Ah yes! we’re talking transmissions today.
The Datsun 280z came with two manual transmission options in it’s lifetime: the 4-speed and the 5-speed (for which the car is also badged noting the upgrade). And after driving the 4-geared ’77 280z for nearly two years, I’m kinda at that point: I want more gears! :]
But wanting is often different from needing, and we just need to build a case to bridge the two. Call it, justification through research – let’s do it.
Here are the gear ratios for Datsun / Nissan transmissions at the time*:
’74-’78 280z 4-speed:
1st…. 3.321
2nd… 2.077
3rd…. 1.308
4th…. 1.000
’77-’78 280z and first year ’79 280zx 5 speed:
1st…. 3.321
2nd… 2.077
3rd…. 1.308
4th…. 1.000
5th…. 0.864 (13.6%)
’80 280zx 5 speed:
1st…. 3.062
2nd… 1.858
3rd…. 1.308
4th…. 1.000
5th…. 0.773 (22.7%)
’81-’83 280zx non turbo 5 speed:
1st…. 3.062
2nd… 1.858
3rd…. 1.308
4th…. 1.000
5th…. 0.745 (25.5%)
As you can see the ratio drastically changes in the ’80 280zx 5-speed when going from 1st to 2nd. Additionally, the ratio of the 5th gear gradually moves further from 4th’s 1.0 ratio as the years go on (differences noted by percentage changes).
With regards to the first difference mentioned, the change to 2nd gear really depends on driving style and fuel economy needs. A taller ratio in 2nd (closer to 1.000), will require more power, higher RPM, and thus more fuel. Gears 3 and 4 are ok because we’ll be moving quite a bit at those gears, but 2nd is tricky. Spend more time in first, or bang through gears?
For me, I actually spend a lot of time in 2nd. I usually take back roads for my commute, and time out traffic lights so i’m rolling into the green. So it’s natural to use 2nd to get the rolling 280z moving again (deeper than that, I’m terribly used to 2nd because i swear we used to have to start my brother’s 510 in 2nd gear – 1st was kind of wonky…though he says it was never that way hahaha).
So just by looking at the gearing, we can see with the early Datsun 5-speeds we’ll get better proportioned low-end, but not as tall on the top-end. Now that we’ve decided on a 5-speed…what are our 6-speed options? :]
Data specs from Ratsun post, DatzenMike, 09 July 2012.
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