reek
Senior Member
- Joined
- Nov 23, 2014
- Posts
- 1,592
- Reaction score
- 733
- Location
- Sacramento
- Ram Year
- 2015 RAM 2500 CC 4x4, 72 D100, 73 D100, 01 RAM 2500 field truck
- Engine
- 6.4 Hemi
Not sure if something like this has been posted before but I figured I'd post my results. Not sure if this detail matters but the following applies specifically to a 2015 Ram 2500 CC 6.4 with 6 ft bed.
I just removed my Mufflex/magnaflow set up and went to a jones JT3535XL, factory resonator still in place. the 1500-1800 rpm boom/drone was killing me with both. it is especially noticeable when the engine is under load trying to gradually accelerate in 6th from 65 mph. so before going back to stock and since I had a bunch of 2 1/2 inch pipe laying around, I figured I'd give the 1/4 wave resonator tube a try.
after a bunch of internet searching and using my smartphone sound frequency analyzing app, I built a "J" tube and welded it on to the exhaust just behind the cats. without the stock muffler in place, there's plenty of space above the Jones can. Significant improvement.
The annoying resonance seemed to be in the range from 70 - 110 hz. Just for fun, I started with a 48 inch tube, took out the very low resonance but the boom was still there. Then tried 24 inch tube with minimal improvement. So then doing the math for 90 hz since that seemed to be the most annoying range while driving, gave me a 36 inch tube. that has reduced the boom by a significant amount. there is still some and from what I can tell it seems to be the 100-110 range that I can still hear. don't think I can kill the whole range so I think I'm keeping the 36 inch tube for a bit and see how it is. My gut tells me a 33 - 34 inch tube would be better but will try that later. the old back and laying on my creeper for the last 2 days, it needs a break.
anyway, the final set up for my truck for now is 2 1/2 inch pipe x 36 inch long.
the formula I used:
343 (speed of sound)/resonance wavelength = X
X/4 = 1/4 wave length in meters.
use online calculator to convert meters to inches and that's the length of tube to start with.
the math stuff is not my work btw, pirated it off the internet.
hope this hasn't already been done and if not hope it helps.
I just removed my Mufflex/magnaflow set up and went to a jones JT3535XL, factory resonator still in place. the 1500-1800 rpm boom/drone was killing me with both. it is especially noticeable when the engine is under load trying to gradually accelerate in 6th from 65 mph. so before going back to stock and since I had a bunch of 2 1/2 inch pipe laying around, I figured I'd give the 1/4 wave resonator tube a try.
after a bunch of internet searching and using my smartphone sound frequency analyzing app, I built a "J" tube and welded it on to the exhaust just behind the cats. without the stock muffler in place, there's plenty of space above the Jones can. Significant improvement.
The annoying resonance seemed to be in the range from 70 - 110 hz. Just for fun, I started with a 48 inch tube, took out the very low resonance but the boom was still there. Then tried 24 inch tube with minimal improvement. So then doing the math for 90 hz since that seemed to be the most annoying range while driving, gave me a 36 inch tube. that has reduced the boom by a significant amount. there is still some and from what I can tell it seems to be the 100-110 range that I can still hear. don't think I can kill the whole range so I think I'm keeping the 36 inch tube for a bit and see how it is. My gut tells me a 33 - 34 inch tube would be better but will try that later. the old back and laying on my creeper for the last 2 days, it needs a break.
anyway, the final set up for my truck for now is 2 1/2 inch pipe x 36 inch long.
the formula I used:
343 (speed of sound)/resonance wavelength = X
X/4 = 1/4 wave length in meters.
use online calculator to convert meters to inches and that's the length of tube to start with.
the math stuff is not my work btw, pirated it off the internet.
hope this hasn't already been done and if not hope it helps.
