Manual seats sit lower?

[mhullihan]

After swapping seat frames, I’m now confused about the commonly shared knowledge that manual seats sit lower than powered.

I bought a 128i about a year ago and in addition to the LSD and 3.73 I put in over the summer, I’ve been on an endless search for a set of manual sport seats. I was looking for them because of all the threads on here saying they sit lower than the powered seats by 1-2”. I’m 6’1”, long torso, and have about a finger’s width between my head and the (sunroof &#128530 headliner. This is fine for the street but means I have to open the sunroof shade and stick my head in there with a helmet on at the track. This fall I found a set of base manual sets locally and set about combining the bits I wanted to keep.

First the good news. My powered seat weighed 63.2lbs, and the base manual seat was 50.2lbs. I didn’t weigh the final seat before putting it in the car but I’d guess 10lbs saved since I took the seat heating, bolster bladders, and ecu over to the manual seat.

Now the bad news: I didn’t gain a shred of head room. Am I missing something? If someone with manual sport seats could take a simple reference measurement near the driver’s hip I’d appreciate it. I wonder if base manual frames are different than sport manual frames because I definitely lost some rake to the seat bottom as well. According to realOEM there is only one manual seat part part number so maybe not.

It’s looking like I might have to go aftermarket to get the seat position I want. The struggle there is finding one that my boys can still climb past because this is a weekend car also.

Thanks in advance.

[ZHPizza]

Ah this hurts as I went on a similar journey in my e46, burning through second hand seats trying to find one that would go lower. I can help you here though because I test drove two e82's back to back the other day, one with manual base seats, one with manual sport seats.

You already know the bad news: the manual base seats don't go low. They sit just as high as the sport seats in my e46 coupe and put me into the sunroof as well.

The good news: the manual sport seats really do go low. Like, real low. I had to RAISE them two notches just to see over the steering wheel.

So stay the course! Find the manual sport seats!!!

[mhullihan]

Wow, that’s interesting. So you’re saying there’s a chance haha.

I wonder what the difference point is, like the ratchet in the lowering mechanism has a different stop? I wonder if the floor or the sliders could be different.

Were both cars you drove coupes?

I really appreciate your experience. While it’s a bummer I lost a couple hundred bucks on the manual base seats, I was feeling pretty defeated and resigned to like a sunroof delete or something. Sounds like there’s still hope!

[mhullihan]

If anyone could take a measurement of their sport manual driver seat in its lowest position I’d appreciate it as a comparison point. In the pic below I’m measuring the back of the rear tilt lever to the bottom of the seat frame rail at just under 4.5”.

[ZHPizza]

Originally Posted by mhullihan

Wow, that’s interesting. So you’re saying there’s a chance haha.

I wonder what the difference point is, like the ratchet in the lowering mechanism has a different stop? I wonder if the floor or the sliders could be different.

Were both cars you drove coupes?

I really appreciate your experience. While it’s a bummer I lost a couple hundred bucks on the manual base seats, I was feeling pretty defeated and resigned to like a sunroof delete or something. Sounds like there’s still hope!

Yep, both cars were coupes - one sport package and one base. There's no way that there's a difference in the floor, so it's definitely something in the sport v standard seat frame. I see what you mean with RealOEM only showing one manual adjust frame. The difference is so significant that I feel like it has to be more than foam thickness. Real head scratcher.

I'm going to pick up the new car tomorrow so I'll try to remember to grab a measurement for you.

And delete the sunroof anyway! More headroom AND 35lb out of the roof!

[ZHPizza]

Originally Posted by mhullihan

If anyone could take a measurement of their sport manual driver seat in its lowest position I’d appreciate it as a comparison point. In the pic below I’m measuring the back of the rear tilt lever to the bottom of the seat frame rail at just under 4.5”.

Ok I have some more investigating to do because the 2008 sport package that I drove last week had seats that went to the floor. The 2013 m sport package that I just bought has seats that don't go down far enough for me either. My only thought is that BMW commonized the seat base between sport and standard after the first model year, or updated the design of the sport seats, but I can't find proof of any of that in RealOEM.

I'm not happy either now. I want my seats to go low like the 2008.

[mhullihan]

Wow that’s odd. I’ll do some more digging as well and let you know if I find anything.

Oh and thanks for taking the measurement. Looks like sunroof delete might be back on the table. I emailed a company called Nelson Racing Wheel and they said they’re still making e82 carbon fiber plugs that bolt right up if you’re interested. 35lbs saved for ~$400.

[BMWCCA1]

I'm 6'-1" and can fit comfortably in my '13 128i M-sport with sunroof and power sport seats while wearing a helmet. The inseam of my Levi's is 32". But maybe my sleeve length of 35" has me with the seat further back which may also make it lower?

[mhullihan]

If anyone with Sport Manual seats could take a measurement from the seat base to the rear adjustment handle I’d really appreciate it. I want to put this debate to bed whether manual seats really sit lower. Maybe it’s an LCI vs non-LCI, or seat pad thickness thing.

Thanks in advance.

Mike

[xrockoutx]

This is on a 2011 (technically 2010.5) manual msport seat...looks like it's right at 4.5". I also have a 2008 powered msport seat and the manual seat does FEEL much lower while sitting in it.

