F-2 Stang

[earthman]

Yep, it depends on who you talk to. Which office did you go to Dan?
I've got a pair of motorcycle supertrapps over here.The round outer baffle plates are gone but the inside tubes have small perforations.You are wecome to cut them up and try to use them.

 

[earthman]

Yep, it depends on who you talk to. Which office did you go to Dan?
I've got a pair of motorcycle supertrapps over here.The round outer baffle plates are gone but the inside tubes have small perforations.You are wecome to cut them up and experiment with them.

 

[DJ3100]

Thanks Earthman, I might take you up on that. I'd like to at least look at them.

I have a new plan.

I'm going to make 2" diameter baffles, 14" long, with the exit end closed and a plate to block off the megaphone at the engine end. the exhaust will have to go into the 2" baffle, through the slots and out the megaphone. Many of the commercially make baffles look like this.

 

[Sam_Fear]

Just make sure to do some math to keep from reducing flow. Don't wanna choke out at higher RPMs. It takes four 1" circles to equal the same area as one 2" circle. 16 half inch circles. I made my own muffler for kicks not long ago. It'll be awhile before I get a chance to see if it chokes the motor though.

How big are your cones at the end?

 

[DJ3100]

The cones are 3.5" diameter.

Yeah, I'm concerned about too much back pressure. The minimum restriction is the 2" diameter baffle (3.1 square inches). After it gets through the baffle there is about 5 square inches between the cone and the baffle. There are 21 slot/ dimples in the baffle which are about 3/8 x 5/8 or .23 square inches x 21 = 4.9. Does that sound like enough or did I overlook something?

I'll post some pics tomorrow.

 

[clamor]

I've found something as simple as kickouts makes a really big difference.

Just direct the noise away from the cab.

PA41

I wondered if that might help.
-Chaz

 

[earthman]

If any of you get a chance to see this noisy truck in person you will be talking about it for a long time to come.
The proportions, details and craftmanship are truly awesome.

 

[DJ3100]

It has been a while since I updated this so I'll share the noise solution.

I bought a sound level meter ($60 from Radio Shack). I recorded 110 dbA in the cab at a high idle - painfull

I established a baseline from about 3' away from the open end of the exhaust (outside the cab) and got 109 dbA at 2000 rpm with the original perferated baffle wrapped in steel wool with a 90 deg turnout.

Earthman brought over the SuperTraps; I cut them up and tried them and got a couple db reduction - not enough.

I tried around 40 cominations of things including
glass pack muffler, with the case cut off.
modified Hushpower.
IMCA mufflers that claimed to give 9 db reduction
Cones inside the baffle
Auger acround the baffle and inside the baffle
The best I could get with any of those was 103 db

Then, I stumbled on an article about Harley exhaust that said they force the exhaust through the fiberglass.

I made a perferated metal tube, blocked the center (no air or sound can go straight through) and wrapped it in Motorcyle fiberglass muffler packing.

91 db at idle. 93 eb at 45 mph but much of that is tire and wind noise.

The drivability change was amazing -just like all the stuff I have read about. With straight through baffles it didn't want to idle and had almost no torque until 3000 rpm. - then it would go to 6500 almost instantly.

With the restricted baffles it idles and pulls strongly from 1800 to 6000 - it is now a nice dirver and still quick enough to terrify Earthman and mildy impress Truckster.

 

[CORPO]

it is now a nice dirver and still quick enough to terrify Earthman and mildy impress Truckster.

Haha! good stuff

 

[earthman]

Yep, it runs as good as it looks and my knuckles are'nt white any more so i'm ready to go for another ride. I can't wait to hear the comments when the public gets to see it up close.

 

[Sam_Fear]

it is now a nice dirver and still quick enough to terrify Earthman and mildy impress Truckster.

Haha! good stuff

Agreed!

It's great you figured it out for the rest of us too.

 

[sneakysnake]

I put a fiberglassed baffle in mine. It will make you itch especially if you have suicide doors.LOL and its getting louder.

http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC-D-2538

 

[Sam_Fear]

I put a fiberglassed baffle in mine. It will make you itch especially if you have suicide doors.LOL and its getting louder.

http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC-D-2538

I wondered if it would burn out. Could you use metal lathe shavings like an old Smithy?

 

[Cookie's Customs]

That thing is just awesome,nothing but respect for your craftsmanship its a work of art[dr

 

[DJ3100]

I put a fiberglassed baffle in mine. It will make you itch especially if you have suicide doors.LOL and its getting louder.

http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC-D-2538

How loud is it? I used a similar baffle, as well as others, but when I measured the sound level it only reduced the sound by a couple db's. All the straight through baffles seemed to change the frequency but didn't actually reduce the noise level very much.

Thanks for the comments and compliments. Maybe someday I'll find someone with a video cam and post a video of it actually doing something.

 

[earthman]

 

[sneakysnake]

How loud is it? I used a similar baffle, as well as others, but when I measured the sound level it only reduced the sound by a couple db's. All the straight through baffles seemed to change the frequency but didn't actually reduce the noise level very much.

Thanks for the comments and compliments. Maybe someday I'll find someone with a video cam and post a video of it actually doing something.

Never tested it but going down the road with no side glass its plenty loud but can be lugged through town and its nots so bad.

 

[Caddad65]

NICE! You've come a long way since I was there in April. I'm really digging the rag top.

 

[DJ3100]

Good pics Earthman, thanks for posting them.

CAddad - I finally got the rag top to fit correctly last week. It came with a headliner which was preventing it from closing and latching. I took the headliner off and it worked fine. I like seeing the aluminum bows better anyway.

Sneakysnake -that was pretty much the result I had, It was just loud enough to be uncomforatble.

 

[clamor]

Awwwww man, I'm so bummed I never got down to see it before I moved out of town.
:-(
Lookin GREAT, man!
-Chaz