kahmann Posted July 5, 2009 Report Share Posted July 5, 2009 What is the standard drivetrain loss for the SGT? I've heard anywhere from 12% to 19% from some reputable people whose opinions I trust. I was told by AFBLUE in my last dyno thread that it's 12%, based on the fact that several SGT's base dyno'ed at around 280 RWHP. Taking into account the advertised 319 crank HP, you come up with about 12% loss. Are all of those STD or SAE #'s? Is the 319 crank HP verified by some sanctioning body? I honestly don't know how that works, but if not accurate, the actual flywheel # would probably be less than the advertised HP, further confusing the issue. In the April 08 edition of Motor Trend, however, they run a comparison test of the 08 SGT against the Roush Stage 2 and the Saleen S281-3V. They dyno'ed each car to compare and mentioned that they would be "expecting a 15% loss due to drivetrain inefficciencies." The SGT-C that Motor Trend was using pulled 273 RWHP on their corrected dyno. Assuming that the advertised 319 HP is accurate, then the drivetrain loss on that SGT-C was just a hair below 15%. So which is it? This has always been kind of novel to me when running my SGT on the dyno, because a higher drivetrain loss meant that the final crank HP would be higher. So after hearing 17%-19%, I never looked back! My 347 RWHP would equal 420 crank HP based on 18% loss, but would only equal 409 HP based on 15% loss or 400 HP based on 12%, which simply means less bragging rights I guess. Nothing too important. But now that I'm about to install a supercharger on an already modified engine (with stock internals), this calculation has become much more important to me, since it will help determine how much boost I inevitably operate the blower at. Two final points: 1) Regardless of what the actual drivetrain loss is generally accepted to be for the SGT, is the % any different for the GT500? If so, why? 2) Is there a dyno sheet thread in the SGT section of the forum? If so, I can't find it. Perhaps it would be useful for all of the guys that have had their SGT's on a dyno to post their #'s and sheets in a dedicated thread (especially base dyno's)? Thanks for any and all input, citations, or experience. Ken Link to comment Share on other sites More sharing options...
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