When it comes to working on your classic Ford there is always the choice to do something yourself or to farm the work out to a professional. As a beginner in this hobby there are many things you must farm out simply because you do not have the skills or tools to effectively do the job your self. The good news is that this hobby is cumulative and the more little project you can do the more experience you will have, allowing you to tackle bigger and bigger projects.
Some times you farm out the project, simply because you don’t THINK you can’t do it, but the reality is you probably can. A perfect example of this is the exhaust. A lot of people do 99% of the work on their car from mechanics to paint and everything in between and then take the car to a muffler shop to have the exhaust done. I think there is two reasons for this, first they don’t have a pipe bender, and the second reason is that they are worried about all the different directions the exhaust needs to go to get it to fit properly. I am here to tell you that any one with a good metal cutting chop saw and a welder can make their own exhaust. I made what I like to refer to, as an “eXhaust” for my Mustang and it was not that hard.
![Image]()
Materials
It doesn’t take a lot of materials to make an exhaust. Obviously you need exhaust pipe, Mufflers, and either manifolds or headers to come off of the engine. There are also the optional pieces such as exhaust tips and exhaust balancers such as an “X” or “H” pipe. In some cases you may want to buy some pre-made elbows, or take a stick of pipe to a local exhaust shop and have some bends put into it so that you can cut out the bends you need and weld them in to place. Having the stick of pipe pre-bent is a nice option if you want mandrel bent exhaust however is not required as there is still another option that I like to refer to as cut and rotate method.
Cut and Rotate
The cut and rotate method is simple enough but does take a specific technique to get it to work correctly. The first thing I like to do is mark the pipe on opposite sides with a straight line. The lines are applied by putting two marks equally spaced apart on the end of the pipe and then using a piece of angle iron as a straight edge to extend the mark down the length of the pipe.
![Image]()
![Image]()
![Image]()
This is not necessary on a single cut bend but as you will see is very important on multi cut pieces.
Once I have the pipe marked it is time to start cutting. The basis of the technique is to put the pipe in the chop saw with one of the lines positioned in such a way so that the pipe can easily be removed from the saw and then repositioned in the same orientation or the exact opposite orientation. To facilitate this I used a silver sharpie to make a mark on the back side of the chop saw guide to give me a place to line up with lines on the pipe.
![Image]()
With the pipe in the saw it can then cut at an angle leaving you two angled pieces.
![Image]()
![Image]()
If you take one of those pieces and rotate it 180 degrees so that the opposite lines match up and the put the tubes together, the angled openings on the end of the pipe will also line up and can be welded together giving you a bend that is twice the angle of the original cut.
![Image]()
The beauty of this type of technique is that you get a smooth transition as the tubing openings will line up perfectly. Keep in mind that with this technique the final angle of the bend results in the sum of the individual pieces. Example on ten-degree cut creates two pieces with a 10 degree angle on them, phase one of the pieces out 180 degrees, and welded them together and the result will be a bend of 20 degrees. In the same way two, eleven-degree cuts, resulting in four angles on three pieces (one wedges between two piece of angled pipe) will result in a 44-degree bend.
Multi-cut bends are where the lines become critically important. After the first cut the pipe will need to be removed from the saw and repositioned for the next cut. Each cut will need to be the opposite of the cut before it and to achieve this the pipe will need to be rotated 180 degrees from the direction was originally positioned in for the previous cut. The reason for this is so that the second cut can be the opposite direction of the first one with out having to change the saw cutting angle.
Even if you did change the saw cutting Angle the pipe would still need to be repositioned so it makes more sense to leave the saw angle alone and simply reposition the pipe. By having the lines you have a mark to go by to insure the cuts are truly opposite. You simply rotate the pipe so that the second line is in the same position relative to the saw as the first line was.
![Image]()
Once you have the piece rotated you can make the second cut, and from there you can simply weld the pieces together resulting in a nice bend.
![Image]()
With the cut and rotate technique you now have an option that will allow you to make all the bends necessary to build the exhaust and is fairly smooth flowing on the inside.
![Image]()
Obviously this technique will not be as free flowing as a mandrel bent exhaust but for the average street machine it will function very well.
