Making an Adjustable Front Sway Bar
by Nathan Dyck

No one seems to make a perfect front anti-sway bar for the 91 MR2 turbo, so I decided to make my own.

To complete this project, I used a 50 Ton Press, 10mm drill bit, acetylene torch, a welder (only if you have cracks), white primer spray paint, sand paper, and a metal file. I took the bar to a machine shop to crush the bar with the 50 ton press and do the fixit welding.

I started with the TRD bar for the MR2. According to TRD it is 38% stiffer that stock, so in order to make the bar stiffer, I drilled more holes in the arm of the bar.   This effectively shortens the lever arm and increases the torsion that must be applied to bend the bar.

I drilled my holes with about 5mm of metal between them. This gives rates of about 38%, 70%, and 112% stiffer than stock. You may want to change these based on your individual setup, but these seemed like a good staring point to me.

Before crushing the bar flat, you should heat the area to be crushed.  The side I didn't pre-heat very well developed some stress cracks near the edges.  This was fixed by adding some weld material into the cracks.

I was able to use the stock end links on all three holes and the geometry looked good.

I used the formula below to calculate how to modify the bar

B=260mm (Length of the arm)
L=846mm (Length of the bar itself)
D= Diameter of the bar

I calculated that D=20.6 was a good value for the TRD bar by solving for D
using a K that was 38% greater than the stock K.


        1125000 (D^4)
K = -------------------
              L (B^2)

	This is what the bar looked like before I started.  Their may be just enough room to drill a hole at 50%-60% stiffer that stock without crushing any of the bar.
	A lot of heat and a 50 ton press flattened the bar nicely.
	Oops, I guess I didn't heat that side long enough. I had to add some weld material to fill some small stress cracks.
	The finished end after painting.
	Finished bar with new mounts and bushings from the TRD kit.