Seats, E34 -> E12?

Rusty Shackleford · Post by **Rusty Shackleford** » Mon Aug 10, 2009 2:08 pm

It seems as though I've seen this swap done somewhere. Maybe Zane's car, or the likes.

I found a nice set of tan leather power E34 seats, and I'm considering pulling the E21 recaros out and installing the E34 seats in their place.

I'm slowly coming to the conclusion that I'm getting too old to climb over the bolsters on the hip hugging Recaros. Plus having a little more "luxo" might encourage the wife to ride in my car more than hers.

So, is the E34 seat into an E12 gonna be "involved?"

YouTube · Post by **Peter Florance** » Mon Aug 10, 2009 6:28 pm

Jeff Caplan did it (odometergears)
I can't recall if he modified the seats or the floorboard.
This was on a 1980 car; yours may be different.

You might PM him but I think he's at the shore on holiday

alotawatts · Post by **alotawatts** » Tue Aug 11, 2009 2:13 am

I have been compiling info...
E34 Seats to E28/E12

From what I've read on this and heard from other members while asking, "How does that work?" with a stunned look on my face, the E34 uses a hook in front and then your standard 17mm bolts in the rear. The rear bolts in, but you need to drill out the rivets holding the hook in place and expand one of the holes, which coincidentally fits over the stock E28 mounting hole. You should be able to see it when it's all going together

The process of installing these seats is actually safer than many of the approaches by many for E30 seats into an E28. E34 seat rails are the same width as the E28 ones, so all you're doing is making the mounting points like the ones for the E28 - 4 holes through which a 10mm bolt with a 17mm head passes through
E34 seats are very comfortable as I recall, and plentiful (although not in my color). This sounds like a relatively simple bolt in with a minor modification. What about electrics, any idea?

Also, if I remember correctly, the bolts used on the E28 mount to the nuts in the floor structure - meaning that, once you drill the front of the E34 seat rail, the existing bolts should go right through the new hole and directly into the exisiting nut on the floor - unless the rails are longer, in which case, all bets are off. So, are the rails longer? Or, will new front mounting holes need to be drilled in the floor? Answer - No new mounting holes. The hole you need to enlarge mates up perfectly with the front hole.
The e32 and e34 seats are exactly the same. They have the same rail width and bolt in the back as the e28. However, on the front of the rails they have a hook instead of a bolt hole. In order to fit them you need to drill out this hook (since it's right over where the front bolt hole is located in the floor of your car) and bolt it up.

e36 seats (which I have fitted in my car) have the same rail width but the bolt holes are slightly farther apart. If I remember correctly, (and pardon me for using standard instead of metric) the e28 bolt holes are approx. 12.5" apart and the e36 are approx. 14" apart. Also, the e36 seats are more set "in" towards the center console. I made an adapter plate for each rail to move them out towards the edge of the car and to space out the bolt holes.

e30 seats have skinnier rails that you need to make an adapter plate or bits to go in between. If you search american ebay there's a guy who makes them and sells them as a kit. They're not very complicated and that'll let you know exactly what they look like and how to make them.

E34 seats
You'll see that the front hook is held in with two rivets. Drill them out. You'll then see that one of the holes almost perfectly lines up with the hole in the floor. Enlarge it so the bolt slides through freely. I would recommend not doing this in the car, as you'll drill through the floor and get upset. Bolt them in and voila!

Making the electrics work isn't terribly difficult either

wkohler · Post by **wkohler** » Tue Aug 11, 2009 2:32 am

For the E12, I think the biggest hurdle is the electrics. In '80/'81 cars, it's not difficult at all to physically install them.

Like said above (some of that is my text), Drill out the two rivets in front that hold the hook. Then enlarge the hole that lines up with the hole in the floor.

Since all of the switchgear for the seats to move is on the seat, you'd just need to find a circuit to pull power from, or have your own fused source going to the battery. Shouldn't be too bad.

Good luck!

Rusty Shackleford · Post by **Rusty Shackleford** » Tue Aug 11, 2009 1:27 pm

Thanks for the replies.

