Remove the pre-silencer!! There's been two posts about this already, and I was a bit skeptical, but I just did it earlier today @ my local muffler shop for about 35 bucks and replaced it with a straight pipe. I CANNOT EMPHASIZE THE IMPROVEMENT!! The car sounds like it should have from the factory, it's the same sound but a bit more burbly, not much different from stock @ low RPM's, but when you push it at full throttle the exhaust sounds exquisite! No droning on the highway, and you can actually hear the exhaust, one big complaint I had before was that all you could hear was the engine on the Z, no exhaust sound.... Now you can actually hear both and it's great. I was apprehensive because I didn't want my car to become too loud, but this is PERFECT! All it involves is them cutting the silencer (it's a small glass pipe muffler) and welding in a piece of same diameter piping in its place. For wicked4u2c who did it first, great find!
Also, the engine does rev a bit more freely, don't know if there's a power increase, but it does feel like it. Would be interesting to dyno a before and after.
Especially because many of the current exhausts out right now don't add power without replacing the Y-pipe this is a great alternative to the 1000 dollar exhausts which only add like 3-5 RWHP anyways...

Here's a pic of the cutout silencer, it's about 14x8 inches.

 

Interesting, the pre-silencer is made by Calsonic. Always wondered what they made...

I'd really love to know if this increases HP. In any case, maybe I'll try this out while I'm getting the new exhaust fitted.

 

z461, wickeds videos sounded a little..well, "farty" (?). How much of that is the video?

 

i didn't think wicked did it first, i thought j's350z did it first over a month ago? maybe i'm thinking of someone else! don't mind me..

 

I can't say I was the first one to do it, but I sure was the first to post videos... Anyhow, it sounds a lot better in person and like he said top end feels great! I say its the cheap way for an exhaust without getting pulled over... And also sounds EXOTIC!!

 

now i know i may be the biggest idiot for asking this but did the muffler shop provide you with the straight pipe or did you already have it. i am gonna get this done tommorrow so get back to me as soon as possible. thanks in advance.

 

the muffler shop will have the straight pipe for you.

 

thanks lr! where are you in nj?

 

I don't know if I was the first either but my car came in on 10/15 and I had a bolt in pipe made on 10/20.... I didn't want to cut the stock pipe so my shop made me a direct bolt in replacement. It sounds kinda shitty when cold but after 10 mins of driving sounds great......
Jason

 

It is VERY raspy when the car is cold. I couldnt handle it so I took it off. I will admit it sounded pretty good when warm, but when your in a hurry and have to leave without the car warming up, it sounds like A$$!

NittoZ

 

ppw350Z
thanks lr! where are you in nj?


i live in monmouth county(marlboro township)
where do you live

 

When I heard people saying they were removing the pre-silencer, I wondered about its construction. Is it just a straight pipe with perforations inside the body, or do the internals make a "loop?" In other words, if you look in one end, can you see out the other?

Since some of you said it sounds too raspy without the silencer, particularly when cold, I was wondering about welding in something like the old "Cherry Bomb" muffler. As I'm sure you know, these are basically a straight pipe with perforations that lead to a "glass-packed" body. If you look in one end of the Cherry Bomb, you can see straight through it.

Think this would get rid of the raspy sound and yet provide a reduction in back-pressure?

 

hmmmmm sounds like an interesting idea.

 

I believe if I memory serves me right, you were the FIRST to do this. I did it after hearing from your experience, but didn't like it. Welded the pre-silencer back the next day. My recommendation is DON"T try to do this mods unless you have heard it from other 350z that has done it. It's not for EVERYONE.

 

The pre-silencer that they remove is, as you described, "basically a straight pipe with perforations that lead to a 'glass-packed' body".

 

If I decided to do it, I ask the Muffler guy to remove all the things that are inside the pre-sil and put a straigth pipe inside the pre, this way its looks stock but have the perfect sound also.
(I do it with my last car, but with the cats).

 

where's this video? is it with the straight pipe mod? i tried searching for it but i couldn't find it. Can some link me?

 

It is basically a "cherry bomb" glasspipe... But with lots of fiberglass insulation inside. It goes straight through. BTW, it IS raspy at first, but to tell you the truth, it sounds EXACTLY like the M3, the raspiness IMO is AWESOME... It makes it sound even meaner like the engine is snarling. Combined w/ my Injen intake, man oh man, it's 400% better sounding!