Since I'm always looking for a reason to tinker in the shop, I decided to build an Air Horn. I don't claim any gains. I'll show you what I built compared to the factory horn and you can make your own decisions about what gains might be had.

I started with a 3" 90 degree elbow and a 3" 45 degree elbow. I built the plate from 5/16" flat stock. I added a 1/4 NPT plug at the backside to attach a boost gauge to later. I built the dipstick bracket out of 1" angle iron with a 5/16" course thread nut welded to it. Because the angle of my elbows didn't quite match the factory horn I had to loosen the clamp at the cooler and twist my factory tube slightly to match the new angle of the horn.

I bolted the plate down and loosely stuck the 90 into the plate. Then I matched the 45 to the end of the 90 to best match the rubber clamp of the factory tube. Took a guess at what needed to be cut at each end of the 45 to get the best fit and chopped it. Then slipped the 45 into the rubber clamp and held it against the 90 at the angle it fit best and marked all pieces with a sharpie. Removed the assembly and tack welded it together. Reinstalled and verified fit. Removed and headed to the welding table. When welding the plate to the end of the 90 I bolted it to a matched plate to minimize distortion of the plate surface.

 

After completing the welds I remounted the tube and again verified fit. Then removed and painted with what I had lying around in the paint cabinet.

 

This set of pictures shows the difference in the homemade horn and the factory horn. I'll let you make your own decisions about flowrate gains.

Cost of this project was around $50 plus the Beer tab. Good afternoon project.

 

Looks good I need to get some pipe and make one for mine.

 

That looks like a fun afternoon project. It turned out nice.

Have you driven it yet? Has your butt dyno detected a gain from your mod?

 

looks good, now just charge 325 a wack like most vendors do and you will be loaded then

 

looks good to me ,did u leave ur toaster grid in or take it out ?

 

Yea looks great. Curious about the toaster also. I've had a prodject like this in mind for a little while but was going to use Alu instead. Looks killer though.

 

Spend another $2 on a flap disc...

 

Yea looks great. Curious about the toaster also. I've had a prodject like this in mind for a little while but was going to use Alu instead. Looks killer though.

 

I thought about doing something similar a while back, now I'm seeing more and more folks doing it. Just wondering though what yall are using for gaskets. Did you make a new one, use a factory gasket, or use RTV or something?

 

second that. grind some of that weld down. smooth things out a bit.

 

Yeah I knew some would be critical about the finish. When you two build yours you can polish them and then post up pictures.

 

As for gaskets, I used stock ones.

As for the toaster, I think you can still see it in the pics. I left it alone. Being my first winter with the truck I was leery of pulling it. I looked it over though and think you could gut it and leave the block or build it taller and remove the heater block. I'm guessing you would again gain some flow by removing the heater.

 

Very nice job, wish I had a shop at home to make my own.