Sounds pretty straight forward.

I'll probably pick up the seats this weekend. $120 for two tan leather power seats in good shape. I'm not going to pass them up.

Odometergears · Post by **Odometergears** » Tue Aug 11, 2009 6:02 pm

All the ideas above are great and better than I did. I fabricated two hooks and welded them into the floorboard. I can't reverse them so I would go the other way if you can.

For wiring, you can use a relay and I would connect to switched ignition power. I had problems with my switches sticking and running my battery down. Also use a resister for the heated seat portion otherwise you will burn your car down. I almost did. You only need a few of the wires in the bundle. Make sure you get both sides of the wire harness. I can look at mine to see the wire you need if you want. Just let me know.

Bottom line, the seats are great. I did the same thought process as you, E30 sportseats or captain chairs.

GL and call if you need help.

Jeff
1980 528iT 5 speed
757-593-3478

Rusty Shackleford · Post by **Rusty Shackleford** » Wed Aug 12, 2009 9:38 am

Thanks Jeff.

I'm not sure if these seats are heated. They're from a 525i that's fairly low end.

There's a white E34 540i sitting beside it with gray leather, power, memory, etc. which I'm sure are heated, but the gray won't match my interior.

I had planned on doing ignition switched relays for all the power feeds. I've never found myself needing to adjust the seat with out my keys in hand, I just don't see the need for the seats to have power when the car's off.

My wife's SC300 has power to the seats constantly and it seems a little silly.

I've looked at a bunch of different seats, trying to figure out the best option, and while I've found some E34 M5 seats, and some sport seats from a later 540is, and they're nice and offer better support in the curves than the low end seats, they're just too dang expensive.

I saw some Honda S2000 seats that were awesome, but that would involve fabrication and sacrificing small farm animals in order to make them work.

I'm just trying for a nice comfy seat that doesn't feel like I'm sitting on a bench, or sitting in a bucket.

Mike W. · Post by **Mike W.** » Wed Aug 12, 2009 12:35 pm

I had planned on doing ignition switched relays for all the power feeds. I've never found myself needing to adjust the seat with out my keys in hand, I just don't see the need for the seats to have power when the car's off.

Not really. Depending on who and how many drive the car, having them powered with the key off can be a big convenience. Like at work, I share a pool car with several people. When one person drives it, my knee is several inches too long to get by the steering column. And I'm only 5-9 with a 29" inseam! Literally I can't get in without adjusting the seat.

Rusty Shackleford · Post by **Rusty Shackleford** » Wed Aug 12, 2009 12:49 pm

Mike W. wrote:
I had planned on doing ignition switched relays for all the power feeds. I've never found myself needing to adjust the seat with out my keys in hand, I just don't see the need for the seats to have power when the car's off.
Not really. Depending on who and how many drive the car, having them powered with the key off can be a big convenience. Like at work, I share a pool car with several people. When one person drives it, my knee is several inches too long to get by the steering column. And I'm only 5-9 with a 29" inseam! Literally I can't get in without adjusting the seat.

Ah, luckily I'm the only one that drives my car, and I'm 6'4" tall, the seat is always all the way back and the wheel is all the way forward. I do understand the knee problem. I ditched the E12 bus wheel and installed a small Grant wheel.

I'm a little concerned that the E34 seats are going to sit higher, decreasing my headroom. The recaros feel like I'm sitting in the floor.

The car the wife and I share ('95 Corolla) has manual seats, so it's pretty easy to pull the lever and move it back so I can get in. Her SC300 has memory buttons and the 3rd setting is for me. It's handy, but I just don't see the need in a 31 year old car that only I drive.

I did look at a set of tan leather M6 seats today. They're nice, but the power buttons are all in the center console and I'm sure the wiring would be a complicated beasty.

