311 Miata Seat Install
Early Miata seats(90-95) are a great replacement for the stock roadster seats. The later seats should fit also. They are relatively cheap, easy to install, look great and are comfortable to boot. I picked a pair up off of Ebay for a reasonable sum. These early seats either have speakers installed or pockets for speakers. The later seats 96 and above should fit as well but I have no first hand experience with them. Please do not blame 311s.org if you run into problems. I try to be as accurate as possible and since I have not installed the later seats-you are on your own.
The first thing I did was remove the Miata seat belt latch mechanisim from the inside of each seat. It leaves kind of a nasty looking mess but it will not show as the seats fit up against the center hump. NOTE:One set of seats had this and two others did not. At any rate, it is not a big deal either way.
Next, take a look at the bottom of the seats and you will notice that the mounting brackets are angled to fit the Miata floor pan. You will also notice a pointed pin right behind the front mounting hole on each side. I left them on and used them as locating points for the seats. Some people prefer to grind them off. What ever makes you comfortable works for me.
Well, we don't need no stinking angle so I took my rubber mallet and banged them flat.
Others have cut the pins off-to each their own.
We need to remove the old seats. Hopefully, the eight bolts are not rusted too badly. Put the seats away for possible retro restoration or give 'em to a friend. Once you have tried the Miata seats, I doubt you will want the old seats back in the car--EVER!!! Remove the carpeting until you get the new mounting holes drilled. You may have the swiss cheese effect where some PO tried other seats or moved the seats around. I use aluminum tape to cover all exisitng holes. It is good stuff and will keep the elements out. If the floor pan needs some attention now would be a good time to do that. Seal that old rust up with Eastwood's Coroless rust sealer. Great stuff.
It is time to drill our first set of holes. I started with the passenger seat but any order is fine. First I made sure the seat slides were even. Then I set the seat in place and positioned it where I thought was the best fit. I crawled in and sat in the seat. Yep, pretty comfy ride. I then marked the two pointed locating pins with a marker and preceeded to drill pilot holes with a 1/4" drill bit. I then followed with a 1/2" bit.
Try the seat again and hopefully the pins line up with your new holes. Next, we will drill out the front mounting points. Again, using the marker, mark the locations of the moutning holes. Remove the seat and drill with the 1/4" pilot bit first. Follow that up with the 1/2" drill bit. I used 1/2" x 1-1/2" Grade 5 coarse bolts to mount my seats with a fender washer and lock nut on the bottom and several washers on top to provide enough clearance for the sliding mechanisim to work over the carpet.
Put the seat back in place and try your new mounting holes. If you marked carefully everything should be fine. Fasten the seat loosely and mark the back two mounting points. Again remove the seat and drill your last set of holes.
Next take your carpeting and lay it in place. You need to cut out for the mounting bolts. I used an awl to locate the center of the holes and a utility knife to cut the carpet. The seat is ready to be installed. NOTE:After flattening the mounting points you may find the seat sits to low to slide easily. Just use a couple of washers to raise the sliders off of the floor pan a bit. Set the seat into place sliding the mounting bolts into their holes. From under the car install the 1/2" fender washers and the 1/2" locking nut. NOTE:Passenger side in board rear I had to run the bolt from the bottom up as there was no room for the bolt below. E Brake bracket was in the way. Tighten all of the nuts securely and move on to the other seat. Repeating the steps above.
These are great seats especially if you score some with the speakers built in. Mine do not have the speakers but boy are they comfortable. Enjoy the ride!!!