sneaky7980

iTrader: (15)

That's kind of what i had in mind but with the "swingarm" designed a little different. I know it's just a rough pic to get the basic concept across, but the whole upper mounting surface would have to be as flat/thin as structurally possible to keep unwanted lift while in normal mode. I'll draw a pic real quick, stand by.....

sneaky7980

iTrader: (15)

The actuator end of the swingarm could be moved a outboard to keep fender intrusion to a minimum.
We would have to make sure the attachment point for the strut wasn't to close to the fulcrum, or it will pushed down a little then pulled inbd.
I was thinking about the top of where the strut, (yeah i know it's not a strut but im trying to abbrev a little), attaches to the swingarm. You could even notch out the top of the fender well also for more clearance. I personally would like to keep cutting to a minimum.

thoughts?

topdownTA

No no no...I'm talking about having the air spring sit on an adjustable height lower spring perch. The top mount should be no more of an obstacle than it would be when going with any of the air spring setups that you have suggested.

Instead of struggling with spring rate issues, I'm suggesting that you find a rate you like at a certain PSI. Adjust the vehicle's ride height with the location of the spring perch (like on an adjustable coil over setup), rather than with the air pressure in the bag. So now I have somewhere around my desired spring rate and desired ride height right? If I want to raise my vehicle to clear a speed bump, driveway, etc., I just add pressure to the bags for a quick increase in ride height.

What I am getting at is that this would enable us to overcome (somewhat) the weakness of air springs, which is that spring rate increases with ride height and bag pressure.

Keep in mind the only benefit I'm seeking from going to air suspension is the ability to raise up to stock height to avoid scraping my car on speed bumps and my driveway. I am only looking to find 1.75" - 2.00" drop, which can be momentarily undone by inflating the bags.

Here is a crappy ms paint drawing...kinda like mixing coil overs w/ an air spring

JasonWW

iTrader: (2)

OK, I'm pretty sure I already talked about this type of setup for the exact same reason. The problem comes from the fact the air strut bag will not slide over a threaded sleeve added to a Koni or Bilstein shock. The only way it would work is if you used a shock with a threaded body and that means a new shock. QA1's have a threaded body, but are not known for their handling performance. I really want to continue using my koni's.

JasonWW

iTrader: (2)

I drew this pic as your looking from the side. With the swing arm rocking front and rear you are able to maintain the stock 1.7 motion ratio. In your drawing you moved the cylinder inboard with the swing arm rocking left and right. Now I did take a good long look and I think that it is probably the better way to package the setup. In your picture I see you already figured that the arms are going to be so long that you'll need to mount part of the arm inside the fender well.

In order to adjust the ride height up and down the full 8" (maybe we should reduce that?) the shock will need to move 4.7". The hydraulic cylinders have plenty of range, from 6"-20". So lets say we decide to move the shock mount 4" (6.8" of height change) how can we keep the swingarm length compact so it can all fit under the fender?

BTW, I think the lower A-arm shock mount can be lowered a good 2-3 inches to give some more room up top, plus I don't mind cutting out the center of the upper A-arm mount to give more room. As long as it stays under the hood, I'm good.

It may be better to mount a 90* swing arm on top of the fender sheetmetal. The cylinder can be mounted horizontally with the bottom pointing towards the front of the car. This way the arm will rock mostly front to rear and help maintain the 1.7 motion ration. When the upper shock mount moves further inboard or outboard the spring rate and shock valving changes. On the other hand, maybe thhis is a moot point as long as the shock has the 1.7 ratio at it's ride height. I guess it doesn't matter at full drop or full lift. Yeah, I guess it doesn't matter.

JasonWW

iTrader: (2)

I think a setup like this would work.



It looks bigger than it would actually be. I'm pretty sure we could get 4" of travel on the shock and still keep the rocker arm under the hood.

JasonWW

iTrader: (2)

It occurs to me that this whole setup can be much simplified if I could just get a shorter, fatter cylinder with 3"-4" travel. It could be mounted right on top of the shock with a swivel bearing.