Odometergears · Post by **Odometergears** » Wed Aug 12, 2009 9:50 pm

You are correct on the headroom with the E34 seats. You will lose a little. On the other hand, last year at Watkins Glen, my friend drove my car with a race helmet on. He is 6.4 and with the helmet, he was rubbing the fabric on the roof. Do your measurements but I think you will be ok. These cars have a lot of room.

The seats are great for just driving around in everyday. They don't stink of horse hair gone bad and they are easy to get in and out of. I recovered mine to go with the custom interior. If you do get two seats from different cars, make sure the plastic does match. I ended up with two slightly different colors after replacing the melted drivers seat. Most people don't even notice but I certainly do. I'll fix it one day.

In regards to the back seat, either recover it to match or you will be doing some fabrication to the frame. The seat belt issue is what caused me to stop and reuse the E12 back seat. Make sure you get all the nuts and bolts, wire harnesses on both sides for the front seats and deal with ALL the cables before installing. You can use a 12 volt battery to move the seat motors around. Just tap the (+) and (-) to the motor to figure out which way it moves.

GL

Jeff

alotawatts · Post by **alotawatts** » Wed Aug 12, 2009 10:08 pm

Are the non powered seats hard to find ?

Rusty Shackleford · Post by **Rusty Shackleford** » Wed Aug 12, 2009 10:13 pm

Odometergears wrote:You are correct on the headroom with the E34 seats. You will lose a little. On the other hand, last year at Watkins Glen, my friend drove my car with a race helmet on. He is 6.4 and with the helmet, he was rubbing the fabric on the roof. Do your measurements but I think you will be ok. These cars have a lot of room.

The seats are great for just driving around in everyday. They don't stink of horse hair gone bad and they are easy to get in and out of. I recovered mine to go with the custom interior. If you do get two seats from different cars, make sure the plastic does match. I ended up with two slightly different colors after replacing the melted drivers seat. Most people don't even notice but I certainly do. I'll fix it one day.

In regards to the back seat, either recover it to match or you will be doing some fabrication to the frame. The seat belt issue is what caused me to stop and reuse the E12 back seat. Make sure you get all the nuts and bolts, wire harnesses on both sides for the front seats and deal with ALL the cables before installing. You can use a 12 volt battery to move the seat motors around. Just tap the (+) and (-) to the motor to figure out which way it moves.

GL

Jeff

The front seats are from the same car, so they match. As for matching the interior, the car they're going in has a babysh!t yellow/tan vinyl interior. I'm not going be too concerned. This is my daily driver / experimental car.

The back seat was recently replaced horsehair/frame/springs and covered with the original vinyl which is apparently very durable. I do like that E24 rear seat. However from what I can tell it requires a lot of customization. And it's not like anyone sits in the back of the car.

Rusty Shackleford · Post by **Rusty Shackleford** » Wed Aug 12, 2009 10:16 pm

alotawatts wrote:Are the non powered seats hard to find ?

If you're talking about E34 non-power seats, I'm pretty sure they're out there, but I haven't seen a pair yet.

Even the low-end 525i E34 seems to have received at least a power driver's seat.

But I'm no E34 expert.

alotawatts · Post by **alotawatts** » Thu Aug 13, 2009 12:50 am

I'm liking the E24 rear seat too..BKBIMMERS car -

DMS · Post by **DMS** » Thu Aug 13, 2009 6:29 am

alotawatts wrote:I'm liking the E24 rear seat too..BKBIMMERS car -

I also like it a lot but the guys who ride with me are all tall guys so they don't have enough space when they sit straight. Guess I've to make me a different rear seat.

Rusty Shackleford wrote: I'm a little concerned that the E34 seats are going to sit higher, decreasing my headroom. The recaros feel like I'm sitting in the floor.

I had that problem. I have E34 non-electrics in my E12 but I removed the subframe below the original seats and welded new brackets in. I now sit quite low unlike the bus drivers position you're in with the stock seats. I can really recommend the E34 seats as they are very comfortable also for long drives etc. I also like the arm rest which is mounted on the seat itself.

Firstfives.org

Seats, E34 -> E12?

Seats, E34 -> E12?

Thanks.