BMW e23, e24, e28 DIY Air Suspension Solutions

[NegativeCamber]

Bagging an old school BMW couldn't be easier. Why wait for offshore air suspension companies to build you over priced assemblies that take forever to receive and cost more because these certain models are not "popular enough." That being said, contact the good guys at Bag Riders and Airlift and they will set you up with the universal air suspension parts you need to tackle the job. I have no affiliation with them, but they had been most helpful in supplying me with everything I needed and came through quickly.

My project is an e23. For the front you have two options. A UAS aerosport bag or an Airlift Lifestyles universal bags. Starting with the aerosport:

I used Koni g60 corrado inserts. You can see the difference in length.

http://farm6.static.flickr.com/5029/5650801241_89e35ae5d1_z.jpg

The stock gland nuts hold the Koni well, but the outside diameter needs to be machined down in order for the aerosport bag to slip over.

http://farm7.static.flickr.com/6023/6019072962_7c738bdb59_z.jpg

machined....

http://farm7.static.flickr.com/6015/6018520921_91cec40992_z.jpg


Cut off the stock spring mount from the strut assembly and tack weld on the aerosport bag mount onto the strut. Since the spindle on these cars is attached to the strut, it is easy to design off the car. Mount the wheel on to the hub to see how low you can bring the bracket before it interferes with the tire. The collapsed bag length is 4" , so take that into account when deciding on the bag mount position so that it does not sit below the gland nut. If it does, you need to shorten the housings.

http://farm7.static.flickr.com/6232/6253295864_7bc20d95a3_z.jpg

When you are set with that, mount the insert into the strut housing. If you dont plan on shortening the housings, you will need to install a spacer inside the housing to raise up the insert as it is much shorter. You can get an idea of the length of the shaft at full collapse and fully lifted. There is enough travel between both extremes.

http://farm7.static.flickr.com/6078/6046408626_48bc1e078f_z.jpg

Using a 1/8" or 1/4" steel plate, cut it and drill out the stud pattern for the top mount. A thrust bearing will be used to allow the assembly to twist just as the stock strut mounts do.

http://farm7.static.flickr.com/6166/6139712308_7d1a63cbca_z.jpg

Done.

http://farm7.static.flickr.com/6200/6139160821_7741634d34_z.jpg


Second option for the front is the Airlift Lifestyles Universal Bellow bag.

http://farm7.static.flickr.com/6100/6253330996_91636a48b1_z.jpg


Same procedure as the aerosport bags applies when choosing the mounting height but this time you will need to cut the strut housings. After measuring how close the bag needed to be before interfering with the tire, I cut the housing leaving a small amount left on the spindle to act as a base for the bottom of the Airlift bag to rest on. This would also allow you get a general idea of the angle needed to clear the tire. Tack weld and adjust appropriately in order to achieve that angle. If you need more negative camber, that can be achieved with the strut mounts.

http://farm7.static.flickr.com/6113/6252800695_3a82eabf63_z.jpg

http://farm7.static.flickr.com/6156/6252821245_a0c212d8e1_z.jpg

http://farm7.static.flickr.com/6158/6253331074_50de90fb9a_z.jpg

Airlift supplies you with a top plate. Drill out the stud pattern and mount.

http://farm7.static.flickr.com/6034/6252814205_1063137825_z.jpg


The rear assembly for these cars couldn't be easier.

Using Airlift Universal Lifestyles Universal sleeve bags, cut the eye mount off an old rear strut assembly. Again, Airlift supplies you with the top plate to act as the strut mount. Trim to the appropriate side and drill out stud pattern.
Full shots of the completed car to come later with a build thread.

http://farm7.static.flickr.com/6162/6139712020_d204c3fb15_z.jpg

http://farm7.static.flickr.com/6180/6139160749_0d2efc551f_z.jpg

[Jorge]

You make this sound way too easy, the same for an E24 then? What are the costs so far you've put in...

I can't decide if I love you or **** you for making it so much easier to spend my money

[P78]

^lol

i guess that would be **** for spending your money
and love for your e24 getting stance

[NegativeCamber]

You make this sound way too easy, the same for an E24 then? What are the costs so far you've put in...

I can't decide if I love you or **** you for making it so much easier to spend my money

haha. i'd have to say it is that easy. same setup for your car as well. these models all pretty much are all the same. the only thing that may differ is the strut mount stud pattern and possibly the height of where the front bag will sit. the bag setup cost me a bit over 1100 usd... less than a "good coilover" kit would and still much less than a prefabbed air setup would. air management will just be your personal preference on how much you want to spend...from a couple hundred to thousands.

[Zack01GC]

I love this information. Can't wait until I can afford to do it.

[Jorge]

Yeah, that is my exact argument, decent coils for these are in the £800+ bracket and I swear I could do a DIY air install for sub £1200 if I went with crappy management rather than some Accuair, but then save for that in the long run.

[Francois Dillinger]

complete set of air struts for significantly less than half of what a pair of bagyards would cost. good stuff.

