Focus Fanatics - View Single Post - Focus ST Dyno Numbers
View Single Post
Old 09-13-2012, 08:08 AM   #14
swansong
Focus Addict
 
swansong's Avatar
 
Join Date: Feb 2011
Fan#: 83576
Location: Appleton, WI
What I Drive: 2008 Saab 9-3 Aero SportCombi XWD

Posts: 1,418
FF Reputation: 9 swansong Good Standing Member
Buy-Sell-Trade Rating: (4)
Quote:
Originally Posted by Outlaw5.0 View Post
Comparing engine Dyno to chassis Dyno is impossible without knowing the actual drivetrain losses. Maybe the loss is less than 15-18%?. The 2013 GT500 is a good example of reduced losses. Lets not leave out dyno accuracy. If believing the ST makes 267 horsepower or what ever makes you happy, then so be it.
Right, we can't know exactly how these real world numbers compare to the crank numbers, because of the uncertainty in drivetrain losses. Dyno accuracy and peculiarities are mitigated by the sampling of many different dyno's and averaging the results out. Of course we only have a small sample to deal with, but it's a start. So, even if we assume a 10% loss, the numbers still look good:

Average HP: 227.04 x 1.11 = 252.27 HP
Average TQ: 276.316 x 1.11 = 307.02 ft/lbs

It certainly seems as though the torque number is being underrated. By quite a bit.

(Aside: hopefully we all realize why I'm multiplying the whp/wtq by 1.11 instead of 1.10 for a 10% loss, and 1.18 instead of 1.15 for a 15% loss. Can explain if necessary.)
__________________
Mine: 2008 Saab 9-3 Aero SportCombi XWD: 82k, Black, MANUAL
Gone: 2002 SVT, #1654

Hers: 2010 Focus SES: 70k, Ebony, Auto, Moon and Tune
swansong is online now  
    Reply With Quote