Thread: Securing Header Baffles

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I made up a new set of baffles, using the basic design from Car Chemistry in heavier material and larger mounting rings to yield more sound deading volume. They're basically a piece of 2.25" exhaust pipe (originals were 1.75"), a couple of pieces of 0.125" plate with 2.25" holes cut to make big "washers", and a pair of donuts of larger exhaust pipe, one 3" and one 4". Each donut is welded to a "washer", then positioned on the baffle pipe such that they wedge snugly into the megaphone.

They slide into the laker megaphone, fitting nearly flush with the end:
Baffles 024.JPG

The outboard ring has about 1/2" of room between the baffle pipe and the ID of the 4" ring:
Baffles 025.JPG

And they whole baffle:
Baffles 026.JPG

On my store bought set the baffle rings were stamped steel, something like 14 gauge, and I had one mounting screw through the bottom side of the header, screwing into a nut welded onto the baffle ID. Over time the heat and pressure of the exhaust warped the baffle plate quite a bit, and they rattled a bit at certain points in the exhaust flow, like decreasing rpm's under load.

Anyone have a better idea for mounting? I've considered the expanding capture nuts at 180* on the header, attached to the baffle ring to accept 1/4x20 button heads, but I'd have to tweak the baffle plate for clearance as they need to fit very snug and drilling to hit the center to the baffle plate is dicey. I've also considered some sort of "ring" that slides back against the outside of the baffle ring with three legs welded , each thick enough to be threaded 1/4x20. This would yield three holes spaced 120*, near the end of the header. I'm open to suggestions or ideas, as I'm still deep in the thinking mode on mounting.

How about making a clamp device similar to those you might have seen used as line clamps, that would pull down on the flanges. If you've got the clearance, a wrap of some heat resisant material around those flanges could muffle any potential rattle.

Bob, I'm not sure what you mean by line clamps and I don't follow your explanation of pulling down on the flanges.

There are all kinds out there, but this is similar to what I had in mind: Stainless Steel Line Clamps - Speedway Motors, America's Oldest Speed Shop Not so much the specific part as the general shape/design. My thinking is these would be less likely to be disturbed by the heat than the direct welded nut, even though a clamp like this would have a secured fastener so that you could tighten from the outside of the header as needed if thermal cycling caused it to loosen. The "tongue" of the clamp would overlap the cup shaped flanges on the baffle inside the header. If, with or perhaps without the insulation material, the baffle were a snug fit you might be able to get away with a single clamp at the current hole you have.

Thanks for the visual on your idea. I like the idea, but I turned the outer ring inboard to help retain insulation better and that would make it harder to ensure that a line type clamp was aligned and grabbing. Also, with the cup inboard it would be only friction holding the baffle, and I'm a bit concerned that the continual heat & vibration would allow it to slide free. I'm sure it could be made to work, but I'm not sure I'd ever be 100% comfortable that a baffle wasn't going to be bouncing down the highway behind me.

After sleeping on it I think I'm going to weld three long "tabs" to the outer side of the baffle ring spaced equally @ 120*, extending close to the end of the megaphone, say 3/16Tx1/2Wx(length to fit). Because of the exhaust port orientation and my suicide door clearance issues the passenger side megaphone is almost 3" shorter than the driver's side (ports sit E/I front to back drivers, and I/E front to back passengers) which makes the baffles different - same sound attenuation length, but different projections. This means the old mounting hole is too far forward, and will have to be welded and ground smooth before the headers are recoated, and this method will make both sides look the same from the outside.
Baffles 018.JPG

I appreciate the idea of the clamp, and had I turned that ring around like the old one was I'd have used it for sure. It's stored away for the next set

I think i would have a mechanism where it 'pulled' the baffle into a seat. The seat could be a perminant piece of the header and it woyuld take the place of the very 1st ring of the baffle, it would have threaded inserts (similiar to used in wood) welded at about 120deg with allthread extending to near the end of the collector. Slide the baffle up into the collector working the allthread thru the remaining ring and start the motor end of the baffle into the seat, slide some larger o.d. sleeves over the allthread and run a nut down to the sleeve and pulling/pushing the baffle into the seat and clamping the whole mess in place without any hole to the outside. You could have the allthread just long enough to hold a trim ring to finish off the face of the collector.
I like your baffle, might have to copy it.

