Miata Seat Mounting Kit for TR4, TR250 & TR6
Miata Seats are a very common upgrade to the TR4, TR250 & theTR6, but one of their drawbacks is finding a way to mount them to the car so that removing and re-installing the seats is a simple task. Many guys just drill holes in their floor and drop bolts through the Miata seat rails and bolt them down. Others make up their own “brackets” that bolt to the Miata rails and then bolt to the floor. There’s even someone making a custom bracket that bolts to the Miata rails and then bolts to the floor. All of these approaches that try to re-use the TR6 seat mounting locations have the same thing in common…… they first bolt to the seat and then they bolt to the floor. Anyone who has installed a TR6 seat knows what a pain it is to thread those 1/4″ bolts through the seat rail, pass the carpet and underlayment and into the blind nut mounted under the car. No wonder there’s so many stripped or cross threaded mounting bolts & nuts for the stock seats. And now more and more guys have added products like FatMat or Dyna-Mat which adds another layer to work that bolt through.
My goal was to design a completely different approach with a unique design that molded to the shape of the Miata brackets and once installed would not have to be removed i.e. the brackets bolt to the floor and the seat bolts to the bracket. When you want to remove the seat you slide it back and remove the front two flange bolts, then slide it forward and remove the rear two flange bolts. The seat lifts off the brackets and the brackets remain in place.
My design also takes into account the need to position the Miata seat as far toward the tranny tunnel as possible to clear the “B” pillar. The brackets are slotted in such a way that they can move laterally as well as pivot.
I can tell you that what I thought was going to be a simple product turned out to be both a design & machining challenge…………and I got real good at removing and installing the seats in my TR6.
For a detailed step by step installation, please visit Bob Danielson’s site where he did the test fit for the final production design.
What Year & Model Miata Seats Fit?
Patton Machine Miata Seat Mounts are designed for Miata seats from 1993 to 1998 also known as the NA model. The seats from 1999 to 2005 are known as the NB model and while the seats will fit in a TR6, the NB seat rails will not work with my brackets. If you buy an NB model seat you will have to swap out the seat rails from NA seats. More details can be found in this document along with a source for NA seat rails.
Seats from 2006 and newer are too wide and will not fit in a TR6 without serious modifications to the folding top frame.
Now that you’ve bought your Miata seats, it’s likely that they will need to be recovered as the stock seat covers are prone to rips and tears, not to mention discoloration, over the past 20 years of use. I’d suggest you visit Mr. Mike’s web site and view the wide selection of seats covers that can be customized for TR owners.
Miata Seat Mount Kit
The kit comes with eight brackets and all the necessary hardware to mount them to stock TR6 blind nuts. If you’ve drilled out and re-tapped to a different size you will have to source the correct sized bolts locally.
Here’s how I cut eight brackets from one block of 6061-T6 billet aluminum
The difference between the NA and NB seat Rails is pretty obvious
The stock Miata rails need to be straightened which is easily done in a vice.
This mounting piece (red arrow) needs to stay and that pin has to be removed at the step indicated by the green arrow.
Here’s one of the front brackets and you can see the detail in the machining to match up with the bracket design. The green arrow points to the hole that the alignment pin in the photo above fits in to. The black arrow is where the hold down bolt goes and the pink arrow is the threaded hole for the flange bolt.
Here’s the passenger side loosely bolted in place. Position the seat on the brackets, push it toward the tranny tunnel and all the hold down bolts (green & yellow arrows). The seat uses four flange bolts and go into the threaded holes (red arrows)
It’s the same idea for the driver’s side with one exception. The right front bracket by the tranny tunnel uses the long hold down bolt provided in the kit. That bolt holds BOTH the seat and the bracket in place.
Here’s a better look at the driver’s seat bolted in place…… the red arrow shows the long bolt holding both the seat and bracket in place. The other side has one bolt for the bracket and the flange bolt for the seat.
And from the rear….