Choosing the correct exhaust pipe diameter
There is a common misconception in the automotive world that bigger is always better when it come exhaust pipe. I have herd people recommend that you run the biggest pipe that you can easily fit under your car. This can be bad advice. Yes the bigger the exhaust the more freely it will flow, however bigger also means slower and the slower the gasses exiting the exhaust are moving the less scavenge you will have in the combustion chamber which will result in less power.
On the flip side, to small of an exhaust will be restrictive at high RPMs robbing the engine of horsepower. As with most things relating to engines there is a balance to be had between low end torque and horsepower in contrast to overall torque horsepower. With this in mind engine RPMs under normal use will effect desired exhaust size with lower RPM engines needing smaller diameter pipe than higher RPM engines so as to maintain exhaust velocity.
A good rule of thumb is to use 2” to 2.25” dual exhaust for a 300 to 350 cubic inch engine (depending on desired RPM use) and then increase or decrees the exhaust size proportionally to the engine size. Keep in mind that exhaust pipe that has twice the diameter of any given size will flow four times the CFM. Example a 3” exhaust will flow twice the CFM as a 2” exhaust and for times the CFM as a 1.5” exhaust.
Parts I Chose
For my specific application I started with 2 headers, two collectors, one home made X pipe, two 24" glass packs and a 10' stick of 2.25" exhaust pipe. I chose all these components specifically because the engine in my Mustang has a fairly lopey cam and I wanted it to breath freely at higher RPMs.
Start at the engine and work back
Prior to redoing the exhaust on my car coming off my heads were an old rusted set of headers that had come in contact with the road enough times that the bottom tubes were at about half capacity, so when I decided to redo the exhaust I new I needed new headers. My Mustang has the first generation Uni-steer manual rack and pinion steering unit in it and one of the downfalls of this particular unit is only a few stiles of headers seams to clear the Uni-steer steering shaft. To make matters worse these headers are over $500.00 a set and I didn't want to pay that kind of money for headers.
I decided to get a quality set of headman 88300 which have ball type collectors and 1 & 5/8" tubes. They cost me about $160.00 for the set. When I installed them (with the Uni-steer steering shaft removed) the fit was fantastic they cleared the shock towers by at least 1/8" and more than that in most places. When I went to reinstall the steering shaft there was an obvious problem. The steering shaft had to pass directly through the middle of one of the header tubes. I was fairly sure I would have a problem like this when I ordered the headers so I had already decided I would cut the tube and relocate it to clear the shaft.
Header Modification
The first step in modifying the headers was to mark the tube where it needed to be cut. With the headers bolted in place I eyeballed were the shaft needed to pass, marked the tube and then remove the header from the car and cut out the section that was in the way. Let me tell you there is something kind of heart breaking about cutting in to a brand new set of headers, especially headers that seamed to be such a perfect fit. With the tube out I reinstalled the header and the rack and pinion steering linkage to make sure that I had removed enough of the tube.
The next step was to determine where to reroute the tube. On a unmodified classic Mustang the drivers side header is always going to be an extremely tight fit because there is a steering box to try and get around not to mention clutch linkage on any manual transmission car. Obviously since I had upgraded to a rack and pinion, the steering box was gone, and even though my car has a manual transmission the clutch actuation is hydraulic so I had removed both of the parts that typically cause drivers side header clearance issues. This meant that I had a huge open cavity to which I could route my pipe.
Once I new approximately where I wanted to put the pipe I began cutting up the section of tubing that I had removed from the header using the cut and rotate method and was able to adjust the direction of the tubes and tack a piece in to place. I then did a test fit of the header. It took several test fits and slight modifications, but I was able to modify the headers to flow around the shaft.
In this picture of the last test fit, You can see just how much I had to modify the tube. Like I said before the original tube location would have gone right through the middle of the steering shaft.
![Image]()
Once I new I had the headers the way I wanted them I welded up all the seams from the modification.
![Image]()
I used the same technique used on body panels of putting individual small welds about .5” apart all the way around the tube and then filling in the gaps one weld at a time. This was done to produce a clean weld that could easily be ground off and would not burn through the tube.
![Image]()
After getting the header tube welded up I took an angle grinder to the welds and am very pleased with the result!!!
![Image]()
As I was grinding I was worried about the thickness of the header tubing and did not want to weaken it so I was very Conservative with my grinding which is why it is not perfectly smooth.
