(Trying to get my dead-linked DIY’s back in order, mods feel free to merge with the original or replace the original posts with this)
original thread: http://www.nyspeed.com/forums/showthread.php?t=12339
The Scope: To design/build aggressive seats with good support and a good look while maintaining all of the power features including heat and adding A/C cooling.
So I’ve done plenty of body work, paint work, welding, plastic welding, powder coating, composite fabrication, machining…etc, etc. But I’ve never done upholstery, this was my chance.
I purchased these seats for a show vehicle to be used for SEMA last year, but never ended up using them. So now, I have a set of these grey leather power/heated non-sport seats out of a '00 325ci just waiting to be abused.
What I started with:
I started to modify the inner structure of the seats. Since these ARE custom for me… I took measurements of my body frame and started ‘sculpting’ the main supports keeping my dimensions in mind. Measured my hips, thighs, shoulders and lats.
Since the stock non-sport seats offer virtually no bolster support I have to enhance the design. These tubes will obviously be wrapped in foam, but if these supports weren’t there, the foam would basically fold over, offering no support and completely defeat the purpose of building these seats.
I took some steel tubing, bent it, cut it, and then welded the tubes to the frame. You can start to see the new shape of the seats now. From here I will continue designing/building/fabricating the guts of the seat and start playing with foam.
I know it looks horrible at this point…but it’s going to take a bit of finesse. It’s tough to envision, but somewhere in there lies a nice shaped piece of ass foam
I purchased an electric carving knife from Wal-Mart ($9.95) and it works AWESOME! Perfect for this application. It makes quick work of big trimming. Once you have fine tuning to do… the carving knife doesn’t work very well.
For the fine tuning and smoothing I found an Angle Grinder with a grinding disk works the best.
I had already welded the bolster bars on then simply covered with home pipe insulation. It’s dense enough that I won’t feel the bar through the Alcantara.
Started filling in the open voids under the bolsters:
With a bit of gluing and trimming:
I then glued the seat bottom in place… It looks a bit rough (and it is) but all the fine tuning will take place once I get everything situated.
I also started to shape the thigh supports and figure out where it sits best for me. The 3 different color foams you see are all different densities. I use the varying densities to make some areas more firm then others. The black foam is a closed cell polypropylene. It’s pretty rigid. I’m using this for the thigh supports because it will be overhanging the front of the seat and needs to strong enough to support without internal framework.
The grey foam is very thin foam and I use that for “patching”. If I need to build up the surface or fix any surface imperfections, I glue it over the area that needs attention and then reshape it. I can do that several times if need be to get the shape right
And a nice comparison between the seat I made and the OEM non-sport cushion. A HUGGGGGE difference. It’s nice that the foam looks kind of like Alcantara too so I can imagine it wrapped better.
Longer and deeper seating, with thigh support. Nice fitting, aggressive thigh bolsters. So far I’m very pleased. Have a long way to go though still.
I received my roll of Alcantara from the UK. Material looks awesome.
