Upgrade rear sway to 16mm
 

So i enjoy experimenting from time to time. Have done this a bit with my 04 WRX which desperately needed sways. But the BRZ is pretty good stock for DD and spirited runs.

With sticky summer tires I feel that the car was not as playful. So I just upgraded to a 16mm rear bar from Perrin on the 2nd setting. And the car feels really good. I was wondering because most people upgrade the front bar first. I have not testied in the wet or with my all season tires for winter. Anyone else just upgrade the rear?

I will drive for awhile and then may upgrade the front bar as well. Just need to see how big to go. I am currently on stock suspension for 16 BRZ. Of course this will all change when I upgrade the suspension in the future. Likely getting RCE yellows and B6.

I did the Perrin 19mm F / 16mm R at the same time. I had the front bar on soft and rear bar in the middle, on stock 2017 suspension. It felt really great and still playful on sticky tires.

I'd do (did, actually) springs first. For street and some track, springs + Bilsteins should be fine, I've run that way for years. I did go to sway bars (Eibach 25mm front 19mm rear with two adjustment holes each) this year as I had points available and specifically wanted to address mid-corner understeer due to (I think) the outside front spring rate going way up due to getting into the bump stop.

Yeah I am at 62k miles. The stock suspension is working fine. So I may change at 80k depending on how the car feels. No need to spend 1200 when the car is a blast to drive. I do believe the yellows/b6 will improve the car but I like to spread the costs out if possible. If a stock shock fails it will happen then.

I run OEM 17+ rear and 20mm whiteline in the front on stiff.

Just put the front 19mm on. Car feels great on PS4s. Thanks.

I went smaller rear bar. :)

Why?

Why would I need a bigger rear bar?

The platform isn't the best at rear droop or powering down and I want to be able to be aggressive on corner exit. Car makes plenty of front grip.

Eh? Thicker rear bar imho will overload rear outer tire even more, adding more oversteer on exit. Rather install MCA mod or add a bit toe-in in rear, or be less agressive with stomping on go-pedal too quickly. And if antirollbar, then opposite, less thick one in rear.

I didn't say you should put on a bigger bar. Or keep the stock bar, or anything else. You did something that's different than what 99% of others do. I thought it would be good to learn why you did that.



Do you find that changed the steady state cornering balance of the car? Any issues with running into the bump stops too much? What's other, if any, suspension mods to you have? What size bar did you start with and where did you end up? Where did you find a smaller bar?

I'm on 245/40/17 Yokohama A052 on 17x9 RPF1's. Megan Racing coilover bodies with guts from ProPartsUSA, 400/400 spring rates, 25mm Eibach front bar on soft. -4.2 camber up front, -2.5 camber in the rear. I've got the Mann Engineering 13mm rear bar.

This is the first bar that I went to with this setup, though I had the Eibach rear bar before with an entirely different setup.

The sways are used to fine tune the balance of the car. Some people like an oversteer feel, others like a more neutral car. Doubt people like understeer, buts it is the safest for DD. People say loose (oversteer) is fast, but really I think a neutral car is best. You want that rear to come around nice and smooth which feels good and inspires confidence. However, oversteer in this car is fun and makes it playful. That’s why I went with a 16mm bar to keep it playful. No auto x or track for me just spirited runs.

Just experiment a bit and see what you like. Make changes to adjustable sways or different sway sizes and take that same turn in your town and see how the car feels. I did this with my 04 WRX wagon which had the typical AWD subie push (understeer). That bigger rear bar with pink springs and a better damper really makes that rear end come around in a turn, but nothing close to snap oversteer. Car just feels right this way. After I found what I like I set it and forget. And remember different tires also have a dramatic effect on how it feels. Going from great summers to my snows feels like going from a rally car to an econobox grocery getter, unless you are in snow, then it’s a rally car again.