Okay, I know we want to shift so that the rpm at the next gear is at the same torque level as the previous gear. In other words, shift on equal sides of the torque/rpm curve of the engine. Or is there a better way?

What I need to know is the proper formula to derive this. I used to have a complete breakdown and the exact formula and how to compute it, but now I cannot find this. This sux.

BTW, I don't mean this just for our Lightning. Obviously it needs to be shifted around 5500 from the factory, even though it's not.

BfB

 

don't have a clue what the formula is , but I was raised in Mobile and got a brother who is still stuck there and will never leave. Bought my L there on the 19th of this month from Coastal. Wife got an 02 Explorer also. Maybe when I come back on my way to Biloxi we can have a beer and talk truck!! Long Live the Flora-Bama!!

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'01 White Lightning <1K miles presently a '97 Ram with a little ol 318 also

 

Lots of theories about what RPM is ideal for/after a shift:
1) be right at your torque max after a shift,
2) be half-way between torque max and Hp max
3) be at the same torque # after the shift, as before the shift, this is your "equal sides" of the torque curve.

I'm not sure how well #3 would work on the L, as the torque max is so low.
Anyway, a very simple forumla to get shift point is based on your desired post-shift RPM.

1-2 shiftpoint = desired rpm * 1st gear ratio / 2nd ratio
2-3 shiftpoint = desired rpm * 2nd gear ratio / 3rd ratio
etc.
So if in 2nd you want to end up at 3000rpm, ideal 1-2 shift point is: 5313rpm.


Useful data for 2001 L:

1st gear ratio: 2.71
2nd gear ratio: 1.53
3rd gear ratio: 1.00
4th gear ratio: 0.71

Max torque: 3000 rpm
Max Hp: 4750 rpm

 

You can calculate till your fingers go numb or you can goto www.extremegeez.com and buy a data recorder and throw away the calculator. They work way cool. If you call, tell Byron that Andy sent you.

AW