Brakes & Suspension Forum sponsored by The Tire Rack
|04-23-2012, 11:49 AM||#1|
Join Date: Apr 2012
Location: South Burlington, VermontVehicle:
06 WRX Wagon Ltd.
BAG RIDERS - Air Ride Technical Q&A
How Reliable is Air Ride?
To put it simply: incredibly reliable! The reliability of air suspension is highly dependent on the quality of the installation, just like any car modification. If you rush your install, or cut corners to “get the job” done this may come back to bite you. Truth be told, a carefully installed and well maintained air ride setup will last as long as any other aftermarket suspension. The bags themselves will outlive the life of the vehicle. If you won’t be installing your air suspension yourself, be sure to bring your vehicle and air ride components to a qualified and air ride experienced shop! If you aren’t sure of any qualified shops in your area, please contact us! Throughout our years in business we have established a network of qualified and experienced air ride installers whom we would be happy to refer you to.
Can Air Ride be used in the Winter?
Absolutely! Bag Riders is located in northern Vermont which tends to get very cold and snowy during the winter months. That doesn’t stop any of us from driving our air ride equipped vehicles year round, or prevent us from traveling to resorts in the area to enjoy snow sports. We do recommend a few steps of preventative maintenance during the winter months to ensure the cold doesn’t adversely affect any air ride components. First off, we always add about two caps of air brake antifreeze to our air tanks as soon as the temperature starts to drop around freezing at night. This helps prevent condensation from freezing inside air lines, valves, fittings and otherwise clogging up the system. Furthermore, we tend to empty our tanks and water traps more frequently during the colder months - typically once a month.
What kind of Maintenance is Recommended for my Air Ride System?
Air ride doesn’t call for much in regards to maintenance. We recommend emptying your air tank every couple of months, and if you have water trap(s) in your system we recommend draining those at least once a month. Both of these procedures are recommended to drain any moisture from the system, making both of these procedures less mandatory in dry climates. We find that it is convenient to drain water traps while you’re filling up your gas tank, and helps keep you in the habit.
What is the difference between B.O.C. (Bag-Over-Coil) and Threaded Air Struts?
With the recent advancements in air ride technology, we've found that the term Bag over Coil is being used a bit too loosely (read: incorrectly) nowadays. The term Bag over Coil refers to replacing the coil spring on a coil over (or OE strut/shock) with an air spring, typically the Universal Air Aero Sport bag which could be described as a "donut" bag. The Aero Sport bag slips over the pressure tube of your existing shock and is a cost efficient means of bagging a car, so long as you do your homework and measure accordingly! This process has been around for a while and has a rather wide range of potential results. The B.O.C. approach works great on certain applications, whereas other applications tend to not go low enough, have poor ride quality, or do not have a sufficient amount of lift.
A threaded air strut (for example, the new Air Lift Performance Subaru Struts) is completely different than the bag over coil approach since they do not use donut bags and are a completely engineered solution. Air Lift Performance threaded struts are re-valved using Air Lift's propriety valving which is designed to be ideal for the physics of an air spring. When using a threaded air strut, you have complete control over your ride quality since you can adjust the length of your suspension without sacrificing stroke; they are truly the best of both worlds!
How do I apply Teflon Tape?
Although a relatively simple process, it is kind of hard to explain clearly with words. That said, watch this video!
How do I drain my tank?
We recommend draining your tank every couple of months to release water and debris that may have collected inside. Draining your tank can be done in numerous ways. The first thing to remember when draining your tank is to always exhaust all the air from your system before beginning to remove any fittings! That said, the most straightforward method to drain your air tank is to remove it from your vehicle and unscrew a fitting from the tank to drain any water out that has collected inside. We’ve seen creative setups that utilize an elbow fitting on the bottom of the tank connected to an electric valve which is actuated by a push-button as a tank drain. There are plenty of possibilities, but the general idea is that water will collect at the bottom of the tank, so if you plan on draining your tank without removing it be sure that the “drain” is located on the bottom of the tank!
I think I have a leak... HELP!
Don’t worry! Leaks are very normal, especially with a new installation! That doesn’t mean that you should ignore a leak though, since they are very easy to track down. Grab any squirt bottle and fill it with a bit of soap and water, then begin spraying down any connection in your system. Even the slowest leak will cause bubbles to form. If the leak is audible and coming from a PTC fitting, be sure the air line is pressed firmly into the fitting. We have found that Alkon and SMC fittings are very reliable for PTC connections due to the inner “sleeve” that hugs the inside of the connected air line.
Management Related Questions
What is the Best Management?
