After hours of searching I'm still not 100% on which x-pipe that people are using with the HKS/XO2 exhaust. Some are using a perforated oval muffler type x-pipe (11385/11386/14385/14386 magnaflow muffler stainless/polished in 2.25 for HKS/2.5 for XO2). Others are using a Tru-X crossover from magnaflow 10790/10791 which is just the x-pipe with no muffler around it. I have the HKS with berk non-resonated test pipes and a motordyne spacer installed. Just like everybody else who's done this I have rasp and it's annoying and awful sounding at high rpm. From what I've gathered from the other x-pipe threads here the oval muffler x-pipe greatly reduces rasp/drone but requires cutting out the resonators/h-pipe. The other tru-x crossover has the same x design but without the muffler and doesn't require as much cutting (just the h-pipe).

Now to the point of this thread. I don't care as much about reducing the overall sound volume of the exhaust as much as I would like reduce the rasp at high rpm. I'm actually wondering if the muffler type x-pipe might reduce sound volume too much in my case. I'm hoping for reduced rasp with only a slight amount of sound volume reduction. Do you guys think the non-muffler type x-pipe would accomplish this? Has anybody installed the tru-x crossover x-pipe with either the XO2 or HKS? I haven't been able to find a youtube vid of the HKS with non-resonated test pipes and the x-pipe mod (muffler type or non muffler type).

Links to the 2.25 versions of respective parts:

http://www.magnaflow.com/02product/s...e=main&id=9199

http://www.magnaflow.com/02product/s...e=main&id=9642

I realize a little rasp is inevitable and I'm fine with that. I'm just hoping to reduce it as much as possible. Thanks guys.

 

Use the perforated core because it has better sound reduction capabilities. It will def. reduce the rasp. Now as for size I think it's the 2.5" you should look at. It is the same size as the piping for the HKS.

 

the xpipe muffler will bring the vq sound back also while killing the rasp. you will love it.

 

I did read a thread about somebody who did the tru-x crossover on a borla exhaust and experienced even worse rasp. Maybe I should just go with the muffler since it's far more likely to get rid of the rasp/drone. Not too mention with test pipes I can afford to quiet things down a little.

Any idea how it installs? I haven't seen anything for the hks/xo2 exhausts, only people with borla. The resonators get cut out but what about the h-pipe? Does the x-pipe muffler replace the h-pipe AND resonators?

 

https://my350z.com/forum/intake-exha...pipe-loud.html

The muffler replaces the resonators and the crossover pipe.

 

make sure its real HKS yer talking about.. the off brand uses a larger diameter than the true HKS. i believe the HKS is 2.25 and the XO2 like i use is 2.5

magnaflow makes both, and plus one vote here for using the full muffler version and not the simple x shaped pipe.

 

Sounds like the muffler will be the best bet for me. Going to have to find a good welder and make sure that everything lines up properly. Anybody know how to make sure the flanges match up with the new muffler welded in?

 

There is no need to worry about the flanges. It just replaces the resonator.

 

I've had the x-pipe on for a few days now and I'm not very happy with it. It drastically reduced the sound to the point where it's not even noticeable. Above 4k rpm it's almost silent and the lower rpm's barely have any notable volume. More importantly however, it feels like I've lost a large part of my bottom end. The car feels very sluggish. I'm pretty sure I'm going to put it back to stock and scrap the whole piece of garbage exhaust.

Now I see what all the hks haters are talking about. For what I've spent on it plus getting the stupid xpipe de-mod I'm close to the price of the tdx v2. Also, the hpipe did have the quarter inch or so protrusion in it. I'm completely disappointed with the whole thing.

 

cutting out the H-pipe and resonators on the HKS replica is a big section of the exhaust. if the x-pipe mod is done.... will there need to be an extension welded on also? or is the 20 inches from the magnaflow x-pipe enough?