Quote:
Originally Posted by Red Bread
Ultimately he's really just asking for a deeper overdrive, which can easily be accomplished with a six speed. Having driven the Corvette and 991, I'd happily choose a 6s over either of those, just as Porsche did with the GT3.
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The problem with that is the massive GAP between gears. I happen to have a 7 speed manual, and the gap from 4th (1:1) to 7th (0.6:1) is insanely large. Like unusably large. You'd pretty much have to wind out 5th to a pretty high RPM to go into 6th, if 5th is the usual 1:1 and 6th is the overdrive like most 6 gear setup.
If a tall 6th is the goal, it's probably better achieved with say, a 0.8x:1 6th and a 2.7x final drive rather than the typical 2.9x or 3.1x rear that BMW puts into their manuals. Or a 7 speed with 5th being the typical 1:1, and 6th being 0.8x:1, then a 7th that drops down to 0.64:1 or something to that effect, and retain a short-ish final drive.
But again...Since all the 7 speeds on the market are mated to specific rear drives via a transaxle setup, it isn't like the current ZF 6 speed where the transmission and diff are connected via a driveshaft therefore opening up all the world of possibilities for rear end ratios. On the Tremec TR-7060 7 speed you only have like 3 rear end ratios you can possibly pick from, take it or leave it.