![Image]()
Fabbing Up the Main Pipes
With the headers in place I positioned the X pipe where I wanted it, just behind the transmission and blocked it up. Keep in mind when setting up an X pipe type exhaust that at some point you may need to pull the transmission. In my case I set the exhaust up so that it could easily be removed as one whole piece should I need access to the transmission.
With the X pipe n place I bolted the collectors to the headers and then began cutting up the 10' stick of pipe using the “cut and rotate method” so that I could tack weld the pieces together to attach the collectors to the X pipe. From there connecting the X pipe to the to the mufflers was a simple straight run toward the back and side of the car so that the exhaust could exit just in front of the back tire.
Straight Through
From the driver’s side collector through the passenger’s side glass pack and the passenger’s side collector through the driver’s side glass pack I have a true straight through flow, which is why I call this an eXhaust.
![Image]()
After the mufflers I made two sharp 45-degree (cut and rotate) bends to achieve the correct angle for the exhaust to leave the car. I did this with one 22-degree cut rather than several lesser degree cuts because I figured I would not make that much of a difference especially considering the location so I went with what was easiest. From there I simply tacked on some stainless steel tips to the end of the pipe so that the exhaust exits in stile. With the entire system tacked together, I removed it from the car and welded it all up solid using the same one weld at a time technique that I had used on the headers.
The last step was to take the headers and the exhaust to the powder coater to get ceramic coated. This coating not only looks good, but also will protect my exhaust from rusting. The interesting thing about ceramic coat is that you can polish it by glass beading it or with steel whole. The headers had been glass beaded at the powder coater but the full exhaust had not.
![Image]()
![Image]()
I polished up the ends near the stainless tips with some steel whole, but decided it was more work than I wanted to do on a part that would rarely be seen.
![Image]()
The final install of the system was was easy and it went in with no issues
![Image]()
Sounds different
The original exhaust on my car was long tube headers going in to duel pipes with no crossover. The glass packs were at least 30 years old and so the car was very loud, had a lot of deep rumble, and a nice lopy sound at idle.
![Image]()
The new eXhaust I built with its straight through design, new glass packs and an "X" pipe in the middle, was, As expected quieter, has a slightly higher rumble and is not as lopy at idle. I hate to see those things go, but I new the "X" pipe and new mufflers would do that. The car should get a little louder and the rumble a little lower as I put some miles on the car which will break in the mufflers. The up side is that the car now has that circle track roar when you step on it and that along with the HP increase from balancing the exhaust banks makes the new exhaust well worth it in spite of what I lost.
.
Some times you farm out the project, simply because you don’t THINK you can’t do it, but the reality is you probably can. A perfect example of this is the exhaust. A lot of people do 99% of the work on their car from mechanics to paint and everything in between and then take the car to a muffler shop to have the exhaust done. I think there is two reasons for this, first they don’t have a pipe bender, and the second reason is that they are worried about all the different directions the exhaust needs to go to get it to fit properly. I am here to tell you that any one with a good metal cutting chop saw and a welder can make their own exhaust. I made what I like to refer to, as an “eXhaust” for my Mustang and it was not that hard.
Materials
It doesn’t take a lot of materials to make an exhaust. Obviously you need exhaust pipe, Mufflers, and either manifolds or headers to come off of the engine. There are also the optional pieces such as exhaust tips and exhaust balancers such as an “X” or “H” pipe. In some cases you may want to buy some pre-made elbows, or take a stick of pipe to a local exhaust shop and have some bends put into it so that you can cut out the bends you need and weld them in to place. Having the stick of pipe pre-bent is a nice option if you want mandrel bent exhaust however is not required as there is still another option that I like to refer to as cut and rotate method.
Cut and Rotate
The cut and rotate method is simple enough but does take a specific technique to get it to work correctly. The first thing I like to do is mark the pipe on opposite sides with a straight line. The lines are applied by putting two marks equally spaced apart on the end of the pipe and then using a piece of angle iron as a straight edge to extend the mark down the length of the pipe.
This is not necessary on a single cut bend but as you will see is very important on multi cut pieces.
Once I have the pipe marked it is time to start cutting. The basis of the technique is to put the pipe in the chop saw with one of the lines positioned in such a way so that the pipe can easily be removed from the saw and then repositioned in the same orientation or the exact opposite orientation. To facilitate this I used a silver sharpie to make a mark on the back side of the chop saw guide to give me a place to line up with lines on the pipe.
