UPDATED: AirCups on F80

[x.shell]

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ORIGINAL POST:

I promised some people I would make a thread about air cups on the F80, so here goes. But due to the highly customizable nature of these add-ons, forgive me if I'm kinda vague. Basically, it's not a one-size-fit-all situation and this is not a install diy nor a comprehensive review.

I bought this system because I wanted to run a GT4 splitter but didn't want to raise the static height of the car. However, I still wanted to get over bumps and driveways without scraping. This Air Cup kit allows me to have my cake and eat it too. It lifts to about stock height with a push of a button. The lift itself only takes approximately 1 second to lift the piston up to full height, but there is a pressure adjustment knob that adjust the speed of raising the car and another knob for lowering the car.

These are not to be confused with air-ride systems like Accuair or AirLift. My air cups are just air pistons that put downward pressure on the springs to temporarily lift the car -- you still drive static with your normal coilovers.

With that out of the way... onward to the many hurdles!

First off, you need to have a set of coilovers that uses 2.5" or 60mm or 2.25" Inner Diameter linear springs. The cup fits over the main shaft of the shock piston (normally 22mm), but you need to measure your own to be sure (see pic). I installed these on my JRZ RS Pro 3-Way coilovers.

Secondly, you may need a spacer to add in between the cup and the top mount. Some coilovers will already have this in place, and for others you have to source something. This is what I mean by the "one-size-fit-all" thing not being the case here.

Follow the schematics in the instructions provided and you should be good to go. The biggest pain in the ass was running the cables and air tubes. You can find your own way, but I ran them along the inside of the rocker panels on the passenger side.

Thirdly, you may have to find a way to tether the cup from "spinning" too much when you turn lock to lock. The air tube should act as a tether but it's possible that the air tube could "pop out" of the air cup fitting if the air cup decides to turn too much. If it does happen you will lose pressure and the air piston won't lift. It's a simple fix though -- all you have to do is plug the tube back into the fitting. I haven't had this problem, but I plan to tether it some how in the near future. UPDATE: I added a tether to the air cup using some DIY Home Depot McGuyver techniques. See pic below.

Lastly, you need to make sure the cup clears the wheel/tire. The air cups are outer shell is designed to be modular and work with 2.5" ID, 60mm ID, and 2.25" ID springs. The inner piston is what changes to the correct spring seat. I understand why these companies did this (to keep costs down), but I wish there were smaller diameter pistons just for 2.25" ID spring set ups. I was running a very aggressive wheel/tire set up -- 20x10 et14 with 265/30/20 PS4S (see pic). So I had to get a 20x9.5 et8 wheel with the same tire to let the cup clear. You can probably make it work with a 20x9.5 et10 wheel (still pretty aggressive for most people). OEM wheels will clear just fine with a spacer. Use an online offset calculator to make sure your set up works.

As you can see, there are quite a few hurdles to make this all work. Most people aren't up for it. But I wanted to provide this info to you because I couldn't find any information on this prior to me purchasing this kit. So once again I signed up to be F80post's guinea pig.

I purchased the Complete Front Kit from Stanceparts. It basically provides everything you need to get this done. I did buy a 1/4" NPT male/female fitting to angle the tank hose. This modification allows the entire assembly to fit in the trunk space cubby very nicely (see pic).

Here's the sort of review:
It works! It does exactly what I need it to do without changing the behavior of the suspension... I think. So about that... Technically it's not supposed to alter any feeling to the suspension when it's disengaged. It's basically a solid aluminum top spring perch and spacer when it's disengaged. But I'm super OCD about how my suspension feels -- so I keep looking for slight discrepancies or deflections within the air piston seals... If I feel a slight discrepancy in the road, I tend to think it may be some suspension anomaly due to the air cups. But if I'm honest with myself, I can't say I "feel" anything different in my JRZs before/after installing the air cups with absolute certainty. Almost everyone that installs these say they don't feel any change in how the suspension behaved before/after installation. So I'm gonna go with that for now. Hope this helped.

The only universal air lifts I know of are Stanceparts and HybridAir. Stanceparts uses an air piston and HybridAir uses an air bag system -- both are the same concept.

Special thanks to:
@Frode_M3 (instagram) for helping me with the installation. His F80 is legendary.
Signature Wheel BMW for getting me new wheels delivered in record time.

Pics below:



Fitment in trunk and fuse:


My shock shaft piston:


My wheel/tire clearance fail:


How I tethered the air cup to prevent spinning:


Air cups engaged with GT4 splitter!


Air cups disengaged with GT4 splitter!

