# DIY--Manual Lumbar support installed...



## bmw325 (Dec 19, 2001)

I have a 325i w/ manual sport seats and have found that the lack of lower back support causes me pain after about 40 minutes of driving. I considered a number of different options, but wanted something:
-cheap
-easily removable
-easily installable
-unobtrusive

After doing some research, I came across this post on a Subaru Forum:
http://www.wrxfanatics.com/index.php?act=ST&f=12&t=2880&

which gave me the idea of buying an inflatable Corbeau lumbar support and installing it in my seats. With the Subaru seats, you can basically lift up the seat cloth and slide the lumbar support between the cloth and the foam. BMW seats are a little different--the upholstery is clipped onto the foam along the seam lines, and with stuff like seat heaters in there, I didn't think it would be a good idea to do it that way. On the other hand, its fairly easy to remove the rear plastic planel and gain access to the seat support structure. I had the idea of slipping an inflatable lumbar support between the support wires/springs and the seat foam-- similar to how the OEM BMW power inflatable support is mounted.

I received my Corbeau lumbar support on Friday. There are no mounting flaps or holes, so I was hoping that it would stay in place by friction (which it did).

I know this "thread is worthless without pics"; I'll try and take some and add them to the post later.
-Before you begin, buy a bag of BMW seat clips for the e46 (costs about $4 and contains all the various plastic clips used in e46 seats)
To remove the plastic seat panel
-tilt the seat all the way up and all the way forward
-Locate the 2 plastic screws on either side of the bottom edge
-Take a screw driver and try to pry them out a little bit.
-Use a small saw, or knife and cut off the heads of the screws. Its possible to pull them out w/ the right pliers, but I couldn't manage to do that. Plus, they'd get really chewed up and you'd have to replace them anyway
-Pull out along the bottom edge of the panel and slide the panel down. You should be able to easily remove it.

Now, the hard part. Installing the lumbar support
-The e46 seat is built like a tank. I had looked at pictures of the inside of e36 seats prior to my project-- and thought the e46 seats would be similar. In the e36, once you remove the back cover, you basically have unobstructed access to the seat support and foam. In the e46, the seat frame has a number of thick metal cross members, so you don't have clear access. Of course, you could remove the upholstery and foam, but I didn't want to have to do that.
-I took the upper right corner of the lumber support (the tube should face towards the bottom of the support) and inserted it on the lower right hand side of the seat back, and worked it under the seat support wires. Eventually, I got it worked across the width of the seat back and moved it up into position. I'll warn you that the sharp edges of the seat frame made hamburger-meat out of my hands during this process. You might want to consider wearing work gloves.
-I tested it out. I was a little worried about how it pushed back on the seat wires and springs--- but then I realized that the BMW OEM lumbar support would do the same thing-- so it can't be that bad. I sat in the seat and tried inflating and deflating it. Success! I was much more comfortable after only a few pumps of the sqeeze bulb.

Next, I considered how to route the tube and sqeeze bulb. I routed it out the bottom of the seat towards the center of the car. The tube reaches to about the front of the seat cushion, and I just squeezed the bulb between the seat and the center console to "store" it. You can't see it unless you look directly at it.
-I re-attached the seat panel (its kind of a pain to get the clips on the side of the panel properly lined up), and then secured the bottom w/ my new plastic clips.

I took a half-hour drive, and felt much more comfortable. I felt like I could drive for hours-- so I knew it was a big improvement-usually I start to have pain by that point. The sqeeze bulb is very conveniently located-- so its easy to adjust while driving-- even more so than the OEM power lumbar support w/ its switch along the side of the seat. I'll see how it holds up-- hopefully it won't pop or start leaking air. To be nit-picky-- It would be more comfortable if the seat foam was a little less firm, and if the lumbar was a little more localized. If I had to do it over, I'd probably go for the Sparco unit- which is a little more compact and looks to be a stronger (its also more expensive). I may also attempt a larger project to graft the more comfortable e39 seat foam into the e46 seat.

Its too bad that BMW can't/won't offer some sort of manual lumbar as standard equipment-- it would be so cheap and easy to integrate something as part of the seats. But, I'm happy for now.

You can buy the Corbeau lumbar support from many different vendors-- do a search and you'll get tons of results. I ended up buying from Apex Performance:
http://www.apexperformance.net/securestore/c190632p9610581.2.html
because they had free shipping (and the price for the lumabr support itself is pretty much $49 everywhere. They didn't have any of the Sparco lumbars in stock- another reason why I chose the Corbeau. 
Here's the Sparco:
http://www.racing-seats-usa.com/1027.html


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## Kaz (Dec 21, 2001)

Sounds pretty good. You're right, the OE lumbar bag also goes between the foam and the support wires (in fact it sits between the 3 lowest ones).

If I can't, or otherwise decide not to, retrofit the OE bits (taken out of either a E46 or E53 seat), I would definitely consider going this route.


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## Masskrug (Feb 11, 2003)

Nice writeup. Sounds like your back will thank you.

Would love to see pics when you get a chance.


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## bmw325 (Dec 19, 2001)

Masskrug said:


> Nice writeup. Sounds like your back will thank you.
> 
> Would love to see pics when you get a chance.


Thanks. Will try to snap some pics.


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