Just wanted to add my experience. I was a certified Vibration analyst for NASA. One of the issues discovered about vibration or "Drone" was that it is all about "Frequency Resonance". Where did the Frequency/Drone occur? Without any testing or frequency readings on your vehicle, "Just add Mass". Example - find some lead sheeting or heavier sheet metal and wrap it around the muffler and secure. By adding enough "Mass" to the muffler it will change the frequency of the vibration inside the muffler, thus moving the frequency to another level. It might take some playing with the amount of mass but it worked on many of the vibration frequencies" affecting critical NASA equipment. Just food for thought.
Adding mass or extra weight to an exhaust system will have an effect on frequency. This is a fact and many manufacturers have been doing this for many years. It does not necessarily have to be wrapped around a muffler. You can pretty much weld on a bracket with mass attached. It's similar to taking something that is vibrating and placing your hand on it. Your hand (mass) would absorb some of the resonance therefore changing it to a different frequency which may or may not solve the frequency that One personally hate to hear/feel. But this is surely trial and error on the extreme side.
@@reborn74nova I got an 1989 Chevy short bed truck 350 and had 40 sires flow masters dules on still have to dules but took the flows off because of the clapping sound I hate that clapping sound we I put magna flows on we still the same and ya i got drone to but if you can help with the clapping sound thanks and hey think glass pack sound the flows do it and magna flows do it my system is a y pipe system
I actually did try getting footage of the before or after. But the difference could not be shown through video. So I left it out. Thank you for Watching.
Great job with the video the demo canceling out sound was excellent and explained it all. Pipe length you explain came through the calculation, what wasn't clear was how you determined the pipe size to use.
I have watched all your videos as you have been restoring your nova. Great videos very detailed. You have made some things easy for myself in restoring my 1973 nova keep up the great work
Thanks for the simplest explanation I've found! What I want to know is how do OEM's dial the factory exhausts in? I know they don't use this quarter wave resonator.
Jdm guy here with a q50 with a custom 2.5inch exhaust n after 4 resonators ... still fighting with drone .. this was a really good really informative but simple sweet ride as well man 👏🏻✌🏼
Wholesome video! Thanks for your time in doing this! I now have a MUCH better understanding of what needs to be done thanks to your visual and illustrative demos! One last question, does it matter if the J-pipes are before or after an H/X-pipe?
Thank you! From my experience, drone appeared after installing a H pipe. So for me I wanted to make sure to install J pipe after what i felt was the source of the drone. So from that experience I would conclude that it would be better to install the J pipe after.
@@reborn74nova Had you thought about relocating the H pipe? Just a thought, and I see there isn't much latitude with that undercarriage: looks like you have at the most a foot to the rear if you tried that, and stayed clean with good clearances. The question of where to locate the J pipe is the finishing touch, and... great problem solving! .
@@flinch622 Looking at the real estate I have under the Nova, and you will see that it's at an extreme premium. I have a torque arm suspension and that does not allow a H pipe anywhere but where I have it. I have solved my problem and therefore sharing my knowledge about this subject to the community.
I'm not an engineer but have been told that many times. I just love understanding how things work and can spend enormous amount of time researching and learning about things I want to understand. Thank you!
Good thinking - wave theory is always in effect regarding any machine and movement. There is alot that can interplay, including pipe diameter, round vs oval tubing variances, distance between bends & offsets, and anything that promotes or diffuses reflection [which I am still learning more about all the time]. Even hanger points could be a factor - just like length vs cross section on a tuning fork. Little details inside a muffler like...where to use clean cuts and when to bell internals matter. Go look at any major symphony hall, hollywood bowl, etc: it takes a tour guide to actually know why and what they did to their stage areas - it's usually no accident and a constant study of what promotes or dampens resonance is underway [by the conductors ear if nothing else, but especially when anybody sets up to record].
When I was testing pipe resonance with the water, I did try pipes that had bends in it to see if it would make a difference. And found that it did not make any difference if the pipe was straight or if it had a 90 degree or even a 45 degree bend. What mattered more was length and diameter. The other thing to consider is age of the person. Did you know that as we age, we lose the ability to hear certain frequencies? Therefore other frequencies become more pronounced and we notice it more.
Just echoing other comments, this video is clear, concise and easy to understand. very happy with what ive learned from it. Now going to build a J pipe setup for my V70R track car. Its droning at 99Hz, 199Hz and 299Hz. im guessing the two higher frequencies are harmonics? so might be attentuated with a single J pipe. Subscribed :)
I'm getting ready to have a J pipe built and installed very soon. However, I have a question about the formula used for calculating the length. What is the 1100 figure at the start of the formula? That's not the speed of sound in ft/s is it? If so, that would mean that the air temperature is about 65 degrees fahrenheit. Don't we need to use the temperature of the exhaust gas to get an accurate speed for sound to plug into the formula?
The purpose of the J-pipe, in general, is to make driving your vehicle less annoying by canceling out the frequency that annoys you. The result gives you a small range of cancellation that makes the exhaust note quieter (for the targeted RPM range) on those steady state drives.
