Actual Spring difference BRZ vs FRS
 

I found this bit of information regarding the spring rate differences between the twins. The majority of the FRS owners will stick with what they have I assume. But for those BRZ owners who wish to induce a bit more oversteer (while maintaining close to the factory feel):

Car: Front OE Spring Rate:
Subaru BRZ 27 N/mm (153 lbs/in)
Scion FR-S 23 N/mm (131 lbs/in)

Rear OE Spring Rate:
Subaru BRZ 34 N/mm (195 lbs/in)
Scion FR-S 37 N/mm (211 lbs/in)

Source and credit from BRZ Club and Eibach Springs

are the dampers also different?

That's a big difference! Surprising.

Good info, thanks!

Cool, thanks for the info.

Can anyone find the OEM part numbers and retail pricing for the stock spring set?

RCE said 185 for both front and rear on the BRZ....

Yeah we tested the BRZ springs on a spring tester and saw 185 lbs/in front and rear. Not sure where these numbers are coming from. Also I saw at least 1 other data point agreeing with our measurement.

- Andrew

I'm sending this link to Tony @ Eibach for his input since the OP seems to have implied Eibach measured them.

Might be wheel rates?
(er, scratch that, not likely to get 195 or 211 lb/in wheel rates with 185 lb/in springs...)

Were those springs from a pre-production car? Not sure if that matters, just thinking.

EDIT:
Original spring rates that were measured were based off of the Toyota 86 in Japan.

I thought that the Subaru was supposed to be more softly sprung and the FR-S a bit stiffer?

Probably not. Those rates are close enough that the OEM dampers could be engineered to handle both fairly well.

I think the thinking was the Subaru has stiffer front springs to promote more understeer at the limit which is more in keeping with what is typical of a Subaru car. Scion wanted the car more free, hence the softer front springs. But to counter that the Scion has front struts that are valved differently (stiffer). I suspect they are stiffer on compression a bit, not sure how much more, if any more, rebound they possess.

Eibach has another set of springs they are going to test to confirm today. I'm sure either Tony will post in here or I'll get an email from him at some point.