[NegativeCamber]

you said it.... i didnt want to drop any names ;)

[Francois Dillinger]

i don't mind ;)

in strut tube, is there anything between the airlift strut and the bottom of the airlift strut? or is it welded to the spindle above the eyelet with the outer tube just for support?

[NegativeCamber]

if i correctly understand what you are asking, yes there is still a piece of the stock strut housing between the airlift strut. i should have taken a picture before it was welded on but essentially its the same deal with what Nic did with the Bav.
Pic from Nic's setup.......

http://farm7.static.flickr.com/6193/6071338835_5a68933cf9_b.jpg


the airlift strut itself sat on this portion and the outer tube as welded on the spindle and above the adjuster. you can still see the stock strut tube in the window for the adjuster.

http://farm7.static.flickr.com/6113/6252800695_3a82eabf63_z.jpg

[Francois Dillinger]

ok, that's what i thought. can't wait to see the build thread!

[Zack01GC]

I want to see the build thread, too. I love me some E23

[uvebeenrobd]

http://www.dorbritzdesigns.com/2011/10/air-bag-build-on-bmw-e28-5-series.html?spref=tw

[NegativeCamber]

car looks great man. were you able to lay out with your design?

[Rali@BagRiders]

Looks good so far Eric!

[MikeG]

THANK YOU! This is uber helpful

[Gottalovethexi]

Oh man, I was able to follow The Neek's Bavaria air build, but this helps my confidence that it is that easy.

[NegativeCamber]

thanks guys. you wont be dissapointed after your work. my car lays hard with the airlift setup all around. front crossmember and oil pan lays out flat on stock bubble tires....

http://farm7.static.flickr.com/6103/6262742184_35e824487d_b.jpg

[Average_Jerk]

lovin it Eric! Everything came out really awesome

[NegativeCamber]

thanks Dave. its coming along. slowly but surely.

[Zack01GC]

Awesome.

How is the height at full lift?

[NegativeCamber]

these bags have a nice stroke length. the range is about the same in your sig pic down to laying out.

[TheNeek]

Just saw this Eric. Great build. Happy that I could pave the way. I wish your aerosport setup had worked. We spent a good amount of time trading ideas on that.

[NegativeCamber]

thanks Nic. Much appreciated on brainstorming with me on that aerosport setup. To those wondering, I probably could have made it lay on aerosports , but then would have had to use massive spacers for any wheel to be used, since the bag would essentially be behind the wheel.

how the car sits....

http://farm7.staticflickr.com/6038/6276814421_e48566f365.jpg

[Jesus Christ]

thanks Nic. You did enlighten me on many aspects of the setup. Much appreciated. To those wondering, I probably could have made it lay on aerosports , but then would have had to use massive spacers for any wheel to be used, since the bag would essentially be behind the wheel.
the UAS bag is that much bigger in diameter? im guessing these bags were designed to not expand?

[NegativeCamber]

nah, about the same diameter. the issue is the UAS bag didnt collapse as much as I needed at the desired position. Airlift's bag is 3" collapsed, including the mount length.

[Jesus Christ]

nah, about the same diameter. the issue is the UAS bag didnt collapse as much as I needed at the desired position. Airlift's bag is 3" collapsed, including the mount length.

ahhh, i see.

3 " collapsed is awesome, cant wait to see where you take it man

[NegativeCamber]

i texted you when it was first dumped, but you never responded. im guessing it never went through.

[Jesus Christ]

i texted you when it was first dumped, but you never responded. im guessing it never went through.

i didn't receive it to my knowledge, text that shit again!

[NegativeCamber]

someone has been looking through your phone and deleting texts! jk. a couple of pics are now in the build thread. i'll keep you updated on the latest dude.

[Rali@BagRiders]

More!

[pfcrayb]

do the koni g60 inserts fit the e28?
and lets see some pics

[NegativeCamber]

More!

working on it! :D

do the koni g60 inserts fit the e28?
and lets see some pics

the g60 body is 44mm in diameter. if e28s use inserts that are the same size or a bit less, then you can use them.

[Mike E30 UNT]

This idea would also work on the E30 as its also MacPherson struts, but the rear setup is different. I have a pair of complete, brand new air front struts and am looking here at how to attach the bottom assembly of the OEM BMW strut to the bottom of my air strut.Thanks for the photo of that in your thread.
What I need to know now is how did you calc what you wanted your final ride heights to be?
I figure the normal air pressure in the bags for normal driving would be similar to the poundage of a normal OEM BMW front spring - give or take - say 180lbs. Then I need to inflate my bag to this poundage on the garage floor so I can compare the strut length to the OEM BMW strut and work out my desired height. Mine's a daily driver so I need to be practical. 4 inches of clearance under the car was always considered MINIMUM clearance on lowered cars for practical daily drivers.
I've been lowering cars since the seventies but this is the first time with air.
Loving your car though, can I see a picture with the suspension pumped up to maximum?

[D Unit]

NegativeCamber,

Do you own a shop I could take my car to for us local Bay Area peeps? How much did you spend on parts? How much would you charge for install? Please send me a PM if you don't want to post a price.

