How long is your J-pipe / HelmHoltz resonator?

Jay-rod427 said:

P.S. those are NOT stainless. highly recommend you spend a little more $$$

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I'm not too concern with the finish since I live in CA. I hardly see any snow around my home so for me the finish on Jegs J-pipes are enough. I also coat them with some high temp black paint for any small amount of rain my car might see. Stainless for sure would be best but for me it is just not necessary.

Alright thanks for the info guys!!

Anyone in the Tampa area done this? Looking for a shop that knows how to do it.

anyone have pictures of them installed

[MENTION=26494]jt351[/MENTION] - Here is Google Images search results for "j pipe helmholtz resonator"
https://www.google.com/search?q=j+p...y-zSAhVDxSYKHQfvAJIQ_AUICSgC&biw=1547&bih=904

[MENTION=17433]kenbidwell[/MENTION] - Any shop that can make exhaust pieces can put one of these on. Just tell them what you want and show them where you want it. It's just like them making an Hpipe or Xpipe.

well I have my own shop that's why I was asking for a picture on mustang with them on and an optimal place that has worked for them. the ones on the net are mainly Camaro and older stangs

This post is basically an extension duplicate of a couple other posts...
[MENTION=26494]jt351[/MENTION] my original post has a decent pic of my setup.

http://www.mustang6g.com/forums/showthread.php?t=77513

Jay-rod427 said:

If you understand the science the 180° actually attributes to covering a broader range of frequencies. The idiots that say the straighter the better....:headbonk:

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Do you have the source for this scienceing you speak of? I would like to read up on it as I do have the 2k drone at 65mph, but on the way to work this week I found out that at 80mph it starts again.

Well no I don't. It might exist somewhere, but my head is the source.

Is there an rpm correlation of your 65 & 80 mph drones? same gear? different gear same rpm? I'd assume same gear, and at 80 the poor PP gears have the engine screaming along relative and may just be actual engine load decibels not drone.

here goes...

The premise of the j-bends entirely revolves around the length the sound waves travel. If the sound waves travel down a straight tube and are reflected back they all pretty much cover relatively the same distance(more on that later). But if a bend of any kind is introduced the sound waves end up covering a multitude of distances due to the sounds waves bouncing around the corner. Sound waves DO NOT flow around the bend like a fluid/gas would. They are reflected off of the tubing walls, so depending on their path bouncing around the bend, bouncing off the end cap, and bouncing around the bend again to return back to the exhaust stream that distance is drastically altered. In the instance of a 26" on center line pipe some of the sound waves travel say 24" and some 28" and everything in between. These are just rough figures I haven't and won't do the actual calculations. This small variation in the distance the waves have to travel is exactly what covers a little bit of the drone outside of the target rpm range.

Hope that makes sense, and yes I am an actual engineer so it makes sense to me. HEHE

Sorry to all the exhaust companies claiming their proprietary/patented technology, but this is nothing new.

I installed my J-pipe last Friday and let me say, the drone is 99.9% eliminated! I can hear my exhaust while on the hwy but no more drone. I can use my phone and the person I'm talking to can hear me perfectly clear. Wish I should have done it sooner. Even my wife noticed the difference when we went on our 1.5 hour cruise down to the beach. I'll snap some pictures as soon as I get home from work so you guys can get an idea of how I installed them. Size of J-pipes were 2" OD and approx. 24" Long

El_Centenario said:

I installed my J-pipe last Friday and let me say, the drone is 99.9% eliminated! I can hear my exhaust while on the hwy but no more drone. I can use my phone and the person I'm talking to can hear me perfectly clear. Wish I should have done it sooner. Even my wife noticed the difference when we went on our 1.5 hour cruise down to the beach. I'll snap some pictures as soon as I get home from work so you guys can get an idea of how I installed them. Size of J-pipes were 2" OD and approx. 24" Long

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Good deal!

All the drone threads lately.... soooo many people are just like buy this $2,000 corsa and you'll be set.... For relatively small $$$ you can fix the issue AND use the mufflers you want for the desired sound.

[MENTION=24577]Jay-rod427[/MENTION] Ok cool thanks, I understand what your saying. Thanks for the explanation about the bends. That's what I didn't know. It's RPMs, I got a GTpp. At 2k and roughly 25k. I wanted to understand the bends so I could shoot for a pipe that can get all of it or most of it. So do you know how far + or - can cover RPMs? I was in hopes to get one for 2k and it would at least maybe get some of the 25k to relax as well.

This is the material I used

http://www.jegs.com/i/JEGS-Performan...19025/10002/-1

Start Measuring from the short end and cut to about 23-25" and you should get the drone eliminated from 2,000 RPM-2,300 RPM. Worked on my GT PP with my exhaust set up.

natepcbfl said:

[MENTION=24577]Jay-rod427[/MENTION] Ok cool thanks, I understand what your saying. Thanks for the explanation about the bends. That's what I didn't know. It's RPMs, I got a GTpp. At 2k and roughly 25k. I wanted to understand the bends so I could shoot for a pipe that can get all of it or most of it. So do you know how far + or - can cover RPMs? I was in hopes to get one for 2k and it would at least maybe get some of the 25k to relax as well.

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natepcbfl said:

[MENTION=24577]Jay-rod427[/MENTION] Ok cool thanks, I understand what your saying. Thanks for the explanation about the bends. That's what I didn't know. It's RPMs, I got a GTpp. At 2k and roughly 25k. I wanted to understand the bends so I could shoot for a pipe that can get all of it or most of it. So do you know how far + or - can cover RPMs? I was in hopes to get one for 2k and it would at least maybe get some of the 25k to relax as well.

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Best guess I'd say +\- 200 maybe 250 rpm. So I'd say if you target 2,000 you won't catch the 2,500... 2,200 at best on the high end of the range.

Here's a few pictures of how I ran the J-pipes