Aperture Controls

The 2015 Subaru WRX electric steering rack conversion


As we know, the basis of the whole system is the crossmember so that's where I'll start. The crossmember bolts straight up to the car as long as you don't have an exhaust. My car has a Grimmspeed external wastegate up-pipe with flex joint. The flex joint made the modifications a lot more involved since it rests right where the crossmember is. I started cutting in an asterisk shape in the middle of the surface of the top of the crossmember, so I could hammer down and fold over the existing metal. The idea is to keep as much stock material as possible, and brace what I remove. Luckily, the swaybar bracket comes up right under where I had to cut, so it braced the insert nicely.

2015 crossmember modification for exhaust routing

The crossmember is made from steel that's between 12 and 14 gauge. I needed a radius to fit inside the hole (on top of the sway bar bracket) made from 12 gauge, but I barely had the equipment to cut metal that thick. I ended up going to Home Depot and buying an EZ Fix fencepost repair plate. It's a 12 gauge C channel with a radius in the middle that you're supposed to use to hammer it in. I cut the radius out and TIG-welded it into the crossmember. I then cut some extra material off the repair plate to cover up any other holes. I blended the welds on the top side, and welded up the seams underneath for strength.

Modified crossmember

Electric rack installed

It's a poor quality photo, but in this picture you can see all the extra bracing that Subaru put on the newer crossmember. My original setup and only 1 brace, the 2015 setup has 4 braces on the crossmember, and two additional braces that go to the body where the control arm mounts (I don't have these yet.)

Steering linkage modification

Now when I tried to hook up the steering wheel to the rack, I found that the linkage was about 1/2" - 3/4" too short. After some research, I found that the new steering linkages have rag joints installed. Ipicked up some 5/8" bar stock from Home Depot, cut the existing bar out and added 3/4".

2015 WRX sway bar modification

Now that I had the steering system mounted and connected to the steering wheel, the last mechanical part to put on was the sway bar, which we've already seen is a different size and shape. With the Energy Suspension mounts, it bolted up to the crossmember, but the holes for the end links on the 2015 bar are larger than the 2010 bar. I ended up welding up the holes (don't get too much heat into the bar or it will lose its internal tension) and drilling them out to the 2010 size. Here you see a piece of copper plate clamped to the hole so I can fill it and to draw away a little heat.

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