Budget Exhaust System 2 into 1

[jamesroney]

Having done every possible combination of wrong, I decided to post my latest addition to my Project. I just installed my new exhaust system. I got tired of paying high prices for mediocre work. The last shop I used welded a hanger stud to my freshly powdercoated frame. Tired of cheap mufflers, and tired of poor workmanship.

So I decided to do it myself. (sort of.) I bought USED cat-back take off from a 2020 F150. Muffler is 2.5 inlet, 3 inch outlet, with a stainless tip. Early Bronco Factory cast iron exhaust manifolds into a 2.25 H-pipe from a 1970 F250. (The listings are wrong in the catalog, and the Walker 40516 + Walker 42371 do NOT fit a 302 in an F250. They are for a 360 FE engine. But they are 2.25 with nice tight bends.) Added a V-band clamp at the muffler, and a couple of o2 bungs. The 2.25 exhaust flanges are too big for a 302, so you need to buy a pair of 2 inch flanges.

I didn't want an exhaust pipe down the left side past the transfer case. There is no room, and it's in the way of everything. Also, when you get to the rear axle, the brake line, and gas tank get in the way. So the answer for me was a single exhaust in the factory location. The single exhaust on the F150 5.0 Coyote puts out 400 HP all day long. It's plenty for my EB.

Walker 40516 y-pipe = $55.
Walker 42371 crossover = $22
Walker 41772 collector (x2) = $11
Mahle F17250 donut (x2) = $3.19
APH 339820S hangar (x2) = $6
Summit 610400 hangar (x2) = $6
Summit 694250 v-band clamp = $35
reducer, 2 inch OD to 2-1/8 OD to center donut. (x2) $5.00 each.
Cat back take off - $100.
Total spent $268.38

If you can weld and fabricate, then this might work for you. My MIG skills are not great, but my welds don't leak. You do have to "unbend" the accordian bend on the left side head pipe to get it to hug the pan. And you have to cut and turn the muffler. and shorten the over-axle tailpipe. But for $268 (and a long weekend) I'm pretty happy.

The goal was an exhaust that would be absolutely quiet, non-restrictive, and idle all day long without annoying anyone. Needed to be serviceable, and allow for maintenence. The muffler is 7x12 oval, with a 26 inch body. I don't think a bigger one would fit.

 

[jamesroney]

More pics

 

[JKH67302]

Hey James, looks great. Can you take a pic of how you navigated the pipe around the hanger on the M1A1 tank? I am about to put my exhaust in and I know I have a conflict coming. Thanks.
James

Sent from my SM-G975U using Tapatalk

 

[jamesroney]

Hey James, looks great. Can you take a pic of how you navigated the pipe around the hanger on the M1A1 tank? I am about to put my exhaust in and I know I have a conflict coming. Thanks.
James

Sent from my SM-G975U using Tapatalk

Oh yes! The j-bolts. So I looked at that for a long time, and could not come up with a design reason for the j-bolt. So I got a piece of formed metal out of a 2x3 rectangular tubing, and added it to the skid plate bracket. Then added a hole in the frame and bolted it together. I gave myself enough room for adjustment, but I don’t think I needed it.

 

[1buckeyefan1]

Pardon my ignorance of how exhaust systems actually work. What is the function of the upward u-bend just before the rear frame rail? I'm planning to have a similar 2-1 system made up (maybe myself) soon and would like to have it planned out

 

[DirtDonk]

If by upper frame rail you mean the rear crossmember, it’s not the frame alone that dictates the U-Bend, but primarily it’s a method of keeping it clear of the rear axle. Raising the tubing to a High Point in that area allows for maximum suspension travel without any contact with the exhaust system.
This is a standard practice in the industry and has been for as long as someone has needed extra clearance between suspension, driveline, body and exhaust.
Usually there’s more than enough room in a truck chassis, but not always. Especially once you start modifying the suspension for more wheel travel.
But in a standard passenger car, especially an older one such as a muscle car, you needed to make some pretty extreme bends to tuck it up against the body to keep it out of the way of the rear axle.

And in short wheelbase utility vehicles you typically have to watch out for a gas tank as well. Not a lot of clearance between the body, the gas tank, the leaf springs and suspension, and frame members. Exhaust tubing gets the short end of the stick and is last into the game sometimes.

