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Deslock · 04-07-2012, 08:54 AM

Not to resurrect an old thread, but I thought it'd be interesting to compare the COBB dyno to the January 2012 screencap.

To recap, Spaceywilly and Ryephile plotted curves based on the Jan 2012 screencap, but the plots showed peak power and torque coming at earlier RPMs than the official numbers, and much lower tranny losses than one could reasonably expect (only 3.5%). It seemed too good to be true, and there was speculation about the hard-to-read scale. WingsofWar plotted a hypothetical curve with a different scale.

Earlier in this thread, old greg and I had plotted wheel torque for the original crude curve from the .jp website, and then I later plotted against both interpretations of the screencap.

Now a video has surfaced showing results from a COBB dyno run of a stock BRZ. My initial reaction was "Oh, only 164 whp... that's a bit low." Then I looked more closely and realized its shape is close to the original interpretation of the Jan 2012 screencap. Output is lower, but it still seems too good to be true. If COBB's dyno run is representative of a typical BRZ:

Peak torque is at 4500 and 5800 RPM (official spec is 6600 RPM)
Peak power is at 6200 RPM (official spec is 7000 RPM)
Peak power is a tad low due to the 6200 RPM dropoff
The FA20 is underrated below 6200 RPM (since it shows a tranny loss of only 6%)

COBB's dyno stopped at 6800 RPM; here's a plot assuming it continues to drop at the same rate until 7400:

Wheel torque for 6MT with 4.1DR (using a tire dia of 24.3"... it might be as low as 23.9" or as high as 24.6"):

Estimated Acceleration vs 2004 WRX:

Something seems amiss because the 2004 WRX's traction advantage shouldn't be enough to overcome a deficit this large (going by MT's BRZ test, the 2004 WRX hits 0-60 and the 1/4 in less time, but the BRZ traps at a higher speed).

Of course, I'm comparing cars run on different dynos with different conditions (and perhaps COBB's BRZ had an especially strong engine or the WRX from that dyno was on the weak side).

Estimated Acceleration vs 2009 WRX:

Estimated Acceleration vs GTI:

04-07-2012, 08:54 AM	#205
Deslock Senior Member Join Date: Oct 2009 Drives: 2013 DZE/01 (sold for MX5 ND1) Location: western MA Posts: 871 Thanks: 265 Thanked 269 Times in 133 Posts Mentioned: 15 Post(s) Tagged: 0 Thread(s)	Not to resurrect an old thread, but I thought it'd be interesting to compare the COBB dyno to the January 2012 screencap. To recap, Spaceywilly and Ryephile plotted curves based on the Jan 2012 screencap, but the plots showed peak power and torque coming at earlier RPMs than the official numbers, and much lower tranny losses than one could reasonably expect (only 3.5%). It seemed too good to be true, and there was speculation about the hard-to-read scale. WingsofWar plotted a hypothetical curve with a different scale. Earlier in this thread, old greg and I had plotted wheel torque for the original crude curve from the .jp website, and then I later plotted against both interpretations of the screencap. Now a video has surfaced showing results from a COBB dyno run of a stock BRZ. My initial reaction was "Oh, only 164 whp... that's a bit low." Then I looked more closely and realized its shape is close to the original interpretation of the Jan 2012 screencap. Output is lower, but it still seems too good to be true. If COBB's dyno run is representative of a typical BRZ: Peak torque is at 4500 and 5800 RPM (official spec is 6600 RPM) Peak power is at 6200 RPM (official spec is 7000 RPM) Peak power is a tad low due to the 6200 RPM dropoff The FA20 is underrated below 6200 RPM (since it shows a tranny loss of only 6%) COBB's dyno stopped at 6800 RPM; here's a plot assuming it continues to drop at the same rate until 7400: Wheel torque for 6MT with 4.1DR (using a tire dia of 24.3"... it might be as low as 23.9" or as high as 24.6"): Estimated Acceleration vs 2004 WRX: Something seems amiss because the 2004 WRX's traction advantage shouldn't be enough to overcome a deficit this large (going by MT's BRZ test, the 2004 WRX hits 0-60 and the 1/4 in less time, but the BRZ traps at a higher speed). Of course, I'm comparing cars run on different dynos with different conditions (and perhaps COBB's BRZ had an especially strong engine or the WRX from that dyno was on the weak side). Estimated Acceleration vs 2009 WRX: Estimated Acceleration vs GTI: Last edited by Deslock; 04-07-2012 at 09:48 AM.