H-Pipe Install
Why an H-Pipe?
If you have headers, with a true dual set up (two pipes straight back) you need to install an H-Pipe. An H-Pipe is also known as an exhaust crossover. An exhaust crossover is a pipe that connects the two separate exhaust pipes and allows the pulses to even out. Without the crossover, from an exhaust standpoint, your engine acts as two separate halves. That's not to say it's a requirement. No engine damage will occur without an H-Pipe, but your car will sound better, the interior will have a better quality sound, and you may gain power.
Follow the pictures below, along with the comments, and you'll see how we added an exhaust crossover to my car.
Before I had the crossover, my head ached after every drive. Now that I have the H-Pipe, the sound quality of my exhaust is greatly improved. The resonance that made the car sound like a tin can on the freeway, is gone. Now it just sings, and yet the tone is as aggressive as ever.
If you have headers, with a true dual set up (two pipes straight back) you need to install an H-Pipe. An H-Pipe is also known as an exhaust crossover. An exhaust crossover is a pipe that connects the two separate exhaust pipes and allows the pulses to even out. Without the crossover, from an exhaust standpoint, your engine acts as two separate halves. That's not to say it's a requirement. No engine damage will occur without an H-Pipe, but your car will sound better, the interior will have a better quality sound, and you may gain power.
Follow the pictures below, along with the comments, and you'll see how we added an exhaust crossover to my car.
Before I had the crossover, my head ached after every drive. Now that I have the H-Pipe, the sound quality of my exhaust is greatly improved. The resonance that made the car sound like a tin can on the freeway, is gone. Now it just sings, and yet the tone is as aggressive as ever.
Depending on where you live, you may have difficulty finding a shop that will install an H-Pipe for you. I've heard some say it cost them $20 at a local shop.
My experience, being that my community is subjected to E-checks, was different. No shop would touch my car. Not only that, but no shop would even discuss it with me. Ironically, as one muffler shop manager read me the riot act, stating I had broken the law by tampering with my exhaust system, a shop rag was burning, out of control, on his shop floor. I am not lying about this. Oh well.
Luckily, because the state considers my car a classic, it's not subjected to emissions tests. But the environmentalist with the open fire in his shop, would not listen. So I had to resort to other means.
I called my friend, Jim. Jim is a master welder, and he's no stranger to cars. We got together one evening, and a few hours later, the car was done. I documented everything. My hope is that you can learn from our experience. There is no reason this job should take you more than two hours. And it can be done with a shop welder and normal tools.
My experience, being that my community is subjected to E-checks, was different. No shop would touch my car. Not only that, but no shop would even discuss it with me. Ironically, as one muffler shop manager read me the riot act, stating I had broken the law by tampering with my exhaust system, a shop rag was burning, out of control, on his shop floor. I am not lying about this. Oh well.
Luckily, because the state considers my car a classic, it's not subjected to emissions tests. But the environmentalist with the open fire in his shop, would not listen. So I had to resort to other means.
I called my friend, Jim. Jim is a master welder, and he's no stranger to cars. We got together one evening, and a few hours later, the car was done. I documented everything. My hope is that you can learn from our experience. There is no reason this job should take you more than two hours. And it can be done with a shop welder and normal tools.
Here is the stock we used to create the H-Pipe. What you see here are two 1 7/8" tail pipes. These pipes are available at any auto parts store for very little. I think I spent $6.00 for the two.
It's important to choose pipe stock that is smaller than the pipe currently on the car. You need smaller stock for two reasons:
1. The pipe welded should be smaller than the pipe it's being welded into. Right? Smaller into larger.
2. You want a smaller H-Pipe for reasons beyond the scope of my understanding and the scope of any website I'll ever create. But the explanation lies within fluid dynamics. Just remember this much: smaller H-Pipe=better
It's important to choose pipe stock that is smaller than the pipe currently on the car. You need smaller stock for two reasons:
1. The pipe welded should be smaller than the pipe it's being welded into. Right? Smaller into larger.
2. You want a smaller H-Pipe for reasons beyond the scope of my understanding and the scope of any website I'll ever create. But the explanation lies within fluid dynamics. Just remember this much: smaller H-Pipe=better
Here's Jim measuring the exhaust system. A lengthy discussion followed, as we tried to locate the best spot for the H-Pipe as well as a way to ensure the pipe was perpendicular to the exhaust system, and not on an angle.