D

[NegativeCamber]

I dont own a shop or have any affiliation with any that could do the install, so I am not sure of a good place to go in the bay. A driveway is where I do all my work. Sorry, I am not doing any sidework for anyone at the moment. Contact Rali @ bagriders to get a quote on the universal air suspension struts. I got these a while back before there was a small price increase in the airlift products.
Honestly, you can do this yourself by measuring your desired maximum drop and working backwards to measure the needed stroke length of the strut. Measure for clearance, then prefab the brackets and bring them to any competent welder, if you cant weld.

[uvebeenrobd]

car looks great man. were you able to lay out with your design?
Sorry for responding so late. My control arms are bottoming out on the pavement when I air out, so yes.

[righteousrags88]

so how much did everything cost including the tank, compressors, bags, etc, basically everything??

[NegativeCamber]

This idea would also work on the E30 as its also MacPherson struts, but the rear setup is different. I have a pair of complete, brand new air front struts and am looking here at how to attach the bottom assembly of the OEM BMW strut to the bottom of my air strut.Thanks for the photo of that in your thread.
What I need to know now is how did you calc what you wanted your final ride heights to be?
I figure the normal air pressure in the bags for normal driving would be similar to the poundage of a normal OEM BMW front spring - give or take - say 180lbs. Then I need to inflate my bag to this poundage on the garage floor so I can compare the strut length to the OEM BMW strut and work out my desired height. Mine's a daily driver so I need to be practical. 4 inches of clearance under the car was always considered MINIMUM clearance on lowered cars for practical daily drivers.
I've been lowering cars since the seventies but this is the first time with air.
Loving your car though, can I see a picture with the suspension pumped up to maximum?

sorry, i missed this. my final ride height would be whatever came about from the length needed to lay the front out. the strut bags have a good amount of stroke, so i wasn't worried too much about where the ride height would be.
granted, this method is not for "proper" air suspension installs, as they suggest to leave clearance under the car when fully aired out...but we know there is no fun in that. :)

the issue with inflating the bags off the car is that they will not be the same length as they would be with the weight of the car on them. 30psi off the car will probably have them fully extended, while 30psi with the weight of the car may have them half compressed. the manufacturer of your bags should tell you what the length of the bag should be at ride height...more or less the mid stroke range.

in your case, you will want to measure the length of the strut assembly (coil spring) with the weight of the car on them. if you design your strut bag to be that length at midstroke, thats how high the car will sit, at whatever pressure it takes to get there. subtract the length of the strut bag fully collapsed and thats how much lower the car will be when aired out.

hope that makes sense and helps you get started...

[NegativeCamber]

so how much did everything cost including the tank, compressors, bags, etc, basically everything??

a bit over 1100 for the Airlift strut bags, and i went with the autopilot V1 air management kit from BagRiders. i dont remember the exact price but right now the V2 is 1150.

if you dont want to spend that much on management, you can get the manual kit. so to bag the car with everything you need is around 1700 with the manual kit. a good set of coilovers is near that, so its not far off.

[Jeremy@AirLift]

Very cool build!

[Clark]

This thread makes everything look really easy. Great work! Do you have any idea if the suspension on these BMWs are the same as a W126?

[got splits?]

a bit over 1100 for the Airlift strut bags, and i went with the autopilot V1 air management kit from BagRiders. i dont remember the exact price but right now the V2 is 1150.

if you dont want to spend that much on management, you can get the manual kit. so to bag the car with everything you need is around 1700 with the manual kit. a good set of coilovers is near that, so its not far off.

Yup I went the manual route.
Should be on the ground soon :)
<3

[happYseff]

This thread makes everything look really easy. Great work! Do you have any idea if the suspension on these BMWs are the same as a W126?


Its not the same!

Read this thread, and youll see that the front suspension on w126 is gay, but doable
http://forums.vwvortex.com/showthread.php?4863646-W126

[sketchbmx]

wow you make it look so easy, thinking about doing this to my 323 e21. just need to work out the basics and go from there. thanks for all this info.

[papercutout]

Does anyone know if E28 and E23 struts are the same? I need to produce some coilovers for my E28 here in the UK, and knowing exactly what strut inserts are much shorter, but the right diameter would be a huge bonus!

[NegativeCamber]

Does anyone know if E28 and E23 struts are the same? I need to produce some coilovers for my E28 here in the UK, and knowing exactly what strut inserts are much shorter, but the right diameter would be a huge bonus!

they arent. e23 inserts are 44mm and the e28 are 36mm. any shorter koni or bilstein insert will work. take a look at their catalogs for the dimensions. you will just need it re-valved for the e28.

[papercutout]

36mm? Really? Wow, didn't expect them to be that skinny - the OD of the strut leg is 52mm! Thanks though.

[NegativeCamber]

36mm? Really? Wow, didn't expect them to be that skinny - the OD of the strut leg is 52mm! Thanks though.

That is what the catalog says. I measured my insert with a caliper and it was 44mm just as stated in catalog, so I'm sure its the same deal with the e28.