Very underrated video yet I echo what everyone else on here is stating, amazing explanation! I sure hope your channel grows and gets the views and subscriptions that it deserves,🍻
Good job. I wonder if adding a flat formed small chunk of metal to the out side of the pipe would make a difference. That alone would change the resistance frequency of the pipe
I just did my 2014 Audi A6 3.0T prestige and I did a muffler delete and kept the resonator and cats... but im still getting drone and vibrations inside the cabin so I went back and they added those little tubes next to the pipes in the back but its still noise in the cabin once I get to 40 miles an hour I like the aggressiveness.... outside the cabin just not inside the cabin what should do....also I love the sound when I'm at 70 miles but it drones and has vibration....
First, Did you target a specific frequency when they added those tubes? Because its not just a matter of "adding tubes" to the exhaust stream. Second you can only target a small frequency range by using J pipes. I show this in my demonstration with the bucket of water in the video. So basically you can only pick one frequency and it will affect a small range around that specific frequency. Now if you wanted to target more than one frequency, it is possible but then you run into space constraints because in order to target more than one frequency, you need more than one J pipe. Then each J pipe you add (using the mathematical formula) would target each frequency you calculated for. Hope that helps you understand better for your specific needs.
Thank you for that very informative video. I have on question about the measuring: did you measure the drone frequency with the app inside the cabin while driving? Thanks for the help. Toodles M
Thanks much for the detailed explanation. One question - say for example the calculated j pipe length is 22 inches for 150Hz freq. So thats the lenght for only 150Hz freq right? How about i want to have a range of frequency (for instance 140-160 Hz) captured in the j pipe to eliminate to have more accurate result? How to calculate the length of the j pipe then? I think you mentioned about it somewhere in the video but couldn’t get it myself! Any clarification is appreciated.
When I created my setup, I made it have adjustable lengths. Basically, it's made up of 3 sections so that I can vary the length. This is what I talk about in the Tunability section of the video.
I believe I explained this but you want the J pipe to be at least within 1/2" of main exhaust pipe. So yes you can use 2.5" J for your 3" exhaust. I have 2.5" exhaust and used 2" j Pipe.
Excellent work and lesson, very good! I apologize for bad english because i am portuguese .. i have a question, in a 6x2 line with intermediate of origin and back sport muffler, i bought a flat drone, to remove it i must put the tubes that explained before or after the intermediate? The car is bmw z4 2.5 / 6-cylinder (23I) model e89 from 2010. Thank you very much
You really can't find enough space in this car. In your opinion, in this line of 6x2 su instead of a double resonator as it was originally I put two larger resonators (individual and longer ...) if that resolves ???. An xpipe will be a solution by accelerating the gases .... I apologize for the questions ... and thank you very much! FAlmeida
When you calculate the length of pipe needed for your target frequency using the method I show in my video, that is the size you have to use to remove that frequency. If you use a different size pipe, than the target frequency the new pipe size would eliminate would also change. So it would not work as you are describing. Remember that the pipe does not have to be straight. It can be round or in a loop if needed. You can also put it right before the mufflers running towards the front of the car. The direction is not important. The size of the pipe is the most important part of this modification. Also The X pipe would not be a solution to drone. It will change the sound a bit but may OR may not eliminate the drone.
Just curious, how would you compare the Fuel Injection 454 vs the LS? I have a carb 454 debating in Sniper 2 or going LS. It’s my weekend car but 7 mpg is terrible.
I went the route of fuel injected carb for my old 454. And hands down, the LS is the best decision I made. It's better in every respect, especially if you are concerned with fuel mileage.
Very detailed step by step process! Thank you for your time and energy it took to make this video. I’m downloading the sound analyzer as I type. I have a question. I think I know the answer already, but want to ask just to be sure I get it right. Should the J-Pipe have the same diameter of the main exhaust? For example, I have a 5.0L v8 F-150. The Y-Pipes from the manifolds go into a single 3” resonator. From there it’s a 3” pipe to a single inlet muffler, but after the muffler it branches out to two 2.5” pipes and exits out two tail pipes. Should the J-Pipe be 3” and attached to the mail 3” exhaust? Or would a 2.5” J-Pipe work the same off of the 3” main since we are talking sound pulses? Thanks again for creating an informative video!
First thing to consider is how much real estate you have under truck. After that in my opinion you may want to create a 3" J pipe off the main exhaust.
Yes, I have plenty of space underneath. I like the idea of putting a trombone type end pipe for fine tuning. I will let you know how it goes when I do it, but it will be about two years. Long story short, I need to wait until my warranty expires. Thanks again for the great info and great video!
The J pipes have to be created after the exhaust system is fully complete in order for you to correctly target the offending drone. So to answer your question, my exhaust system was fully created with the H pipe. Then I drove the car for months before finally deciding to add in the J pipes to eliminate the drone from my exhaust system.
Just to clarify, is the length of the 90 degree bend included in the J pipe. Let's say I calculated that I needed a pipe 20 inches long, could I have a 90 degree bend (mounted perpendicular of course) and then 20 inches of pipe, or would I need to start my 20 inch measurement from the beginning of the 90 degree bend. I hope that made some sense. Absolutely fantastic video though, very very well presented and extremely well thought out, good job.
