32V-SVT Posted May 19, 2018 Report Share Posted May 19, 2018 Hey All, I'm looking for a Transmission and was wondering if anyone knew what the OEM gear ratio is on a 2011 GT500 with the SVT-Performance pack? The website I'm looking at shows two different 1st gear ratios... http://www.ddperformance.com/05-up-ford-t-56-magnum-xl/ I'm wondering is the "BA-77" what's considered the Close Ratio version? Also, I'm hoping someone can confirm that this is what is in my vehicle now? Thanks! Quote Link to comment Share on other sites More sharing options...
Robert M Posted July 3, 2019 Report Share Posted July 3, 2019 (edited) On 5/18/2018 at 11:12 PM, 32V-SVT said: Hey All, I'm looking for a Transmission and was wondering if anyone knew what the OEM gear ratio is on a 2011 GT500 with the SVT-Performance pack? The website I'm looking at shows two different 1st gear ratios... http://www.ddperformance.com/05-up-ford-t-56-magnum-xl/ I'm wondering is the "BA-77" what's considered the Close Ratio version? Also, I'm hoping someone can confirm that this is what is in my vehicle now? Thanks! There was a discussion a couple of years ago about the GT500 6 speed transmissions and the gear ratio changes and shifter ratio changes between 2007-2014, but I can't find it right off hand over on SVTPerf.com. Of the two Tremecs shown in your link, the BA-77 is the close ratio. The closer the first gear is to forth (1 to 1), the closer the gear spread between shifts which means less rpm drop between shifts. The further away first gear is from 1 to 1 ratio, the greater the rpm drop between shifts.........wide ratio. A close ratio transmission will best keep the rpms in the "sweet spot" for power and the wide ration will wind up the engine quicker right off the line, but then drop the rpms futher between shifts. Of course gear ratio in the rear end and "use" of the car also has to be factored into the equation. In the old days a 2.32 first gear Top Loader was considered a close ratio transmission, the 2.78 was wide. With the Muncie's it was a 2.20 first for close ratio and I don't remember the wide, possibly 2.54, or maybe that was a Borg Warner T-10? <<<That was too long ago...... With the addition of Overdrive in these newer transmissions (5th and 6th), the first gear ratio's have gone out a little further. If you have ever been around dirt bikes, you will notice they wind the engine up and then there is very little rpm drop between shifts, that is close ratio, it keeps the engine in the desired power band with minimal drop in HP and Torque between shifts. R Edited July 3, 2019 by Robert M Quote Link to comment Share on other sites More sharing options...
Secondo Posted July 4, 2019 Report Share Posted July 4, 2019 The 2007-2012 GT500 stock Tremec TR6060 transmission has a 1st gear ratio of 2.97. The 2013-14's are 2.66. https://en.m.wikipedia.org/wiki/Tremec_TR-6060_transmission Quote Link to comment Share on other sites More sharing options...
Robert M Posted July 4, 2019 Report Share Posted July 4, 2019 (edited) 15 hours ago, Secondo said: The 2007-2012 GT500 stock Tremec TR6060 transmission has a 1st gear ratio of 2.97. The 2013-14's are 2.66. https://en.m.wikipedia.org/wiki/Tremec_TR-6060_transmission ^^^Thanks for that link, I was thinking that all 2007-2012's were the same, but did not dig into it further. I knew that 2013/14's were different. So between these two, the 2013/14 transmission would be considered the "close ratio". It would be interesting to compare the 2013/14 transmission and the 2007-2012 transmission side-by-side in a swap in the same car with the same horsepower and the 3.31 gear as was standard in the 2007-2009 and 2013/14. Did 2010 also have a 3.31? I don't remember......It looks like there were changes in 2011 also, but not 1st, 2nd, 3rd or 4th......only o.d,'s and reverse........... What a large drop in rpms from 2.97 1st to 1.78 2nd in comparison to 2.66 1st to 1.82 2nd......... 2007 Ford Mustang Shelby GT500 2.97 1.78 1.30 1.00 0.80 0.63 2.90 2011 Ford Mustang Shelby GT500 2.97 1.78 1.30 1.00 0.74 0.50 3.98 2013 Ford Mustang Shelby GT500 2.66 1.82 1.30 1.00 0.77 0.50 3.98 R Edited July 4, 2019 by Robert M Quote Link to comment Share on other sites More sharing options...
Secondo Posted July 4, 2019 Report Share Posted July 4, 2019 I agree with your assessments. The 2010-2012's have 3.55 rear axle ratios. I felt the 3.31's were too tall in the 2007-09's. Shelby installed 3.73's in their Super Snake builds of those years. I enjoy the 3.73's in my GT. I haven't ridden in or driven a 2013-14 GT500 yet to assess the gears. But I would imagine the 3.73's would work best for the street and strip. Quote Link to comment Share on other sites More sharing options...
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