Air Suspension: DIY or Off The Shelf. Let's Find Out. 

ALL HAIL GOOD ENOUGH (tm)

My goal as a Mechanical Engineer is to have Matt's humor!

No such thing as poor break over angle with enough speed

This comment is Good Enough™

@4:06 A properly designed 5-link is not over-constrained - it is ideal. Just count degrees of freedom: there are 3 translational and 3 rotational degrees of freedom, and the suspension needs to move in one degree (controlled by the spring and damper), so the remaining 5 degrees must be controlled. All of the links of a 5-link locate in only one dimension (they are under compression or tension only, not bending) except the spring link (for designs like this that mount the spring and damper to a control arm instead of directly to the hub carrier), so if ball joints are used there is no binding. The bushing deflection occurs because they are not ball joints, and not perfectly parallel to the instantaneous axis of rotation of each link end. The bending load mentioned in the construction of the adjustable link exists only because the bushings on the ends are not ball joints.

Stiffness in an air spring is not simply a function of the air pressure - it also depends on the air volume relative to the effective piston area. You can soften an air spring by plumbing it to an additional rigid chamber. That means that for the same vehicle weight, a higher ride position means *softer* springing (because there is more air volume and the same pressure); however, those convoluted style bags don't act as ideal air springs at all because the rubber resists both stretching for suspension extension and collapsing for suspension compression. This is why good air springs are of the rolling lobe (a.k.a. reversible sleeve) type. RideTech offers both the double convoluted air springs like these, plus reversible sleeve and a variation of reversible sleeve which is tapered to change the spring rate progression, in both versions that mount over dampers and versions that mount separately.

I’m currently in the middle of building a HomeKit controller for my unpowered sky light blinds. Project is about a month in now, I went from DC motor, to steppers, to now using a DIY servo motor. The code is getting insane and I haven’t even gotten to the PID parts. I should have just spent $300 on an OTS assembly but at this point I’m too far down the rabbit hole to quit and I’m learning a lot in the process.

Like my dad would say “ good enough for government work”

All my friends know the low rider The low rider is a little higher

am I the only person that wants an "All hail the Algorithm" T-shirt? (with UK shipping)

"The perfect is the enemy of the good enough." That's the essence of engineering.

All hail the algorithm! Seriously, love your show and your humor style. It makes your videos enjoyable to watch. Seriously, thank you for not starting your videos with a scream.

Matt; I would have bet money that you would have gone with the self-leveling Citroen Hydro Pneumatic suspension. But then there is Future Matt that will do that.

Ah yes, the gargaflargs. Always wondered about those.

Isn't the pressure the same regardless of ride height? You have the same mass at each corner, so the force on each airbag is the same, so the pressure is the same. Unless the airbag shape or suspension geometry changes. You just have more air in the bag at higher ride height which makes it longer. Which would also make it ride softer because you need more travel to halve the volume and double the force. Or am I missing something??

Your narration is poetry 😍

If you're welding sleeves into/onto tubing you should drill holes around the perimeter for plug welds. Or if you want to keep it in the jaguar spirit you could use rosette welds.

I would love to see a project using the junkyard pneumatic valve. Adjustable height work tables?

Thanks for always putting a smile on my face. All hail the algorithm. 😁🍻👌

Can you make a quick vid where you compare aerodynamic drag at different ride heights at highway speed to determine power consumption and affect on range? Nice system

@7:10 Thanks for the metric conversion, imperial units don't make any sense. I don't know how you can make anything functional with them. I mean what the hell is a volt? definitely can't be as sensible of a unit as a flarg.

I love this Jaaag project so much

3:14 I missed the appearance from future Matt but I guess I'll take the Good Enough™

It brings peace to my heart knowing that I'm not alone with lots of ongoing and unfinished projects... Also, good enough™ just made my day. Thank you Matt!

this channel is one of the best on youtube. . You deserve 1.68 milion subs, not 0.168

Oh shit he said "lathed down". Have to unsub now...

@SuperfastMatt, Lovely video *But* ... In the future, please refrain from giving me thoughts of using cheap automotive parts for costly non-automotive projects at the very time that other projects are running behind. Thanks!

Still reckon the aero wheels would look better. All hail the algorithm! #teamaerowheels #goodenoughisgoodenough

I believe the technical term you're looking for is "shock condom."