The main thing about where to place the J pipe is whether you have the room to fit it under the car. The exact location you can then decide dependent on the available space. The J pipe does not have to be completely straight nor does it have to face in a specific direction. The only requirement is that it has to start off 90 degrees from the main exhaust pipe. It can be placed anywhere on the exhaust stream.
Question about the J pipes... When you calculated the length of the pipe, is the length of 90 degree bend considered as well? In your video you figured out the length to be 23.5" for the straight portion of the pipe, but you added a 90 degree bend. So you have changed the length of the tube.
When making the J, the calculated length is with any bends you put into pipe. So yes, make sure to include the bends. Take a string and run it down length of created J to see total length with any and all bends. Do not measure from sides of pipe as measurement would change depending on which side of bend you place measuring tape.
You want to get the entire length of the J pipe from end to end which includes the bends. The way to do this is to take a string and run it down the middle/top of the J pipe then measure the string to get the length. If you wanted to get the measurement from the sides, you would take a measurement from the front and the back of the J pipe then average the two to get the measurement that way. I find it easier to just take the string and lay it on top center of the J pipe. Hope that clears things up.
@@reborn74nova that’s how I was thinking about doing it with the string. It’s a different approach to what I’m used to. I’m an electrician and when we run pipe with 90 degree bends the measurements are taken either in front or behind the 90 if that makes sense.
In the video I provided you with the tools needed to answer your own question. Get the app and see what your drone frequency is. And then you will also be able to see if its the whole way through. I take it that you don't like your car much if you are saying that there is drone everywhere in all rpm ranges and all speeds. 🙃😝
I have a Ford Mustang 2015, i remove the resonator (is in the middle of the car) and the two mufflers, and install two borla s-type, the drone is terrible, did you tink that the drone improves if reinstall the resonator? thanks!
There is no way to tell you if reinstalling the factory resonator would solve your drone issue without you actually trying it yourself and seeing what happens. Drone is a frequency. And the frequency that the factory resonator is designed to eliminate (or enhance) is unknown. It was paired with the factory exhaust (and mufflers) as a whole with a target sound level in the design of the vehicle. So you would just have to try it to see if it works. Or just take the steps to find out what frequency bothers you and create the J pipe to target and eliminate the bothersome frequency, which I outlined in this video. Either way it requires some modification to your current setup.
I have a question. I have been watching your build since day one. On the 454 bbc you had in car before with power steering. Do you happen to remember what brand and size exhaust headers you had installed. I am building one for my 73 with power steering and trying to figure out headers that will clear no problems. Thanks.
Remember to check Description box for links. Also Added Chapter to this video to make it easier to navigate through information presented in this video. Don't forget to Subscribe
Make them both at 25 inches. Don't divide the length in half. By making the length smaller, the frequency would change and no longer target what you are looking to eliminate.
@@alexvega9181 Its best to stay within 1/4" of your main pipe size. So I have 2.5" exhaust system. I used 2.25" J pipes. But i could have also used 2.5" J pipes. The 1/4" difference does not affect the results of the cancellation of desired frequency. But I would not go more than 1/4" difference.
No part of the exhaust system is resting or touching any part of the undercarriage. So no, the H pipe is not touching the crossmember. In fact there is actually plenty of clearance all the way around the H pipe. I could not have wished for a more perfect fit.😀
The exhaust pipes are like guitar strings. The body and interior are like an acoustic guitar cabinet, or the body of the acoustic guitar. Makes sense. Automatic trans makes no sense, however.
I would have replaced that tube with a glass pack of equal length. Then i probably would have had to make the same thing but for a different frequency... lol I do like your explanation and solution though. Awsom work...
I didn't want to change the exhaust note. A glass pack would have more than likely changed the sound as it would be inline with the exhaust flow. And could also introduce another unwanted frequency. J pipe just focuses on frequency elimination with no effect on over all sound. Thank you for your comment 🙂
@reborn74nova you did the rite thing. I never heard of this solution until I watched your vid. So I would have wasted money. I probably would have liked the change, but I also probably would have not fixed the problem you were having. I would have just changed it a bit. I'm not a gear head though. I am mechanically inclined, I do have a small machine shop/ fab shop for hobby reasons. I just purchased a Sherco 300SEF. I want to make it quieter, so I looked up exhaust mod videos and came across yours. Great job by the way, and thank you for the info in your video, and for your response. Sweet ride by the way...
Not following your question. Exhaust in general exists to carry spent (ate up) fuel away to the rear of vehicle. I address the drone sound in this video and regardless, it does not change anything to the exhaust system other than frequency. Hope that helps.
This is not new my 1968 GTO had a tube that was attached 18 inches from the exhaust exit, it was just a dead end pipe on top of the exhaust pipe. When I cut the end off the car got loud and I loved it
@@reborn74nova I was a ford engineer and would see these on the hi performance cars for a long time it was used to keep the Noise and Drone down on a low back pressure exhaust systems but as the technology got better they stopped . I thought your explanation was great, are you a engineer, if not you should try it . Keep thinking its good for the brain!