[Spielmp3206]

I just installed manual sport seats instead of my base seat I used them as is for a week and then noticed the rails were rusty and not sliding smoothly so I decided to swap my old rails which are in perfect condition on the sport seats. And I can let you know that the seat height was about the same, I also had the slider mechanisms side by side and they were identical

[ZHPizza]

Originally Posted by Spielmp3206

I just installed manual sport seats instead of my base seat I used them as is for a week and then noticed the rails were rusty and not sliding smoothly so I decided to swap my old rails which are in perfect condition on the sport seats. And I can let you know that the seat height was about the same, I also had the slider mechanisms side by side and they were identical

Good info! Any idea what year the sport seats came from?

I still think about this all the time. Wondering if the 2008 sport models had lower seats and BMW responded to complaints by raising them, or did a cost-savings measure and commonized the rails with the base seats (more likely).

Glad you bumped this - maybe we can find someone with 2008 manual sport seats to take a measurement!

[Spielmp3206]

Originally Posted by ZHPizza

Good info! Any idea what year the sport seats came from?

I still think about this all the time. Wondering if the 2008 sport models had lower seats and BMW responded to complaints by raising them, or did a cost-savings measure and commonized the rails with the base seats (more likely).

Glad you bumped this - maybe we can find someone with 2008 manual sport seats to take a measurement!

Base seats 2012 and sport seats I dont know but they are LCI

[ZHPizza]

Adding some info to this thread as I continue to search for ways to make these manual sport seats go a little lower.
It won't let me insert the pictures in line, so I'm just going to have to describe my findings here in a big block sorry guys.

So I pulled the seats out to see if there was any room to gain. Found nothing on the seat frame itself (no surprise), so I started looking at the mounts on the floor.

So looking at where the seat sliders mount, the rear sits right on the rail. Nothing to be done there without cutting and rewelding the frame.

The front, however, sits up on a boss that is 18mm higher than the rail. I got to looking at it and saw that it continued down through the rail, so I took some rough measurements and found that there was about 26mm of threading all the way through.

I wanted to see how it mounted so I got out the borescope and took some pictures from inside the rail. Looks like it anchors hard into the lowest section.

So could we cut that boss down and reduce the height of the seat? Sure! Would it be safe? Let's see...

The rear mount has a thread depth of 10mm, which holds to the commonly accepted thread engagement minimum depth being equal to the diameter of the M10 bolt.

The front mount has 26mm of threading, so you could theoretically cut 16mm off the top of that boss and still have the 10mm to meet the rule. Hell you'd probably be fine if you cut the whole 18mm exposed portion off as you'd still have 8mm of threading anchored under the rail.

Is it worth it? That depends on how much space you're after.

I was going to lay out some triangles and do some math, but then realized I could just do a practical experiment. I set the seat on a flat surface, then added 18mm blocks under the front mounts and measured to a point roughly where your butt would be (call it 2/3 of the way to the backrest). Then I pulled the blocks and checked the difference: 10mm

So if you cut 18mm off of those front mounting bosses, you'd likely see 10mm of increased headroom. Is that enough for you to be comfortable?

Edit: added a crude drawing of what I'm seeing

[houtan]

Did you go through with the cuts?

[ZHPizza]

Originally Posted by houtan

Did you go through with the cuts?

No, not yet. I'm still considering aftermarket seats and like a little bit of rake, so would feel real dumb if I cut 18mm off the front to make the OE seats fit better now, then ended up stacking a bunch of washers under the front of an aftermarket seat to give it some rake.

[mhullihan]

I found a thread where someone unbolted the seat rails and mounted the four legs to aftermarket seat mounts in his 1M (link below). He lost the fore-aft adjustment but by my measurements it looks like you could gain about 2”!

I’ll see if I can find the thread. I need to take some more measurements but it looks like the front/rear bolt distance is the same as any aftermarket bucket seat (~11.25”) and the width would work with a set of the Brey Krause mounts. If you’re the only one driving your car it could work. I might give it a shot. Worst case I have a set of mounts for an aftermarket seat.

https://www.1addicts.com/forums/showthread.php?t=698747

[houtan]

Originally Posted by mhullihan

I found a thread where someone unbolted the seat rails and mounted the four legs to aftermarket seat mounts in his 1M (link below). He lost the fore-aft adjustment but by my measurements it looks like you could gain about 2”!

I’ll see if I can find the thread. I need to take some more measurements but it looks like the front/rear bolt distance is the same as any aftermarket bucket seat (~11.25”) and the width would work with a set of the Brey Krause mounts. If you’re the only one driving your car it could work. I might give it a shot. Worst case I have a set of mounts for an aftermarket seat.

https://www.1addicts.com/forums/showthread.php?t=698747

Thanks for sharing the link! I have never seen that thread before. It’s hard to tell what side mounts they use though. The link provided in that thread is no longer working. Does anyone know what side mounts they used?

[mhullihan]

He mentions Sparcos but I think the important point is that they are direct floor mount and about the right length and width for the four mount points on your seat rails. I think the Brey Krause might work too but haven’t finished taking measurements to confirm