We decided the best location for the pipe is 8" back from the crossmember, at this point, the distance between the pipes is roughly 10". But my exhaust system was created by Bubba himself, with a lot of generic stock and a truckload of clamps. So to pin down where exactly we should weld, with the exhaust still on the car, is impossible.
I feel it would be impossible regardless of your configuration, to pin down exact measurements while the system is on the car. So I suggest removing the system and finalizing the measurements on the bench. But you still need to get a feel for where the H-Pipe is going to be placed while the system is on the car. Measure carefully and make bright, visible marks while the system is on the car. These marks will serve as your guide.
We decided the best location for the pipe is 8" back from the crossmember, at this point, the distance between the pipes is roughly 10". But my exhaust system was created by Bubba himself, with a lot of generic stock and a truckload of clamps. So to pin down where exactly we should weld, with the exhaust still on the car, is impossible.
I feel it would be impossible regardless of your configuration, to pin down exact measurements while the system is on the car. So I suggest removing the system and finalizing the measurements on the bench. But you still need to get a feel for where the H-Pipe is going to be placed while the system is on the car. Measure carefully and make bright, visible marks while the system is on the car. These marks will serve as your guide.
Here the system is off the car. Jim is hammering off the pieces we don't need. At this point, I would suggest removing all but the pieces that will be welded, as the mufflers are heavy and make the system awkward to handle.
Some pieces might need heat and a little gentle coercion to separate them. If that doesn't work, just beat the hell out of them until they give in.
After all the extraneous pieces are removed, Jim and I mocked up the exhaust system as it would sit on the car, and marked where we felt the holes should be made.
Some pieces might need heat and a little gentle coercion to separate them. If that doesn't work, just beat the hell out of them until they give in.
After all the extraneous pieces are removed, Jim and I mocked up the exhaust system as it would sit on the car, and marked where we felt the holes should be made.
Here, Jim and I are cutting the first hole in the exhaust system. Jim used a normal hole saw with a 1 7/8" diameter blade. The cut may be a little rough, but that's okay. When the pipe is welded in, any irregularity will be filled.
The key when cutting the hole, is to make sure the angle of the cut within the pipe is correct. If it's not, your crossover will be crooked. Nothing shouts amateur night more than a crooked crossover. I guess.
Here, we are heating the exhaust pipe to remove the muffler assemblies, which are heavy an awkward.
After making our measurements, we cut the crossover to fit. To be safe, leave some length. An inch or two should be enough. You'll need to trim some excess anyway.
Here, you can see a shot inside the end of the exhaust pipe, with the crossover installed. While it's okay to have a small amount of pipe entering the main exhaust, this is too much. So Jim and I took our marking pen and made an outline around the hole in the exhaust pipe, on the crossover. Then we went back to the saw and cut around this newly marked line.
Here we are cutting around the newly scribed lines to compensate for the roundness of the exhaust pipe. The closer you cut along the lines, the easier welding the piece will be.
For the sake of taste, I left out the picture, taken shortly after this, where Jim removed 1 7/8" of his hand. Thankfully, he finished the job before leaving for the emergency room.
After test fitting the piece, Jim tack welded the system together. Then, we test fitted the system on the car.
It's important to test fit the system on the car before making final welds, because if you made an error measuring, the tack welds are easily broken. Your final welds are not easily reversed. Or at least they shouldn't be.
After test fitting, we made the final welds and then bolted it all back together.
The results were fantastic. I noticed a difference, even at idle. But on the freeway, the system really shined. What used to be a mind numbing droan became a sweet howl. I wish I would have tackled this job sooner.
It's important to test fit the system on the car before making final welds, because if you made an error measuring, the tack welds are easily broken. Your final welds are not easily reversed. Or at least they shouldn't be.
After test fitting, we made the final welds and then bolted it all back together.
The results were fantastic. I noticed a difference, even at idle. But on the freeway, the system really shined. What used to be a mind numbing droan became a sweet howl. I wish I would have tackled this job sooner.