Don't be so hard on yourself. There lots of reasons to live. You just need to appreciate the small stuff and not worry about the big stuff. Your life is always worth living!
@oujee1988 I have an 18 in resonator plus the dynomax, drone is definitely coming from the muffler. I ordered a spiral slip in resonator and see if that helps before I start getting drastic.
There is no actual sound change from doing this modification. If you want to hear the exhaust sound go to LS Rebirth Ep 27. There's a cold start and a couple revs for your enjoyment.
If you don't do long drives, drone will not be a nuisance. But on long steady state drives, that can be a half-hour hr or longer it can cause headaches and make the drive a bit uncomfortable. Big difference on those long drives.
@johnperales5431 it's not my daily, but if I take a road trip (like Las Vegas), it's the first to be chosen. Plus, doing burnouts is fun in different cities, lol.
Just wanted to add my experience. I was a certified Vibration analyst for NASA. One of the issues discovered about vibration or "Drone" was that it is all about "Frequency Resonance". Where did the Frequency/Drone occur? Without any testing or frequency readings on your vehicle, "Just add Mass". Example - find some lead sheeting or heavier sheet metal and wrap it around the muffler and secure. By adding enough "Mass" to the muffler it will change the frequency of the vibration inside the muffler, thus moving the frequency to another level. It might take some playing with the amount of mass but it worked on many of the vibration frequencies" affecting critical NASA equipment. Just food for thought.
Adding mass or extra weight to an exhaust system will have an effect on frequency. This is a fact and many manufacturers have been doing this for many years. It does not necessarily have to be wrapped around a muffler. You can pretty much weld on a bracket with mass attached. It's similar to taking something that is vibrating and placing your hand on it. Your hand (mass) would absorb some of the resonance therefore changing it to a different frequency which may or may not solve the frequency that One personally hate to hear/feel. But this is surely trial and error on the extreme side.
@@reborn74nova I got an 1989 Chevy short bed truck 350 and had 40 sires flow masters dules on still have to dules but took the flows off because of the clapping sound I hate that clapping sound we I put magna flows on we still the same and ya i got drone to but if you can help with the clapping sound thanks and hey think glass pack sound the flows do it and magna flows do it my system is a y pipe system
It's kind of sound damper@@reborn74nova
I appreciate the time and detail you put into this, I know it isn't easy. Thank you!
1 of the best exhaust drone explanations so far
Your really nailed the mechanism of how the drone is produced. Thanks for the video!
Best informational video! I hope your channel grows!
I appreciate your words. Thank you. I hope so too!
Awesome video. Very clarifying. The only thing missing is driving the car before and after, but thank you for sharing.
I actually did try getting footage of the before or after. But the difference could not be shown through video. So I left it out. Thank you for Watching.
@@reborn74nova thank you for clarifying.
Thank you for Crawling under your car for us!! Great video as always Steve. I will have re-watch your video again. I may have to do this to mine.
Thanks 👍
Great job with the video the demo canceling out sound was excellent and explained it all. Pipe length you explain came through the calculation, what wasn't clear was how you determined the pipe size to use.
You can use the same pipe size or close to the main pipe size as main exhaust pipe size. My pipe size is 2.5" and I went with 2.25"
Thats great thanks for your reply
@@reborn74nova
I have watched all your videos as you have been restoring your nova. Great videos very detailed. You have made some things easy for myself in restoring my 1973 nova keep up the great work
Awesome, thank you! I'm so glad to help!
SOUND ATTENUATION AT IT'S FINEST ! Great job my friend! KUDO'S TO YOU YOUNG MAN!
Seth
THANK YOU.
St Paul's cathedral uses resonators and chambers to eliminate resonance.
Roman amphitheaters do the same
In theory this is similar to subwoofer tuning where you want to take advantage of the resonant frequency of the enclosure such as a tuning port.
Thanks for the simplest explanation I've found! What I want to know is how do OEM's dial the factory exhausts in? I know they don't use this quarter wave resonator.
They do it within the resonator. Usually different size tube in there with some fiberglass packing to absorb the unwanted frequency.
They do it's within the resonator.
Jdm guy here with a q50 with a custom 2.5inch exhaust n after 4 resonators ... still fighting with drone .. this was a really good really informative but simple sweet ride as well man 👏🏻✌🏼
Thank you!
Wholesome video! Thanks for your time in doing this!
I now have a MUCH better understanding of what needs to be done thanks to your visual and illustrative demos!
One last question, does it matter if the J-pipes are before or after an H/X-pipe?
Thank you!
From my experience, drone appeared after installing a H pipe. So for me I wanted to make sure to install J pipe after what i felt was the source of the drone. So from that experience I would conclude that it would be better to install the J pipe after.
@@reborn74nova Had you thought about relocating the H pipe? Just a thought, and I see there isn't much latitude with that undercarriage: looks like you have at the most a foot to the rear if you tried that, and stayed clean with good clearances. The question of where to locate the J pipe is the finishing touch, and... great problem solving! .