[SYT_Shadow]

Super cool, thank you for the writeup

I wish two things:
That the cups had a smaller diameter to not affect wheel clearance
That the air system did not require a big tank in the trunk

[x.shell]

Originally Posted by SYT_Shadow

Super cool, thank you for the writeup

I wish two things:
That the cups had a smaller diameter to not affect wheel clearance
That the air system did not require a big tank in the trunk

The tank is actually on the smaller side. If you don't like their tank, you can certainly source your own. You don't have to buy their kit, you can pick and choose individual components.

I wouldn't really want a smaller tank though. You still need to put it somewhere. And if it's going in the trunk anyways, why not this one?— it fits perfectly.

It can lift the car about 3 times before the pressure valve kicks on the compressor. A smaller tank will have the compressor turn on every time you push the button.

[D_SheerDrivingPleasure]

Very cool.

Can you program your cups to activate as you approach geolocated steep inclines?

[x.shell]

Originally Posted by D_SheerDrivingPleasure

Very cool.

Can you program your cups to activate as you approach geolocated steep inclines?

I'm sure you can rig something up if you've got that kind of tinkering mind.

Me personally, I wouldn't want a feature like that.

[D_SheerDrivingPleasure]

Originally Posted by x.shell

I'm sure you can rig something up if you've got that kind of tinkering mind.

Me personally, I wouldn't want a feature like that.

Stuttgart would probably send you a nasty letter that you ripped off their PFAL patent.

[Frode D]

Great write up! Happy I could help.

[Jr0587]

How/where did you run the lines?

[x.shell]

Originally Posted by Jr0587

How/where did you run the lines?

I ran the air hose along the aluminum strut brace side to side. Then ran the line to the back by going down and behind the fender liner to the rocker panel. Then ran down the length of the rocker panel. Then under the rear fender liner and poked through one of the grommets into the trunk. But my way isn't the only way to do it. You can get the hose into the interior of the car and run it behind the panels if you want. That's how I ran the wires.

[mikeyymonster]

Did you consider the KW HLC while you were researching? The driveway to my home is ridiculous and scrapes even at max angle on OEM ride height, so I've been trying to find a solution and am thinking about going the KW route so I can lower my car again.

[x.shell]

Originally Posted by mikeyymonster

Did you consider the KW HLC while you were researching? The driveway to my home is ridiculous and scrapes even at max angle on OEM ride height, so I've been trying to find a solution and am thinking about going the KW route so I can lower my car again.

There are two reasons why I wouldn't consider the KW HLS. First, the system takes way too long to lift the car when it's engaged — I want the lift to happen immediately. And secondly, the HLS system itself prevents the coilover from lowering the car enough.

And I hate KW products.

[SM2]

Reason for install of the tank vs tankless system.

[x.shell]

Originally Posted by SM2

Reason for install of the tank vs tankless system.

There are no benefits to running tankless — only penalties.

[SM2]

Originally Posted by x.shell

There are no benefits to running tankless — only penalties.

What takes about 15-20 seconds longer? Tank will give you instant? Only reason I ask I don't think the M2 has enough space underneath the storage area.

[Jr0587]

Did you go for the optional 110mm cup or the standard 120mm?

[x.shell]

Originally Posted by Jr0587

Did you go for the optional 110mm cup or the standard 120mm?

There is a 110mm cup?

[x.shell]

UPDATE: I added a tether to the air cup using some DIY Home Depot McGuyver techniques. See pic below.

How I tethered the air cup to prevent spinning:

[Jr0587]

Originally Posted by x.shell

There is a 110mm cup?

Yea its listed in small letters on their site. I also spoke with them directly and they have them in stock. Look here on the clearance section https://www.stanceparts.com/fitment/

[x.shell]

Originally Posted by Jr0587

Yea its listed in small letters on their site. I also spoke with them directly and they have them in stock. Look here on the clearance section https://www.stanceparts.com/fitment/

Well f*ck me. A 110mm cup would have saved me so much drama. I don't know why they wouldn't have suggested that from the get-go. I may have to just buy a pair.

[Jr0587]

Originally Posted by x.shell

Well f*ck me. A 110mm cup would have saved me so much drama. I don't know why they wouldn't have suggested that from the get-go. I may have to just buy a pair.

Yea I started looking around since your post. My adv1s are 20x9.5+20 in the front on 265/30

[x.shell]

Originally Posted by Jr0587

Yea I started looking around since your post. My adv1s are 20x9.5+20 in the front on 265/30

Yeah, the 20x9.5 et20 is gonna rub. With the 120mm cups, you will need a 12mm spacer. With the 110mm cups, you will need to add a 7mm spacer -- which is not really a big deal given that you will have camber plates.

If you do get the kit, go for the 110mm. I just emailed Maarten about a pair. Thanks for that info.

[x.shell]

Update: I just ordered the 110mm cups. Those extra 5mm of wheel offset will help me out a lot.