08mojo

Awesome work! What was your process for modifying the stock tip? Is there any drone with the valves closed (since you stated it was louder)?

dart.deanda

Wish I had the welding skillz necessary to pull this off! Congrats, that is a *way* stealthy mod! Hope you get some b2b dyno numbers soon! Can't wait for the video. thanks!

v8sten

I figured it would sound like the Fusions open, they are 3" straight pipe too

a striper

Great work!

Josh B.

Thanks for the comments. My welding ability is so so, but I tried my best! Wire feed is just adding marble, grinding wheel is the sculpting act The stock tip is double walled ss. To separate the inner and outer "walls" I used flat grinding wheel to flush grind the edge of the tip. I probably took off about 1/8" or so, but the grinding complete separated the two halves. Once the inner wall was relieved of duty I worked on increasing the inlet ID to work with the 3" pipe, since the factory 60mm was much smaller. I accomplished this by cutting the outer wall about midway through the taper from 3.5 to 2.5. Cutting it on the taper worked out perfectly, but the tip is a bit shorter now, which you can't even see while mounted on the car. Hope that helps, I will make sure I detail that in the write up. NO DRONE!!!!! I was worried I might induce a little drone but I am GLAD to report there is zero drone, none, nada. I hate hate hate drone and would report back to you guys if there was any (LG headers, no cats, BTW). The tone is louder, but zero drone. IMO it sounds phenomenal, throttle response is vastly improved, which I was not expecting, I tested it out a few more times to make sure I wasn't imagining things, and things are absolutely more crispy on tip-in.

Best $200 you'll ever spend on your Z!

Picture of the tip modifications

v8sten

I was just wondering, arent the valves normally open. the link you posted is for normally closed.

I also noticed they are coming from China, how long did it take to get yours?

Here is the link for normally open

http://www.aliexpress.com/store/prod...789782919.html

08mojo

Thanks for the reply and making this DIY. Our welding skills appear to be on the same level, well you might be more advanced than me. It was a huge PITA to weld the skins back on my mufflers when I modded them. The grinding wheel was absolutely needed in my case.

Josh B.

You're correct. When I went to order the "open" model, they were not available for some reason. The "closed" model was available, and since I was reutilizing the factory actuator (to ensure complete compatibility, think vacuum range) it did not matter between the two since the open/closed is dictated by the actuator body, not the butterfly body. I was hoping the open model would have been available, but it didn't set me back at all. Future customers might be able to get it, who knows with China. I thought it was cool to get a priority shipment all the way from China, they must have flown it because I received the butterflys in like a week.

The only margin note on reusing the Pierburg actuators is that the triangular bolt circle of the Pierburgs are smaller in diameter than the 76mm butterflies, so you have to file/drill the holes towards the inside by about 2mm each. Then, no fitment issue, completely the same operation as the stock NPPs, only more evil.

Josh B.

Here is a quick video of free revs to give an idea of how it sounds now. Let me know what you think!

jasonz28camaro

Not sure how it sounded before lol. Can you tell big difference and do you like the outcome so far?

v8sten

No MTW???? Pull the fuse while its running so we can hear the difference at idle

Josh B.

No M2W switch yet. Thinking about getting one. Roger that, I'll get another video in better lighting tomorrow and pull the fuse while its running.

Josh B.

Fair point, I found a similar "before" mod video, I'll put them together. Didn't I send you a PM regarding GS seats for sale, I don't recall a response? I love the new exhaust, sounds much throatier, cackles and pops on decel now. Looking for other peoples feedback as well.

v8sten

im gunna order the valves tonight and the piping shouldnt be an issue to get. once it all comes in im gunna do this either over Thanksgiving or Christmas, whenever the parts get here

Josh B.

That's awesome man. The 60 degree bend with the 3" CLR is critical, any longer of a radius and the pipes wont be able to make the turns tight enough inside the can. I could only find one company selling the 3" CLR, all others were like 4" or 5". One more note on the Chinese actuators, the vacuum nipple is facing side to side, and the factory hose connects from the rear. The hose would probably stretch far enough to make the turn, but something to think about. I'll make sure I have those how to notes prepared before Thanksgiving.

Josh B.

Updated video with before/after format. Let me know what you think!

v8sten

I though about the CLR on the way home, I just opened CF up and saw your comment, thanks that helps a lot

tbran6

Sounds healthier with the 3in upgrade. It's gotta be making more power, at least a little more.

v8sten

Ordered the valves, looking for the pipes, gunna see if i can get them local

****** EDIT ******

Everything is ordered, it was a little more than you stated. So far I am at $259.68 in parts to be exact, not including shop supplies

Josh B.

Rock on man. Did you order the bends from amazon? I came in right about $200. I went through 2.5 lbs of .030 welding wire Welding the can back together is, well, you'll see

The only two tools that are specific to the job are the 3" holesaw and the 3/4" holesaw (for the 4 bypass holes 3 inches foreward of the baffle). Both holesaws are available at Lowes, I went through two of each, you can save by buying one with an arbor each, and another blade only of each. If you have a drill press one holesaw each will last, but I had a hand held drill that allowed the holesaw to "walk" slightly and it put too much heat on the cutting edges and wore out faster. Locking it all in place will make the tools last, lots of WD40 on the saws, obviously. I'll put the notes into the how-to. Seemed like I couldn't go 45 mins without somekind of hurdle that was unanticipated, hoping to have other people avoid the unanticipated stuff.

Looking forward to see your project, I can't stop driving my car today, just happy with how it sounds now, like a Z06 is meant to sound.