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Cool thanks for the clarification on the transmission ratios. I'm curious then why bother? The overall gearing in both cars remains nearly unchanged.
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That assumes my math is correct. I think overall it is, but I would like someone to double check it.
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The gearing ends up nearly the same except for 4th gear will benefit noticeably from the 3.91 gears in the back, and to a lesser extent 3rd.
I guess actually that makes sense as 3rd and 4th gear are geared a little bit lower than an SS, because you will probably spend most of the time on road course in those two gears... I can especially see the lower ratio helping out in 4th where you would likely be when blasting down a straight. The rest of the ratios remain the same (an nearly identical for 5th a 6th for cruising).
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It does make sense and personally for the cars intention I think they did an excellent job on the transmission. I would not have been as happy if they just slapped a 3.91 in there and kept the ratios the same. It would have sacrificed fuel economy and maybe even driveability in certain gears.
The first 1-4 (even 1-3) gears are acceleration gears. The overdrive 5-6 gears are just there for fuel sipper mode. For the most part that's their job in life.
I agree with your assesement and it's really nice that when this car goes back on the street and you're on a long road trip you still have the same rpm and speed in 5th and 6th so you don't have to sacrifice fuel economy or rev out the engine to cruise.
I just have to say again. I'm really happy with that they did considering this is intended to be a street/track car. Who wants to be on the expressway revving out the engine on a road trip especially since you will not be using 5th or 6th on a track.
Final drive ratios of 3.91 aren't always as big as they seem. It also depends on the wheel/tire size and ratios in the tranmission. The Challenger (slightly different transmission ratios) has 3.91 final drive too, but with similar gearing to this so at 60 mph in top gear the engine is spinning at around 1400 rpm. The camaro ss with 3.45 final drive in top gear at 60 mph is also spinning at around 1400 rpm and the 1LE package with 3.91 final drive in top gear at 60 mph will still be spinning at 1400 rpm.
The mustang, on the other hand, with the optional 3.73 final drive ratio (in their track pack) which is taller than a 3.91 final drive is spinning at 2000 rpm at 60 mph in top gear because of transmission gearing and wheel size. So in reality is it geared shorter. I have not driven one, but the mustangs just keep the transmission ratios the same and put on a different final drive, which I have heard with a 3.73 final drive makes 1st gear too short. I would much rather have the 1LE gearing, but that's just my personal preference.
I also like the extra cooling added to the transmission. I am just curious if cooling and gear ratios are the only changes or if there are other changes that make the transmission beefier. Does anyone know? Can they even be revealed at this time?