Originally Posted by xluben
The STI has a 1.1:1 center diff ratio. The front is a 3.9 and rear is a 3.54. Due to the center diff ratio the rear 3.54 matches the 3.9 of the front.
You need to use the 3.9 FD for Virtual Dyno.
I'll look into the tire diameter. It should be correct. I believe the vehicle weight is an average between the two trim levels.
Thanks, xluben, for the correction about the FDR.
In my case, however, I'm certain the tire info is incorrect... possibly due to the optional tire/wheel combo it came with. First I checked the manufacturer's info, then I took the tire off and repeatedly measured it to verify.
The weight is what's in the book, although I haven't actually weighed it yet.
In the end it's somewhat moot, as VD has been a tuning tool... and a good one. Differences are what matter to me, not bragging rights.