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Originally Posted by mrbrans5
The system included what they called an adjustable “J” pipe that you use to “tune out” the frequencies responsible for the droning in the cabin. The pipe in the shape of a “J” is “T”ed 90 degrees into a straight section of the exhaust pipe. It then dead ends, into an adjustable cap. This cap slides in or out much like a musical instrument and must be tuned such that the total length of the dead ended pipe is a certain length. The idea here, as I understand it, is that the actual exhaust travels past the “J” pipe and out the tail pipe. The sound waves on the other hand, travel into the “J” pipe, bounce back off the end of the pipe, then return back to the main exhaust pipe cancelling out the drone. The only problem here is that the system was developed for the G8 and would not work, or fit on my Camaro.
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Awesome post, Mrbrans5. You got it. There is a specific frequency (measured in Hertz) that the drone is at, and that frequency is louder than all other normal "exhaust sounds".
The J bends target that frequency's soundwaves (remember math sine, cosine, etc? Soundwaves look like that!)
and reflect those soundwaves off of the capped end in the exact opposite pattern... which eliminates them.
Similar to "the sound of silence".
Since the end of the J-pipe is sealed, no real "exhaust gasses" go into here, and if they accidentally do, they harmlessly return to the exhaust stream immediately since there's no where for them to exit out of a capped end. In fact, with the car running, if you were to put your hand on the J bends, they'll be
cool to the touch, further proving this point. Be careful not to burn yourself when you touch other piping on your exhaust system, as where the exhaust gasses pass through, it's most definately quite hot!
The end result is that the target frequency "drone" is elliminated, without destroying the greatness that is aftermarket exhaust "rumble" and "muscle". The best of both worlds!
These are adjustable because if you mod your car for additional performance later down the road, that specific frequency that your car currently "drones" at may shift to a higher pitch or lower pitch, slightly. So lets say you add a CAI to your setup, and you've had the SOLO setup on for several months, completely drone-free. Now with your powertrain change, the drone is back, alebit slightly. Well, simply make the adjustment on the total length of your J-pipes, (in or out on the Tuba, so to speak), and you can re-target the drone-zone and make it once again, drone-free, while it's still on your car, in your own driveway!
Here's an example: If you've ever heard two people "Humming" a constant note, and then just one of those people goes a half (sharp or flat, for those into music) step away, you'll hear the difference in those sounds as they both continue to hum. Amplify that by 304hp and that's kinda like the engine drone. What you're doing by adjusting the J-pipe, is you're having the second singer bring their "note" up to what the first person has been humming, now they're both singing the same note, and the 'drone' is gone. It's fascinating, at least to me.
Quote:
Originally Posted by KMPrenger
Wow. Neato stuff.
I'm sure its not much, but I wonder if this 'tuning' option causes any slight performance decreases? I would think if any exhaust does happen to get in that J tube, it just trapped there and will end up causing interference with the exhaust trying to escape through the other piping.
I'm also more curious about the tuning itself. Can you really....noticeably change your exhaust note with it? Or is it just for controlling the drone levels?
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the "tuning" aspect of the J-pipes allows for "fine tuning" of the cancellation of the soundwaves of the 'drone zone', as your mods change over time. For example, you may be at a stock intake now, but if you get an aftermarket CAI later, the specific Hertz frequency of the 'drone' may be shifted slightly by your CAI mod. Thus, simply loosen up the bolts on the adjustable part, slide the "tuba part" in or out, and take a test drive. If it get's worse, that's easy, it just means you slid it the wrong way, so crawl underneith and go back to your starting point, then back the other way and re-test.
Since the ends of the J-bend pipes are capped, it's a "high pressure" area, so no exhaust gasses will go in there. Similar to blowing through a straw with your finger firmly covering the other end. Just won't happen. These only target the soundwaves, which are present throughout the entire exhaust system, and can travel through high pressure areas like the capped J bend without issue.
There are no performance decreases either, once again, as this technology only targets the soundwaves as they exit the rear of the car. Exhaust gasses bypass the J-bends harmlessly, while the soundwaves get cancelled out effectively by this technology.
The J-pipes have been a huge hit on the G8 SOLO offerings, and I've been proud to be a part of the initial testing phase with my own car. The L76 engine, like the v6 camaro engine, is a "harmonics nightmare" ... and I worked with Jeff and the crew at their Buffalo shop to bring this J-bend technology to SOLO to see how it would work. The rest is history, and I'm really glad that it now is being applied to the V6 camaro.
I've had a SOLO Catback on my g8 since Thanksgiving 2009, and had the initial pre-alpha "proof of concept" J bends on my G8 in January 2010. That led to the development of the adjustable J bends from SOLO for the G8, and it is one of two "drone free" exhaust offerings for the G8 community, and has turned out to be a very successful product for the G8 guys. Really glad to see the technology can be used in other similar zeta chassis applications as well!
If anyone has any questions, feel free to ask me!
--zepcom