What Are The Transmission Ratios On A 1970-1973 Fairlady Z Five Speed?

[WingZr0]

HI FOLKS

TRIED THE SEARCH ENGINE AND CAME UP EMPTY.

I SAW ON EBAY A FEW MONTHS AGO A 1970-1973 JDM FAIRLADY Z 5 Speed Close Ratio Manual Transmission but i can't remember what tha 1st, 2nd, 3rd, 4th, 5th and Final Drive Gear Ratios were.

He had them listed but i can't seem to find it in my saved emails file. I'm trying to see what the set up be like on my New Old Stock R180 4.37 diff from Datsun Competion in a 1970 L24.

Please help if any one would know. Also is a 1980 ZX engine faster at top speed than a L24?

Thyanx guys!

~Z~

[Arne]

Ratios for the early Type A 5 speed are in the middle column of the attached spec chart.

[WingZr0]

Thyanx Arne

so far the calculator says at 8000 RPM (45, 72, 103, 134, 158 MPH) for 1st through 5th gear.

At 5000 RPM i got (24, 45, 64, 83, 100MPH).

Think tha one i saw on the Bay started off with 1st gear being at something like 2.2XX give or take maybe. I jus found ~though the search engine~ there were different types of trannys for five speeds offerd for the 240z.

I thought they only came with 4speeds though.

they must be rare cause i only that one for sale.

~Z~

[Nigel1943]

Problem you have with a 4.37 diff is that you need a "tall" 1st gear and if the one you saw was 2.2ish that would be about right with 14" wheels. Alternatively you could up a size in wheels to 15" or 16" depending on what tyre profile you intend to use.

[WingZr0]

Problem you have with a 4.37 diff is that you need a "tall" 1st gear and if the one you saw was 2.2ish that would be about right with 14" wheels. Alternatively you could up a size in wheels to 15" or 16" depending on what tyre profile you intend to use.

THYANX NIGE

Thats vey interesting but i really don't grab tha concecpt of gears to well yet,

Is that the lower the numbers the taller the gears or is it reverse?

I know that on old Railroad Steam Engines the rule was the taller the driving wheels were the quicker and faster the top speed would be. Thats why all passenger train engines had big wheels so they could go from city to city with the least amount of time. Competition betwen Train companys was fierce in tha 1930's and 1940's and times fell like rocks as wheels became ridiculously huge!

What i'm trying to get at is that your saying If i had bigger rims on my Z my top end would be faster?

If so (or) not, what would be the problem witt having a 4.37 rear end?

~Z~

[WingZr0]

WOW !

jus found out thyat with 18 inch Tenzo Racing rims the speeds come out at 8000 RPM as

(49, 78, 111, 149, 171 MPH !) with 4.37 Diff

(58, 92, 131, 172, 201 MPH) with 3.70 Diff

Yeah, think ima get those Tenzo's ^_~

[nwcubsman]

THYANX NIGE

Thats vey interesting but i really don't grab tha concecpt of gears to well yet,

Is that the lower the numbers the taller the gears or is it reverse?

What i'm trying to get at is that your saying If i had bigger rims on my Z my top end would be faster?

If so (or) not, what would be the problem witt having a 4.37 rear end?

~Z~

~z~,

The higher the number, the lower the ratio. Just like in the transmission, when you move to a taller gear the ratio moves lower. Your 4th gear should be 1:1. Over drive is when you get below 1:1, or something like 1:.78. Think of it as for each revolution of the engine the tires move fewer revs. As you move up in gears, the ratio gets closer to 1:1. The engine spins slower and the tires spin faster. Hope that is more clear. Somehow, I don't think so.

Good luck.

[WingZr0]

Cubs fan hunh?

I was born in Vancouver, WA and have family there. I was raised mostly in Indianapolis Indiana and had my first beer when i was 8 with my Great Grandpa watching a Cubs Game!

I love Cubs !

And yes, it all makes since now, time for me to do some ~MAD~ calculations!

I jus missed this on EBAY. It has rust and stuff but i was wondering if i could get ya's oppinion on wheater or not it was a good deal.

I was think about dropping a GT-R engine in it untill i came across a 260Z i saw for the same price but in better condition.

I figured if I waited for another 1970 240Z, I could find one in better shape and save the money on body work I would of spent on this one and spend it on parts instead.

Somethings telling me to kick myself though

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=006&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=160069396004&rd=1,1

~Z~

[WingZr0]

added the link :stupid:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=006&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=160069396004&rd=1,1

[nwcubsman]

More of a baseball fan really. Allegences alter from time to time. Always a soft spot for the Cubbies.

I think the '70 needed an awful lot of work. But that and a '70 parts car, which I could get ahold of cheap, and you could have had a very inexpensive project. With the salvage title, it leaves an opening to really bastardize it. I am one of those that think a series one car is better off stock. Thats why I ended up with an extra '73. But, to each his own!

[Nigel1943]

WOW !

jus found out thyat with 18 inch Tenzo Racing rims the speeds come out at 8000 RPM as

(49, 78, 111, 149, 171 MPH !) with 4.37 Diff

(58, 92, 131, 172, 201 MPH) with 3.70 Diff

Yeah, think ima get those Tenzo's ^_~

18" rims are a bit too big for your purposes. Don't assume you are going to pull those speeds you mention, in fact you certainly are not! I would think 16" would be big enough with low profile tyres or 15" with 70 series tyres using any of the standard 5 speed Z trannies and your 4.37. You'll have to do the calculations yourself. Get a late 280zx tranny if you can for the best ratio's.

[WingZr0]

Hmmm... You do make a point.

That did sound kinda rediculous, maybe i should switch out for monster truck rims. A nice set of 82's should do !

~Z~