@@flinch622 Looking at the real estate I have under the Nova, and you will see that it's at an extreme premium. I have a torque arm suspension and that does not allow a H pipe anywhere but where I have it. I have solved my problem and therefore sharing my knowledge about this subject to the community.
3 minutes in and I'm already confident I'm going to learn a lot here 👍🏼
Glad to hear it! Thank you!!!
it looks very clean. 👍
Not sure about the pipe near the tires. In case there are problems you can have them wrapped
Thank you. The exhaust is far enough from the tire that it does not even get warm.
Nice work, You must be an engineer. Us old hotrodders use trial and error. Usually more error than than we like to admit. I like your videos, thanks.
I'm not an engineer but have been told that many times. I just love understanding how things work and can spend enormous amount of time researching and learning about things I want to understand. Thank you!
Good thinking - wave theory is always in effect regarding any machine and movement. There is alot that can interplay, including pipe diameter, round vs oval tubing variances, distance between bends & offsets, and anything that promotes or diffuses reflection [which I am still learning more about all the time]. Even hanger points could be a factor - just like length vs cross section on a tuning fork. Little details inside a muffler like...where to use clean cuts and when to bell internals matter. Go look at any major symphony hall, hollywood bowl, etc: it takes a tour guide to actually know why and what they did to their stage areas - it's usually no accident and a constant study of what promotes or dampens resonance is underway [by the conductors ear if nothing else, but especially when anybody sets up to record].
When I was testing pipe resonance with the water, I did try pipes that had bends in it to see if it would make a difference. And found that it did not make any difference if the pipe was straight or if it had a 90 degree or even a 45 degree bend. What mattered more was length and diameter. The other thing to consider is age of the person. Did you know that as we age, we lose the ability to hear certain frequencies? Therefore other frequencies become more pronounced and we notice it more.
Just echoing other comments, this video is clear, concise and easy to understand. very happy with what ive learned from it. Now going to build a J pipe setup for my V70R track car. Its droning at 99Hz, 199Hz and 299Hz. im guessing the two higher frequencies are harmonics? so might be attentuated with a single J pipe. Subscribed :)
Thank you.
Very nice video & demonstrations, awesome Nova 454!
I'm getting ready to have a J pipe built and installed very soon. However, I have a question about the formula used for calculating the length. What is the 1100 figure at the start of the formula? That's not the speed of sound in ft/s is it? If so, that would mean that the air temperature is about 65 degrees fahrenheit. Don't we need to use the temperature of the exhaust gas to get an accurate speed for sound to plug into the formula?
Thank you so much for this very informative video.
Looking at the timestamp 21:01 I can’t help wondering if you didn’t cancel all the harmonics but leave the primary resonant note in place.
The purpose of the J-pipe, in general, is to make driving your vehicle less annoying by canceling out the frequency that annoys you. The result gives you a small range of cancellation that makes the exhaust note quieter (for the targeted RPM range) on those steady state drives.
Very underrated video yet I echo what everyone else on here is stating, amazing explanation! I sure hope your channel grows and gets the views and subscriptions that it deserves,🍻
Much appreciated! Thank you.
Good job. I wonder if adding a flat formed small chunk of metal to the out side of the pipe would make a difference. That alone would change the resistance frequency of the pipe
Adding more mass to the exhaust does help but J pipes work in a more detailed manner as you are targeting a specific frequency.
I just did my 2014 Audi A6 3.0T prestige and I did a muffler delete and kept the resonator and cats... but im still getting drone and vibrations inside the cabin so I went back and they added those little tubes next to the pipes in the back but its still noise in the cabin once I get to 40 miles an hour I like the aggressiveness.... outside the cabin just not inside the cabin what should do....also I love the sound when I'm at 70 miles but it drones and has vibration....
First, Did you target a specific frequency when they added those tubes? Because its not just a matter of "adding tubes" to the exhaust stream. Second you can only target a small frequency range by using J pipes. I show this in my demonstration with the bucket of water in the video. So basically you can only pick one frequency and it will affect a small range around that specific frequency. Now if you wanted to target more than one frequency, it is possible but then you run into space constraints because in order to target more than one frequency, you need more than one J pipe. Then each J pipe you add (using the mathematical formula) would target each frequency you calculated for. Hope that helps you understand better for your specific needs.
thanx much appreciated
Thank you for that very informative video.
I have on question about the measuring: did you measure the drone frequency with the app inside the cabin while driving?
Thanks for the help.
Toodles
M
Yes. I did it several times. In various situations such as driving up hills etc. While watching the rpms.
Thank you very much. That helps a lot.
The drone in my car is around 2000 rpms and it is just deafening. I will give the 1/4 resonator a try. 👍🏻👍🏻👍🏻
Thanks much for the detailed explanation. One question - say for example the calculated j pipe length is 22 inches for 150Hz freq. So thats the lenght for only 150Hz freq right? How about i want to have a range of frequency (for instance 140-160 Hz) captured in the j pipe to eliminate to have more accurate result? How to calculate the length of the j pipe then? I think you mentioned about it somewhere in the video but couldn’t get it myself! Any clarification is appreciated.