This is probably the most common question we receive, and for good reason! However, there is not one answer that is suitable for everyone. Imagine if you asked every enthusiast you know what the best type of car is? You would likely receive a large range of responses. The same goes for air ride management; the best kind of management is ultimately up to the individual who will be using it. For some, manual management may be the ideal solution for a low-budget build, whereas another person may find the precision, quality and reliability of AccuAir e-Level to be the perfect companion for their daily driver or shop stopper.
We offer a selection of pre-built Bag Riders exclusive management packs which include all the management parts you need for your air ride setup, aside from the suspension components.
Does my choice of Management affect the way my vehicle will handle?
The answer to this question is a bit tricky, as the answer could be both yes and no. For starters, all (6) of the Bag Riders Management Packs will handle the exact same, so we’ve got your back there! However, it is absolutely possible to build an inferior management system that will adversely affect the way your vehicle handles. The definition provided on this page for FBSS provides a basic explanation of a system that would not handle as well as our Management Packs. All of our air ride management packs are 8-valve setups, meaning each corner of the vehicle has (2) valves: one for dump and one for fill. In the past, when air ride was merely for show and rarely if ever used on a performance application, it was very common to build a 4-valve system.
In a 4-valve system, front and rear bags are “paired” together. Although this may save a few bucks in parts, the vehicles handling will suffer severely! This is because in a 4-valve setup, since front and rear air springs are paired together, air can transfer between each pair of bags which is especially apparent when cornering. As you may have guessed, 4-valve setups suffer from severe body roll. This type of setup is largely responsible for the common misperception that air ride handles like a boat. In modern day 8-valve setups such as any of the Bag Riders Management Packs, your air springs are isolated for optimal handling characteristics.
What is the difference between Manual and Analog Management?
It is very common to confuse manual and analog setups, but the two systems are very different! The main difference is that analog management systems use electronically controlled valves, whereas manual management systems do not. The word “manual” refers to the fact that you are using your energy to manually/physically actuate valves with your fingers whereas in analog systems it is electricity that actuates the valves. The two systems could be compared to driving a car with a manual transmission vs driving a car equipped with a direct-shift gearbox. When driving a manual transmission, you are physically actuating the gear stick throughout the gears of the vehicle with your arm motions, whereas when driving a DSG equipped vehicle in tiptronic mode you are sending an electric signal that causes the vehicle to switch gears.
Technicalities aside, the two systems have slight differences in performance. First off, manual management systems are much slower to lift/drop than analog management. This is due to the size of the orifice in a manual paddle valve being very small and thus restrictive of air flow. Also, when installing manual paddle valves you need to find a place to mount them which often times involves sacrificing an interior panel or DIN slot. We have seen creative locations for paddle valves which don’t involve cutting anything, but a wire harness for an analog switch box can come out of the smallest nook in your vehicle which may save some headache.
What is the difference between Analog and Digital Management?
Digital systems have an ECU which receives a digital signal from a controller and acts upon that signal in contrast to an analog system where the buttons you press on the controller send an electric signal to a valve. The ECU or “brain” of a digital system makes advanced features such as presets, system monitoring and quick changes to tank pressure possible.
What is the difference between Height-based and Pressure-based Management?
Digital systems provide preset heights using one of two methods: bag pressure or physical height-based measurement. Neither of these methods can be labeled as “better” than the other as they differ so much in methodology. One thing that must be understood about pressure-based presets is that pressure values are in no way a perfect means of determining the actual height of the vehicle. That is to say a vehicle could be the exact same height with 50 psi in all air springs or 100 psi in all air springs; it is totally dependent on the weight of the vehicle including passengers and cargo. The presets stored in a pressure-based controller are preset pressures, not preset heights. The user should monitor the physical height of the vehicle to ensure that the desired height is reached.
This is where the advantages of height-based managements, such as the AccuAir e-Level system become apparent. No matter what the weight inside the cabin is, a height-based management will remain consistent. Height-based systems like e-Level use height position sensors to determine the height of the vehicle rendering pressure values completely irrelevant. With e-Level you no longer have to deal with the hassle of installing pressure gauges. In a vehicle equipped with e-Level, you and four friends can hop in the car and your “drive preset” will be the same height as when it is just you in the vehicle. For a daily driver or vehicle that will be used to transport passengers, a true height based digital controller is the best option.
Still not exactly sure how these two systems behave differently? Check out this short video we made demonstrating both pressure-based and height-based systems reacting to additional passengers entering the vehicle:
Specific Part Related Questions
What is the difference between Air Line Size?
