Rear/Front Sway Bars on the BRZ
 

I have a noob question for you all. I am looking at putting in a Perrin (either a 19 / 22 mm) rear sway bar for the BRZ to induce a little more oversteer when AutoX'ing. I know you need to change the sway links to something beefier as well.

My question is, do I have to add a front Sway Bar as well to counter act this? What other considerations should I think off when I install a stiffer sway bar? Do I need to install other parts?

Or should I just shut up and leave the suspension alone? :)

A little more research won't hurt. (A 22 mm rear bar, assuming the same arm lengths, will be 6X stiffer than the stock 14mm rear. That's, err... a lot.)

Just going to a stock WRX rear bar is 70% stiffer. Check out here: http://www.ft86club.com/forums/showthread.php?t=5413

They get a bit tail happy with just the 16 mm WRX stock bar but are still refining their setup.

I put a WRX (16mm) rear sway bar on my frs, it's not overkill by any means. And you don't need aftermarket endlinks right away either if at all for street driving. I did a drift event with just the 16mm sway and some 16" WRX wheels in the rear, and it slid with such ease.
http://i275.photobucket.com/albums/j...6/f6f7dae4.jpg


Here a vid:
[ame="http://www.youtube.com/watch?v=Ka81eMy5I2c&feature=youtube_gdata_player"]2013 FR-S Drifting at Sonoma Raceway - YouTube[/ame]

After that event I did install some Kartboy solid endlinks and Cusco trailing arm braces. Tightened up the rear a little more and gives a little more stability when breaking traction.
http://i275.photobucket.com/albums/j...6/2f97a60d.jpg

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I would not recommend a bigger rear bar without an accompanying larger front bar, and by a good bit. The cars are loose at the limit with any sort of negative camber in otherwise stock trim.

My car is quite well balanced, but it is not stock as it's on KW Variant 3's which have a slightly different spring rate ratio (front to rear vs. stock and I have mine setup a little different than they come from KW). I have stock bars, but also -2 camber all the way around too... and stickier tires (which tightens the car up).

I am working on bars for the car. I'd love to do adjustables, and I will try but there isn't a lot of room on the front and the rear endlinks make that a bit of a pain (but doable with different links).

I have a customer that tried a 16mm rear bar and the car was all over the place.

There is NO WAY I'd go with a 19 let alone bigger. I'm looking at 22-25mm front and 16-19mm depending on what I end up doing in the front. A large consideration for the front bar is what we find the C-stock cars are going to want (which I suspect will be larger than smaller).

Yeah for AutoX you're not suppose to slide. You get points doc'd or time added correct?.. I haven't done autoX yet, and I can imagine with traction control off with all the sudden steering changes you'd probably slide the rear out a lot with my setup. I will be doing some open track days at Thunderhill Raceway in July and/or August, and I plan on tuning the front suspension/chassis maybe before the event, but definitely after once I have more data on the car's behavior. I'm keeping the springs and struts stock for now, upgrade around them, then once I feel I can control the car to my liking I might go to coils. I'm not the biggest fan of coils since I do drive my 86 on the street every now and then, but to progress competitively it will only be a matter of time till I install some.

I think I'll keep the setup stock for now since I am doing wheel changes this week. I have a few autocross events coming up soon which I can test my new setup 1 step at a time. Awesome advice guys! thanks

I think I'd enjoy 16mm rear WRX and 22mm front from whomever. Just seems... healthy.