What Is An Underbody Air Compressor?

DTM70-RAM-Install-Render2An underbody air compressor is any air compressor that has been designed to mount under the body of a service vehicle. These air compressors are small but mighty, and are widely appreciated by upfitters and operators because they’re out of sight, save space, and reduce weight.

“Underbody air compressor” is a colloquial, less common term that isn’t widely used within the industry. Rather, these systems are more frequently called underdeck air compressors, PTO air compressors, or vehicle-mounted air compressors.

All underbody air compressors use rotary screw technology, as rotary screw air compressors are smaller and more efficient than reciprocating air compressors. Only a few manufacturers throughout the world design underbody air compressors, with VMAC serving as a leader in this innovative space.

Although technically not “under the body”, a popular alternative is the UNDERHOOD™ air compressor, which is mounted directly to a vehicle’s engine and provides similar benefits.

Types of Underbody Air Compressors

Underbody air compressors use one of two existing power sources on a vehicle:

  • PTO Port
  • Hydraulic Port

In theory, it’s relatively straight-forward to mount an air compressor to an existing PTO or hydraulic port. In practice, however, it becomes a bit more challenging. There is a very limited amount of space under a vehicle for additional components and manufacturers require ingenuity to overcome this challenge.

In addition to the two power sources, there are two common types of underbody air compressors:

  • Shaft
  • Direct-Mounted

Shaft: The most basic way to fit all the components under a vehicle is using a shaft. A shaft allows a manufacturer to place the components wherever they can easily fit and then connect it to the air compressors with a shaft. Unfortunately, shafts can cause alignment issues, are more likely to break, have unnecessary moving parts, require modifications to the truck’s transfer case, and add both parts and installation labor costs.

Direct-Mounted: The more professional type of underbody air compressor is designed to place the air compressor components directly on or beside the power source. This requires proper engineering and manufacturing capabilities, as components must be smaller and more intentionally designed, but results in systems that are compact, powerful, and durable. All of VMAC’s underbody air compressor designs utilize this style.

VMAC’s Direct-Transmission Mounted air compressor mounted to the PTO port of a RAM truck

Hydraulic Options For Underbody Air Compressors

Many underbody air compressors come with a hydraulic option, which allows operators to add hydraulic power to their vehicles. Underbody air compressors with hydraulics are popular with crane operators, as they easily allow operators to run hydraulic systems and air compressor systems simultaneously.

For example, VMAC’s DTM70-H system allows customers to operate small to medium sized air tools, as well as a hydraulic crane or other equipment simultaneously. Check out this video to see it in action:

Additional Underbody Air Compressor Resources

To learn more about underbody air compressors, explore the following resources:

Southern Tire Mart’s Quarry & Mining Manager Put VMAC’s DTM70 Air Compressor To The Test

STM logoWhen Rick Fleenor had the chance to test the first VMAC Direct-Transmission Mounted air compressor in the United States, it was an opportunity he couldn’t pass up. Two years later, Rick has no regrets.

Rick is the Quarry & Mining Manager at Southern Tire Mart, where he works alongside a fleet of over 1500 vehicles. He uses his personal work truck, a 2015 Ford F-550, to service heavy duty OTR tires.

“I do a lot of service and maintenance on construction fleets and mining fleets. I check all the tires and use an air compressor to maintain tire pressure,” said Rick.

Trying out the new DTM70 was an easy “yes” for Rick, who was already familiar with VMAC’s line of UNDERHOOD air compressors.

DTM-Air-Compressor“My career in the tire industry spans over 45 years, and I’m used to seeing VMAC compressors under the hood. When I had this new truck built, my dealer at Arrowhead called and said they had a brand new VMAC system that used the PTO drive. I said, ‘Great, sign me up!’ I couldn’t pass up the opportunity to try it.”

Arrowhead Truck Equipment is a certified VMAC Dealer located in Bixby, Oklahoma, an easy 20 minutes from Southern Tire Mart’s Tulsa headquarters.

It’s been a couple years since Arrowhead installed Rick’s DTM70 and he now knows it was the right call. The DTM70 is dependable, easy to use, and enables Rick to provide fast and efficient service to his Southern Tire Mart clientele.

