View single post by Art DeKneef
 Posted: 04-26-2014 09:42 pm
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Art DeKneef

 

Joined: 03-12-2005
Location: Mesa, Arizona USA
Posts: 298
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Seats that fit the JH? From what I know and have heard, the original seats, Fiero seats, Miata seats and the seats from the Acura NSX. Bear in mind except for the original seats you will have to modify the seat rails.

Here's what I wrote on the Miata seats recently on the Jensen list.

The quick answer on whether they fit is of course, it depends.

Here are rough dimensions between the 2 seats. Each seat has the seat rails attached, sitting on the floor, roughly adjusted for sitting in.

Width - Overall: JH 1974 - 19.75" Miata 1999 - 19.5" This is the overall seat width. Both seats fit fine in the appropriate space.

Width - Seat Bottom: JH - 9.5" Miata - 12" This is seat cushion before it starts to slope up sideways. The Miata seats look deeper compared to the JH seats.

Height - Overall: JH - 34" Miata - 32.25" JH headrest extended. Miata seats do not adjust.

Height - Seat Bottom: JH 7" Miata - 8" I could tell the Miata was a little higher in the front when sitting on them both in the car and on the floor.

The seats rails for the JH are approximately 13" across for the mounting bolts. The length is 13". Surprising, the Miata seat rail width is also approximately 13". The length is 16" and need to be adjusted because they have an angle on each end.

The car is in the finishing stages of redoing the interior. My new custom dash is installed and I am finishing some extra wiring before I finish installing the wood dash part. The steering wheel is not install at present but I have installed it when trying out the seats. A roll bar is installed. There is no soft top installed.

I am 6 feet so take these comments based on that and my personal trial and error fitting that is still ongoing.

When sitting in the car with the stock, old, worn out JH seats in their normal position it feels OK. I can see out the windshield and feel that I am not sitting too high. When trial fitting, the steering wheel feels too close and I don't think I can get the seat back adjusted farther because of the roll bar.

When I first installed the Miata seats using the same mounting locations and sitting in the seat I could tell differences quickly. The seat was more comfortable but I was too high. My eye level was at the top of the windshield. Definitely too high. Also the seat brackets weren't quite right because of the length and the middle of the seat is sunken in that it was hitting the floor some. I then put the seat rails right on the floor behind the mounting bracket and it felt better being a little lower but I think it still was a little too high. I cut out part of the sunken seat metal from the bottom and that lowered it slightly.

The very front of the seat bottom feels too high and in a quick trial fit I think it would pose problems with the steering wheel. I am planning on a 15" steering wheel but I haven't found one yet. I am contemplating trimming about an inch from the top of the seat bottom near the front in the hopes of improving the fit.

Art