Seeking to bolster our knowledge of everything air ride, we replaced the Air Zenith OB2 and Seamless Tank in Kevin@BagRiders’ BMW F30 with the new AccuAir ENDO CT Tank. The nifty thing about this new product line is that the compressor actually lives inside the tank, so you can retain more of that precious cargo space.

We won’t get into the general procedure of an air ride install, but instead we will focus on what these tanks offer and how to make them work with an Air Lift 3P, 3H or even their less expensive variant, the Air Lift 3S. One other note: it is important to understand we are using the ENDO CT Tank which is the “tank plus compressor” package.

Look out for a future post that covers the ENDO CVT, the version with integrated valves. The CVT version of the ENDO isn’t compatible with a combination manifold such as Air Lift 3P/3H, due to the fact that the 3P/3H manifold has its own set of valves.

Installation Part 1: Size Matters

Let us take a minute to appreciate the compact size of this 3 gallon setup. We were able to squeeze the entire air management system within a small OE compartment in the BMW F30 trunk. This would not have been possible with a “traditional” setup involving a standalone compressor. What you see here is the entire air management system minus the actual handheld controller: let that sink in!

With the carpet installed the trunk looks completely factory; you would never know the air management system was there.

Installation Part 2: Compressor Control

We realized that the ENDO internal control unit is in complete control over the compressor. We proceeded to disconnect the Compressor Analog Adapter Harness and simply supplied the ENDO CT an ignition signal. We set the 3H “MAX TANK PRESSURE” to 160 PSI and this setup is working perfectly. The Air Lift 3P and 3H will naturally kick the compressor on when the air supply drops to 15 PSI below the maximum. By selecting 160 PSI in the 3P settings menu, we are telling the system to request more pressure when it hits 145 PSI. Since the 3H isn’t communicating with Kevin’s ENDO, the ENDO will always operate within its pre-programed range, topping up the tank when it reaches 160 PSI and turning off at 200 PSI. Now you may be asking yourself, “why bother with adjusting the settings in the 3H control system if it doesn’t communicate with your compressor?” The reason for doing this is due to the “Compressor Freeze” detection that Air Lift Performance has built into their 3P and 3H ECUs.

If the Air Lift 3P thinks its telling the compressor to turn on, but doesn’t detect any pressure increase via it’s internal tank pressure sensor, that will cause it to signal the user with a message on the screen saying “Compressor Freeze”. The whole point of our “hack” is to keep our 3H’s pressure requirement happy, while still providing the convenient on-screen tank pressure display as seen below. Also below, see our installation guide.

Performance Review: Sound and Speed With the products installed and working as they should, it was time for the fun part: performance testing! Worth noting: both tests are performed using the same ENDO CT tank, so the internal volume remains consistent.

Ask anyone who has some experience with air compressors and you’re likely to get similar feedback, compressor noise sucks! AccuAir has implemented vibration absorption and of these solutions enclosed the compressor, keeping it’s 12v rumble completely isolated from passengers. Their patent pending technology softly suspends the compressor, reducing vibration from being transmitted into the vehicle’s body and chassis. This design is unlike anything we’ve seen before and if you ask us, it is just brilliant.

In order to make a fair comparison to the speedy WABCO brand compressor found in the AccuAir ENDO CT, we opted to use the Air Zenith OB2, the fastest stand-alone compressor Bag Riders offers. While the fill rate of the two compressors were very comparable, the noise level was not even close, with the ENDO CT being nearly silent. The following video demonstrates the difference between these two systems.

As for fill rates, the two compressors were very comparable, see the following table:

An interesting takeaway is that while the OB2 was slightly faster to fill from empty up to 200 psi, the WABCO unit in the AccuAir ENDO CT was actually faster from 160 to 200 PSI. This is important because for day to day use, the compressor will typically be operating within this range as opposed to starting from empty.

Takeaway: The best of both worlds! At the end of the day, you can have your pick between the control systems offered by both companies: you really can’t go wrong with either solution. However when it comes to compressor noise and speed, there is nothing out there that rivals AccuAir’s ENDO CT system. We applaud AccuAir for their ingenuity in delivering an awesome product to the air ride industry. As icing on the cake, the ENDO comes in a variety of sleek finishes and can provide valuable space savings as was the case in our install. This is a product we’re happy to recommend!