HornBlasters Outlaw 127 Review

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Highest Rated Train Horn Kits

1HornBlasters Conductor's Special 540
2Viking Horns 101C3
3HornBlasters Outlaw 127
Overall Rating
HornBlasters Outlaw 127 has an average rating of 4.67 out of 5 based on 3 user reviews.

Every day people get in car accidents because they are not paying attention to the road. Not long ago, the biggest concern you had to worry about was someone driving while intoxicated or simply not being careful. However, with the near ubiquity of smartphones and other smart devices, people drive distracted now more than ever. In order to help protect yourself and potentially prevent an accident on the road, you may want to consider getting a train horn. These horns are made to be especially loud and mimic the sound of a train to get people’s attention. HornBlasters accomplishes this goal arguably better than most and has even entered the budget-friendly, consumer-grade market with their Outlaw 127 train horn kit.

HornBlasters Outlaw 127

The HornBlasters Outlaw 127 is HornBlasters’ lowest priced complete train horn kit. Though it may be budget-friendly, you should not underestimate the quality of this train horn kit. HornBlasters is arguably the most respected manufacturer of train horn kits on the market and with good reason. That said, this train horn kit does come with a few caveats.
The biggest issue with the Outlaw 127 is that neither the air compressor nor the air tank are sealed. This means your best bet is to provide the Outlaw 127 a metal toolbox or some other such form of protection to prevent dirt and debris from potentially clogging or damaging those components. Still, if you are looking for a fairly true sounding train horn at a lower cost, there are few kits that can compete at this price.


The Outlaw 127 comes with 3 metal trumpets that are them powder coated black to help protect them from any rust or corrosion. Ideally, you would want a train horn kit that came with 4 or 5 trumpets to produce the best quality and most realistic train sound. That said, the Outlaw 127 does manage to provide one of the better 3 trumpet train horn imitations that we heard.
The installation of the trumpets should not pose any real trouble as this train horn is a bit more compact than many others in this price range. This is especially true in the width and height of the trumpets which both clock in under 1’. The length of the trumpets is 15”, but this is a fairly standard measurement. Ultimately, this means that you will be able to comfortably fit the Outlaw 127 on smaller vehicles than most other budget-minded train horn kits.

Air Compressor

There are some mixed considerations when it comes to examining the Outlaw 127’s air compressor. The HornBlasters’ website states that they use a Viair 275C air compressor. If this is true, then you are in luck as Viair is easily one of the most dependable and reputable manufacturers of air compressors on the market. That said, there is a bit of debate about whether this claim is true or not.
This is because most of the people who have actually purchased the Outlaw 127 report that the air compressor is a HornBlasters OEM model made in China. While this may not necessarily be bad, it is certainly unlikely to perform as well as a legitimate Viair air compressor. Thankfully, none of the customers who have received a HornBlasters’ OEM air compressor have noted it working poorly or failing within any short time frame.
Regardless of whether the air compressor is a genuine Viair or not, it does still leave a bit to be desired. For instance, the air compressor only provides a maximum psi of 120. While this is not terrible, it is generally preferred that train horns use a psi in the 150 or better range. Another potential issue is that the air compressor runs at only a 25 percent duty cycle at 100 psi. This means it will take longer for the air compressor to fill the air tank back up once the air reserves are exhausted.

Air Tank

The HornBlasters air tank is nothing to write home about, but neither is it anything to take off marks for either. It holds 1.5 ga, or 6.6 liters, which is about average for a budget-friendly train horn. Actually, this air tank holds about half a liter more air than some of its comparably priced competitors, but that will likely only provide 1 second additional blowing time–which is negligible at best.


Unfortunately, HornBlasters does not provide a nifty decibel rating like some of their competitors. In fairness, this is likely a bit more honest as whatever decibel level a manufacturer can achieve in a controlled environment while testing is almost certainly not going to be the actual decibel level the product produces when out in the real world due to differing air pressure and humidity or moisture levels.
That said, HornBlasters does provide one bit of information that can help us get an idea of the decibel level. They suggest that you do not blow the horn when people are closer than 100’ away. Without getting too deep into the math, you can estimate that for the final volume of 100’ to be 100 decibels–which is equivalent to a subway train horn–then the starting decibels would be around 140.
While this is definitely not quite as loud as some of the other budget-friendly train horns on the market, it should still be plenty loud to get people’s attention. Moreover, this is just an estimation based on the mathematical equations for sound volume over distance. Though, if the Outlaw 127 was around 150 decibels–like some of their competitors–the final volume at 100’ would be 110 decibels.


