How to get more driver legroom in your LHD e46.

[etrentasei]

Hi,

As a taller driver (6’7”/201cm), I noticed that the passenger seat on my preface e46 LHD sedan go back further than the driver one. After asking on Reddit if RHD seats have this u/Simple_Resident_1160 confirmed on their RHD face sedan that RHD seats do indeed travel back equally.

The restriction is caused by an internal "limiter" inside the E46 seat rails (circled in red in pic 1). Unlike the E38 and E39, which use easily removable clips, the E46 limiter is built into the rail itself. To resolve this, I found a set of RHD rails from a coupe that had been converted to LHD. The RHD rails offer significantly more forward and backward travel range (pic 2— original LHD rail on the right, "new" RHD rail on the left at maximum forward extension, there is the same difference backward).

Because the donor rails came from a coupe—which mounts the seat belt loop to the chassis rather than the rail—I had to modify them to fit my sedan: I drilled out the original seat belt loop bracket from my LHD rails (pic 3) and secured it to the new RHD rails using a bolt (pic 4). A simillar procedure had to be done for the seat belt buckle on the other rail but I sadly did not take pictures of it. If you use RHD sedan/touring rails this can possibly be skipped.

After reinstallation, the driver's seat now matches the passenger seat's rearward travel (pictures with seats fully back and backrests fully forward in pic 5 and 6). The driving feel is vastly improved and I feel like I’m actually driving the car not just trying to fit in and I no longer even need the seat rolled all the way back.

The final step to clear my knees under the steering wheel is installing a spacer. User Bry5on on this forum here has previously fabricated one. Due to my account not having 30 posts, I cannot message them directly so if anyone could reach out to them on my behalf I’d be very thankful.

[sapote]

To resolve this, I found a set of RHD rails from a coupe that had been converted to LHD. The RHD rails offer significantly more forward and backward travel range (pic 2— original LHD rail on the right, "new" RHD rail on the left at maximum forward extension, there is the same difference backward)..

1. do the 2 rails have same mounting holes distance? The pic shows R rail distance longer than L rail holes distance. I would think they should have the same distance.
2. pic seems to show these rails are for manual and not power seats as I see the latch stop 2 pins latched to the bottom rail holes. Motorized seats need no such latch pins. Or the pins things are the travel limiters? If not, what exactly is the limiter, pic of one?
3. in pic orientation, hammer is rear and bottom is front?

[etrentasei]

1. do the 2 rails have same mounting holes distance? The pic shows R rail distance longer than L rail holes distance. I would think they should have the same distance.
2. pic seems to show these rails are for manual and not power seats as I see the latch stop 2 pins latched to the bottom rail holes. Motorized seats need no such latch pins. Or the pins things are the travel limiters? If not, what exactly is the limiter, pic of one?
3. in pic orientation, hammer is rear and bottom is front?

1. No, the 2 rails of each seat absolutely do not have the same mounting hole distance. On the front they are equal, but on the rear they are not. This is a left, driver seat, so the outer side is longer than the inner side and this is the case on the passenger seat as well.
2. Yes, I should have mentioned this - this is entirely written from the perspective of manual seats, both original and replacement rails are for manuals and I do not know if this "problem" is present on power seats and if this would solve it. The two white latch pins are not the limiters, they are how the seat is secured in position on the rails.
As to the nature of the limiter, I was not able to determine where and what exactly it is, only theorise, along with my friend who helped me and the gentleman whom I bought the rails from. We think it is somewhere next to the "dimples" fixed inside the rails, I will attach a picture with them circled in purple. The same dimples are present in the same place on all rails (the lhd and the rhd, left and right) and look the same from the outside so it's difficult to say if this limiter is next to them.
3. Yes, in the comparison picture the end propped up on the hammer is the rear and the picture bottom is the front. Also on the picture attached here you can see the yellow arrow, it's pointing towards the front.

[sapote]

1. No, the 2 rails of each seat absolutely do not have the same mounting hole distance. On the front they are equal, but on the rear they are not. This is a left, driver seat, so the outer side is longer than the inner side and this is the case on the passenger seat as well.

You totally confused me now. You're talking the 2 rails of each seat, and I was asking the rails in #2 pic which says they are from RHD and LHD seats. That's how I read it.
"pic 2— original LHD rail on the right, "new" RHD rail on the left at maximum forward extension, there is the same difference backward)."

[etrentasei]

You totally confused me now. You're talking the 2 rails of each seat, and I was asking the rails in #2 pic which says they are from RHD and LHD seats. That's how I read it.
"pic 2— original LHD rail on the right, "new" RHD rail on the left at maximum forward extension, there is the same difference backward)."

Oh okay, my bad, I see what you mean, apologies for the misunderstanding. Yes, the RHD and LHD rails have the same mounting hole distance and the only differences is how far forwards and rearwards they extend and the seat belt bracket (because of coupe vs sedan). I hope that answers any confusion, please let me know if not

[sapote]

"As to the nature of the limiter, I was not able to determine where and what exactly it is, only theorise, along with my friend who helped me and the gentleman whom I bought the rails from. We think it is somewhere next to the "dimples" fixed inside the rails"

In most designs the seat slides off the rail by moving forward. The design must allow the seat to be separated from the rail so might be the limiter can be deleted at you own risk.

[Bry5on]

What would you like to know about the steering wheel spacer?

It’s 3 main parts plus a longer steering wheel fastener and wires:
1) Female spline coupler that goes around the column to turn the male spline into female (made by wire EDM)
2) Male spline coupler that goes into the female to return it to factory style male (made by wire EDM)
3) 3D printed plastic spacer to make it look pretty and keep the clock spring aligned with the steering wheel

[etrentasei]

What would you like to know about the steering wheel spacer?

Hey man, thanks a lot for answering here, I was going to write on your thread but you saved me the trouble. I wanted to ask if there is any chance at all you could be willing to share the CAD files for the two spine couplers and maybe the 3d printed spacer so that I can remake it. I would obviously be okay with a payment of some sort if you would like one to be made. Also, did you make the longer wheel fastener and wires yourself and if there is any documentation/images on that?

Thanks in advance, really!

[Bry5on]

Hey man, thanks a lot for answering here, I was going to write on your thread but you saved me the trouble. I wanted to ask if there is any chance at all you could be willing to share the CAD files for the two spine couplers and maybe the 3d printed spacer so that I can remake it. I would obviously be okay with a payment of some sort if you would like one to be made. Also, did you make the longer wheel fastener and wires yourself and if there is any documentation/images on that?

Thanks in advance, really!

Sure, here ya go! These are the last files that I had, so maybe worth doing a double check by re-CADing them from the DXFs. I just extended the factory harnesses by getting new pins and wires and crimping them all together just like stock but longer. The fastener is nothing special, just measured the factory one, then bought one appropriately longer.

[etrentasei]

That is incredibly generous of you, thank you so much! I've downloaded the files and I will slowly start remaking them and write on here when I manage to fabricate and install the spacer. Thanks again, it really means a lot and I hope it will do a lot for me to enjoy the car even more than I have been!

[Bry5on]

That is incredibly generous of you, thank you so much! I've downloaded the files and I will slowly start remaking them and write on here when I manage to fabricate and install the spacer. Thanks again, it really means a lot and I hope it will do a lot for me to enjoy the car even more than I have been!

Any time and good luck! Just post here if you have any questions along the way.