With the pipe in the saw it can then cut at an angle leaving you two angled pieces.
If you take one of those pieces and rotate it 180 degrees so that the opposite lines match up and the put the tubes together, the angled openings on the end of the pipe will also line up and can be welded together giving you a bend that is twice the angle of the original cut.
The beauty of this type of technique is that you get a smooth transition as the tubing openings will line up perfectly. Keep in mind that with this technique the final angle of the bend results in the sum of the individual pieces. Example on ten-degree cut creates two pieces with a 10 degree angle on them, phase one of the pieces out 180 degrees, and welded them together and the result will be a bend of 20 degrees. In the same way two, eleven-degree cuts, resulting in four angles on three pieces (one wedges between two piece of angled pipe) will result in a 44-degree bend.
Multi-cut bends are where the lines become critically important. After the first cut the pipe will need to be removed from the saw and repositioned for the next cut. Each cut will need to be the opposite of the cut before it and to achieve this the pipe will need to be rotated 180 degrees from the direction was originally positioned in for the previous cut. The reason for this is so that the second cut can be the opposite direction of the first one with out having to change the saw cutting angle.
Even if you did change the saw cutting Angle the pipe would still need to be repositioned so it makes more sense to leave the saw angle alone and simply reposition the pipe. By having the lines you have a mark to go by to insure the cuts are truly opposite. You simply rotate the pipe so that the second line is in the same position relative to the saw as the first line was.
Once you have the piece rotated you can make the second cut, and from there you can simply weld the pieces together resulting in a nice bend.
With the cut and rotate technique you now have an option that will allow you to make all the bends necessary to build the exhaust and is fairly smooth flowing on the inside.
Obviously this technique will not be as free flowing as a mandrel bent exhaust but for the average street machine it will function very well.
Choosing the correct exhaust pipe diameter
There is a common misconception in the automotive world that bigger is always better when it come exhaust pipe. I have herd people recommend that you run the biggest pipe that you can easily fit under your car. This can be bad advice. Yes the bigger the exhaust the more freely it will flow, however bigger also means slower and the slower the gasses exiting the exhaust are moving the less scavenge you will have in the combustion chamber which will result in less power.
On the flip side, to small of an exhaust will be restrictive at high RPMs robbing the engine of horsepower. As with most things relating to engines there is a balance to be had between low end torque and horsepower in contrast to overall torque horsepower. With this in mind engine RPMs under normal use will effect desired exhaust size with lower RPM engines needing smaller diameter pipe than higher RPM engines so as to maintain exhaust velocity.
A good rule of thumb is to use 2” to 2.25” dual exhaust for a 300 to 350 cubic inch engine (depending on desired RPM use) and then increase or decrees the exhaust size proportionally to the engine size. Keep in mind that exhaust pipe that has twice the diameter of any given size will flow four times the CFM. Example a 3” exhaust will flow twice the CFM as a 2” exhaust and for times the CFM as a 1.5” exhaust.
Parts I Chose
For my specific application I started with 2 headers, two collectors, one home made X pipe, two 24" glass packs and a 10' stick of 2.25" exhaust pipe. I chose all these components specifically because the engine in my Mustang has a fairly lopey cam and I wanted it to breath freely at higher RPMs.
Start at the engine and work back
Prior to redoing the exhaust on my car coming off my heads were an old rusted set of headers that had come in contact with the road enough times that the bottom tubes were at about half capacity, so when I decided to redo the exhaust I new I needed new headers. My Mustang has the first generation Uni-steer manual rack and pinion steering unit in it and one of the downfalls of this particular unit is only a few stiles of headers seams to clear the Uni-steer steering shaft. To make matters worse these headers are over $500.00 a set and I didn't want to pay that kind of money for headers.
I decided to get a quality set of headman 88300 which have ball type collectors and 1 & 5/8" tubes. They cost me about $160.00 for the set. When I installed them (with the Uni-steer steering shaft removed) the fit was fantastic they cleared the shock towers by at least 1/8" and more than that in most places. When I went to reinstall the steering shaft there was an obvious problem. The steering shaft had to pass directly through the middle of one of the header tubes. I was fairly sure I would have a problem like this when I ordered the headers so I had already decided I would cut the tube and relocate it to clear the shaft.