I was binge watching the series instead of doing my german revision, guess i have to do that now, or i could watch something else of yours, i love your content

The internal spring pressure is the same at all ride heights. Resistance, like loading the vehicle will increase the internal spring pressure. Here is a question for you. Does your Jag get heavier at the full height of a lift on a hoist? I know it does not. Adding more cubic air to an air spring will cause it to extend until it meets resistance, only then will the internal pressure start to rise to meet or exceed the resistant load.

“SuperSmartMatt” should be your channel’s name.

Yes, LSR project videos soon please? FWIW, I have hated air suspensions ever since I owned a Lincoln Mark VII... OMG you really learn to hate the entire concept.

Matt, if you make a Good Enough™ t-shirt, I will buy it from you. Just saying.

The best kind of good. Good enough.

Brilliant. I will now watch it. (Update, having just watched it, around 1m00 you show a madeupgraph(tm) that ride height is proportional to pressure. I dont think it is. In fact the pressure may be (approximately*) constant as a function of ride height .. what changes with ride height is the volume of gas in the system, not its pressure, cf orthogonally if you change the weight of the car by filling it with fat people, the pressure will need to increase to give you the same nominal ride height even though the volume is unchanged. Maybe. Its just a theory, I haven't inserted pressure sensors in the air suspension of my 21 year old lexus ls to check. You could probably insert 60 seconds of humorous explanation of the gas laws in your next if you wanted. *its affected by bag and suspension geometry etc

Top tip: for comfort use a fridge kompressor - super low noise, won't last 20 years without lubricant, but it will be fine. But perhaps leave the noisy one in for speed. 🧐🤔🤓

AHTA. That's what I love about your videos Matt, they're always Good Enough.

How about making a barrel nut for the one bolt that you have to cut off every time?

Hall hail the rubber bags of air (that's not the tires)

Your next video... future Matt's problem... probably good enough ;) I'm comment 420 lol yes

Good Enough is the best kind of good

Creating the DIY air suspenstion system was like almost every software project I've been involved with. People with way too much talent and skill excited to DIY a solution. Which is awesome if it was a stand-alone side project, but not in the middle of a big production system that noone will know how it works in 3 years.

Does manual air suspension exist? Instead of a tank and pump, could each strut just have a schrader valve?

I'm curious why you didn't use mechanical leveling valves with electric dump valves? Mechanical valves are extremely common on bigrigs

You should make a "good enough tm" t shirt

Thank you for bringing back the old outro :)

I liked this video. but didn't share since most of my friends won't understand Matt's humor. Good Enough™.

Oh the life cycle of making things. And then making way too many things, and the making cheaper ways to do those things, and then giving up because it takes forever and you just buy the thing anyways.

what is a megaflorg or gargaflarg? (I'm almost 100% sure they are fictitious, plz confirm)

The ride height sensors here kind of annoy me. A rod attached to an arm on a potentiometer, seriously? There has to be a better way.

I would "like and subscribe" but I'm using metric so the conversion is too complicated....

Let’s see your code!!! Comments would be hilarious with all the corrections/options.

Another excellent video, this channel is so underrated. Tall your friends about this fun corner of the Internet!

It often comes down to the standard formula: Money vs Time (+ skill).

Matt’s level of skill makes his good enough pretty darn good. Constantly impressed with the difficulty level of the projects he’s willing to tackle.

To future Matt, "Man you are so screwed." All hail the algorithm. :D

i designed my own airride, and i did it the right way. You dont use pressure EVER as rideheight setting. Its completely ret*rded. The reason you talked about in the video, the lower the car the lower the pressure. But then someone gets in, or you load up the back of the car with stuff and now all of a sudden the pressure rises because the bags have to carry more weight. Want to guess what the air suspension is going to do? Its going to lower the car even more in the back even tho it was allready getting lower because of the weight you added there. So instead of the car going level again when the air suspension activates it wil actually lean back even more. So the only way to go is to include height sensors. Height sensors and pressure sensors would be best if the system looks at both and trys to get the pressure left to right equal at all times. If you use that you should prettymuch have the same corner weight on each wheel.

The name Goodenough was good enough for John Goodenough, more-or-less the inventor of lithium-ion batteries. So, Good Enough is excellent in my book.

This is a dumb non engineer question but once the air bag lifts the car up 2 more inches, doesn't it take the same psi to hold it there as the lower setting?

It is amazing how sometimes the OTS is just what you needed. I have come to that conclusion when considering EFI for my MGB.

Matt, I’ve been watching you since the beginning… of the dry sump video, and I gotta say, you’re must watch RU-vid.