When I created my setup, I made it have adjustable lengths. Basically, it's made up of 3 sections so that I can vary the length. This is what I talk about in the Tunability section of the video.
Very detailed video. Positive vibes too. Thank you.
Genius with the water bucket
Does the diameter of the j pipe matter? For instance if I have a 3 inch exhaust can I use a 2.5 in j pipe using same formula for length ?
I believe I explained this but you want the J pipe to be at least within 1/2" of main exhaust pipe. So yes you can use 2.5" J for your 3" exhaust. I have 2.5" exhaust and used 2" j Pipe.
Excellent work and lesson, very good!
I apologize for bad english because i am portuguese ..
i have a question, in a 6x2 line with intermediate of origin and back sport muffler, i bought a flat drone,
to remove it i must put the tubes that explained before or after the intermediate?
The car is bmw z4 2.5 / 6-cylinder (23I) model e89 from 2010.
Thank you very much
If you can place them after intermediate that would be fine. As long as you can find an area to place the pipe, you should have good results.
@@reborn74nova Thank you very much and continued good mods for Nova!
You really can't find enough space in this car.
In your opinion, in this line of 6x2 su instead of a double resonator as it was originally I put two larger resonators (individual and longer ...) if that resolves ???.
An xpipe will be a solution by accelerating the gases .... I apologize for the questions ... and thank you very much!
FAlmeida
When you calculate the length of pipe needed for your target frequency using the method I show in my video, that is the size you have to use to remove that frequency. If you use a different size pipe, than the target frequency the new pipe size would eliminate would also change. So it would not work as you are describing. Remember that the pipe does not have to be straight. It can be round or in a loop if needed. You can also put it right before the mufflers running towards the front of the car. The direction is not important. The size of the pipe is the most important part of this modification.
Also The X pipe would not be a solution to drone. It will change the sound a bit but may OR may not eliminate the drone.
@@reborn74nova Once again my thanks for the advice, the problem is really the space for the modification but let's see ...
Compliments
F, ALmeida
Just curious, how would you compare the Fuel Injection 454 vs the LS? I have a carb 454 debating in Sniper 2 or going LS. It’s my weekend car but 7 mpg is terrible.
I went the route of fuel injected carb for my old 454. And hands down, the LS is the best decision I made. It's better in every respect, especially if you are concerned with fuel mileage.
@@reborn74nova thanks! Been watching your videos, thanks for doing that. They are a big help!
Hi ,, is there a specific diameter on the j pipe to use ? iDoes the exhaust diameter matter when you choose the diameter of the j pipe ? Great info
I believe I explained this but you want the J pipe to be at least within 1/2" of main exhaust pipe diameter.
Very detailed step by step process! Thank you for your time and energy it took to make this video. I’m downloading the sound analyzer as I type. I have a question. I think I know the answer already, but want to ask just to be sure I get it right.
Should the J-Pipe have the same diameter of the main exhaust? For example, I have a 5.0L v8 F-150. The Y-Pipes from the manifolds go into a single 3” resonator. From there it’s a 3” pipe to a single inlet muffler, but after the muffler it branches out to two 2.5” pipes and exits out two tail pipes. Should the J-Pipe be 3” and attached to the mail 3” exhaust? Or would a 2.5” J-Pipe work the same off of the 3” main since we are talking sound pulses?
Thanks again for creating an informative video!
First thing to consider is how much real estate you have under truck. After that in my opinion you may want to create a 3" J pipe off the main exhaust.
Yes, I have plenty of space underneath. I like the idea of putting a trombone type end pipe for fine tuning. I will let you know how it goes when I do it, but it will be about two years. Long story short, I need to wait until my warranty expires. Thanks again for the great info and great video!
Fantastic content. Did you try the H pipe separately or together with the 1/4 wave pipes? I run true duals and am wondering if i need the H pipe too?
The J pipes have to be created after the exhaust system is fully complete in order for you to correctly target the offending drone. So to answer your question, my exhaust system was fully created with the H pipe. Then I drove the car for months before finally deciding to add in the J pipes to eliminate the drone from my exhaust system.
Nice, the mufflers are the Race Pro Mufflers right?
That is correct! The same mufflers I installed originally, which I do have a video of when I initially installed them back in 2012.
The tube for J pipe must be The same diameter as the exaust pipe?
I went a quarter inch smaller. My main is 2.5". My J is 2.25". It is said to have it within a quarter inch.
Should I do sound deadening material in whole car first or after the pipe?
It would not matter much. Sound deadening does not change the drone
Awesome video. Does it matter where in the system the J pipe is added? My car is straight piped from the car back.
In your case, no it does not matter where you put it along the Exhaust track.
Just to clarify, is the length of the 90 degree bend included in the J pipe. Let's say I calculated that I needed a pipe 20 inches long, could I have a 90 degree bend (mounted perpendicular of course) and then 20 inches of pipe, or would I need to start my 20 inch measurement from the beginning of the 90 degree bend. I hope that made some sense. Absolutely fantastic video though, very very well presented and extremely well thought out, good job.
The 90 degree bend is part of the overall length of the pipe. So 20 inch includes the 90 bend.
