Add-on Lumbar Support?

[BlackSpeed66]

See reply below... :hitler:

For a car like my 325is with "sport" seats, one would think they might offer a bit more support for the lower back. Aside from that, I enjoy the seats quite a bit. The drugstore lumbar cushion I have works for long trips but that's getting kind of old.

Has anyone tried to install any sort of power lumbar support on their seats? Searching around online has found me a few different aftermarket kits that hold promise. However, today I found a pump/air bladder assembly from an e46 on eBay that might be the ticket. I've got to take a few measurements... but at first glance it seems like it'll work.

Hmmmmm....

[der affe]

i did the same thing on my recaros with the lumbars from a dodge viper as they were warrentying the seat backs when i worked at the dealer.

you will need to find manual blood pressure pumps and valves along with a little section of hose.

it works out nicely

[BlackSpeed66]

Alrighty. I picked up an e38 power lumbar assembly complete with air pump and wiring. We'll see how far I get. Not quite sure if the air bladder will fit properly as the e30 sport seats are narrower than the e38 seats. The e46 bladder may be an option as well. It has a different part number so maybe it's smaller?

[AbsorbantNut]

bump?

[BlackSpeed66]

Ok, so the 'beta' version is complete. Will get pics up in a few days hopefully. It is fully functional and works very nicely. Probably going to look for another rear console I can do a better job mounting the switch.

[M-technik-3]

I added an inflatable lumbar support in my seat some time ago. It was a pia as it was not designed for it but the leather was trashed so I wasn't concerned. Might look for some early e sport seats that are cloth they would work well with one.

The inflatable lumbar supports are not common these days, in the 80's every aftermarket catalog had one in it.

[BlackSpeed66]

Ok, so here's the fruits of my labor.... sort of.

This is the e38 airbladder assembly and control valve installed. it goes in fairly easily but since it is wider than the center section of the sport seat you need to remove some of the hog rings. I was a little worried about this but everything seems to be staying together alright.



Valve:


Finding a good place to put the pump was more difficult. It comes housed in a plastic bracket that would have clipped onto the seat from of the donor car. This doesn't work to well for the e30, so modifications have to be made. I used my hot knife to trim the bracket to a more functional size, and then used the connector bracket (white thing) that is on the bottom of the sport seat. It's used to hold the wiring harness for the seat belt indicator in place. No biggie.



Cut into pieces




With bracket modified and installed







Fastening it to this area of the seat seems to work best. None of the adjustments seem to bind that I've noticed.



I then ran the wiring and the air hose down the left side and then to the pump and limiting switch.







Limiting switch

[BlackSpeed66]

With most of the wiring out of the way, I chose to mount the switch in the center console where the heated seat switches would have been. There are blanks on the underside you'll see when you remove it. Grinding down the plastic nubs makes it easier get your fitment proper. Unfortunately I don't have a machine shop at my disposal so my Dremel tool is the next best thing



The switch bezel is from an early e38. Not sure exactly what seat style it came with but it works perfect for this application. I stumbled upon it by accident on eBay. My goal is to countersink it into the console so that it looks like the factory put it there. The extra switch was for the thigh support I believe and is currently not functional right now. I might think of a use for it later or retrofit a different switch in its spot.

I picked up a piece of Lexan from Lowe's and used that as the actual mounting bezel for the switch. After grinding the hole to size, I used JB Weld and clamped it in place for the night.



Cutting the proper hole in the console was a bit tedious. The console has two layers - the base plastic and the textured plastic covering that goes over it. This covering can actually be peeled off and wound up being more difficult to work with than I originally thought. It is not as soft or as flexible as vinyl. Here is the underneath shot of the inner plastic ground away:



Power for this whole thing is coming downstream of the window breaker switch. On my car I tapped into the green/grey wire. I ran the power wire through the rest of the console and connected it to the rest of the harness. For the ground connection, I used one of the E-brake bolts with an 'eye' terminal connected to the wire. It must be noted that you need the entire seat harness from the donor car. It has to be peeled apart and so that the lumbar support wiring and connectors can be separated from it. Took me about a half hour.



Still need to get a good pic of the finished switch. I've got less than $100 wrapped up in this. A comparable aftermarket product runs quite a bit more from what I've found.

[der affe]

nice work!
did you do both seats?
are you planning to?

my pass would bitch so i did the MANUAL version of what you did to both seats.

[BlackSpeed66]

I'll probably stick to the one seat for now. Plus, I'm not sure where I'd put the other switch. I'm usually the only one in the car anyway.

Here's a pic of the finished switch. Didn't quite turn out as nice as I wanted it to so I may try and grab another console assembly and try again. I accidentally burned some of the plastic with the Dremel so it looks a little ugly on the one side. Still works nice though!

[glucklich21]

Just curious how much did this run you?

[george graves]

Good work grinding away the plastic and not going through the leather-gain plastic covering. That took way too much time I bet.