TA_C10: Stage 1

[TA_C10]

More pics.

[TA_C10]

At this point, I drove it around a couple different times. Seemed to help a little but nothing drastic. The app on my phone I am using still said the same frequency was there but lower db. I will show these later.

So I saw that Magnaflow was making these quarter wave resonator kits on a set of their muffler kits. I'm using 2" pipe for the resonators on my 3" exhaust and thought 2 things. Maybe it's not working as well because of the diameter, or maybe I have too tight of a bend from 3" exhaust to resonator piping(not perpendicular enough)??

So I built something similar to what I saw on the magnaflow kits using leftover 3" pipe I had.

[TA_C10]

more pics.

[TA_C10]

So here is the first result from my app driving around before I put these resonators on. Then I used the resonator spreadsheet I found online(from Lawrence Tolman(LT) from his youtube channel, powernation trucktech guy).

I ran several tests and the average number was 116Hz. So I plugged that into the calc. My drone is around 1700 RPM mostly so I used the 35" number for length. I went exactly 35".

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[TA_C10]

Basically those new tips, with expanding 3" diameter, didn't do a thing, actually it was louder. With the 2" clamps I bought, I can actually adjust the tips up to almost 3" difference. But none of this made a difference really.

I ended up putting back the original 2" tips back on at same length, and after driving around with them back on, they made the biggest difference in keeping drone down. But it's still there. I'm not sure if my calculations were just bad or what the issue is but this just isn't making enough of a difference to justify. My guess is my design is just not right because I hear a lot of others saying this works.

[TA_C10]

And here is the result, the best I could get it. It dropped from -15 to -20 db almost. So the drone is still there, but quieter. I was expecting it to be completely cancelled. If you guys have any suggestions let me know.

I lengthened the pipe with my clamps, playing with several different configurations. I also shortened the pipe by turning the 2" capped end's 180 degree and putting them in the clamps backwards. But that shorted it probably down to like 25-28" and if you look at the spreadsheet, longer should have worked better than shorter. Nothing worked except the original 35" I originally built them to, which the Hz is still the same pretty much, but the db's went down.

I dunno.....

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[SCOTI]

Originally Posted by TA_C10

And here is the result, the best I could get it. It dropped from -15 to -20 db almost. So the drone is still there, but quieter. I was expecting it to be completely cancelled. If you guys have any suggestions let me know.

I lengthened the pipe with my clamps, playing with several different configurations. I also shortened the pipe by turning the 2" capped end's 180 degree and putting them in the clamps backwards. But that shorted it probably down to like 25-28" and if you look at the spreadsheet, longer should have worked better than shorter. Nothing worked except the original 35" I originally built them to, which the Hz is still the same pretty much, but the db's went down.

I dunno.....

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This is exactly what I wondered. Would the ends justify the means? I guess even that (the answer) is subjective. Some might view reduction as a win. Others seeking complete cancellation probably wouldn't.

Are you happy w/it as-is or are you going to keep @ it?

[TA_C10]

Originally Posted by SCOTI

This is exactly what I wondered. Would the ends justify the means? I guess even that (the answer) is subjective. Some might view reduction as a win. Others seeking complete cancellation probably wouldn't.

Are you happy w/it as-is or are you going to keep @ it?

I would like to keep at it. It didn't cancel out my drone. I think my design is flawed. Maybe I'm WAY off on the length? I found another spreadsheet from internet that has significantly different results in length of pipe. Check it out below. I plug in my frequency at 114 or 116, and length is saying 10", not 35". Maybe I will try shortening them?

https://docs.google.com/spreadsheets...gid=1183590515

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[SCOTI]

Originally Posted by TA_C10

I would like to keep at it. It didn't cancel out my drone. I think my design is flawed. Maybe I'm WAY off on the length? I found another spreadsheet from internet that has significantly different results in length of pipe. Check it out below. I plug in my frequency at 114 or 116, and length is saying 10", not 35". Maybe I will try shortening them?

https://docs.google.com/spreadsheets...gid=1183590515

.

One of the reasons I suggested a telescoping approach (how do I know which calculation method is more accurate?). Do you have pics of one of your finished pipes?

My thought is still make the 'T' into the main exhaust lines. Weld a 90° turn on the 'T'. Make a short (~3"L) 'end piece'. Use the wrap-around style exhaust clamps (2x clamps @ each assembly so 4x total) to secure varying lengths of pipe between the 90° & the end piece.

What size tubing did you wind up using?

[TA_C10]

Originally Posted by SCOTI

One of the reasons I suggested a telescoping approach (how do I know which calculation method is more accurate?). Do you have pics of one of your finished pipes?

My thought is still make the 'T' into the main exhaust lines. Weld a 90° turn on the 'T'. Make a short (~3"L) 'end piece'. Use the wrap-around style exhaust clamps (2x clamps @ each assembly so 4x total) to secure varying lengths of pipe between the 90° & the end piece.

What size tubing did you wind up using?

Post 1173 shows my final setup. I used the clamps your showing. It allowed me to slide my pipe out about 3" so I can adjust that much. I used 2.5" tubing. Those other tips I made from 3" tubing didn't help.

Yeah I will probably cut it down again too 10" or so and with my 3" adjustability try that new length from the second spreadsheet I found.

[TA_C10]

Originally Posted by SCOTI

What size tubing did you wind up using?

oops, I said 2.5" tubing.... I used 2" not 2.5".

[rickcdewitt]

This might hide the drone?

[rickcdewitt]

Seriously though,i wonder if distance from the motor is an issue? Or if they need to be after the flowmasters to cancel their noise?

[TA_C10]

Originally Posted by rickcdewitt

This might hide the drone?

Originally Posted by rickcdewitt

Seriously though,i wonder if distance from the motor is an issue? Or if they need to be after the flowmasters to cancel their noise?

Everything I read was closer to motor the better. Says the exhaust frequency starts from motor. But if the mufflers are what is changing the note causing the drone then that makes sense. The magnaflow kit with quarter wave resonator built in is installed on the muffler itself, it's on the front of muffler, inlet side, not sure here...

[MDPotter]

Beautiful work man. I'll be happy if mine comes out half that nice.