Is that the aspect you were asking about?

 

[lars]

Nicely done! I've been fabbing my own exhaust systems for years, after paying someone else to make one for my shiny new 5.0 install in 2000 and instantly hating it. Mandrel bends and various joints from Summit or where ever, Sharpie pens, a (gasp) hacksaw that later became a DeWalt chop saw, oxyacetylene torch (when the only tool you have is a hammer) that later became a nice little Lincoln MIG. Fun puzzle and satisfying when done. All of mine including the one I recently fabbed for my new 408 have been 2 into 1. Makes thermal management, AKA my floor boards are too damn hot, easier to deal with, among other things.

Something I discovered way back when is that RustOleum zinc cold galvanize spray paint seems to endure exhaust heat on anything beyond about 2 feet back from headers/manifolds, and stops rust on welds, bolts, etc very effectively. Stainless is nice but mild steel plus a can of that is cheaper and seems to be durable.

 

[1buckeyefan1]

If by upper frame rail you mean the rear crossmember, it’s not the frame alone that dictates the U-Bend, but primarily it’s a method of keeping it clear of the rear axle. Raising the tubing to a High Point in that area allows for maximum suspension travel without any contact with the exhaust system.
This is a standard practice in the industry and has been for as long as someone has needed extra clearance between suspension, driveline, body and exhaust.
Usually there’s more than enough room in a truck chassis, but not always. Especially once you start modifying the suspension for more wheel travel.
But in a standard passenger car, especially an older one such as a muscle car, you needed to make some pretty extreme bends to tuck it up against the body to keep it out of the way of the rear axle.

And in short wheelbase utility vehicles you typically have to watch out for a gas tank as well. Not a lot of clearance between the body, the gas tank, the leaf springs and suspension, and frame members. Exhaust tubing gets the short end of the stick and is last into the game sometimes.

Is that the aspect you were asking about?

Yep, you nailed it. I thought about travel, but it appeared to be higher than the bump stop.. makes complete sense.

 

[jperry1290]

I like it! The tube is slip fit welded into place? What mig wire and settings? What transmission you running?

 

[jamesroney]

I like it! The tube is slip fit welded into place? What mig wire and settings? What transmission you running?

The 2 inch header tubes are slip fit into the 2-1/4 FE y-pipe, which goes to 2-1/2 to the muffler. The factory F150 muffler is 2.5 inlet and fits a recess in the band clamp. The 3 inch tailpipe is butt-welded in all locations. I found that a piece of wide masking tape makes a good cutting pattern, and a 4.5 x 1/16 cut off wheel makes a nice cut. Welding is done using .023 wire, and 75/25 shield gas. The settings on my machine are for 16 gage mild steel, at 18.5 volts. and 215 "units" of wire feed. Welded with a Harbor Freight Platinum cheapie MIG machine. It sits on top of my Millermatic 200. (lots more to that story...)

Hardest part was getting the passenger head pipe connected to the y-pipe and cutting the obround hole. Took a few tries to get it to fit. Oh, and the exhaust manifold flanges needed to have the holes slotted more with a rat tail file.

Transmission is an NV4500.

 

[DirtDonk]

So how did you end up making an obround hole? Same cutting wheel? Bandsaw maybe?

 

[904Bronco]

Well done James and completely understand the disatisfaction expressed by substandard work being done at local Exhaust shops for big $$$.

 

[jamesroney]

So how did you end up making an obround hole? Same cutting wheel? Bandsaw maybe?

Scribed the pattern using a Sharpie. Then I used a worn down cutting wheel on my angle head grinder, (4.5 inch worn down to 2.5 inch) and then matched the line using a regular grinding wheel. Then reinstall, verify fit, remove, trim, reinstall, verify fit, tack weld in place, allow to cool, remove, finish weld and reinstall. And yes, the cross member had to come out each time.

...then there was a loud noise in the shop that sounded something like: "Who pointed the O2 bung in THAT direction?"

No Porta-Band blades were harmed in the making of this exhaust.

 

[DirtDonk]

Ya know, I think I might have heard that sound from here!