wow, that exhaust looks good! nice to be different

Thats a good idea on the resonator side pipes; that other thread on this forum was interesting.

I just hate to cut into the exhaust though. It seems like the previous two guys running it had not problems with drone but they were on their stock cats so maybe my HFCs make a difference. I refuse to get rid of my Berks so the Injen has to go under the knife haha.

My Preliminary Exhaust Review
 

I have been driving around with my new Injen exhaust for a few days now and am getting a better feel for it in terms of performance and sound so I figured I would post an initial review.



Craftsmanship/Build Quality: the welds and build quality is top notch with even welds all around the exhaust with no splatter. The pipes are all polished well and the exhaust fit perfectly first try with no surprises. The only thing I wish was that the Y pipes did not have two 90 degree bends on either side as there is plenty of space to allow for smooth bends.

Sound: The sound is incredible. It is extremely deep, smooth, and exotic which is exactly what I was looking for. It is not overly loud but it definitely makes itself known. I smile every time I take it out because every time I touch the throttle, people all turn and look even if they are in their cars which is a great feeling. However, one issue I have is that there is some serious drone around 2,000 rpm. I am not that sensitive to drone or loud exhausts since my Saab was pretty loud but the drone is too much for me and is prevalent from 2-3krpm. I will be dealing with this with a set of Helmholtz resonators (branch resonators) that will be custom installed in the coming weeks to tune out the worse of the drone around 2,000 rpm without affecting the sound or volume of the exhaust (a major concern for me as I love it other than the drone).

Performance: I have become pretty good at feeling whether or not any power is picked up with these types of mods as I don't expect anything and can only be pleasantly surprised it gains are felt. I noticed power and torque gained with the first WOT pull I did, but more importantly the low end power has improved as the car is more willing to pull from low rpms. This is a big bonus but I obviously cannot tell of any proven gains until I get the car on a dyno.


In conclusion, I really love this exhaust and it fits the exact sound and look I was going for. Once the drone is finished, I believe this exhaust setup will be perfect! I will get some more video soon, but for now here is a cold start and a 3krpm rev:

Some Rev Action!
 

Need Your Opinion
 

I went to a relatively high end exhaust shop today to get the car on the rack and consider the various options for getting rid of at least 50% of the drone I am experiencing and came up with a few options that I wanted to get your input on.


Option 1:

the side branch resonators in the same style as the HKS/Ark exhaust systems right before the rear mufflers. Using resonators will take off much of the length I had calculated for my Helmholtz resonator design and will do the same job, plus it is a proven concept both in the aftermarket and on OEM exhausts for reducing drone.

This is going to be between $400-500 TIG welded and fully polished stainless steel. Between what I spent on the exhaust and the cost of this mod, it would still put the total exhaust cost around the price of most mid-high end exhausts on the market.


Option 2:

Sell this exhaust and find another. The previous owners had no issues but they were running on stock cats, plus this exhaust is unique in that it is 1 of 1 which is appealing versus something common. Less inclined to do this to be honest but always an option none the less.




So what would you guys do? I will be upfront in saying that I an inclined to keep it as it sounds different to any other exhaust I have heard for the 370z and has the unique one off factor but am still not sure it is worth the extra coin to get it the way I want it.

Chris, sell it and find something else. The End!

I know, I have an issue of being stubborn and not letting things beat me haha. I guess I will run this until I find another deal or if I figure out alternate plans, one thing I refuse to do is put the stock exhaust back on lol.

I felt a major power increase though, I would love to see what it dynos first.

If drone really doesnt bothers you then option 1, but 500$ to get it fixed is very high cost

I sold my FI just because of similar issue, even though for some who drove my car they were ok with the drone

Sell it man. Do what makes you happy. But think about this, your going to end up paying more. 800 plus shipping then 300-500 to find another exhaust to get what you want. mxp has great exhaust . Might want to check it out. But drone....which exhaust doesnt have it?

Did you happen to video it or know of a video to do it? I am looking to change those out as well, but I am also adding in some flexible LED lights to the exterio and need to tap into that wire.

Haha, trust me I like loud exhausts but living with a loud exhaust is different than dealing with enough drone to make the rear/side view mirrors vibrate like I am bumping a sub in the hatch. It is not a problem around city driving, but it is something else on the highway. Either way, you definitely were right about it sounding unique and I think the sound is absolutely perfect! Just a little work might fix the drone, especially since I got it for less than 800.

I guess I have no context to see how the FI exhaust sounds since I haven't ridden in any of your cars yet!

I can't find the other DIY guide, but this one should help in terms of determining the way you can tap into the parking light wiring:

http://www.the370z.com/diy-section-d...y-drl-kit.html

In response to your Option 1 & 2 for getting rid of drone, are you sure adding those side branch resonators will remove the drone? And if so are you sure they won't change the exhaust note to something you don't like? Cutting into the exhaust seems a bit drastic but make sure you're prepared to deal with it if it doesn't turn out the way you want.

I would be more inclined to just sell it and get one with no drone like the HKS (or so I hear) or whatever the cheaper alternative is.

Stillen doesn't drone.

I know, but Stillen doesn't sound like this exhaust. No knocking Stillen though, I should have searched outside of the370z since 350z guys find the Injen exhausts are notorious for drone.

lol stillen isnt an exhaust its a stock exhaust polished lol