Seat Pan Replacement Idea

[kblagron 14]

I have a 1970 Mach 1 that is currently being restored, and don't have the seat pans installed as of yet.  I already have TMI Sport R seats/foam, the MTF headliner, and have been doing a test fit of the seat pan location, as I already assumed I would need to move it back.   I am 6'3", 215 lbs, and right now I struggle to get in even with a tilt steering wheel.   The steering wheel isn't the problem, it's bending my my neck enough to get it in. 

With the seat pans in the normal location, its a no go - too close to steering wheel and head is against the MTF liner.  With the seat pans about 2 inches back, legs are good, but head is touching the TMI liner slightly.  I then took out the seat pan, and placed a 1" block of wood to simulate the height of the seat tracks, and that is about right (2" from headliner and legs are perfect for a clutch).

My thoughts are to use 1/4" x 2" sheet metal stock that would take the place of the seat pan.  I attached what I was thinking - rectangular, and it would be welded to the trans tunnel and the door frame along with floorboard.  I have read probably every one of the recommendations here on this forum and VMF, and this was mentioned on one.  Just wanted to see what everyone thought.

[Rsanter 149]

I don’t think that is going to be strong enough, the flat metal does not have the dimension to add the strength needed for safety.

so if we take your base idea, and add some material under the car. Think about on the convertable they add that lower pan.

i think you could add the convertable lower pans or you could add box tubing under the seat location

 

 Bob

[kblagron 14]

3 hours ago, Rsanter said:

I don’t think that is going to be strong enough, the flat metal does not have the dimension to add the strength needed for safety.

so if we take your base idea, and add some material under the car. Think about on the convertable they add that lower pan.

i think you could add the convertable lower pans or you could add box tubing under the seat location

 

 Bob

Thanks!  Yes, maybe square or rectangular tube in the front and back of the seat rails, and have the seat pedestal fit in between them.

[jjstang 50]

You're probably on the right track but its going to need much more beefing up. 

[RogerC 124]

Some shallow channel spanning between the tubing should add enough stiffening for the seat attachment.

[RPM 1,143]

You mentioned both MTF and TMI headliners, which one do you have?

[Casgar 21]

7 hours ago, kblagron said:

Thanks!  Yes, maybe square or rectangular tube in the front and back of the seat rails, and have the seat pedestal fit in between them.

I'm the same height as you and will also need to lower the seat. I have played with a similar idea, but with the square tube running from rocker to rocker, and with a bend over the tunnel, and maybe a drive shaft loop. You could probably make it lower and still keep it sturdy since you have plenty of room for a tall tube going mostly under the floor, at least in the front.

So far it's only an idea in my head, so I don't know how feasible it is.

[kblagron 14]

8 hours ago, RPM said:

You mentioned both MTF and TMI headliners, which one do you have?

I meant MTF, I have the TMI sport seat covers

[kblagron 14]

Before I go all in on this, I am going to modify the existing pan by lowering it.  I have an extra pan for each side that came with the car, so if I screw it up I still have a backup.  I have lowered the rear so far, and it sits very close to the floor pan, and temporarily removed the middle bracket to modify the front about the same amount.  I will post some photos when I am done.

[EastYorkStang 58]

Look into earlier model Mustang seat pans. An acquittance is your size who put earlier pans in his. Fits comfortably.

[RPM 1,143]

Sectioning to lower the seat pan will decrease its strength, and is a shit ton of work. I'm 6-2¼", pretty close to the OP. This is what I did, and it should work for anyone 6 foot 3.

I moved the seat risers back ¾ inch, which still allows access to the attachment nuts from below, and moved the seat tracks back a couple of inches. 

 

[kblagron 14]

 

11 minutes ago, RPM said:

Sectioning to lower the seat pan will decrease its strength, and is a shit ton of work. I'm 6-2¼", pretty close to the OP. This is what I did, and it should work for anyone 6 foot 3.

I moved the seat risers back ¾ inch, which still allows access to the attachment nuts from below, and moved the seat tracks back a couple of inches. 

 

How did you move the seat tracks back? Drill new holes in the seat frame? 

[RPM 1,143]

I have Audi seats in mine, and had to build a frame to mount to the seat and the seat riser. Seat rail extensions have been sold, and others make their own. Mine are made from ¼ or ⅜ x 1½ inch flat bar. 

 

[Rsanter 149]

On 4/21/2023 at 11:12 AM, kblagron said:

Thanks!  Yes, maybe square or rectangular tube in the front and back of the seat rails, and have the seat pedestal fit in between them.

Personally I think you need more.

if it was me I would be looking at that box section that extends from the front frame rail.

i think you could make or buy another section of that for each side. Then you can run some rectangular tubing side to side from that. Weld to that as well as the floor.

then if you add some strap material on top going front to back.

 

look at the Cox body cop cars, they had an issue with floor pan cracking around the seat attachment points.

ford make an add on kit that was standard on the cop mustangs but the rest of us could buy them.

they looked kind of like frame connectors with wings that went and grabbed the seat attachment points, this is along the lines of what I am thinking.

now if you tie the rectangular tubing to the outer rocker and the rail I recommend then you get a good seat attachment point and you improve the chassis 

[kblagron 14]

I decided to cut down the seat pans since I had an extra set, and was able to get the seats pans lowered 7/8 inch.  I used both a 3 inch steel plate along with a 1/2 inch by 2 inch rectangular tube.  I also modified the existing brace so it is sitting lower.   My novice welding skills show up in the photos below, but I feel this give me the same if not better structural integrity than the original seat pan.

Since I did this, I started looking at the Fiero seats, and found a decent deal.  Using the Mustang seat tracks, I can get another 2 or so inches.  I have an order in for new seat covers that mimic the 70 Mach 1 look, and about 95% sure I will go in that direction.  Maybe, if I am lucky, I can sell the TMI Sport  R seats to someone that is 6 foot tall or less.