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914World.com _ 914World Garage _ 912 5 speed gear ratios?

Posted by: Bleyseng Aug 10 2005, 07:52 PM

anyone know what the stock gears are in a 912 901 5 speed tranny?

thanks

Posted by: lapuwali Aug 10 2005, 08:39 PM

Yes. A F M S X. The 4-speed is A H Q X.

Posted by: Aaron Cox Aug 10 2005, 09:57 PM

and then the legendary 923 box for a 912E ( a 915 with a 901 splined input shaft)

someone said there was an early 911/912 5 speed that was A E I O U

Posted by: lapuwali Aug 10 2005, 10:21 PM

QUOTE (Aaron Cox @ Aug 10 2005, 07:57 PM)
and then the legendary 923 box for a 912E ( a 915 with a 901 splined input shaft)

someone said there was an early 911/912 5 speed that was A E I O U

The so-called "vowel" box would have been a close-ratio for short-circuit racing, or maybe for hillclimbs. U would be pretty short for 5th (105mph at 6000rpm). The X top-gear in the 5-speed 912 is quite a bit shorter than the top gear in a 914. 70mph is 4000rpm. The earliest 911 pattern (1964) was AA GA O U Y.

Posted by: Bleyseng Aug 10 2005, 11:01 PM

QUOTE (Aaron Cox @ Aug 10 2005, 08:57 PM)
and then the legendary 923 box for a 912E ( a 915 with a 901 splined input shaft)

someone said there was an early 911/912 5 speed that was A E I O U

sometimes "Y"?

Posted by: Kostamojen Aug 11 2005, 12:10 AM

Just curious, but is there a good reference website or thread with various porsche transmission gear ratios, final drives and such? And since im a Noob here, maybe a reference for what the A E I O U, etc. lettering refers to exactly in gear numbers...

Posted by: redshift Aug 11 2005, 12:13 AM

QUOTE (Bleyseng @ Aug 11 2005, 01:01 AM)

QUOTE (Aaron Cox @ Aug 10 2005, 08:57 PM)
and then the legendary 923 box for a 912E ( a 915 with a 901 splined input shaft)

someone said there was an early 911/912 5 speed that was A E I O U

sometimes "Y"?

AND W!

"Nucalear"

M

Posted by: Jake Raby Aug 11 2005, 12:26 AM

My 923s gearing was the same as the same year 915- Both my tranny's are... The difference was the "E" had a shorter tire....

923 trannys areweird, much more is changed than just the input shaft.

Posted by: ArtechnikA Aug 11 2005, 06:59 AM

QUOTE (Kostamojen @ Aug 11 2005, 02:10 AM)
Just curious, but is there a good reference website or thread with various porsche transmission gear ratios, final drives and such?

of course!

if Charlie Davis got $1 for every time someone linked to his page, he'd be a very rich man...

http://members.rennlist.com/chuxter/901&915ratios.htm

Posted by: Bleyseng Aug 11 2005, 07:07 AM

QUOTE (lapuwali @ Aug 10 2005, 07:39 PM)
Yes. A F M S X. The 4-speed is A H Q X.

Hmm, I don't see it listed on Chuxter's site like that. I guess I will swap in the shorter fourth gear thou.

http://members.rennlist.com/chuxter/901&915ratios.htm

Posted by: Matt Monson Aug 11 2005, 08:24 AM

QUOTE (lapuwali @ Aug 10 2005, 08:21 PM)

QUOTE (Aaron Cox @ Aug 10 2005, 07:57 PM)
and then the legendary 923 box for a 912E ( a 915 with a 901 splined input shaft)

someone said there was an early 911/912 5 speed that was A E I O U

The so-called "vowel" box would have been a close-ratio for short-circuit racing, or maybe for hillclimbs. U would be pretty short for 5th (105mph at 6000rpm). The X top-gear in the 5-speed 912 is quite a bit shorter than the top gear in a 914. 70mph is 4000rpm. The earliest 911 pattern (1964) was AA GA O U Y.

The "vowel" box is the 902/50 if you are looking at the case mark to try and identify one, while the 902/0 and 902/1 are respectively the four speed and 5 speed boxes that were in the 912's. Even though they got a 902 transmission type, they were still 901 boxes when it comes down to it.

For quick reference the ratios are as follows:
A: 11:34
H: 19:32
Q: 24:27
X: 28:24
&
F: 18:34
M: 22:29
S: 25:26

Let me know if you need ratios for any other letter designations or spec boxes. I have all of the factory Technical Specifications books as the ratios changed significantly from year to year and model to model in the 911 line following '64...

Posted by: Kostamojen Aug 11 2005, 12:50 PM

QUOTE (ArtechnikA @ Aug 11 2005, 04:59 AM)

QUOTE (Kostamojen @ Aug 11 2005, 02:10 AM)
Just curious, but is there a good reference website or thread with various porsche transmission gear ratios, final drives and such?

of course!

if Charlie Davis got $1 for every time someone linked to his page, he'd be a very rich man...

http://members.rennlist.com/chuxter/901&915ratios.htm

Thanks alot

Posted by: Aaron Cox Aug 11 2005, 01:13 PM

scanned factory stuffs....
user posted image

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