Strengthening and Improving the Geometry of the S13 Subframe With GKTech and ZSM Custom

The GKTech bushings are CNC machined out of solid aluminum billet, not one bit of give here.  This, combined with the lower control arm relocation will eliminate all wheel hop and make the car much more stable under hard cornering loads.

Before starting, we removed our stock suspension parts from the subframe and had the rust, undercoating, and grime media blasted off for a good base surface to be welded.

Zachary Mallin of ZSM Custom did all of the fabrication on the subframe.  Here he is scotchbriting all of the areas to be welded to make sure they are totally free of any oxidation.

Bare steel rusts really quickly and our blasted subframe had a slight amount of surface rust that had to be completely removed for clean Tig welds.  Although many fabricators blast this sort of work out with a Mig welder, Zac only Tig welds and uses a fine electrode and a small filler to reduce the amount of heat going into the work, not to mention that it looks really clean!


  1. Thats some awesome attention to detail. I can only see myself crashing the car on its maiden voyage with all these nice parts. Love the photo documentation as well.

    1. You guys always do it right. Kinda of rare. If I ever need or one of my friends needed some work done or just good advice I would reccommed your outfit 100% Mike. Thanks.

  2. i’ve installed quite a few of the s13 and s14 gktech weld in reinforcement kits (haven’t done the s13 roll center correction one yet) and i HIGHLY recommend this for ALL 240 owners. if you’re dropping the subframe to install solid bushings, its a great time to have the whole thing sandblasted and the gktech kit welded in.

    Personally, i mig weld them, but if someone wanted to pay for the additional time to tig weld (most of the time is spent getting super tight fitment for all parts prior to welding) i don’t see any downside to it in this application.

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