Seat Mounting Details

The one detail that has dominated the most time seems to be the seat mounting. Yeah, we coulda bought one of the standard Corbeau sliders and mounted it to the stock points, and it would have been safe, but it would have been way too high. I'm 6'1" and even the stock seat was too tall; the aftermarket Corbeau wouldn't have cut it.

We tossed around a lot of ideas, and they ran the gamut of wacky to impractical. At one point we were so frustrated we were just going to bolt the damn thing straight to the floor, fixed.

Running through scenario, I decided to see what I could do with the stock seat tracks. I removed the tracks from the stock seat and soon noted that the right inner side was not flat, so it would not bolt to the Corbeau seat. Instead, I took the outer adjustable track from the passenger seat. To my surprise, there were two holes in each track that aligned perfectly with the holes in the bottom of the Corbeau seat. I mounted each outer adjustable rail to the seat using factory machine screws.

From there we worked on various ideas. We could have attached them to the stock transverse rail, but the seat would have been too high. We tried placing the seat on the floor behind the factory mount, but the seat was much lower and interfered with it. Finally, I just said, "forget about it" and drilled out all the rivets and removed both the front and rear stock seat mounting points. Now we had a somewhat flat area to work with.

The members of a Nissan racing list pointed out that this transversely-mounted rail could provide some measure of intrusion protection as well (a point I have some disagreement with). Whether that safety issue is true or not, it led to our idea of welding in our own transversely-mounted 1" square steel tube. We tacked it in until we got the angles and locations all perfect (much lower than the stock one.) To make it more secure we welded in some 6"x6" steel plate into the side rails and the exhaust tunnel, then welded the square tubing in place.

For the front factory rails, we bent the front tabs until they were at 90 degrees, then welded in some reinforcements so that the holes would not pull out. The seats were placed so that the rails were resting securely on the tubing, and then the holes in the tabs were re-drilled. We will be welding studs (through-bolts) to the square tubing so that the seat rails will slide over the studs and be held in place with nuts.

Exhaust Tunnel side

Close-up, exhaust tunnel

Driver's side

Close-up, driver's side

Front attachment

The next step was to decide how to mount the rear of the rails. Look at your factory seat rails, and you'll notice a stamped steel bracket at the trailing edge that's riveted on. I didn't like that part, I thought it might fail. So, we removed it and welded on 1/2" thick steel pads. This would give us plenty of "meat" to attach to, and we're going to weld in some studs that will go down through the floor.

We had hoped that when we placed the seat on the new front mount and adjusted it laterally that the rear points would both lay flat on the floorboards. No such luck. So, we had to weld in some steel plates. The plates will be drilled and the studs from the rear mounts will go through the holes and the pads will sit on top of these plates. We'll back it up with a large steel washer and nuts.

Here's some photos of the seat in place (it's not bolted in yet). Note how low we were able to get it; I estimate my butt is about 3-4" off the floorboards.

The most likely cause of failure of the seat will be the rear pads "punching through" the floorboards or the front mounts pulling out, either caused by a strong rearward force. I think we've addressed both concerns with this design.