Not that I'm the first to do this, I'm sure, but figured I'd document it for anyone who's looking to do a swap using e82 seats, since I picked some up in "like new" shape locally for less than the cost of recovering my very rickety and crappy e30 Sport seats. I'm not sure exactly how they compare in shape, size, and mounting points to the more commonly-done e46 and e90 seats, but here's the deal
Bottom Line Up Front, in case you don't want to read the whole thing:
- In terms of overall size, they're almost exactly the same as e30 Sport seats
- require making new mounts for 3 out of the 4 bolts (no, the front two do NOT drop-in fit like they supposedly do for e90 seats)
- They're CANBUS, but I found an easy, if not perfect, workaround to make all the electrics work (except, possibly, the memory function)
- If mounted the way I did them, they sit plenty low enough for me (6' tall) to wear a helmet in an e30 w/ sunroof
- They are pretty damn nice. Comfortable, awesome bolstering with the adjustable bolsters, and tons of adjustments
- They don't wobble, wiggle, rattle, or really move at all, even when physically trying to make them do so
- Looks are subjective of course, but I think they look pretty good in an e30, aside from the modern-looking tilt mechanism up on the shoulder
- e30 seatbelt receiver more or less bolts on. Seat clears the seatbelt "rail" near the sill on early e30s.
Ok, so if you read that and want to see the rest, here's the full writeup:
Got these seats. I have an e30 coupe, so made sure they're from an e82 COUPE so I can keep the tilt-forward. For anyone wondering, I paid $400 for the pair which is way cheaper than rebuilding/recovering my e30 seats (and way less work). So after eyeballing them on FB marketplace, went and got them with hopes they'd fit and I could figure out how to make the electrics work.
These are the M-Sport seats, btw. The non-sport seats are flatter and less bolstered
Lots of motors and electrics. They're not light....but this isn't a racecar, so I don't care. I have an e30 racecar for going fast :)
This is the plug pinout, for your reference
Basically, you're going to use the two brown ground wires (attach them to chassis ground). You're going to use the two red (red/brn and red/blk) power wires (attach to power, switched or constant, whatever you want, and preferably fused). And you're going to use the tiny orange/green wire (more on that later), which is the CANBUS high wire. The green wire is CANBUS low, which you can hook to ground but I don't think you actually need to.
If you have the chassis-side connector from the donor car, you can use that. I didn't so I just chopped the plug and directly spliced the wires I needed.
Now, here's the thing:
- When you first power it up, everything works fine. But exactly 10 seconds after you stop messing with the controls, the seat goes dead (except the upper bolster pump, which apparently is independent of the CANBUS for some reason, so it will keep working). It goes dead because the CANBUS module in the seat isn't getting a signal from the car's CANBUS (since the e30 doesn't have it). So, it goes "to sleep." so to say.
- To get it to "wake up, " you need to provide a pulsed signal to the CANBUS high (orange/grn). Now, electronics guys get a signal generator. Others say a solid 5v power will keep it awake (I tried that, and it does NOT work on these seats). But the thing is, it doens't need a real CANBUS signal. Just a pulse of any kind. So you can just connect-disconnect-connect the power to the CANBUS high wire and it'll wake up. I temporaily put a rocker switch in line so I can just flip it twice and wake the seat (for 10 seconds, then you have to do it again).
- Future plan: use an inline strobe light module ($6 on Amazon) as my "fake" CANBUS signal. It will work, I'm quite sure of it.
So, that's the wiring, basically. You can figure out where you want to get the power from, etc.
Now, mounting it in an e30. As noted, the front two holes don't line up like they do in the e90. The e82 seat rails are about 1/2" narrower. After test fitting, I decided to use the outside front OEM bolt as my reference. So that one stays, the other three get changed. SO I cut the bolts off flush with the floor and drilled a hold in the inside front bolt about 1/2" inside the original one. Then cut off my own bolt into a stud, put it in the hole, and welded it in place through the thicker frame metal underneath. For the rears, you have to move the outside rear bolt directly back 2", which is easy since you can just go through the floor (just don't drill through your fuel/brake lines). The inside rear is the tough one. You have to go back 2" and in 1/2" or so....but there's nothing there, so you have to build a plate with a stud, or some other kind of structure to hold that bolt. I chose to just weld a shaved stud to the side of the slope there, held in place with magnets while I measured. Basically, it's holding in shear for weight and should be plenty strong. Then I welded a washer at the "floor level" to triangulate it with the old floor. Not that complicated if you can do some basic welding, really.
This was before I cleaned it up and reinforced it more, but forgot to take a pic...this is the inside rear. You can see where I cut off the original stud, to the left.
Long story short, it fits great. Just like an e30 seat space-wise, but way better.
clerance to the seatbelt rail
So, hope that will be helpful to someone out there.
