X-PIPES VS H-PIPES
LEARN ABOUT THE DIFFERENCES IN SOUND AND PERFORMANCE
BETWEEN BOTH OPTIONS FOR YOUR CUSTOM EXHAUST SYSTEM
Ahhh, the big debate between X-Pipes, also referred to as Crossover Pipes, versus H-Pipes.
Which one is better? That’s really a personal preference, as one of them only makes a little more power in the upper RPM ranges. So let’s get down to the differences between the two.
An H-Pipe has been the number one seller for quite some time, because it’s been around the longest. Then came along the X-Pipe in the late 1970's to early 1980's. As with anything performance related, there’s always this quest to find more horsepower. This led to someone, somewhere, wanting to maximize the scavenging effects of their exhaust gases, which ultimately introduced the crossover pipe, or commonly referred to as the X-Pipe.
To put it plainly, H-Pipes do a great job of equalizing the exhaust gases from side to side, but at the expense of zero scavenging benefits. The section of pipe that is placed between the two main exhaust pipes can be looked at as a waiting area where the slower exhaust gases sit, which frees up the next wave of pulsed gases. This is what gives the H-Pipe its ability to balance an exhaust system well.
The X-Pipe on the other hand is a fast way to make both exhaust channels have to merge with one another. There’s no messing around with the X-Pipe. This forced blending of pulses actually does wonders as it increases the velocity of exhaust gases. This increase in velocity allows the motor to have room to produce even more exhaust gas from improved engine capability. It allows the slower exhaust side to pick up more speed from the exhaust bank that is pulsing at the moment. This synergy of gases helps any motor run more efficiently, which in turn makes it want to breathe more on the intake and exhaust side.
Where should someone place an H-pipe or X-pipe?
To be honest, there’s no right answer, but generally speaking the the closer to the engine the better chance it does what it's supposed to do. The reason for this is due to the fact that the H-Pipe and X-Pipe can balance the pulses sooner, allowing the engine to benefit from it right away. If you put them too far downstream, you maybe lose all of the desired effect you were after.
In some cases, it comes down to space for where you place it. You have to keep in mind the driveshaft clearances and the structure of the underside of the exhaust channel in the body of your flooring.
An X-Pipe, or otherwise called crossover pipe, will always make more horsepower than an H-Pipe will, but an H-Pipe tends to make more toruqe and horsepower in the lower rpm ranges. This is due to the cooling effect that the H section provides. This is the result of pressure equalization from side to side, which helps to cool the exhaust allowing it to expand more than an X-Pipe can. This adds a little extra backpressure, which shifts the power to the lower rpm band. H-pipes still provide an increase in the upper rpm range, but not quite as much as an X-Pipe will. Most can usually feel a better peddle response with an H-Pipe, but others say it’s not as noticeable as you’d think due to the fact that once you jump past 3,000 rpms you really aren't remembering the difference in a few less horsepower and torque down low compared to the X-Pipe. The Xpipe will make up for it much more than it sacrifices on the low end.
Consider this. If an H-Pipe gives a car an extra 4 horsepower for example over an X-pipe under 3,000 rpms, it's a safe assumption to say that the X-Pipe will give you an even bigger difference in power past 3,000 rpms. When it comes to racing, most launch above 4,000 rpms making the choice for an H-pipe not even relevant when it comes to power gains on the low end. There is one big reason though why some would still choose the H-Pipe over the X-Pipe, and that is for the the sound it makes. The H-pipe is going to give any 6 or 8 cylinder you match it with a much deeper grumble and tone. It's going to make your V8 sound more like a traditional V8. So if you can't live without that deep sound, then an H-Pipe is your route and don’t even question it. Most of the time it’s the specific sound you are after. You can always add more performance parts to make up for small power losses.
The X-Pipe on the other hand is going to change the tone and frequency of the sound of any motor. It’s enough to give your engine a totally different sound, which most would agree is a higher pitched exotic sound. Unfortunately, X-Pipes can tend to add a little more rasp to an exhaust system, depending on if you deleted the catalytic converters as well. The reason it does this is for a few different reasons. X-Pipes do a better job of forcing both exhaust pules to merge together by the way they angle together and then angle away from eachother. This forced collision of pulses creates a much higher pitched frequency as they increase the velocity by default and send off a louder sound through your exhaust tips. A good workaround to the higher pitch would be to add bigger exhaust tips. This will lead to a little deeper of a sound to reduce the high pitch to a small degree. It won’t sound like a true H-Pipe setup, but it could give you some of the deeper tone back if you are worried about losing the classic V8 sound. For the V6 guys that don't like the trumpet sound of their vehicle, an H-Pipe is the best way to give it more of the 8 cylinder characteristics.
What should you look for in an X-Pipe? Go for one that has a longer joined area or weld seam. This is going to do an even better job of scavenging, which in theory, should give you a little more power than a shorter merged X-Pipe. So if you want the most power out of one that you purchase, be sure it has at least a 7” welded section. Most of our Project Exhaust X-Pipes that you can purchase below have at least a 7.5" weld, unless you purchase our center section to build your own from scratch. Our 3” compact, universal X-Pipe features our longest merge at right around 11”. That version will give your engine the most power it could possibly make with an X-pipe. Spend a little extra on yours and you will notice it not only in sound, but definitely in power.
The best part about an X-Pipe over an H-Pipe is it’s ability to lower drone. It’s one big advantage most don’t talk about or even know about. This will come in handy for those who delete mufflers and want a louder sound that won’t kill their ears in cruising rpm ranges. Now will it kill drone completely? Probably not. But each setup is different depending on where you merged the X and what size piping you went with. The other determining drone factor is whether you put aftermarket resonators in your piping to replace the bulky stock mufflers.
All in all, the exhaust side of the performance world is never ending. There's always new sound to be found. Every minor adjustment creates a different symphony. At Project Exhaust, we are here to help you get a unique sound. We want you to love every minute of driving. Bookmark our website so you don’t miss the launch of every new product we release. We are after a different sounding exhaust and we want you to be a part of this journey.
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