Okay, if recoating is one of the options, how about welding studs from the outside to the inside (the studs would protrude inside, ground flush on the outside). Then have equally clocked L or J shaped slots in the baffle collars so that you insert the baffle and give it a twist to lock. The addition of a mild stainless spring at the end would give you a preload to ensure seating. In addition, to ensure the baffle can't be blown out, and to add more sound baffling, put a bolt on turnout at the end.

Originally Posted by ojh

I think i would have a mechanism where it 'pulled' the baffle into a seat. The seat could be a perminant piece of the header and it woyuld take the place of the very 1st ring of the baffle, it would have threaded inserts (similiar to used in wood) welded at about 120deg with allthread extending to near the end of the collector. Slide the baffle up into the collector working the allthread thru the remaining ring and start the motor end of the baffle into the seat, slide some larger o.d. sleeves over the allthread and run a nut down to the sleeve and pulling/pushing the baffle into the seat and clamping the whole mess in place without any hole to the outside. You could have the allthread just long enough to hold a trim ring to finish off the face of the collector.
I like your baffle, might have to copy it.

Not sure how that inner seat would be secured to the header, but I'm visualizing a "washer" with ID to allow slip fit of the pipe and three all threads pointing out? Even when assembling the header it would be a challenge to secure that unless I'm missing something, but I do like the idea of pulling the baffle into place. I think my method is going to be OK, but time will tell.

I took a bunch of step-by-step pics of the build process on this new baffle set and can post them later if anyone's interested?

Roger I must be the slowest guy in the world Could you post a picture of the baffel in place??

Originally Posted by cffisher

Roger I must be the slowest guy in the world Could you post a picture of the baffel in place??

Charlie, look up at post #1, picture #1 for a shot of the driver's side baffle in the megaphone.

Why not put the baffel in where it goes and drill a 3/8" hole all the way through the header pipe and baffel
then use a bolt and nut I doubt the bolt would have any effect on the sound or performance.. Mabe stainless rod or bolt??

Yeah, that would be functional, but it would not be attractive. A small, long bolt would be sufficient, or even a small, long clevis pin with a retainer, but all would look a bit too redneck for my taste. I actually read a post from a guy who did exactly that, and over time the hole in the header elongated from the pressure, heat and vibration. He overdrilled, installed shallow bronze bushings in the header collector, and reinstalled. Not the look I want, but thanks.

I thought those type headers were what rednecks wanted

Just to close the loop, this is what I ended up doing for the baffles on my "Redneck Headers". Three 3/16x3/4" tabs, length to fit, spaced equally. The one for the other side has tabs only about 1.5" long:
Baffles 005.JPG

After adding a wrap of HT fiberglass with foil backing that I got from the fireplace store (scrap piece, freebie) I tried them for noise level. The new baffles use a 2.25" pipe where those from CC used 1.75", so the new ones have a much deeper rumble, which I like. At Tractor Supply I had seen a pair of stamped flanges (used to retain pieces on a shaft?) that form a shallow venturi 1.5" ID. I decided to tack one on the inlet to add just a bit of restriction and turbulence in an attempt to drop the noise a tad. Here's one in place and the new piece in front:
Baffles 010.JPG

And here's the difference with & without the restrictor:Baffles 011.JPGOverall baffle, ready to insert:Baffles 007.JPGAnd the button head screws in place.
Baffles 012.JPG


I'm not wild about the three button head bolts, but they definitely retain the baffle and will prevent distortion by equalizing the retaining points around the ring, as well as the plates being heavier material. They'll work for now

For anyone looking to use this approach I saw another baffle build thread where they guy went to his local building supply store (Lowe's/HomeDepot) and found round, stamped steel electrical box covers in 3" and 4" OD. He had to weld in the stamped conduit plugs and a few miscellaneous holes, but it was a pretty slick idea, FWIW. He also used ready made perforated pipes (~$25 for the pair), or you can buy a glass pack and cut out the core vs making your own, too. I liked not having perforations all the way to the end, so making it myself was a better choice.

Roger, do they resonate at speed? I guess I'm getting old 'cause I don't care for that noise any longer! LOL..

I hope they work out for you! Looks like a pile of work!