stock sway bar?
 

Anyone know what sizes the front and rear sway bars are for the GR86?

My old FRS has the TRD bars which were 20.6 mm solid front and 15.8 mm solid rear, which I absolutely loved. Handling suited my driving style.

Maybe the old bars will fit the new car?

They will fit 100%

Sway bars were one of the main differences between the GR/BRZ, the info should be very easy to find.

However I wouldn't recommend changing any of the suspension unless you REALLY know what you are doing. The new generation is seriously impressive to drive and you can tell a lot of engineering went in to make it the best as possible. The OEM sway bars and coil springs are tuned for each other, like how the TRD springs and sway bars were made for each other. The torque is awesome, but the improvements to ride quality and handling are really unbelievable.

I agree with you. However now that I’m on RCE SS1s, and I have better rubber, I have a feeling that the bars may need to be changed. Maybe not.

At least I’ll get a better understanding if I know what the current bars sizes actually are.

What I do know is stock bars + stock struts + stock tires = awesomeness

I also know:

Trd springs + Eibach lowering springs w/ b6s + MPSS = really excellent