PDA

View Full Version : Custom fabricating your own "coilovers"



Spyke
02-28-2009, 04:57 PM
(Sorry, I can't post in the DIY section for some reason)

Because this is so simple, I'm throwing in a little setup to make it look like there's actually some work involved, lol. As with any DIY, be cautious, and use common sense- grab some goggles and ear protection for this one. I'm not responsible for whatever damage you do to your parts, or if you're missing some digibles/limbs after this. This will also void your warranty, but who needs it since you're doing your own work, right?

So just a few days before my birthday in Jan I had a little accident. Since I knew the car would be sitting around for about a month, I'm completely gutting the front end suspension, and replacing everything I can. So I decided I wanted something that would handle a shit ton better than the tired stock setup on my 94 325i, without droping a lot of cash (important to all of us these days). Hell, even if I was rich, I'm not going to pay ridiculous sums of money for some stranger to work on my baby when I can do the work myself, and know it's done right. So everything else is done except the Springs and shocks. and this is where the DIY comes in.

Parts used:
Koni Sports [Part# 8741.1272 sport]
Eibach/Ground Control springs (Rate: 525 lbs) [Part# 181932 // GC150.64.92]
And I don't have a part number for the adjustable collar, but it should be easy enough for anyone to find. The important part is that it has a 2.125" inner diameter, to match the shock body diameter.

http://i254.photobucket.com/albums/hh108/gregg_drake/e36%20DIY/0228091220a.jpg

You will also need an angle grinder for this job (though there may be other easier methods, this seemed to work fantastic). I went to Home Depot to pick one up, ready for the worst. I ended up walking out with a Ryobi 4.25" grinder for $30, not sure about how all of this was going to work out- I'll be honest. It came with a metal grinding blade, and I also picked up a cutting blade for it as well (this just looks like a very thin version of the grinding blade, and was about $1.50).

So first things first, get that fat ugly spring perch off the shock.

http://i254.photobucket.com/albums/hh108/gregg_drake/e36%20DIY/0227091804a.jpg

As you'll see in just a second, you'll need to cut off the perch right above the factory weld. Using your cutting blade, score your path lightly first, around the whole thing. Then make your passes in little sections, going deeper as you go. Keep checking the other side to see if you're going through if it isn't obvious to you. When you're getting close, you'll see the paint on the other side scorching. Relax- it's fine, we just want to avoid cutting into the shock body if possible, so don't rush. It will go very quick, really no more than 10 minutes even if you're being cautious.

http://i254.photobucket.com/albums/hh108/gregg_drake/e36%20DIY/0227091803a.jpg

So now you've either got it off, or you're super close. If you're close, just bang it off with a hammer and you're set. Now you're left with a pretty ugly looking weld line, so it's time to swap out that cutting blade for the grinding blade and get busy. I can't recommend a particular method/pattern to grind that seems to work better than another, but try a few angles to see what works for you. I happened to go perpendicular to the shock (think ufo following a highway), until it got down pretty close, then i went up and down (ufo going over speedbumps) stripping the paint a little above and below where bottom of the adjustable collar would sit. In my case, it's about 3" down, and an inch thick of bare metal. The finished product should look like this:

http://i254.photobucket.com/albums/hh108/gregg_drake/e36%20DIY/0228091206a.jpg

The grinding only took me about 20-30 minutes per shock with some good music playing. Headphones serve as a motivational tool AND ear protection! At this point, I'll take the shock to a nearby shop where I'll have them simply weld on a nice sturdy ring for my adjustable collar to sit on. I thought about doing this, but also welding the collar down, but for ease of replacement I think I'll leave it just resting, since the weight of the car will keep everything where it's supposed to be. I may however, fabricate some sort of a cap to keep it from travelling upwards just in case I happen to get airborne on my favorite onramp. Here it is mocked up:

http://i254.photobucket.com/albums/hh108/gregg_drake/e36%20DIY/0228091221a.jpg

http://i254.photobucket.com/albums/hh108/gregg_drake/e36%20DIY/0228091321a.jpg

That's basically it. I would recommend repainting the shock when everything is finished so you don't have any rust issues, or at least a really good, hard clearcoat if you don't care what it looks like. Good luck!

-Spyke

dhinez
02-28-2009, 06:38 PM
Good looking out. How much does everything cost? Do you recommend welding the collar onto the shocks at the top and bottom? Let us see the finish product after welded and installed on car.

97black328is
02-28-2009, 06:43 PM
so what was the total cost here?

Spyke
02-28-2009, 06:51 PM
Good looking out. How much does everything cost? Do you recommend welding the collar onto the shocks at the top and bottom? Let us see the finish product after welded and installed on car.