“The DTM70 is convenient and reliable,” said Rick. “There’s also very little maintenance to speak of—all you have to do is check the air filter occasionally—so there’s no downtime. Just 100% uptime.”

Before using the DTM70 system, Rick had to transport a gas drive compressor on the back of his truck. This led to the same challenges many workers in the tire industry experience: reduced space and increased weight, the need to constantly transport gasoline, and quite a bit of inconvenience.

“The gas compressor was always a pain,” said Rick. “I’d have to carry fuel, tie the compressor down, and it took up too much space.”

VMAC DTM70 installed

VMAC DTM70 Installed

The DTM70 solved these problems overnight, providing 70 CFM of air in a compact system that’s completely out of sight. Anywhere the F-550 goes, the air compressor is ready to work.

Southern Tire Mart has built a reputation on high quality workmanship and strong customer relationships. It’s their ability to provide world-class service to fleet managers and business owners that has kept Southern Tire Mart in business for the past 45 years, so it only makes sense that Rick has high expectations of his equipment.

“I know there are lower priced products out there, but I wouldn’t hesitate to buy a VMAC again. You get what you pay for and it’s just the best PTO driven system available,” said Rick. “The DTM is awesome. It always works!”

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Meet The VMAC DTM70 Team: Kyle McWilliam, Mechanical Engineer

DTM70-RAM-Install-RenderAt NTEA’s The Work Truck Show 2019, VMAC released the DTM70 Direct-Transmission Mounted PTO Driven Air Compressor for RAM trucks (also available for Ford). The DTM70 earned a lot of attention due to its innovative design that sets it apart from other PTO air compressors. It only weighs 150 lb, saving up to 260 lb when compared to other underdeck PTO air compressors. Continue reading “Meet The VMAC DTM70 Team: Kyle McWilliam, Mechanical Engineer”

Introducing VMAC’s New RAM PTO Air Compressor

DTM70-RAM-Install-RenderVMAC recently released its latest PTO driven air compressor, specifically designed for RAM 3500 to 5500 chassis cab Cummins diesel trucks.

This RAM PTO air compressor, called the Direct-Transmission Mounted 70 (DTM70), was previously released for Ford F-250 to F750 Power Stroke Diesel trucks and has proven to be a powerful, compact, and effective means of providing up to 70 CFM of mobile compressed air.
Continue reading “Introducing VMAC’s New RAM PTO Air Compressor”

The 5 Best Benefits of PTO Air Compressors For Service Trucks

It’s easy to love PTO air compressors. They provide air-on-demand at 100% duty cycle and are one of the most sophisticated types of air compressors on the market today. In this article, we breakdown 5 of the best benefits of PTO air compressors.

5. Reduce Weight To Increase Your Truck’s Payload

PTO air compressors are a great way to instantly increase payload. Instead of wasting weight on an above-deck air compressors, PTO air compressors let you maximize your vehicle’s GVW. PTO’s ditch a lot of weight because they don’t require a secondary engine and typically weigh 300 to 400 pounds.

But if you choose the right PTO air compressor, you can reduce that weight even further. Some PTO air compressors are designed with as few components as possible, which can save hundreds of pounds. For example, VMAC’s direct-transmission mounted PTO air compressor—the DTM 70—weighs a mere 150 pounds.

When you choose a lightweight air compressor, you’ll have more payload for tools, equipment and other materials you need to get the job done quickly and efficiently.

4. Save Your Deck Space For Other Stuff

One of the coolest benefits of PTO air compressors is that they are completely underdeck, tucked away in the undercarriage of your truck. This style of air compressor doesn’t take up a single inch of deck space, and we don’t have to tell you how valuable that deck space is.

VMAC’s DTM70 frees up to 25 cubic feet when compared to other styles of air compressors with a similar CFM output. By choosing a PTO air compressor, you free up more of your deck space for other things. How you use that extra deck space is completely up to you!

3. Reduce Fuel Consumption To Keep Profits In Your Pocket

While not all PTO air compressors include this feature, the best PTO air compressors will automatically idle the truck up and down to match the air demand. This eliminates excessive high idling, gets jobs done faster, and ultimately reduces fuel consumption—which keeps your profits in your own pocket!

To learn more about a system that has this capability, check out the DTM 70.

