Hey guys, I am posting this before I have a video, but it's raining up here and I wanted to get a daytime video.

Here's the problem. Got the HKS exhaust installed, got it used from a very reputable forum member. Install went smoothly, but the exhaust is silent. On start up you can hear someone of a growl, but when any gas pressure is applied, the exhaust noise does not go up. But when the gas is released it will growl back down. I had the HKS on the car when I bought it, and made the mistake of selling it. Does anyone know what could be causing this problem? I am almost positive this is the authentic one, and even if it is fake... I don't think it'd be silent.

Any help would be greatly appreciated.

I have gaskets from NAPA in there, and from the y-pipe to the h-pipe, I could not find a gasket that would fit (I thought it was just two two bolt flange gaskets) but the exhaust shop that installed my exhaust said that the smooth surface of the flanges would prevent all the leaks. Is that my problem right there? When started up there was no air escaping from the y/h pipe connection.

I remember it sounding like this:

It sounds almost softer than a stock exhaust.

 

Here's a video of my exhaust. Only revved up to about 4.

 

If you had a leak it would sound obnoxiously loud not soft. How many miles are on the exhaust?

 

+ 1...that sounds normal too me. I have the HKS exhaust as well. At a stand still when you floor the pedal it will get loud.

 

I don't know how many miles the exhaust has. But I do expect to hear the exhaust on the freeway. I can't even hear it when I'm driving, more often than not I will hear my z tube....



So this sounds normal? I forgot to say that the exhaust is technically the 350z version with welded extension pipes. I just remember it being way louder when I had it before My brother revved it and I could barely hear it. I highly doubt test pipes are what makes the difference between my video and the one posted before.

 

It sounds normal for the amount of gas you are giving it at the stand still in your video. Then again video's aren't the best to capture the true sound. But on the street or highway at 3/4 to WOT you will definitely hear it. If you really can't hear it then maybe there is an obstruction in the piping. And before anybody try's to give me crap about throwing the seller under the bus I'm just throwing that possibility out there. Maybe something got in the piping.

 

I'm actually thinking that because when the exhaust warms up, it gets softer, and on the highway I really have to gun it to hear it and at the top range of RPM it dies out. If there was an obstruction could I get it removed? I was hoping it was simpler than that.

 

I wish I had this problem

 

Lol... when you pay lots of money for a quality exhaust... and you aren't satisfied... I don't think that's a problem anyone wishes they had. I am guessing the only way is to find another owner with the HKS and compare. Question is if I had art / test pipes would it sound better?

 

I'm sure you could. I imagine you would just have to take the exhaust apart and look into the piping to see if something is caught up in there.

 

Sounds normal to me, I have the same exhaust myself...

 

Answer = YES

 

Just buy the ARTs, you'll be SUPER happy with it then I guarantee!! They'll make the exhaust note louder, deeper, and more resonant.

 

Sounds normal to me also. +1 for ART pipes or consider Test Pipes

 

I wouldn't install any exhaust system without gaskets, surprised yours sounds soo good. You mentioned y-pipe the HKS system doesn't have one, it's a cat-back system. Before installing did you check the crossover to see if there was the dreaded restriction HKS is now famous for? HFCs or ART pipes will change the way your coupe sounds, it's just a matter of how illegal you want to be...
Gary