Air line comes in a variety of sizes, each with a different inner diameter which affects the amount of air that can flow to/from a bag when lifting/dropping your vehicle. Simply put, ⅜” air line allows air to flow faster than ¼” air line. ¼” air line is slightly easier to route than ⅜” air line just because it is smaller in diameter and thus bends a bit easier. Keep in mind that if you have ⅜” air line and decide that is too fast you can always control the flow of air via inline flow controls and dump controls.
Do I need to buy a "Power Kit" with my air ride kit?
Maybe! A power kit serves to provide power to pump and other electronic components in your management (e.g. ECU, Manifold and other accessories). If you already have an aftermarket amplifier with a thick power wire, chances are you can use that same power wire to power your air ride components. You should have a good understanding of how electricity works before making this decision. If you aren’t sure, ask your mechanic, give us a call or shoot an e-mail to [email protected].
What is a Water Trap and should I get one?
A water trap serves two purposes: 1) to filter moisture of the air that passes through it and 2) to filter out debris from the air that passes through it. We recommend installing water traps between the compressor and air tank, one water trap per-compressor. Although we strongly recommend installing water traps, they are ultimately not required but do help protect your investment from water and debris.
What is the difference between all these compressors?
Compressors are a bit of a science. You may notice that compressors are rated by duty cycle, which means basically "how long the compressor can run at the specified PSI without stopping to cool down or otherwise rest during a certain time interval, usually 10 minutes". A 400c compressor has a 33% duty cycle at 100psi, which means while filling at or above 100psi, the 400c can run for 3 minutes and 18 seconds (33% of 10 minutes) before needing to cool down for 6 minutes and 42 seconds. To fill from 110-145 psi (the standard pressure cut off), the 400c takes roughly 48 seconds, so it is well within the duty cycle. The 400c is the fastest VIAIR compressor that we sell, outputting 2.54CFM @ 0 psi (scales down becoming slower as pressure in the tank increases), and is often compared to the 444c compressor.
The 444c compressor is slightly slower (roughly 30%) than the 400c, outputting 1.76CFM @ 0spi. It is also marginally larger than the 400c, and also quieter due to its lower CFM output. Since the 444c is larger and slower, it has a duty cycle of 100% @ 100psi and 50% @ 200psi (which should never be the case in an air ride setup). That is to say, the 444c compressor can run continuously at 100psi without having to stop and cool down.
Should I get a single compressor or dual compressors with my air ride kit?
This is truly a personal decision, however there are certainly benefits to running two or more compressors compared to a single compressor. First off, the more compressors you install the faster your tank will fill up. Another benefit of having multiple compressors is that in the very unlikely event that a compressor fails, you won’t be left with no means to fill your air tank. With every Bag Riders air ride kit or management pack, we ship out an inflation valve as part of the fitting pack so that in dire emergency you can use a normal tire fill station to fill your air tank.
Should I get an aluminum tank or steel tank?
We always recommend aluminum tanks as they are lighter, and aluminum does not rust like steel does. Since compressors produce warm air which cools down in the air tank, condensation (and thus moisture) will inevitably collect inside the air tank. If you have a steel tank, this may result in rust water or worse-- small flakes of rust that could damage your valves, air lines or bags. We offer a variety of tanks for those that require a different port orientation than the “standard” AccuAir 5 Gallon Aluminum tank that is included with our completed air ride kits.
What is the deal with Tank Pressure and Pressure Switches?
All Bag Riders complete air ride kits by default operate within the 110-145 pressure range, which is the amount of pressure inside the air tank. This means that the compressor will turn on at 110psi and turn off at 145psi. Every time you increase the air in an air spring, your tank pressure will decrease. By increasing the pressure in the air tank you are effectively increasing the amount of air you have to expense before your compressor(s) will turn on. Air in your system is measured by volume (gallons in your tank) and density (pressure inside the tank). We offer non-adjustable pressure switches in variants of 110-145, 145-175 and 175-200psi (all “compressor on” and “compressor off” values) as well as adjustable pressure switches. Systems with a digital pressure sensor for the tank allow you to adjust the on/off pressure in your system without replacing the pressure switch.
Bolt-Up Application List
Impreza Platform (includes WRX and STi)
'02-'07 (GD/GG RS/WRX)
'05-'07 (GD STi) 2004 STi uses RS/WRX Suspension
Don't see your application or aren't sure about your model? Don't hesitate to ask!
Our full FAQ can be found on our website!
For more information on who we are and what we do, check out the Bag Riders intro thread here!
Call Us! M-F 9am-5pm EST: 802.735.2574
E-Mail Me! [email protected]
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Last edited by Bag Riders Air Ride; 02-14-2013 at 10:21 AM. Reason: Added a couple new questions & answers
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