How to build Custom Seat Rail Extensions (inculdes pics)!!!

[07EJ255]

I have a 07 STI. Being 6'-6" sometimes the car would get alittle uncomfortable at times, plus i was sick of having the back part of my seat so leaned back. So here is what i did...

1. Took the stock seat out, removed the back of the seat and the levers that control the seat. Detached the seatbelt wire harness. Also removed the fabric and cushion part, from the bottom part of the seat. Then you are left with just the metal frame and the seat rails.

2. Next is remvoing the brackets on the rails. This part took a while. The front two brackets (front as in closest to the front of the car), were held on by two rivets and a penetration weld. The rear left bracket was held be two rivets,two penetration welds and a butt weld on the interior of the bracket (this one takes a while). The rear right bracket has two rivets and a penetration weld. Once you have the brackets off now you have to fabricate your seat rail extensions.



3. Next you fabricate your seat rail extensions. I think i went a little overboard on the steel but i choose 1/4" angle iron. I guess i could have choose something less heavy duty but it is kind of a crucial part plus the whole safety issue. Anyway, i went for a 3" extension. So both pieces of angle iron measured out to be 19.5". You will also have to remove the bracket the guards the wiring harnesses. Lay the piece of angle iron on the left seat rail first. You will notice that the angle iron will lay flat on this seat rail. Use the existing holes in the seat rail as you guide for drilling holes in the angle iron. To do this lay the angle iron on the a flat surface and flip the seat upside down and punch holes into the angle iron, for both existing bracket holes. Drill these holes ( i forgot what size i used), you can gauge it from the existing holes in the seat rail. Make sure when you punch the angle iron for holes that the end of the seat rail (front part) is lined up with the front end of the angle iron. Once you have the angle iron holes drilled out you move the seat rail so now the front part is hanging over the front part of the seat rail, and the back part of the angle iron is flush with the back of the seat rail. Now you punch holes in the bracket again using the existing seat rail holes. The first set of holes was to attach the brackets to the angle iron, and the second set of holes was to attach the angle iron to the seat rails. You also have to notch out a section in the angle iron for the rear bracket because it will not mount otherwise.



The notched out angle iron for the rear backet



4. Next you move on to the right side seat rail. You follow the same procedures as the left side (punch and drilling the holes) but this side is a little different. From the factory the right seat rail is mounted upside down, and the seat rail mountings points as visible, which makes the bottom of the rail not flat. As you can see from the pic below.



5. You have to notch out the inside of the angle and drill a hole so that the angle iron lays flat on the rail. Use the paint on the rivet (blue rivet shown above) to locate exactly where you need to drill the hole. You have to machine off about 1/16"-1/8" from the inside in order to get the bracket to lay flat (see below)



6. Once you have the brakcets fitting perfectly then you are ready to attach them. I used allen head metal nuts and bolts, counter sunk so they would lay flat in the bracket. I had to modify (i.e cut) some of the bolts shorter in order to keep the slide function of the seat working. Once you have all the brackets and angle iron attached. Now it is time to put it in your car and see if it fits. As long as you a precise about your measurements it will fit first time just like mine did.



Notice how much further back the seat is!!!!!!!!!!!!!!!!! The passenger seat is all the way back (just for reference)



I hope you guys like my "how to on custom seat rail extensions". It is definetly going to make for a much more comfortable ride. The best part of this whole fabrication/build it didnt cost one red cent, absolutely nothing.

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[GripGC8]

nice....now build extensions to lower the stock seats as low as possible

[rcdrivercrl]

Originally Posted by GripGC8

nice....now build extensions to lower the stock seats as low as possible

all you do is take off the rails

[axelthrasher]

Originally Posted by rcdrivercrl

all you do is take off the rails

LOL. Hmm.

[aug]

Nice work..

[SubieWReX]

Looks good man, nice job!

[shakur45]

Nice write-up , good job

[07EJ255]

I initially thought about building the bracket so it would sit the seat super low, but that idea presented a huge problem. You just cant take to the seat rails off, because the right side seat rail is attached on a pivot bar that connects to the left side seat rail. This pivot point has to be cut in order to get it off. I was not all about cutting the pivot bar off. The seat sits so far back now the the further you go back the seat is on an angle so it naturally lowers the sitting position the further back you go.

[B00st3dWRX]

I hope that doesnt effect the saftey design of the seats now that more of the weight is centered backwards. If you get in an accident I see those rails snapping...idk...

[scby rex]

I dont think so, you see he angle iron he used?^ good diy

[B00st3dWRX]

yeah I saw those, adds good reinforcement but any one who needs to move their seat back is not a small person. In the event of a crash thats alot of weight and surface area being forced onto that seat. IDk that was the only thing that went through my head when I saw them.

[07EJ255]

the seat bracket has more bolts and is welded more than it was when it was stock