G352NV

iTrader: (13)

Please post up here.

HyperSprite

iTrader: (6)

I have a fairly new system and have put 3k miles on it and I have hair growing on my back bumper

This is an Injen design flaw in their back boxes. You simply can't put a silencer in the middle of a muffler, forcing exhaust though the packing, and not have glass come out.

On the bright side, once all the glass is gone, it will stop coming out, unfortunately it still wont flow any better.

Chris

Bubble

iTrader: (50)

they all have to put the silencer some where and the flow still not come out 100%. Isn't it?

G352NV

iTrader: (13)

Heres what I think the problem is. I think they used the same packing in the mufflers that they used in the resonators. Instead of replacing the FULL exhaust they thought they could get away with just replacing the resonators.

HyperSprite

iTrader: (6)

Bubble, what I am talking about is a restriction in the pipe half way down, Other systems like the HKS have a removable silencer that is held in by a bolt or two (the early angeled Injen was like this), removed they are straight through systems, but usually loud, in the case of the angle tipped Injen, too loud to be legal. This silencer is not a performance part, it is simply a restriction placed in the pipe to make it quieter. To make them legal, Injen changed them to a straight tip and put the silencer inside the back muffler where you could not see it (or remove it).

See my drawing as an illustration of the back box, the light red arrow is exhaust easily going through the center of the silencer, the dark red arrow is where it is forced around the silencer during high rpm (well around 3000 rpm and above) operation.



Don't believe it's in there? check out the video below...
http://www.hypersprite.com/auto/vide...en_str_tip.wmv

So sad
Chris

HyperSprite

iTrader: (6)

I guess what I am saying is, if the system was properly designed in the first place they would not need to resort to "obstruction" as a method of silencing. That is type of cheep trick OEMs have been doing for years to save money on exhaust systems and why in the past it has been so easy to get more power with an aftermarket system.

It's to bad, I think it is one of the coolest looking systems on the market.

Chris

seanlaw

iTrader: (4)

mine blows fiberglass all over my rear bumper...

i cleaned the car yesterday only to find that after less than a mile there was fiberglass starting to layer on my bumper.

lets email injen about it...and have them take the fiberglass out of our mufflers

GWAPITO69

iTrader: (6)

I want to know also what they say about this stuff. i'ved got thesame problem my driver side exhaust is blowing hair like fiberglass and i'ved put in almost 9000 miles

JonsilvZ

Yeah I get the same **** coming out. Its a good looking and sounding system. But they shouldve designed it different internally.

HyperSprite

iTrader: (6)

You can't just take the fiberglass out, it needs to be in there or it's not going to to a whole lot of sound deadening.
From what I can tell, the inside diameter of the back mufflers is to large, the rest of the system is 2 1/4 and it suddenly goes to the universal size of 2 1/2 at this back box. So without the silencer the exhaust simply shoots through the center without much muffling. It may be that the back can is a muffler they already stocked, so it was easy to pull off the shelf for this system. Or maybe it's just not possible to quite the car to below 95db with such short mufflers out back without restriction. It's hard to say.

Tomorrow I am taking this off and putting my stock setup back on until I can figure out a solution or alternative system.

Chris

GQ 350z

iTrader: (13)

Chris, maybe different mufflers? Could you use the old piping and perhaps a different muffler? I'm actually trying to sell my setup, not because of the fiberglass, luckily I dont have the issue but my commute is killing me (the drone).

ravi

Damian

That HKS Dual Hi-Power Titanium (Ti) Exhaust looks like a great design and looks almost identical to the Injen.

G352NV

iTrader: (13)

Im just trying get get as many guys posted as I can so I can show the judge when I take them to small claims court.

HyperSprite

iTrader: (6)

From what I have seen, the HKS also has silencers BUT they are removable and will not cause fiberglass blowout.

So how loud are they without them?

Yeah, I have been thinking about that. I was looking a pair of Jegs stainless turbo mufflers and a x over pipe. The "Turbo" is a misnomer in the name that goes way back but the way these mufflers work they end up with very high flow and usually produce a very nice tone. I could probably ditch the resonators all together with that setup and still not have any rasp and it would be lighter.

My problem is I don't know where in San Jose I can get stainless welded with stainless. Also, if I make these changes, it could end up quieter than stock even or flow less or more and the power would be a total mystery.

I am sort of out of car money right now so I am just going to wait a while and see. Also, I would like to see and hear the APS and DC Sports dual in person.

