about this drone thing. Many here are very vocal about the droning and I don't doubt there is something to it since it's mentioned by more than one. Jason at Performance Nissan indicated to me all the exhaust systems "resonate" at 2800-3000 RPMs. The Stillen was just a bit louder. Drone just seems negative. I hoping one person's drone is another's high performance music.

03.5 5AT-S (Black-Willow-Premium-Sport-Aero-GroundingGear™-Silverstars-PIAA-PopCharger-Z Tube-Tint)

 

Ok, I have the Stillen and enough time for a detailed reply. Obviously, you nailed it when you say that "droning" is subjective. In part, because some people use 'drone' and 'resonance' interchangeably, while others attempt to distinguish between the two. Merriam-Webster Online defines Drone as: 1 a : to make a sustained deep murmuring, humming, or buzzing sound b : to talk in a persistently dull or monotonous tone; 2 : to pass, proceed, or act in a dull, drowsy, or indifferent manner; and Resonance as: a vibration of large amplitude in a mechanical or electrical system caused by a relatively small periodic stimulus of the same or nearly the same period as the natural vibration period of the system.

With that in mind, I will say this: Pre-Stillen catback at a steady 80mph in 6th gear, I couldn't hear the exhaust at all - so I guess that means...no drone. Post-Stillen at a steady 80mph in 6th gear, I can most definitely hear the exhaust (plus my intake, the road, the wind noise, etc.). The sedan has inadequate sound deadening material for its class and, as a result, the exhaust makes itself known at pretty much all rpm levels with the exception of idle. So, if I can now hear it and, particularly since the tone never really changes because I'm holding at a steady rpm, does it drone? Well, yes, I would say it meets the definition of droning as in 1b above. But then, it's not so much that it's too loud, rather, ANY monotonous tone tends to get tiresome for me after about two hours or so. Steady droning of a jet engine on a long flight is like Chinese water torture to me. So, YMMV about "drone".

With respect to potentially offensive resonance: I believe there may be a pattern along party lines shaping up - that is, 6mt vs. 5at. I have a 6mt and as such, do not seem to spend alot of time at rpm levels that may contribute to offensive exhaust resonance. For me, any annoying resonance from the exhaust itself seems to occur at lower than 2800-3000rpm - and then only if I am in a high gear with the engine pulling (gotta love that torque!). But I don't seem to find this as much of a persistant issue as some 5at owners who spend a higher percentage of their driving time smack steady in that rpm range have reported. I would certainly keep this in mind if you have a 5at.

Also, perhaps contrary to what others report, my most annoying resonance does not come from the exhaust itself. Rather, when hitting 5k rpm and above, from time to time several interior plastic pieces will vibrate or buzz. The most annoying is the driver side upper seat belt anchor point right next to my left ear. With the definitions above, because it is not sustained or persistant, I will categorize this vibration as resonance rather than drone. It is important to note however, while this vibration was present before to a lessor degree, the Stillen exhaust now brings it on fast and furious. So, my take is - interior vibrations, buzzes and rattles have been reported by both, drone (at any particular db level) is a personal matter that can effect either, and offensive resonance from the exhaust due to rpms may be more of an issue with the 5at.

On a related note - I personally do not find the increased db level of this exhaust to be excessively loud. Mine has actually mellowed noticably in both db and tone since installed, and I positively LOVE the growl this thing gives off as I row thru the gears. Oh and, yes, the hp and tq gains! Is it offensive for daily driving? Since I drive without tunes most of the time in order to hear the engine/exhaust music, I say no. Maybe others feel it is loud enough to interfere with their music or luxury stealth, but mine is staying on. If you are concerned, you really have to find one and ask for a ride to know if it's for you or not...

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

Dholly, very well said, you nailed serveral offten passed over issue's that needed to be said. Hat's off you you and the effort to do your post.

"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt

 

geeman49 - too bad you don't have a stock baseline. I will be interested in seeing your after dynos though, as I had a z-tube and Stillen cold air box on for my after runs shown above. Please post!

