weird 6th gear problem

wstar

It's about as easy for them to run the numbers as it was for me when I first read this thread (6K in 5th on a 6MT = ~128mph), if I were you I'd find some other way to explain the problem to them than claiming you expect that to work on the street, because they will drag out the "that's illegal everywhere and/or you're tracking the car so we can't help you" angle.

Anyways, running the numbers some more makes for an interesting angle on their claims about 6th either not being designed to be shifted into at high RPM and/or it being limited/locked-out from those shifts.

On the Sports Package wheels and rubber, on a 6MT car, 7500 RPM in 5th is right at 160mph, which is also the ECU speed limiter. So technically, that means there's no reason to go to 6th at high speed at all except as an overdrive gear to drop the revs and cruise with more efficiency. Even then at those speeds it's not much of an overdrive: at 160mph (7500RPM), the 5->6 shift drops you to about 6K. At 128mph, for comparison, the 5->6 shift drops you from 6K to about 4750.

So their angle here may be that they know the 6th synchros are weak for a hard high-rpm shift and they don't care, because honestly if you're accelerating hard at those speed ranges, there's no reason to leave 5th ever on the stock ECU. If you wanted to back off the throttle and then cruise somewhere in that range, then you'd go to 6th, but that would be a soft and simple shift, not a WOT shift into 6th still accelerating.

You might play with it more and see if this line of reasoning holds up. I don't have a 6MT so I can't really help.

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