Chris

GQ 350z

iTrader: (13)

Man, you said it. I'm really at bare bones right now (if you saw my ad in nor cal section). I'm trying to go a different route and my price is pretty low with no bites. Kind of sad. I might get the HKS later this year, or the Greddy that I originally wanted. Seems like getting a true dual is a misnomer, when the xpipe based systems are making more horses.

ravi

Nano

iTrader: (1)

I always thought about replacing the injen muflers with 2 HKS universal CF (or TI) ones...

http://www.hksusa.com/images_products/L_2062.jpg

Problem is it could sound like crap... and my injen is still holding up fine (no fiberglass yet with 5000 miles on it).

what's the piping of the SES? 50 or 60 mm? 2.25" 2.5" .. ???

mario60185

it will go away dont worry. i had it too for a while anbd now its gone.

G352NV

iTrader: (13)

Yeah now all your packing is gone.

Nano

iTrader: (1)

more horses seems like a misnomer altogether when talking about exhausts. How much REAL horses does an exhaust produce in the first place? 3-4 rwhp?
Even the best exhaust gains are pretty much irrelevant. My friend dynoed his borla at 2 rwhp gain from baseline. It seems people with good Y-pipes and stock everything else are producing as much as the best exhausts. 350z aftermarket exhaust are more about sound than power...

If I were to do it all over, I'd just buy a good y-pipe with good hiflow cats... stock sound and tonality, just angrier. Plus you get to keep the stock muffler with the deflector and all... Still... I must say I'm extremely happy with my injen, no issues whatsoever.

DocCNader

I JUST BOUGHT THE SYSTEM AND IT WILL BE INSTALLED FRIDAY SO I EMAILED THEM! AND THEY ANSWERED! HERE IT IS!

THE FOLOWING IS MY ORIGINAL EMAIL WITH THEIR ANSWER>

Dear People at Injen,

I just ordered an injen straight tip exhaust for my 350Z and until now
I thought i was buying a good system that would achieve more HP. Doubt
has risen do to recent posts on www.my350z.com and this article
http://www.hypersprite.com/auto/pict...d002/injen.asp Can you
explain to me if the information on the article is true and what can
be done about it?

Thanks,
Charles

INJEN'S ANSWER>

The fiberglass is due to the exhaust system breaking in and the period in
which it will settle will vary. We have had similar situations with other
350z owners who have expressed concerns about the fiberglass turn around to
tell us that it eventually stopped. Or when they have claimed it to be
completely blown out, to us having them come in and find nothing wrong with
the system whatsoever. We are not saying that this is the case here, but
there are many variables to lead to the difference in break-in period. It
may in some cases take longer than expected.

As for the silencers, what you need understand that the 350z or any car in
that matter, relay on a certain amount of back pressure and/or restrictions.
This is quoted from our R&D dept... "Not all engines need free flowing
exhaust pressure. They need the right combination of free flow with the
right amount of restrictions. For example most people think that
turbocharged vehicles need the biggest exhaust piping you can squeeze in the
car. This is not true due to the motor not being in boost 100% of the time.
It's all about combination...if there is a restrictor there, then it was put
there for a reason...to control exhaust flow to achieve the best possible
air flow for that specific car.

Remember when it come to intake and exhaust systems it not about max air
flow...it's about combination, combination, combination!!!"

Also, we produce products intended to be used in a legal format and hence
abiding to the California Decibel requirement. After our first initial
release of the 350z angled tip exhaust with removable silencers, we listened
to all the 350z owners whom suggested changes to be made to the system due
to the awkwardness of the silencers and overall look. Therefore, the release
of the newly designed straight tips with built in silencers were made. You
may have negated the fact that we in no way hide the fact that there is the
apparent addition of the built in silencer and in fact is also one of our
many key points of the system. Not to mention, the 350z exhaust system along
with all of our cat-back systems are dyno proven pieces that have been tuned
accordingly as a complete system with all components added. So your so
called "[Dirty Little Secret]" is not really a secret now is it?

We do not take offense to your posting, but please be fully aware of what
you are stating and have it backed by information that is relevant and not
just a mere "findings." If you look at any exhaust company on the market,
from a straight flow design or a chambered design, everyone differs and has
engineered their system to a specific design for a reason. Ours, as in the
aforementioned, were to offer a great upgrade on the existing stock
component- adhering to legal requirements and to give you an added
performance gain. I hope this information will shed some more light on the
matter.


Best,

Duy Le
Sales/Marketing
Injen Technology Co., Ltd.
(909) 839.0706 x201
(909) 839.0427 fax
www.injen.com
AIM: InjenDLE



MY CONCLUSION... I HAVE TO WAIT AND SEE WHEN I INSTALL IT, BUT I STILL THINK ITS A GOOD SYSTEM
LATER,
Charles
P.S. I ANSWERED HIM CLARIFYING THAT I DIDNT POST THE ORIGINAL POSTS ABOUT THE PROBLEM SINCE HE THOUGHT I DID IT.