@@reborn74nova Thanks very much indeed. Really appreciated
Does the length of the pipe change if you have true duels? Do you halve the length again? Divide by 2 that is.
No. The length does not change. You make a pipe for each based on the frequency you are targeting.
How I know wich place instal j pipe ,? My dron exhaust is before mid resonator so instal before resonator?
The main thing about where to place the J pipe is whether you have the room to fit it under the car. The exact location you can then decide dependent on the available space. The J pipe does not have to be completely straight nor does it have to face in a specific direction. The only requirement is that it has to start off 90 degrees from the main exhaust pipe. It can be placed anywhere on the exhaust stream.
Question about the J pipes... When you calculated the length of the pipe, is the length of 90 degree bend considered as well? In your video you figured out the length to be 23.5" for the straight portion of the pipe, but you added a 90 degree bend. So you have changed the length of the tube.
When making the J, the calculated length is with any bends you put into pipe. So yes, make sure to include the bends. Take a string and run it down length of created J to see total length with any and all bends. Do not measure from sides of pipe as measurement would change depending on which side of bend you place measuring tape.
Should’ve the j pipe diameter be the same as the main pipe?
The same or up to 1/2" in either direction (+/-) I chose to go 1/4" smaller than main pipe.
Thanks for this video. I had been trying to figure out how to fix my drone but didn't want to go in blind and cause more damage than remedy.
Glad it helped!
From what point on the J pipe do you take the measurement for the length? From the back of the 90 degree bend the front or middle? Awesome video
You want to get the entire length of the J pipe from end to end which includes the bends. The way to do this is to take a string and run it down the middle/top of the J pipe then measure the string to get the length. If you wanted to get the measurement from the sides, you would take a measurement from the front and the back of the J pipe then average the two to get the measurement that way. I find it easier to just take the string and lay it on top center of the J pipe. Hope that clears things up.
@@reborn74nova that’s how I was thinking about doing it with the string. It’s a different approach to what I’m used to. I’m an electrician and when we run pipe with 90 degree bends the measurements are taken either in front or behind the 90 if that makes sense.
@@reborn74nova I just got done making and installing one of these and I can’t believe how good they work. All my drone is completely gone.
@@scrap_metal_magic so glad I was able to be a part of your success and happiness in the quest for a quieter exhaust!!!!
Love it and can't wait to eliminate the drone I now have in my Jeep WJ.
My problem is i get drone from 10-140mph … will that be the same frequency right the way through ?
In the video I provided you with the tools needed to answer your own question. Get the app and see what your drone frequency is. And then you will also be able to see if its the whole way through. I take it that you don't like your car much if you are saying that there is drone everywhere in all rpm ranges and all speeds. 🙃😝
I have a Ford Mustang 2015, i remove the resonator (is in the middle of the car) and the two mufflers, and install two borla s-type, the drone is terrible, did you tink that the drone improves if reinstall the resonator? thanks!
There is no way to tell you if reinstalling the factory resonator would solve your drone issue without you actually trying it yourself and seeing what happens. Drone is a frequency. And the frequency that the factory resonator is designed to eliminate (or enhance) is unknown. It was paired with the factory exhaust (and mufflers) as a whole with a target sound level in the design of the vehicle. So you would just have to try it to see if it works. Or just take the steps to find out what frequency bothers you and create the J pipe to target and eliminate the bothersome frequency, which I outlined in this video. Either way it requires some modification to your current setup.
@@reborn74nova I appreciate your answer
I am saving this video for sure. I am going to try this exact this out on my truck,.
Awesome!
EXCELLENT video and explanation!
Why do you need the j pipe perpendicular?
You do not want the new pipe to allow the exhaust to go into it which may cause a restriction and will decrease the efficiency of the outcome.
Nice work researching and understanding the issue. Good explanation. Thanks again.
Thanks for watching!
I have a question. I have been watching your build since day one. On the 454 bbc you had in car before with power steering. Do you happen to remember what brand and size exhaust headers you had installed. I am building one for my 73 with power steering and trying to figure out headers that will clear no problems. Thanks.
Yes. They were Hedman Hedders for big blocks. Still had to put a small ding to clear for PS box.
Thank you sir. Your awesome. Keep up the great work. Best looking nova I have seen. 😀
Anytime. Thank you so much!
Hey my dude im working on my 74. nova. Stock oil pan sbc 350.. how many quart of oils do i need ... 4. Or the full 5 ????
usually 5 with filter.
Very NICE! Great looking car!
Remember to check Description box for links. Also Added Chapter to this video to make it easier to navigate through information presented in this video. Don't forget to Subscribe
3 years too late for new content :( subbed
My car has basically the same setup as in 2 main exhaust pipes, if i got 25 inches do both j pipes have to be 25? Or 12.5 and 12.5? Great video.
Make them both at 25 inches. Don't divide the length in half. By making the length smaller, the frequency would change and no longer target what you are looking to eliminate.