Something like these:
http://www.supplierlist.com/photo_im...e_cylinder.jpg

topdownTA

If you posted about this type of setup I must have missed it. Someone out there has to make a air bag that will slide over a threaded sleeve....

JasonWW

iTrader: (2)

I may have said it in another thread. I remember saying that one possible solution was having some new snap ring grooves cut into the shock body. People have that done so it's not difficult.

There are only 3 strut bags I know of. One seals up the shock, so it won't work. There's this one, the Universal Air (UVAIR) Aero Sport Single Convoluted Air Bag and then a similar bag from CCE Air Systems, but I can't find much info on it.

Check out page 2 here:
https://ls1tech.com/forums/showthrea...=541244&page=2

BTW, most struts cars a while back had to use air cylinders, 4" in front, 3" in rear. Now you have companies like Air Ride making the one piece sealed units. As far as I know, these universal strut bags are a fairly new thing. It's very difficult to design them so they work well and will last. I just doubt the market is very big for them. That's why there may be so few available.

JasonWW

iTrader: (2)

Hey, I found some 4" stroke cylinders at a lowrider store. $100 pair. I'm guessing their overall length is about 7" maybe a tad more. That should work just fine.

coolcars dot org

sneaky7980

iTrader: (15)

I just did a quick search and found a lot of linear electric actautors that could work.

sneaky7980

iTrader: (15)

btw jason, i checked out your car pc link and may have an idea for you on that...

topdownTA

This thread is getting way abstract....it went from air suspension to hydraulic cylinders to beyond.....so I figured I'd throw this out there in case it hadn't been mentioned before....

Bose (the audio corporation) is developing a car suspension that enlists the use of electric motors on each corner of the vehicle rather than typical springs & dampers. The motors "cancel" the obstacles in the road, i.e. when encountering a dip, the motor extends quickly, when encountering a bump it retracts rapidly. They hope to have this technology in use as O.E. on a high end luxury car by 2010 I believe.

I came across this when I did a report on Bose for school a few months back.

Here is a video on YouTube
http://www.youtube.com/watch?v=eSi6J-QK1lw

sneaky7980

iTrader: (15)

I read an article about that system a year ago and thought it was a really cool concept. Way down the road for any of us shadetree's though.



Speaking of abstract, how about steam powered pistons that have tiny wheels that pick the car up while rolling down the road. You could have the smoke pipe from the coal chamber exit by your back axle so it always looks like your doing a huge burnout. PATENT PENDING

topdownTA

Yea, I was just adding it to the thread as another crazy suspension concept



LOL...Gump, you're a damn genius!

JasonWW

iTrader: (2)

Actuators won't be anywhere near strong enough to lift the car.
I wouldn't say that. I'm basically looking for ways to alter the ride height on the fly to make the car more practical. It was looking like an air strut would be the best solution, but the unknown spring rates is really bugging me. With hydraulic cylinders mounted right on top of the spring/shock you can alter the ride height easily and maintain all the performance of a Koni/Coilover suspension. That seems to me to be the ideal solution. The cost is less than an full air setup, but the weight may be more. I'm still looking into the minimum amount of weight needed to make the system work.

sneaky7980

iTrader: (15)

How much would you need per wheel (approx) after factoring in the mechanical advantage of a lever?

JasonWW

iTrader: (2)

The levers I were talking about before where 1:1.
If you figure the front of the car weighs 2100lbs (ballpark) then the motion ratio of the suspension = 3600 to the front shocks, divide by 2 = 1800lb each front corner. so 1 ton actuators might be just enough. I'd want some extra strength, though.

sneaky7980

iTrader: (15)

Here's some product info for one of the 2000lb actuators i found, it's about 18 inches long retracted,


Standard stroke lengths of: 3,6,12, 18 and 24 inches
Lifting speeds 27" per minute
Fully adjustable internal limit switches are standard clutches.
Potentiometer - optional
12 Volts DC
5 amps

sneaky7980

iTrader: (15)

Forgot to mention, if your willing to get a little more creative electrically, you can go with the 115 VAC/60hz version. Your lift time doubles to 57" per min.