Found: 280zx 5-speed..close ratio!

Since last post I’ve been scouring Craigslist like a fiend (my wife knows). And to everyone else who may not know, it’s part of my morning routine: CL > search ‘datsun’, search ‘240z’, search ‘mgb gt’, search ‘alfa 2000’.

So after doing a search on 280zx, I was able to find a gentleman named Randy who only lives a few blocks away, parting out his 1983 280zx! yes! 1983! close ratio! Close ratio? what’s that? Before we get into the technical nitty-gritty, let’s wrap up the craigslist story with 1) I pinged Randy within 6hrs of his post, 2) he’s got a super clean 1983 Nissan / Datsun 280zx he’s parting out if you want something (sans engine [that’s his], and transmission [that’s mine!]). More on Randy and his exciting 280zx project in the next posting…

“Close ratio”
The 280z’s L28 engine is just too powerful to be held back by exceedingly high RPMs on the highway, governed by a 4-speed. In late ’77, Datsun outfitted the manuals with a 5-speed transmission that would ease the cruising speed woes. Here’s a great table from the guys over at datsunzgarage.com:

Let’s note a few things:
1) The first 5-speed, marked here as “280a” (1977-1980) was geared just like their 4-speed, but with a tall 5th at the end.
2) In 1981, they used a new 5-speed, with ratios different in the 1st, 2nd and 5th gears. This version is often referred to as the “close ratio” 5-speed.
3) Check out the “BW T5” (Borg-Warner) and it’s 1st and 5th ratios. A nice small 1st to rocket it off the line, and a nice tall 5th to safe gas on cruising speed.

Luckily for me, I picked up a 1983, and i think it’ll be just dandy!

About justinyee

engineer, musician, designer, artist, dreamer, positive attitude w/ best intentions, critic and friend. i believe in truth, justice, beauty, and above all: love. View all posts by justinyee

One response to “Found: 280zx 5-speed..close ratio!

  • Jon Tong

    Justin, this is getting ridiculous! We gotta hang out sometime and swap stories about our Zs. I took out the series 1 4 speed out of my 240z and put in the close-ratio 5 speed out of an 81. Best thing I’ve ever done on the Z. Luckily you have a 280 and not a series 1 240 that required a few mods. Yours should pretty much be a clean swap. I ended up swapping my r180 diff with 3:36 gear ratio to the 81 N/A zx r200 with 3:90. In other words I have the drivetrain of a zx in my 240, and it was so worth it. It’s like night and day for performance and mpg. My SU carbs are pretty worn, but after doing these swaps I’ve gone from the stock 19mpg highway to 23.6 mpg highway. Your fuel injection should put you up in the high twenties for sure. I know my zx used to consistently give me around 28 mpg if driven at 65mph for long trips.

    – Jon Tong

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