@@reborn74nova great, thanks! What about width of the j pipe? I have not seen anyone talk about that
@@alexvega9181 Its best to stay within 1/4" of your main pipe size. So I have 2.5" exhaust system. I used 2.25" J pipes. But i could have also used 2.5" J pipes. The 1/4" difference does not affect the results of the cancellation of desired frequency. But I would not go more than 1/4" difference.
Is the H-pipe resting on the X-member?
No part of the exhaust system is resting or touching any part of the undercarriage. So no, the H pipe is not touching the crossmember. In fact there is actually plenty of clearance all the way around the H pipe. I could not have wished for a more perfect fit.😀
The exhaust pipes are like guitar strings. The body and interior are like an acoustic guitar cabinet, or the body of the acoustic guitar. Makes sense. Automatic trans makes no sense, however.
This comment about Auto Transmission makes no sense. This video is not about transmissions.
Very interesting. Thank you!
Great job, way to go. Thanks
DUDE YOURE NOVA IS AWESOME
Thank you!
Can you add the formula and app info to the description so it's easier to find please?
I have added Chapters to my videos. Chapter 4 App. Chapter 8 Formula. Hope that helps.
I would have replaced that tube with a glass pack of equal length. Then i probably would have had to make the same thing but for a different frequency... lol
I do like your explanation and solution though. Awsom work...
I didn't want to change the exhaust note. A glass pack would have more than likely changed the sound as it would be inline with the exhaust flow. And could also introduce another unwanted frequency. J pipe just focuses on frequency elimination with no effect on over all sound. Thank you for your comment 🙂
@reborn74nova you did the rite thing. I never heard of this solution until I watched your vid. So I would have wasted money. I probably would have liked the change, but I also probably would have not fixed the problem you were having. I would have just changed it a bit. I'm not a gear head though. I am mechanically inclined, I do have a small machine shop/ fab shop for hobby reasons. I just purchased a Sherco 300SEF. I want to make it quieter, so I looked up exhaust mod videos and came across yours. Great job by the way, and thank you for the info in your video, and for your response. Sweet ride by the way...
Another great video, thanks!!!
Thanks for watching!
Best explanation on u tube!! Thanks!!
Glad it was helpful!
Thx Man ! I’ll try it on my axle back exhaust (6gen Camaro ss )
WHAT!! and no test before and after??
Before and after was shown with frequency.
Love the intro - very funny!
which set up eats up fuel?
Not following your question. Exhaust in general exists to carry spent (ate up) fuel away to the rear of vehicle. I address the drone sound in this video and regardless, it does not change anything to the exhaust system other than frequency. Hope that helps.
This is not new my 1968 GTO had a tube that was attached 18 inches from the exhaust exit, it was just a dead end pipe on top of the exhaust pipe. When I cut the end off the car got loud and I loved it
Yes I stated this in the beginning of the video.(3:45) Check out the Avinode Exhaust system is you want to check out history.
@@reborn74nova I was a ford engineer and would see these on the hi performance cars for a long time it was used to keep the Noise and Drone down on a low back pressure exhaust systems but as the technology got better they stopped . I thought your explanation was great, are you a engineer, if not you should try it . Keep thinking its good for the brain!
You instantly earned my subscription ! Thank you again!
Thank you
сразу видно умного человека
Lost the will to live! Never known anyone take so long to explain something!
Don't be so hard on yourself. There lots of reasons to live. You just need to appreciate the small stuff and not worry about the big stuff. Your life is always worth living!
Great job man
Thank you.
Will dynomax turbo mufflers kill the drone? Thanks.
No I have one.
No I have one.
@@ShredRMK824 will it help at all, and do you have any other mods on the exhaust system?
@oujee1988 I have an 18 in resonator plus the dynomax, drone is definitely coming from the muffler. I ordered a spiral slip in resonator and see if that helps before I start getting drastic.
@@ShredRMK824 what car do you have? And is the drone horrible on motorways? "About 2000 rpm"
Thank you very much for such a great informative video. It's the best I've seen about dealing with droning.
I'll apply this to my Civic SI soon.
No sound comparison? Damn man
There is no actual sound change from doing this modification. If you want to hear the exhaust sound go to LS Rebirth Ep 27. There's a cold start and a couple revs for your enjoyment.
MotoGp has been doi g this type of R&D for decades.
Now you can do it yourself without having to resort to a so-called expert. You are now the expert. Secret revealed.
Good video
Thank you
*OH Gawd that was the longest video ever! You can't focus or get to the free king point!*
Nope. Need to provide context.
All that video and no clip of how it sound? C'mon man!
There is exhaust sound clip in the video posted before this, man. And right in the very beginning!
why does drone bother you so much?..I don't get you anti-drone people
If you don't do long drives, drone will not be a nuisance. But on long steady state drives, that can be a half-hour hr or longer it can cause headaches and make the drive a bit uncomfortable. Big difference on those long drives.
@@reborn74nova I don't drive my hot rods enough to care..I would rather they sound very mean ...I don't think your hot rod should be your daily
@johnperales5431 it's not my daily, but if I take a road trip (like Las Vegas), it's the first to be chosen. Plus, doing burnouts is fun in different cities, lol.
Thank you! Great info.
Glad it was helpful!