PS, feel free to follow my rally effort at Pitchblack Motorsports/Rally on Facebook or Insta!
Bottom Line Up Front, in case you don't want to read the whole thing:
- In terms of overall size, they're almost exactly the same as e30 Sport seats
- require making new mounts for 3 out of the 4 bolts (no, the front two do NOT drop-in fit like they supposedly do for e90 seats)
- They're CANBUS, but I found an easy, if not perfect, workaround to make all the electrics work (except, possibly, the memory function)
- If mounted the way I did them, they sit plenty low enough for me (6' tall) to wear a helmet in an e30 w/ sunroof
- They are pretty damn nice. Comfortable, awesome bolstering with the adjustable bolsters, and tons of adjustments
- They don't wobble, wiggle, rattle, or really move at all, even when physically trying to make them do so
- Looks are subjective of course, but I think they look pretty good in an e30, aside from the modern-looking tilt mechanism up on the shoulder
- e30 seatbelt receiver more or less bolts on. Seat clears the seatbelt "rail" near the sill on early e30s.
Ok, so if you read that and want to see the rest, here's the full writeup:
Got these seats. I have an e30 coupe, so made sure they're from an e82 COUPE so I can keep the tilt-forward. For anyone wondering, I paid $400 for the pair which is way cheaper than rebuilding/recovering my e30 seats (and way less work). So after eyeballing them on FB marketplace, went and got them with hopes they'd fit and I could figure out how to make the electrics work.
These are the M-Sport seats, btw. The non-sport seats are flatter and less bolstered
Lots of motors and electrics. They're not light....but this isn't a racecar, so I don't care. I have an e30 racecar for going fast :)
This is the plug pinout, for your reference
Basically, you're going to use the two brown ground wires (attach them to chassis ground). You're going to use the two red (red/brn and red/blk) power wires (attach to power, switched or constant, whatever you want, and preferably fused). And you're going to use the tiny orange/green wire (more on that later), which is the CANBUS high wire. The green wire is CANBUS low, which you can hook to ground but I don't think you actually need to.
If you have the chassis-side connector from the donor car, you can use that. I didn't so I just chopped the plug and directly spliced the wires I needed.
Now, here's the thing:
- When you first power it up, everything works fine. But exactly 10 seconds after you stop messing with the controls, the seat goes dead (except the upper bolster pump, which apparently is independent of the CANBUS for some reason, so it will keep working). It goes dead because the CANBUS module in the seat isn't getting a signal from the car's CANBUS (since the e30 doesn't have it). So, it goes "to sleep." so to say.
- To get it to "wake up, " you need to provide a pulsed signal to the CANBUS high (orange/grn). Now, electronics guys get a signal generator. Others say a solid 5v power will keep it awake (I tried that, and it does NOT work on these seats). But the thing is, it doens't need a real CANBUS signal. Just a pulse of any kind. So you can just connect-disconnect-connect the power to the CANBUS high wire and it'll wake up. I temporaily put a rocker switch in line so I can just flip it twice and wake the seat (for 10 seconds, then you have to do it again).
- Future plan: use an inline strobe light module ($6 on Amazon) as my "fake" CANBUS signal. It will work, I'm quite sure of it.
So, that's the wiring, basically. You can figure out where you want to get the power from, etc.
Now, mounting it in an e30. As noted, the front two holes don't line up like they do in the e90. The e82 seat rails are about 1/2" narrower. After test fitting, I decided to use the outside front OEM bolt as my reference. So that one stays, the other three get changed. SO I cut the bolts off flush with the floor and drilled a hold in the inside front bolt about 1/2" inside the original one. Then cut off my own bolt into a stud, put it in the hole, and welded it in place through the thicker frame metal underneath. For the rears, you have to move the outside rear bolt directly back 2", which is easy since you can just go through the floor (just don't drill through your fuel/brake lines). The inside rear is the tough one. You have to go back 2" and in 1/2" or so....but there's nothing there, so you have to build a plate with a stud, or some other kind of structure to hold that bolt. I chose to just weld a shaved stud to the side of the slope there, held in place with magnets while I measured. Basically, it's holding in shear for weight and should be plenty strong. Then I welded a washer at the "floor level" to triangulate it with the old floor. Not that complicated if you can do some basic welding, really.
This was before I cleaned it up and reinforced it more, but forgot to take a pic...this is the inside rear. You can see where I cut off the original stud, to the left.
Long story short, it fits great. Just like an e30 seat space-wise, but way better.
clerance to the seatbelt rail
So, hope that will be helpful to someone out there.
PS, feel free to follow my rally effort at Pitchblack Motorsports/Rally on Facebook or Insta!
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