Install Complete - Gen IV Seats into a Gen II
In an earlier post there was a lot of discussion on whether Gen IV seats would fit into a Gen II. I permanently installed the drivers seat today. Here are the details. Note, all the dimensions are for a 97 GTS and the seats were a 2008-2009.
Benefits and Issues
1. The seat can be installed so that the Gen IV seat bottom height is identical to the Gen II oem height, therefore, if your Gen II seat allows a helmet, so will the Gen IV seat when mounted properly.
2. The Gen IV oem track is used and maintains the adjustability. It is actually better than the Gen II, the adjusting increments are smaller, therefore, you can find the sweet spot easier.
3. The adjusting lever is a full bar in the front, therefore, easier to use. The adjustment lever for the seat back is on the side, also easier to use, although a little hard to access.
4. The support and looks of the Gen IV seat are superior.
1. The seat comes out easy, however you have to position it correctly. The bolts/nuts are both 13 MM. The front bolts are best removed with a ratcheting box wrench. The back nuts are easy to reach with ratchet and extension, just move the entire seat forward and the seat back forward also. Once you have the seat loose move the track until you have directly it under the seat, you do not want the track/brackets projecting out in the front or back. Next, push the seat entire seat forward and move the seat-back to the rear, go past 90 degrees, then, rotate the top of the seat toward the outside, it should come right out. It is probably a good idea to tape a piece of cardboard over the top of the sill kick plate.
2. Once the seat is out you have to remove the four brackets on the corners. The front brackets are held by a bolt and two seam welds. The rear brackets are held by two bolts and two seam welds. Remove the bolts and take a hand held cutoff tool/grinder with a thin cutoff wheel. The welds are not deep, groove them away from the track, then, use a chisel between the track and bracket to pop them off.
3. The Gen II floor studs in the rear are 13" apart. The Gen IV track center line is 13.5". The new adapters are simple, I made mine from 3/16" X 1-1/2" steel bar. A bench top cutoff wheel works real well for cutting them to size. Merely use the old bracket as a template for the position of the three holes (two in track/ one for floor) in the rear adapters. The front adapters will only have one hole/bolt into the track and one for the floor.
Here is the key, the right rear bracket should be mounted to the centerline of the track, however, you want the hole for the floor stud to be 1/4" off center to the right of the track. This pushes the seat to the left by 1/4", that is the sweet spot so that the track functions, it is tight and that was the key to making it work. Once you mount the right rear bracket, then, mount the left rear bracket. The next trick is to make the two holes used to mount the adapter to the track oversize, this allows you offset the bracket so the outer hole (for the floor) can be moved to the inside of the centerline - keep in mine the track centerline is 13.5" and the studs in the floor are are 13.0".
Put the seat back in the car, push the seat forward on the track. This exposes the rear adapters. Drop the adapters over the studs and screw both nuts on a couple of threads so the seat is loose, but, in position.
4. The front adapters are next. Cut the two front adapters at 4.5" long. There is only one bolt holding the adapter into the track. Since the seat front is loose, merely lift it up and and fasten the adapter to the track. Drop the seat and line up the adapter to the center of the floor hole. I took a bolt and cut the head off, ground the top to a point, then, threaded it into the floor hole while holding the front of the seat up. Just drop the seat down and the pointed head of the bolt will mark the adapter. Take the adapter off and drill the final hole when the the pointed bolt marked the adapter. Do the same to the second front adapter and you should be done.