Gear Ratios for a type 911 transmission?

[randywebb]

Does anybody know the gear ratios for a 5 speed trans. from a 1971? It's a 911/01, and the number on the tranny is 7114447.

Thanks!

[TimT]

first: 11:34
second: 18:32
third: 23:28
fourth: 27:25
fifth: 29:22

[Zeke]

Randy, I'm glad you asked, because I've been meaning to look this up for myself. 1st thru 5th are as follows: 11:34. 18:32, 23:28, 27:25 and 29:22.

If you make me work harder, I could give you the letters for each gear. Or someone can post a link to a chart that I've seen.

For the ratios themselves, I know you can figure that one out. And as far I have seen, the T E and S models all used the same unless it was a special order.

OK, here are the charts.

[randywebb]

Thanks!

[304065]

I built a neat little sheet in Excel, you punch in A GA O V ZA and it spits out the gear ratios (it does a simple VLOOKUP function on the gear database). Will also tell you max speeds in gears. For example, Randy, for your box (which is the same as the one in my '71) with the STOCK 185/70 tires on 6x15 rims, with 650mm tire diameter (let's ignore the static and dymanic rolling radius) theoretical speeds are: I-37 II-65 III-95 IV-142 V-152 at the 911E's 6750 redline.

[randywebb]

Nice - can I get a copy of that .xls?

And what if I have 240 hp?

[Early_S_Man]

[304065]

Randy, pm me an email and I'll send you a copy.

If you have 240HP, same theoretical speeds, you just have a better chance of reaching the last one. According to the factory, maximum speed was 137 mph with 155 HP.

[randywebb]

Thx - Email sent.

Warren - what does effective from “Model 70” mean? model year 1970?

[Early_S_Man]

Randy,

It is just a bit ambiguous, but I believe that is what it means, since the Type 911 transaxle was introduced with the 1970 models.

[MACHINEMON]

Does anyone have carts like these for 915'S

[Fishcop]

Could someone explain to me how to 'read' those numbers? For example what does 25:27 mean?

Cheers

[jluetjen]

For example what does 25:27 mean?

25 teeth on the input gear
27 teeth on the output gear

So the overall ratio is (27/25 =) 1.08 to 1, so the input shaft will turn 1.08 times for every one turn of the output shaft.