Thanks man. I would recommend welding a ring on for the collar to rest on, and you can either let it sit, or fab a removable locking ring to go on top of it.Price? Depends where you get everything I guess. My breakdown was as follows:

Koni Sports: $404 on ebay
Eibach Springs: $50 on Craigslist
Ground Control Adjustable Collars: $40
Ryobi Angle Grinder: $30 at Home Depot
Welding: $40-50 should be reasonable, or free if you know someone

Roughly you should have a total cost of $570 for a very decent setup. Beats $750/900 and up for sure, and you go as simple or fancy as you like. Of course this is super ideal for someon who already has aftermarket shocks, but is looking to step up handling a little bit.

Arctikz
02-28-2009, 07:14 PM
so whats the difference from coil overs and regular suspension? never really figured that out. lol whats normal suspension look like and whats the difference between the two?

Spyke
02-28-2009, 07:27 PM
so whats the difference from coil overs and regular suspension? never really figured that out. lol whats normal suspension look like and whats the difference between the two?

Don't quote me, but I think there are a few key elements to the difference between a stock suspension and aftermarket coilovers. For one stock springs are thin, weak, and spaced out too far from the shock body.

Example:
http://www.babym3.com/~babym3c/325Springs.jpg

The most obvious difference would be the customization aspect. On my particular setup I can adjust dampening and ride height, and use different springs with different rates that can be easily swapped in and out. I'm sure there are other things I'm missing, but I'm done with my fun for the day and it's blazing time.

sctrini
02-28-2009, 08:19 PM
Well...this could solve my problem...

http://forums.bimmerforums.com/forum/showthread.php?t=1183942

budget76
03-01-2009, 05:24 PM
Looks like I'm keeping my eye out for a used suspension setup. Sweet idea :cool

SnowDrift318
03-01-2009, 07:41 PM
this seems to be exactly what i was looking for.
I'd rather not spend near $1k on coilovers if I can afford to get something good for half the price.
Thanks a lot.
I'll definitely keep this bookmarked, so I can come back to it later.

RascalKing
03-01-2009, 08:11 PM
Looks cool, nice work, just remember you get what you pay for. I'm all for DIYing things, but when it comes to my cars suspension and safety, I wouldn't settle for anything less then the right way. The extra 250 for a real set of DDM coils is well worth it.

This is just my opinion. You did some nice work.

--JJ

Spyke
03-01-2009, 09:24 PM
I'm just putting it out there that it can be done, and easily. The amount of options this opens up is what's really cool. An I hear you on the safety call, I won't cut corners on suspension parts, ever. I'm only going through with this because I have someone who I trust to do the welding work and it should actually be more sturdy than the factory weld.

turdlecharge
03-01-2009, 10:08 PM
looks like im picking up a set of extra struts! im checkn on the ebay collars that come with the set of "drop springs" ill spend 40 to see if i can make a difference

Stealthyfish
03-01-2009, 10:17 PM
Thanks man. I would recommend welding a ring on for the collar to rest on, and you can either let it sit, or fab a removable locking ring to go on top of it.Price? Depends where you get everything I guess. My breakdown was as follows:

Koni Sports: $404 on ebay
Eibach Springs: $50 on Craigslist
Ground Control Adjustable Collars: $40
Ryobi Angle Grinder: $30 at Home Depot
Welding: $40-50 should be reasonable, or free if you know someone

Roughly you should have a total cost of $570 for a very decent setup. Beats $750/900 and up for sure, and you go as simple or fancy as you like. Of course this is super ideal for someon who already has aftermarket shocks, but is looking to step up handling a little bit.

Sweet setup. What's up greg? I'm kali's friend :stickoutt (I talked to you on myspace)

SnowDrift318
03-01-2009, 10:21 PM
Looks cool, nice work, just remember you get what you pay for. I'm all for DIYing things, but when it comes to my cars suspension and safety, I wouldn't settle for anything less then the right way. The extra 250 for a real set of DDM coils is well worth it.

This is just my opinion. You did some nice work.

--JJ

I guess you're right on that. unless i could find someone to make a good secure weld for it, i wouldn't want to be messing around with that stuff. especially cause i'mma be drifting my car.

turdlecharge
03-02-2009, 01:41 AM
I guess you're right on that. unless i could find someone to make a good secure weld for it, i wouldn't want to be messing around with that stuff. especially cause i'mma be drifting my car.


do u trust automated robot welders? :nono

Stealthyfish
03-02-2009, 02:26 AM
I'm gonna be honest here, I found my Ground control street Co w/ 5000 miles on it in the FS forum for 850 shipped. I found a few sets of PSS setups for 750 shipped. You can easily get a decent used system for the price of one of these setups... just putting it out there.