Header Modification
The first step in modifying the headers was to mark the tube where it needed to be cut. With the headers bolted in place I eyeballed were the shaft needed to pass, marked the tube and then remove the header from the car and cut out the section that was in the way. Let me tell you there is something kind of heart breaking about cutting in to a brand new set of headers, especially headers that seamed to be such a perfect fit. With the tube out I reinstalled the header and the rack and pinion steering linkage to make sure that I had removed enough of the tube.
The next step was to determine where to reroute the tube. On a unmodified classic Mustang the drivers side header is always going to be an extremely tight fit because there is a steering box to try and get around not to mention clutch linkage on any manual transmission car. Obviously since I had upgraded to a rack and pinion, the steering box was gone, and even though my car has a manual transmission the clutch actuation is hydraulic so I had removed both of the parts that typically cause drivers side header clearance issues. This meant that I had a huge open cavity to which I could route my pipe.
Once I new approximately where I wanted to put the pipe I began cutting up the section of tubing that I had removed from the header using the cut and rotate method and was able to adjust the direction of the tubes and tack a piece in to place. I then did a test fit of the header. It took several test fits and slight modifications, but I was able to modify the headers to flow around the shaft.
In this picture of the last test fit, You can see just how much I had to modify the tube. Like I said before the original tube location would have gone right through the middle of the steering shaft.
Once I new I had the headers the way I wanted them I welded up all the seams from the modification.
I used the same technique used on body panels of putting individual small welds about .5” apart all the way around the tube and then filling in the gaps one weld at a time. This was done to produce a clean weld that could easily be ground off and would not burn through the tube.
After getting the header tube welded up I took an angle grinder to the welds and am very pleased with the result!!!
As I was grinding I was worried about the thickness of the header tubing and did not want to weaken it so I was very Conservative with my grinding which is why it is not perfectly smooth.
Fabbing Up the Main Pipes
With the headers in place I positioned the X pipe where I wanted it, just behind the transmission and blocked it up. Keep in mind when setting up an X pipe type exhaust that at some point you may need to pull the transmission. In my case I set the exhaust up so that it could easily be removed as one whole piece should I need access to the transmission.
With the X pipe n place I bolted the collectors to the headers and then began cutting up the 10' stick of pipe using the “cut and rotate method” so that I could tack weld the pieces together to attach the collectors to the X pipe. From there connecting the X pipe to the to the mufflers was a simple straight run toward the back and side of the car so that the exhaust could exit just in front of the back tire.
Straight Through
From the driver’s side collector through the passenger’s side glass pack and the passenger’s side collector through the driver’s side glass pack I have a true straight through flow, which is why I call this an eXhaust.
After the mufflers I made two sharp 45-degree (cut and rotate) bends to achieve the correct angle for the exhaust to leave the car. I did this with one 22-degree cut rather than several lesser degree cuts because I figured I would not make that much of a difference especially considering the location so I went with what was easiest. From there I simply tacked on some stainless steel tips to the end of the pipe so that the exhaust exits in stile. With the entire system tacked together, I removed it from the car and welded it all up solid using the same one weld at a time technique that I had used on the headers.
The last step was to take the headers and the exhaust to the powder coater to get ceramic coated. This coating not only looks good, but also will protect my exhaust from rusting. The interesting thing about ceramic coat is that you can polish it by glass beading it or with steel whole. The headers had been glass beaded at the powder coater but the full exhaust had not.
I polished up the ends near the stainless tips with some steel whole, but decided it was more work than I wanted to do on a part that would rarely be seen.
The final install of the system was was easy and it went in with no issues
Sounds different
The original exhaust on my car was long tube headers going in to duel pipes with no crossover. The glass packs were at least 30 years old and so the car was very loud, had a lot of deep rumble, and a nice lopy sound at idle.
The new eXhaust I built with its straight through design, new glass packs and an "X" pipe in the middle, was, As expected quieter, has a slightly higher rumble and is not as lopy at idle. I hate to see those things go, but I new the "X" pipe and new mufflers would do that. The car should get a little louder and the rumble a little lower as I put some miles on the car which will break in the mufflers. The up side is that the car now has that circle track roar when you step on it and that along with the HP increase from balancing the exhaust banks makes the new exhaust well worth it in spite of what I lost.
.
