Speedway SwaybarA little before going widebody I added a 1 1/4" hollow swaybar with splined ends. We've thought about this as a Ronin project but it's really too much work to make it an easy bolt in solution so I figured I'd post the info here instead.

What's with the black spacer thing? We'll get to that in a second...
Picked up the bar and ends from an FC race car that was parting out locally. Strangely the bar as purchased was about 40" long and I needed 36" to let me turn the wheels at full lock (pretty sure the former owner couldn't do it). The upside is that Speedway Engineering turned out to be local to me and I got it cut down and resplined for not a lot of money.
36" length puts the end about an 1/8" from rubbing the wheel wells so it's tight and it meant I needed to trim the edges of my frame rails...
Before:

After:

Basic pieces (thanks to Mike for the powder coating assist to match my brakes.)

The steel plates were my means of tying in an extra nut so I now have three swaybar mount holes. Stock hardware positions are still accessible plus I now have an extra hole further back for the new hardware spacing. McMaster supplied the bearings...
http://www.mcmaster.com/#catalog/117/1146/=c7na70 part number 3813T18

So that part about cutting down the bar? Well that meant my arms were now bent wrong and didn't land over the control arms correctly. rather than try to rebend I made little tower spacers out of 1/8" steel (already painted in the first picture). Shot glasses anyone?

Bar has ~1/4" clearance all the way across the bottom relative to hard parts. However the straight run meant I was rubbing my oil cooler lines by a hair. Built a couple little sacrificial wear parts out of a PVC coupler to be safe.


One more shot of the end result (there's also PVC as a spacer between arms and bearings on both sides to keep it centered so it can't slide side to side and rub.)

The last thing I'll mention on fitment is that if you're running low and take a healty bump while close to lock you can bind up your steering rod on the lower surface. I was only able to do this (and barely at that) when really romping through a stoplight about to turn red but I ended up notching the bottom surface of each arm by about 1/4" to give me a touch more space. No pics but it was basically just carved out using a 2" diameter sanding drum to keep stress risers to a minimum.
Previously the best swaybar setup I'd tried was using an RB front bar with a stock rear bar (~20 lbs total). This weights ~6 lbs, that's the big upside. That said, their are probably easier ways to drop 10 lbs. For me the added bonus is that I set this up so the torsional spring rate of my setup is just a touch lower than the RB bar so I don't run a rear sway anymore either.
For reference
-stock FC swaybar (s5 na) is 0.95" diameter = 546 lbf/in differential compression side to side
-RB bar 1.13" diameter = 1074 lbf/in side to side
-speedway bar 1.25 OD, 1/8 wall = 966 lbf/in side to side (when used with a 7" lever arm).
End of story: the cornering balance is still right where I like it. Having played at a few autocrosses since I can say that it seems to work nicely.