Spyke
03-02-2009, 04:06 AM
Sweet setup. What's up greg? I'm kali's friend :stickoutt (I talked to you on myspace)

Oh yeah whats up Andy. What are those wheels you ended up with? I actually just got the K1s

Stealthyfish
03-02-2009, 04:10 AM
Oh yeah whats up Andy. What are those wheels you ended up with? I actually just got the K1s

They're ATS Felge Planets. 17x7 and 17x8. They're about as heavy as DSIIs (not as heavy as contours), so around 20 lbs. I'm satisfied with that for now. I'd look for another set but I just have no money, haha. :(

Sweet stuff. Pics of the K1s? :redspot

Spyke
03-02-2009, 04:20 AM
They're ATS Felge Planets. 17x7 and 17x8. They're about as heavy as DSIIs (not as heavy as contours), so around 20 lbs. I'm satisfied with that for now. I'd look for another set but I just have no money, haha. :(

Sweet stuff. Pics of the K1s? :redspot
On the space I think...but no pics of them with rubber. I'll have to fix that

Stealthyfish
03-02-2009, 04:26 AM
On the space I think...but no pics of them with rubber. I'll have to fix that

so what's become of the hamanns? :shifty

XCELMotorsports
03-02-2009, 04:53 AM
What about the camber department? Gonna use after market tops?

Spyke
03-02-2009, 12:07 PM
so what's become of the hamanns? :shifty

:( Front drivers is scrapped, but the rest are fine. The other front probably won't be of use to anyone, but the rears someone will most likely want. They were nice, but far too big and heavy, 30lb 19s just are too much to spin up. The 17lb 17" K1s should feel great now though!

RummelAutosport
03-02-2009, 12:36 PM
cool write-up, I could do this no problem. I have every type of welder you can imagine, and more grinders than you can shake a stick at so I could whip a set of these up in an hour or 2. I have a custom shop so this might be a fun little project for a Sunday morning.
Thanks for the info.

angeleus
03-02-2009, 12:41 PM
do you have pics with DIY coils installed?

mipktb
03-02-2009, 12:44 PM
I'm gonna be honest here, I found my Ground control street Co w/ 5000 miles on it in the FS forum for 850 shipped. I found a few sets of PSS setups for 750 shipped. You can easily get a decent used system for the price of one of these setups... just putting it out there.

:werd:

djwimbo
03-02-2009, 01:13 PM
That's a very similar setup to what we've been doing with Audi's for a few years. Only difference is that the Bilstien spring perches can be pressed off on our dampers(and OEM dampers).

The problem I see with the above method is the fact that you're grinding on a pressurized gas tube. If you don't know what you're doing, and you're not comfortable with a grinder, you can have a major disaster.

My advice is that if you're going to get anything welded onto that damper, it needs to discharged prior to welding (I learned the hard way, trust me).
At that point, your cost/benefit ratio is a bit skewed in comparison to a set of used coilovers.

Spyke
03-02-2009, 01:40 PM
cool write-up, I could do this no problem. I have every type of welder you can imagine, and more grinders than you can shake a stick at so I could whip a set of these up in an hour or 2. I have a custom shop so this might be a fun little project for a Sunday morning.
Thanks for the info.

Welcome!


do you have pics with DIY coils installed?

Not just yet, I'll get some up as soon as I'm done with the finishing for you guys though.

:werd:
I know, I know. It's just an option, and besides, I'd still rather have all new parts than something used. You never how hard someone has beat their car, I've seen some rutheless owners.

dok528i
03-02-2009, 04:32 PM
man has any one thought that springs are amde for a weight spec and if you start to squeeze it may go wrong idk maybe am wrong but i would rather spend the extra$$4

Stealthyfish
03-02-2009, 06:48 PM
man has any one thought that springs are amde for a weight spec and if you start to squeeze it may go wrong idk maybe am wrong but i would rather spend the extra$$4

I think his springs are fine. It's the shocks that would suffer over the long run. Ground control and bilstein CO setups can go low and still have good shock life since the shock body is shortened and are revalved to the spring rates (revalve is more to remove harshness). My ground control Koni shocks are noticably shorter than my standard Koni SAs by a few inches when the piston was full extended (the GC's are yellow SA's as were my previous shocks). Any lower than what the shocks can take and those shocks/struts will be blown in no time. It's a great idea for a cheap CO mod but I think without the rebuild and shortening, you'll probably be on your second set of shocks by the time the more expensive CO setup goes.

And IMO, good choice on running 17s. That's a ton of rotating mass that's been removed... weight reduction big time! =D

Spyke
04-28-2009, 05:50 PM
Just realized I never got pics up, so here you go gents.
http://i254.photobucket.com/albums/hh108/gregg_drake/e36%20DIY/0415091935a.jpg
http://i254.photobucket.com/albums/hh108/gregg_drake/e36%20DIY/0416091757a.jpg

CoolJoe
04-28-2009, 06:28 PM
Hmm interesting...

Pretty clever there Op, never crossed my mind. Now you got me pondering this idea. :D

blackbimmer96
04-30-2009, 10:49 PM
nice:alright

3lm3rom3ro
04-30-2009, 11:18 PM
haha that looks really nice!! DIY FTW!