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

I shall indeed post and I appreciate greatly the time you took to respond. I suspected it was in part a case of semantics and also what your expectations are. No post I've seen anywhere complains about the increased power. That is a good thing.

I had an SUV prior to the G (so kill me) and had a a K&N CAI, ECU mods and custom exhaust with 14" Magnaflow on it. I absolutely loved the sound. I liked the constant rumble and the roar when you got into it. I'd shut off the music, open the windows and just tool around doin' my business happy as a clam. I'm not worried about liking the sound of the Stillen. I know it's not everyone's taste though. Hell, before I got the pop charger/z-tube I used the manumatic (Man I love those marketing terms. At least it's more descriptive than Tiptronic. What are they tipping anyway?) maybe 40% of the time. Since installation I'm manual 95% of the time just to keep the revs up in the tonal sweet spot. Side effect of this was discovering the "real" G35 and what an capable power plant it has. Couldn't be happier and the smile it brings to my face when I drive has paid for the pop charger/z-tube combo 200 times over. We are lucky people to have Gs.

Dyno, Stillen install, dyno after spring break. If any Gs in Kona let's have a beer. I'll miss my G and I'll take you on in my Ford Taurus rental!

03.5 5AT-S (Black-Willow-Premium-Sport-Aero-GroundingGear™-Silverstars-PIAA-PopCharger-Z Tube-Tint)

 

Stillen exhaust too loud for my daily driver.Stillen says local muffler shop can install resonator or considering putting stock back on and taking out the "box" in the exhaust and putting in a straight pipe..Technosquare says many 5AT have found that to be a good solution.Will welcome any suggestions .thanks

 

dholly,

I'll second gsedan35's comments on your excellent post.

I totally agree that an exhaust note is very subjective. To me my Stillen exhaust doesn't drone. While it's mellowed out with time, it's still a little louder than ideal under some midrange loads. (But then I'm an old f^rt.) And no, I'm not going to change it. I love the performance improvements and powerful sound it brings to the party.

My observations on my recent trip to Phoenix/Scottsdale, Arizona. At 2450rpm (70mph) it's as quiet as my stock system was with the resonator changeout. At 3000rpm (84mph) it makes a pleasing, reasonably quiet, exhaust note. You can converse in a normal tone of voice and you can certainly tell it's there if you turn the music way down.

I drove another G35 Sedan today with Crawford's Cats and Stillen's exhaust. While it had a deeper sound, it didn't drone and was just slightly louder at similar speeds noted above.


catusboy,

I'm confused by your post. The Stillen G35 Exhaust System has is made up of a head (x-) pipe, two resonators, a single muffler and mandrel bent 2.5" tubing connecting it all together. I don't know of a "box" that's incorporated into its design.

I was told my system would "mellow out" with time. It certainly has! If I was going to quiet the system down I'd look into longer/larger resonators as a starting point.


DaveO - 2003 G35 Sedan / DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TS ECU / E-Fans
Street Edge TC / B&M Cooler / Stillen Exhaust

 

I just installed the Catback system on my AT sedan. I have to say that stepping on the gas at the 2500-3000rpm range (where a lot of my highway cruising happens), the exhaust is a bit loud. The sound is more of a brrrrrrr than the low growl that you get at higher rpms (dunno if this is considered a drone or not). You basically here it when you step on the gas and the engine's reving in that range. It's actually quieter when you accelerate above that RPM range and sounds much meaner (better).

So is there a way of reducing the volume at that RPM range? Or will the system simply mellow out over time and be less loud overall? What would happen if you remove the resonators and replace them with a straight pipe? Would it be louder or quieter? Anyways, I think the exhaust sounds nice at higher RPMs, but at lower ones, it sounds too much like a big mufflered Civic for my taste (what I mean by a big mufflered Civic is a subjective impression of the sound of a Civic where the owner puts in a big muffler so the tiny engine can sound tougher. I would prefer the growl that you get from more like a Corvette that knows it's got lots of power. Anyways, it's just a subjective opinion).

I'm planning on putting in the Z-Tube/Pop charger next cause I here it does a nice job of letting out the growl.