Thanks to the combo system that HornBlasters provides with their air compressor already mounted directly on top of the air tank, the installation itself is a little bit easier than some of the other comparably priced train horns on the market. Aside from the fact that installing the Outlaw 127 is a bit easier, it will certainly take less time and you will not have to worry so much about finding an appropriate place for the various components.
That said, this is definitely not HornBlasters’ high-end model, so you will have to take note of a few quirks during the installation process. For instance, as has already been noticed, neither the air tank nor the air compressor are sealed. As such, HornBlasters recommends that you install this train horn kit upright to prevent any air pressure issues.
However, not being sealed carries with it some other concerns as well. Specifically, HornBlasters acknowledges that dirt and other bits of debris may be able to get inside of the air compressor or the air tank. This means that not only does the Outlaw 127 kit have to be mounted upright, but you must also provide some degree of protection from the environment or risk various opening allowing in dirt and debris which could clog or damage the air compressor, air valves, or air lines.


If ever you are in doubt about how the Outlaw 127 sounds, you can simply go to HornBlasters’ page for the Outlaw 127 and take a listen for yourself. That said, it is important to remember that this is intended to be HornBlasters’ budget option, so a certain degree of reasonable expectation should be practiced. Basically, the Outlaw 127 will not sound exactly like a train horn.
Still, it is a bit surprising how similar the Outlaw 127 does sound to an actual train horn. In terms of tonal quality, the resemblance is more than slight. However, there is definitely a trilling reediness that stands out as not being altogether genuine. Though, it is nice that the trumpets manage to replicate the hollow resonance that gives train horns their distinctive sound. Essentially, at a consumer grade level of train horn, the Outlaw 127 performs admirably if imperfectly.
The two factors that likely play most against the Outlaw 127 in this respect is the air compressor which only uses 120 psi–as the most realistic sounding train horns employ air compressors pushing 150 psi–and the fact that this kit only comes with 3 trumpets. Still, this is a difficult value to beat for an air horn that can easily be mounted onto your consumer vehicle.


The HornBlasters Outlaw 127 is not a perfect consumer grade train horn by any measure. To be honest, it is not even the best consumer grade train horn that we reviewed (which, for the moment, continues to be the Viking Horns 101C-3). Though, the reasons for such have more to do with the air compressor and air tank combo than the actual trumpet or sound.
That said, if you are more of a purist who is looking for a train horn that provides a far more realistic mimicry of a train horn at a budget-friendly price, you will be hard-pressed to find one better than the Outlaw 127. Though it may not truly replicate the sound of an industrial train horn with perfect accuracy, the Outlaw 127 gets about as close as you can at this price point.

User Reviews

Posted by Mitch

  • 5/5

These horns are amazing – and way louder than you’d think. The instructions could be better, though. Instead of going step-by-step they only have pictures. Not helpful when doing a lot of installs, things can get confusing. It’s like trying to assemble IKEA furniture. I couldn’t figure out how to get the toggle switch to work no matter what so I just went with a separate horn button.

Posted by robzr

  • 5/5

Amazing horns. I wanted to do a clean install and that took a lot of work. The only thing I had to do was to add a bit of wire and an in-line fuse from the switch to the battery as well as a cut-off to the tank. This may just be for my setup and truck, though. I mounted all the hardware except the horns inside the toolbox and the horns fit perfectly under the toolbox. A great surprise for traffic.

Posted by CraftyK

  • 4/5

This kit is not quite what it looks like on this web page inside the box. It can be overwhelming – I thought it was too much but I’ve installed fog lights and stuff before so I wanted to give it a try. I thought my 2011 GMC 2500HD would have plenty of room anywhere I wanted to go but the parts are a little bigger than you might think so it was hard trying to get it all to fit. I’d say it took me about 10 hours of actual work and much of that was just trying to get everything put someplace safe. I ended up putting most of it in the toolbox in the bed (so a big problem if you don’t have a toolbox or half-cab to hide this in) with the horns under the frame on the passenger side. Do yourself a favor and get some real heat shrink and all-weather connectors from the hardware store, the provided ones don’t seem very robust. Still, the only thing I really wish about this kit is that it could be louder.

Posted by Backatcha


Got 127 in march, love it ! put tank in truck bed, horns behind grill. got tri- fold bed cover to protect it, hide it. SUPER LOUD ! 90% am trak sound. recommend it !

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