2. Tie Into Your Existing Fuel & Power Sources

When it comes to a no fuss, no muss air compressor system, it’s hard to beat PTO options. They are just so convenient. PTO air compressors tie into your truck’s existing PTO port on the transmission and thus uses the same fuel as your truck, resulting in a hassle-free solution for air-on-demand.

You don’t need to maintain a separate engine or run out to get extra fuel because the air compressor integrates into the truck’s pre-existing systems. Simply maintain your truck like you always do and you’ll have air available whenever you need it.

1. Easy to Operate & Get To Work

Best of all, PTO air compressors are easy to turn on and operate. PTO air compressor systems use remote controls and can tie into the crane remote, which makes it easy for you to operate the air compressor from a distance. When you need air, just turn the system on and you can instantly get to work!

Read more about PTO air compressors with these articles:

Lodi Installs PTO Driven Air Compressor With Hydraulics

Lodi VR70 InstallLodi Truck and Equipment is a truck and equipment dealership located in West Sacramento, California. Lodi has been in business for over thirty years, earning a reputation for providing high-quality and customized mechanics trucks. Spencer Hinson is Lodi’s owner and GM, having purchased the business in 2002. Before owning Lodi, Spencer spent 15 years with PACCAR in various management roles including truck production and finance. He was on the National Truck Equipment Association (NTEA) board of trustees as Distributor Trustee, serving three years from 2006 – 2009, and from 2009-2010 served as Executive Committee Member. With this background and proven reputation, it’s clear that Spencer knows the service truck and equipment industry.
Continue reading “Lodi Installs PTO Driven Air Compressor With Hydraulics”

Underdeck PTO Drive Compressor Saves Weight On Truck

Phil Fanelli is the owner of Hilmar, CA’s Fanelli Equipment Repair, with a fleet of seven trucks. Having been in business for 12 years, owner Phil Fanelli focuses on repairing and servicing all types of CAT equipment. In the article California’s Fanelli Equipment Repair Upgrades To VMAC DTM70-H, Saves 500 lbs On Truck GVW, Phil explains how he was able to move from a Peterbilt truck with a 14-ft service body down to a smaller and more flexible Ford F-550. He was able to achieve this downsize thanks to the VMAC DTM70-H, a direct-transmission mounted PTO driven air compressor with hydraulic pump. Weighing just 180 lbs, this multi-power system saved Phil 500 lbs of weight on his Ford truck.
Continue reading “Underdeck PTO Drive Compressor Saves Weight On Truck”

Fanelli Equipment Repair Upgrades to VMAC DTM70-H

Located in Hilmar, CA is Fanelli Equipment Repair. Owned by Phil Fanelli, this company has been operating in the Central Valley area for over 12 years, repairing and servicing all types of Caterpillar equipment, including landfill, recycling, and compost equipment for waste management companies, as well as servicing equipment used in the dairy industry.

Phil Fanelli has successfully grown his equipment repair business to include seven service trucks, each which puts on thousands of operating hours and up to 50,000 miles every year. “I work my trucks hard, and so I rotate through them every five years, to ensure there’s no downtime,” says Fanelli. “Because of this, I expect any piece of equipment to last me five years as well.”

Up until recently, Phil’s service truck was equipped with a reciprocating air compressor. This reciprocating air compressor resulted in a lot of challenges, the first and foremost being weight. The compressor was terribly heavy on his truck, which at the time was a Peterbilt with a 14-foot service body. Phil also found himself waiting for compressed air to be produced, resulting in downtime as his compressor tried to catch up to him. This slowed down his work.

When it was time to bring in a new service truck to the fleet, Phil seized the opportunity to “right-size” his truck. Because he’s often travelling to visit his technicians on different job sites, he chose to downsize to a Ford F550 truck. He also needed to address the weight and air supply concerns associated with reciprocating compressors. For this truck build and upfit, he went straight to Spencer Hinson, owner and GM of Lodi Truck and Equipment, located in West Sacramento.

“I’ve been getting Spencer at Lodi to build my trucks for over 10 years now, and I wouldn’t go anywhere else,” says Phil. “I go in, tell him what I want, and he keeps me involved in every step of the build.”

