LEVELING SYSTEM FAQ
Q: Why do I want a height sensor based control system instead of pressure based?
A: Pressure based systems have proven to be very inaccurate. First, typical pressure sensors have an accuracy of +/- 5 psi, which can result in as much as 1” in ride height on lightweight vehicles. Second, pressure sensors don’t account for changes in load. As your vehicle load increases, the vehicle drops, and your air spring pressure increases. A pressure based control system will reduce the pressure in the air springs back to the target pressures, which will further lower the vehicle. The e-Level System uses TruPositionTMheight sensors and will provide adjustment accuracies of better than 1/8” at the wheels as well as compensate for changing vehicle loads by adding whatever pressure is necessary to obtain the target vehicle height.
Q: I see some other systems have ride height sensors along with per air spring pressure sensors, claiming that this method prevents crossloading of air springs. Is this true?
A: No. First, the definition of crossweight also known as “wedge”; This is the comparison of the vehicle’s per wheel weight totals at diagonally opposite corners to the car's total weight. For the average street handling application, road-course, or slalom event, the goal is zero-wedge, or 50 percent crossweight, which results in equal response for both right and left hand turns. When the wedge is positive or negative, the vehicle is considered to be crossloaded. AccuAir has conducted extensive testing on corner weight scales with the e-Level system vs. the competition, (Read “Air on Scales”). The results proved that controlling the heights as accurately as the e-Level system does yields wedge repeatability of better than 1%, whereas the competition struggled to get within 10%. Not only does the use of per air spring pressure sensors not work, but it also increases the total cost of the system and adds to the number of potential leak points and parts that could eventually fail… leaving you stranded.
Q: What is so special about your RideMonitorTM Mode? Does your competition have anything similar?
A: AccuAir’s e-LevelTM System with RideMonitorTM Mode is the result of 3 years of development and provides flawless corrections while parked and driving. Extensive strategies have been developed to avoid unnecessary corrections by detecting transient driving scenarios like stopping, turning, and accelerating. This results in a vehicle that is always within height specification yielding improved ride quality and consistent handling characteristics.
The majority of the competition’s systems level once and then go to sleep, (This is actually how the AccuAir Gen I System operated). If you change the load in the vehicle, or initially level on an off-angle driveway you would have to remember to hit the button to re-level. Only a few have attempted semi-active leveling and the results were unsatisfactory (corrections at every stop and turn with the vehicle out of height specification the majority of the time while driving). The proprietary technology that makes the RideMonitorTM Mode so effective is currently patent pending and promises to hold its superiority in the marketplace for years to come.
Q: I see some other systems use valve-pulsing to work with fast-valves, does this work?
A: Yes it does work, but not without compromise. These systems cycle each of your valves as many as 20 times per adjustment reducing the life of the valves and significantly increasing the adjustment time. The e-Level System utilizes a Straight-to-HeightTM adjustment strategy and automatically learns the characteristics of your valves to perform accurately even with fast-valves. This strategy achieves the fastest adjustment times possible and maximizes the life of your valves. Because the e-Level system does all of this automatically, the need for user tuning and “valve pulse number adjustment” is completely eliminated.
Q: Many of your competitors have interfaces that display pressures and height indication bars. Why doesn’t yours?
A: There are a number of reasons:
Air spring pressure readings are absolutely irrelevant when it comes to setting the height of a vehicle because they vary with load and temperature, (two conditions that will be constantly changing on every vehicle). Most vehicles have unequally loaded corners due to offset fuel tanks and other components which can require as much as 15 psi differential between sides to get the vehicle level. We see no need to display these variations because they are simply confusing and unnecessary.
At first, height indication bars or graphs seem like a decent idea. Yet, most companies utilizing height bar displays have broken them into only 10 divisions. The e-LevelTM System’s resolution is so high that it breaks your total suspension motion into 1,024 divisions. We feel that displaying anything less than this would be misrepresenting the system’s accuracy, so we would have to use a decimal type display like “100.0%” of vehicle height. The problem with going this route is that any height display has to be based on the measurements taken from the ride height sensors, which are spanned during calibration based on the total suspension travel (which is usually not exactly equal from side to side due to geometric variations in the suspension system). The result would be that with the fender measurements equal from side to side the height display could read 49.2% on the left side and 52.2% on the right side even though the vehicle is actually level. This again leads us to the best method for saving a height; using a tape measure at each wheel opening on flat ground to set the vehicle level from side-to-side.
The bottom line is that the average customer simply wants to know “is the vehicle at my highest saved height, my driving height, or my lowest saved height?” As the user, you will know exactly where each of these heights is saved because you will have measured the ground to fender distances while saving them. The e-Level System guarantees that the vehicle is exactly where you saved it when the given position indicator is lit. This makes for the cleanest interface and overall simplest system to operate.
Q: Will the e-Level System work with other manufacturer’s solenoid valves?
A: Yes, our system will work with any 12-volt solenoid valves on the market. The benefit to using the AccuAir VU4 Valves with the e-Level system is the ease of wiring because the harness is plug’n’play for this case. If you are using other manufacturer’s valves, you will have to make sure to connect the solenoid drive wires from the e-Level in the correct orientation to your valves. (We do offer adapter harnesses for some other manufacturer’s valves, but in all cases our harnesses are color coded for easy hookup.