Hi Matt, While your example of low ride height equals soft and hi ride height equals stiff is probably somewhat true for the double bellow airbags you are using, generally in an air suspension pressure is a function of load whereas height is actually a function of volume. If the bellows volume is sufficient (or if you were to utilize sleeve airbags such as most OEMs generally use), there would be next to no stiffness change (or pressure change) at different ride heights. Have you fallen prey to the balloon analogy (bigger balloon = higher pressure)? :-p And drop the Viair compressor and pick up a used compressor out of an OEM air suspension. You won't have to redesign the mount and you will not hear any compressor noise anymore.

There is virtually no problem that can't be solved by throwing money at it.

You do realise that a kitten dies every time you say "lathing" instead of "turning", right?

Goodenough is one of the greatest engineers of the modern era :-D

Sunday morning + iced coffee + Superfastmatt new release video = wife, leave me alone for 10:59 minutes!

"Rubber over" is for... other parts

go pull some compressors from spme junk mercedes w220. they are v quiet.

Neat, thanks.

"It's not just good, it's good enough!" -Krusty the Clown

Definitely one of the best Podcast of the entire RU-vid Channels. I buy a t-shirt Good Enough... why.. Because it is ... good enough.

I made a very similar 2 wheeled skateboard!! I love it! With my steering system design I needed a steering dampener to get rid of random speed wobbles

Good enougH!

That rear multilink has very specific bushes that bind in weird ways to provide passive steering effort depending on where the wheel is throughout it's travel. I hate modifying cars with multilinks because changing things even very minorly can throw the whole thing off.

To funny ya

Here's hoping you'll come back to the Jag at some point :)

@SuperfastMatt I just discovered your channel, lots of great stuff! I believe what you said about air suspension at :55 is backwards; to raise the car you need more air volume, not pressure (the weight doesn't change). A greater volume of air has lower spring rate than a smaller volume.

There's a madness to us all. We see a problem, and from a very high altitude, it looks like we can easily put together something that is just as good as a commercial solution. We are nearly always wrong, and what we learn in the process is of dubious value unless you do a number of similar projects. Which would definitely cause concern to your loved ones.

Who's that Al Gorithm person anyway??? 🤔

Many factory air suspensions, like that on my 2001 Audi allroad, have a lower spring perch that is kind of pear shaped (as are many things on a 22 year old car), so the spring gets stiffer as the suspension gets lower. In the rear, they also have dampers that are adjusted by an air valve so the damping adjusts as the suspension adjusts.

yeaaahhhhh..... (definitely looks better lower.)

Another great video! I like the way you narrate the story and the decision making process. Much more informative and interesting than watching other "build" channels that just bolt together free parts from sponsors and never experience a setback. A project is never a linear path and it's kind of reassuring to watch someone change directions during a projects the way the rest of us do. ("All hail the algorithm!")

i’d def. toss a couple inches of polystyrene foam on the inside of the air compressor box, wild how loud those things are.

"Save some money" Muhahahahahahahaha

All hail the algorithm!

All Hail the bugs………

One of my favorite builds!!!

Good enough tm That had me laughing for 10 min.

Always a thumbs-up. Great vids

All hail the algorithm

Commenting to appease the all powerful algorithm.

all hail the algorithm

This was golden :)

There is another solution to the ride height adjustability problem, hydropneumatic suspension uses a cylinder and piston filled with hydraulic fluid at each corner to sort of act as a spring. The cylinders are attached by high pressure hoses and hardlines to a nitrogen filled sphere (which is attached to the car's chassis) which acts as a compressible springing medium. Further more, there is a hydraulic system with a pump and valves which adds or removes hydraulic fluid from each corner to change the ride height and keep the suspension level. This system, introduced by Citroen for the DS was also used by Mercedes for its hign end cars, most notably the 300SEL 6.3 and later 450SEL 6.9. It was considered miraculous at the time but the system's complexity made it something of a maintenance hog. This may not be a problem for a high end Mercedes, but was a thorn in the side of many less than wealthy Citroen owners. Over time, these systems lost favor with manufacturers. Air suspension may have its faults, but it can be good enough for most purposes. Hydropneumatic suspension is a fun system to re

Love the Jag videos. All hail the algorithm !!!

Nice work and explanation. Look up plug welds for your contrl arm tubing. Add a lot of strength

Some time ago I found a guy who used an Arduino and ride height sensors from a truck on his Audi. I thought it was cool, but probably still better to buy one that already works. lol

Just a comment

10:50 ohh... Gold...