S2000 Seat Swap in 240Z

[Sean240Z]

I have a 1973 240Z and the foam in my driver's seat was sagging and the fabric was worn and torn. I considered new foam and leather seat covers from Motorsports Auto; however, when I compared the cost, I decided to look for a seat swap. I found these S2000 seats locally on Craigslist. Previous owner had them installed in an Integra. After negotiations, I purchased the seats for $460 with a signed declaration from owner that the seats were not stolen (including his driver's license number).

Seat Comparison:

- S2000 seat mounting holes are further apart than 240Z seats

- on this pic I have not yet bent back up the front part of the seat rails to straighten them

- outside seat rail on S2000 seat is longer

- I aligned the rear mounting holes for installation, so the outboard front mount hole is further fwd than the inboard (this reduces seat forward seat adjustment by seven notches, but not a concern for me)

- no modifications required to the S2000 seat or rails

- removed 240Z seats

- I used a Dremmel to cut the rear vehicle seat mount cross piece on both sides 0.5" inboard and outboard of the "notch" and then beat down with a mallet, to allow the adapter plate to sit flat

- used stiff cardboard silhouette of the S2000 seat base and adapter plates to determine mounting position

- I lined up both seat rails at the rear (the outboard seat rail is longer)

- used stiff cardboard cutouts of adapter plate (5"x21") to determine location of vehicle seat mounting holes

- trial fit seats multiple times to finalize mounting location

- designed four adapter plates from 5"x21", 11 gauge steel (~1/8" thick) plates, I had them cut and vehicle seat mount holes drilled by local shop (~$80), I used both rear vehicle seat mount holes (three holes in total to attach the adapter plate to the vehicle seat mounts)

- I bolted the adapter plates into the car, then test fit the seats to determine the seat's final position, marked the four seat mount holes on the adapter plate, unbolted seat adapter pate and drilled holes

Notes:

- I had to cut the carpet and underlay behind the seats to make room for the adapter plates and allow access to underside to bolt in place

- I bent the mount plate for the aftermarket seat belt retractor rear words and angled it slightly to allow more seat back clearance

- front inside seat mount requires hole to be drilled through the front vehicle seat mount and adapter plate (see above pic)

- to drill holes in 11 gauge steel, marked centers with a punch, predrilled with smaller bit, then drilled the holes with the larger bit, I oiled the bit and repeatedly bumped the drill trigger with lots of pressure (low speed=low heat), drilled fairly easily

- I used a jig saw to cut notches at the rear of the plates and the front of the outboard plates to allow easier access to mount the adapter plates, I used a bi-metal blade and oiled the blade (slow but effective)

- I cleaned up all cuts with my Dremmel

- outside adapter plate is 5"x21" with notches

- inside adapter plate is approx 5"x19" with notches

- I installed the adapter plate and seats with new hardware

Notes:

- though the S2000 seats have a seat belt mount on the inboard sides of the seats, I decided to use the original vehicle seat belt mount location as I know the vehicle structure is designed to withstand the seat belt crash loads and I wasn't comfortable that the vehicle seat mounts would withstand crash loads if they also had to withstand seat belt loads.

- rear seat travel is more limited by the seat back hitting the wheel arch (i.e. Seat could slide back further if less recline on seat back)

- I'm 6'1" tall with a long torso, my seated height is ~38" (i.e. measurement from butt to top of head when seated) and I have two finger's clearance between top of my head and headliner, when I'm in a comfortable driving position

I am very happy with the results.

[Powderkeg]

Nicely done!

Dave Ruiz

[Carl Beck]

Great write-up. Thanks for taking the time to share it with us.

Carl B.

[madkaw]

Hell, you stole the seats for 460$

[240260280z]

Nice!

[Travel'n Man]

I still have my original seats but doubt I will ever put them back in the Z. Upgraded seats and steering wheel is a must IMO. Great job with the S2000 seats.

[Jeff G 78]

- I'm 6'1" tall with a long torso, my seated height is ~38" (i.e. measurement from butt to top of head when seated) and I have two finger's clearance between top of my head and headliner, when I'm in a comfortable driving position

For comparison's sake, is that more, or less than your stock seat? Almost every non-stock seat is taller than the original and I'd like to know how the S2000 seat compares. I too have a tall seated height and most seats don't work with a helmet. I had to make body mods to get my race seat low enough in my 260. My 280 has the stock seats because I've never found anything that sits low enough.

[Sean240Z]

After driving for the first time with the new seats yesterday, I'd have to say that I sit fractionally higher. My driver's seat was fairly soft (foam needed replacing). With a helmet with my old seats in my normal driving position, the helmet would occasionally rub the headliner. I just tried the S2000 seats with my helmet, and by reclining my seat one more notch and sliding the seat fwd one notch, the helmet just grazes the roof, only slightly higher than with the old seats. Still a good driving position. My 240z has the stock headliner which feels fairly thick (I hadn't pushed on it before).

Note that I've never driven my 240z with my helmet. I bought the helmet to do some auto crossing and got busy with life. Maybe I'll have a go this summer.

[Jeff G 78]

Thanks for the update Sean. It sounds like they would work well for street seats.

[troubledz]

I like the plates you made. I also installed the S2000 seats in my 280 but i welded the stock sliders to the seat frame.

And i have 3 inches from the headrest to the headliner.

Only problem i find is that you rub the side/wing of the seat when entering and exiting the car.

[Sean240Z]

I did some research and found some pics of an S2000 seat install on HybridZ (Icehound). That 's where I got the idea of using a plate to install. As for rubbing the wing on entry / exit, I'm quite tall and have the seats quite far back and reclined so that is not a problem for me.

[Sean240Z]

In response to a query from Carl, 18 3/4" is the seat track width (i.e. distance between outer edges of the inner and outer seat tracks) for the S2000 seats.