There's a scientific study somewhere that says if you round the junction where the QWR T's into the exhaust; it works over a wider frequency/rev range. Think velocity stack or bell mouth flattened on 2 sides kinda story... Also less restriction was mentioned IIRC.
OK so, using the calculator you provided I'm looking to eliminate 108Hz @ 2700-3100 rpms on a 4cyl with sound temp @462.8m/s. The read out on the calculator at the top shows 42.1 but the numbers in the bottom right table shows 50.52-45.47" what length am I really looking at and does the diameter of the J pipe vs the main tubing matter?
It's targeted. You base your tube length on the calculations in the excel sheet I linked. You'll have to note the rpm and hz you are trying to mitigate.
@@BadlandIndustries correct I get that, but say if we built it to take care of 100hZ drone. How wide of a hZ/RPM would it dampen also? 95-105hZ, 99-101hZ? Any general idea?
@@pegleggreg3627 if you center your calculations on the hz and rpm you are having an issue with you'll notice an increase in effectiveness as you get closer to that point. This didn't seem to be anywhere as loud all around that 2500 mark. As we crept up to 2700+ I started to notice more cab noise.
@@BadlandIndustries Thanks for the help, one last thing does the placement matter like if it is in the back or middle of the system. My drone is at 88 Hz to 94hz
I have been looking for a the sound meter/spectrum analyzer or link for a long time. Most everyone gives the Excel sheet but nobody but nobody shows a link for the sound meter / spectrum analyzer and or a LINK‼ Sorry but isn’t this the most critical equation?
I love the beginning lol. Saying alright let’s go for a drive
There's a scientific study somewhere that says if you round the junction where the QWR T's into the exhaust; it works over a wider frequency/rev range.
Think velocity stack or bell mouth flattened on 2 sides kinda story...
Also less restriction was mentioned IIRC.
Yea I can see there being alot of variables to make this work for different situations.
for multiple tones/tubes firstly use smaller hz tubes near the engine and then deeper tones closer to the rear axle
OK so, using the calculator you provided I'm looking to eliminate 108Hz @ 2700-3100 rpms on a 4cyl with sound temp @462.8m/s. The read out on the calculator at the top shows 42.1 but the numbers in the bottom right table shows 50.52-45.47" what length am I really looking at and does the diameter of the J pipe vs the main tubing matter?
Lemme double check the form but the tube I personally used and have seen used is the same as the exhaust.
The link to excel file seems broken, could you relink it? great video!
I took a quick look and it looks like the blog post might be buried. It's in June 22 catalog.
What sort of RPM range did this help in? +/- 2-300RPM?
It's targeted. You base your tube length on the calculations in the excel sheet I linked. You'll have to note the rpm and hz you are trying to mitigate.
@@BadlandIndustries correct I get that, but say if we built it to take care of 100hZ drone. How wide of a hZ/RPM would it dampen also? 95-105hZ, 99-101hZ? Any general idea?
@@pegleggreg3627 if you center your calculations on the hz and rpm you are having an issue with you'll notice an increase in effectiveness as you get closer to that point. This didn't seem to be anywhere as loud all around that 2500 mark. As we crept up to 2700+ I started to notice more cab noise.
What do I do if I have dual exhaust pipe on a v6
The sound is still going through both pipes. My understanding is that you may need to do both but you might start with one side.
@@BadlandIndustries does the cylinder change for the size of the motor like 3 cylinder
@@gabrielkidder8112 because the sound is being created by a 6cyl yould calculate for 6
@@BadlandIndustries Thanks for the help, one last thing does the placement matter like if it is in the back or middle of the system. My drone is at 88 Hz to 94hz
@@gabrielkidder8112 yes you'll change temperature and that affects the equation.
I have been looking for a the sound meter/spectrum analyzer or link for a long time. Most everyone gives the Excel sheet but nobody but nobody shows a link for the sound meter / spectrum analyzer and or a LINK‼ Sorry but isn’t this the most critical equation?
Yep. Use your app store and search for frequency analyzer. I used a few free ones and they all came back very similar.
@@BadlandIndustries Thanks! I will look and see if I can find one.