This is for a sedan BTW. But it should hold true for coupes. It's been done on Borla equipped 350zs also.

My borla dual was always drone prone. Oddly enough the wife never really bitched about it :lub: (and you KNOW that woman isn't afraid to speak up :secret: ) Would resonate right at 1500-2000 rpm. Basicly the cruise and shift points. So it was always at this annoying drone rpm. Athough this mod was for intented for more hp/torque, it still did a good job at reducing the drone. But IMHO, most of the drone is from the rear muffler. But I wanted to do this first to see what happened.

The Borla had this crappy 2 in / 2 out premuffler out of the cats. Straight though design. Yeah, stupid: (thing with "borla" printed on it.




I replaced it with this:



Material: 100% Stainless Steel - Mirror Finish
Body Shape: 4in.x9in. Oval
Inlet/Outlet Size: 2.25in./2.25in.
Body Length: 14in.
Overall Length: 20in.
Core Size: Dual 2.5in.
Position: Dual/Dual


Features and Benefits: Straight-Through Wide-Open Performance, Reversible, Tru-X Perforated Core,

I'm trying to get this review done before I throw on my coupe 19s again. So I had a chance to drive it on my work commute:

Although decreasing this boominess/drone was one of my ultimate goals, I wasn't expecting alot with this addition. But after driving it for a few days, I can tell the drone is noticably reduced. Maybe by a 1/3rd or 1/2 at the most. It's still there but not nearly as loud. Cruise rpm is alot quieter. I was hoping the resonated X would help with this and it did! But I considered a bonus and not an expectation.

Overall sound is alot more exotic vs again boomy. The vibrations that this thing has because it doesn't have flex pipes is also reduced (by 1/2). The sound is sorta like a coupe but louder and better. Again once you hit the high revs, it quiets out just like before. The exhaust is smoothed out too.

Performance. Again, the streets are wet and I'm on my blizzaks. Everytime I get on it from a roll and shift into 3rd, it just results in wheel spin. But the low end torque is improved and the high end hp seems to be better. The torque band seems to have moved maybe a few hundred rpm lower. For us autos, any improvement in this area is good. Not as dramatic as when I added the crawford plenum, but it's definately there. The Z guys that have done this to their Borla or HKS etc... dual setups have raved about the performance (mainly torque) improvement. As I get to drive it more, I notice more torque while in each gear thoughout the rpm range. The x pipe lived up to what it was supposed to do and sound like. This exhaust should have had this in the 1st place.

I'll probably forgo replacing the rear muffler. It's quiet enough. Plus doing that would make this an used $900 system by the time it was all said and done. Shop said I could have had a custom system done with these components for $500-$600. Live and learn.
I'm going to try to take pics when I get around to putting my coupe 19s back on.

 

that is one of the reasons i always favored custom vs aftermarket exhausts.

X-pipe is always a good thing. Congrats.

 

Thanks Klubb

 

What did you use for a connection to the cats? Can you draw out how the system looks?

 

Shop hacked up the original Borla 2 in / 2 out straight through pre-muffler and added the magnaflow 2 in / 2 out resonated X pipe. So they used the original Borla flanges/pipe from the pre-muffler, welded those to the magnaflow.

Borla Y pipe flanges -> magnaflow X -> Borla dual resonators -> rest of Borla system

 

Gotcha, how much did it cost overall?
-Magnaflow
-Shop cost

This is something that I am VERY interested in becasue I would rather keep the Borla than spend a lot of money on a new exhaust.

Also, can you shoot me the links for the my350z threads on this mod? Has anyone else on here tried it? Sorry to be a pain, but I appreciate all of the help.

One last thing, you say the sound has changed? Besides eliminating some drone, how so?


EDIT: I found the part. I believe it's Part No. 14385, and it lists for about $120 in most places.

Since this is a muffler, have you considered removing the rear muffler? Has anyone tried that?

 

https://g35driver.com/forums/g35-sed...ll-review.html

A good read. It has impressions and cost of the unit. Install was around $160.

You'll have to dig up the Z threads yourself. If you are serious about researching, you should do some investigating yourself as I did. But punching in x pipe or magnaflow or the model number in the right section comes up with most everything.

My research here probably eliminates 90% of the time I had to research. Hopefully you can build on it.

 

This is something that I am very interested in doing. I want to keep my Borla, and this seems like an interesting way to gain some more power and reduce the annoying sound.

I'll take a look on my350z. I suppose that my main curiosity will be if there are gains with removing the rear muffler and putting in straight sections. I'll have to ask around.

 

removing muffler and putting in straight pipe = counter intuintive to your goals

 

Gotcha, I found out about performance peddler, so I will probably order the x-pipe soon. The installation might have to wait until May when I can try and arrange a dyno appointment. Hopefully I'll be able to provide some before and after plots. I am also very interested in the "higher" pitched sound that comes with an x-pipe. At least in videos, I feel that my Borla is too boomy and too deep. I want more of a coupe sound.

Here is my car:

 

That would be great!

If I can figure out how to make a sound clip, I'll post it. But since the drone all us Borla owners are concerned about happens while driving, it's difficult. I tried with my camera but nada.

 

If you can, that'll be great. In fact, even if you can get one revving from the outside that would be useful too. Then I can compare to my clips. Either way, I'm excited! I've been searching for something fun to do with my car.

 

just ordered one of these for my coupe w/greddy evo2 + test pipes i hope it works!!

 

Good luck! I think you'll like the results. All the Z guys liked what it did to reduce rasp from their test pipe installs.

Let us know how it goes

 

For those who want the performance benefits of an x-pipe and are not as concerened with noise reduction here is another option. I used a straight thru x-pipe, not a muffler containing and x-path.Total cost was $50. I should mention that after breaking it in a little I do hear a little ringing in the extreme upper rpms close to redline-(which i have raised to 7200) so this may not be a problem for others.
https://g35driver.com/forums/g35-sed...ml#post4137443