At first, Phil was interested in an UNDERHOOD™ 70 air compressor, which fits neatly in the engine compartment of the truck, supplies up to 70 CFM of air continuously, and weighs just 150 lbs, saving up to 260 lbs. But when it was time to start the truck build, Spencer recommended a different product: the newly released VMAC DTM70-H, a direct-transmission mounted PTO driven air compressor with hydraulic pump. The DTM70-H is the best choice for customers like Phil who are concerned with saving weight on their service truck, and who also need compressed air and hydraulic power at the same time.

“Spencer knows I’m really concerned about weight. It seems like I’m always overloaded, and he thought this set up would be the best fit,” explains Fanelli. And the weight savings were significant: “The VMAC DTM70-H saved 500 lbs, which is a big deal when you’re trying to set up an F550. With these weight savings, it was the only way to go. We were looking at aluminum doors and aluminum fuel tanks, but to save 500 lbs with one change tFinelli-VMACo the DTM70-H was a no-brainer.”

The VMAC DTM70-H weighs only 180 lbs, which frees up hundreds of pounds of weight, and allows customers like Phil to downsize their trucks, and at the same time load the truck up with more supplies. “I added more tools, a drawer set, tool boxes, and an oil tank, thanks to the weight savings,” says Fanelli.

It’s been several months since Phil picked up his new F550 truck from Lodi, and he’s been using the DTM70-H to power his air tools and crane simultaneously. Spencer’s expertise and recommendation was key in this new truck build and was exactly what Phil needed. “When I got the truck, it was show room quality, detailed, everything worked. It was exactly the way I wanted it.” And as for the DTM70-H? “It’s lightweight, which is what I needed, but it also produces the air I need, when I need it. It’s bulletproof.”

Subscribe to the VMAC blog to continue reading about Fanelli Equipment Repair’s experience with the VMAC DTM70-H, and to learn more about Lodi Truck & Equipment, located in West Sacramento, CA.

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Reduce Truck GVW By Up To 600 lbs With VMAC’s PTO Driven Air Compressor & Hydraulic Pump

When spec’ing out equipment for a medium duty Class 5 truck with a max GVWR of 19,500 lbs, like a Ford F550, every pound counts. Truck upfitters are supplied with a list of required equipment from a customer, and it can be tough to accommodate everything when under tight weight restrictions. Preferring not to upsize to the next weight class, upfitters and customers are always looking to get creative with Lightweighting and save as much weight as possible, while retaining functionality on their service trucks.

VMAC DTM70-H PTO Driven Air Compressor & Hydraulics Saves Weight

VMAC’s Direct-Transmission Mounted PTO Driven Air Compressor & Hydraulics (DTM70-H) weighs only 180 lbs and combines two systems, allowing customers to run both the air compressor and the hydraulic pump at the same time. Combining these two types of power into one innovative multi-power system not only saves space, but also reduces weight on service trucks to save up to 600 lbs. This PTO driven system saves hundreds of pounds of weight as it requires no air storage tank to mount on the truck deck and requires a 50% smaller hydraulic tank size compared to other hydraulic systems.

What would you do with up to 600 lbs of weight reduction on your service truck? Some ideas include:

  • Carry more materials or equipment
  • Take advantage of better fuel economy
  • Install taller tool cabinets
  • Downsize your service truck classification

More on the DTM70-H PTO Driven Multi-Power System

The DTM70-H is a direct-transmission mounted multi-power system that is designed for the F250-550 Super Duty 6.7L Power Stroke Diesel. As described above, these light and medium duty trucks benefit from lightweighting initiatives, which can help provide more options for customers.

While lightweighting is becoming an increasingly important consideration, the performance of the equipment used cannot be compromised. Here are some fast stats on the DTM70-H:

  • Up to 70 CFM @ 175 psi*
    • A VMAC North-American made rotary screw air compressor produces up to 70 CFM at 100% duty cycle. This provides enough CFM for air tools such as 1” impact wrenches, 60 lb jackhammers/pavement breakers, backfill tampers, OTR tire inflation, and more.
  • Up to 14.9 GPM @ 3,265 psi*
    • The DTM70-H control system integrates with standard crane controls for easy and simultaneous operations with the air compressor.

*Dependent on pump size and engine RPM.

Visit the DTM70-H product page for more information, and to request a quote.

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