 trans gearing ?'s |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
| ottox914 |
 Dec 31 2008, 10:37 AM
Post
#1
|
|
The glory that once was.  Group: Members Posts: 1,302 Joined: 15-December 03 From: Mahtomedi, MN Member No.: 1,438 Region Association: Upper MidWest   |
OK, here's what I know, and would like to know. Our 901 has a 2nd gear that can't be changed w/out alot of $$$. If I want a shorter 3rd gear, the shade tree method would be to "flip" a 5th gear set.
If I want a taller 5th gear, would a "flipped' 3rd gear in the 5th gear location be taller than the factory 5th gear, and calm things down on the highway at 80 mph? Yes, it might make for some odd gear spacing, I'll have to think hard about that as well, but as the car is mainly an auto x toy, the short 3rd would be nice, and a taller 5th for the trip to and from the events would be welcome, although the 3,4,5 spacing might not be so good for a track day. |
   |
 
|
  |
Replies
| Dr Evil |
Dec 31 2008, 01:29 PM
Post
#2
|
|
Send me your transmission! Group: Members Posts: 23,041 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region 
|
The best way to get a taller 5th is to flip an H second and put it in the 5th spot. A stock ZD is a .710 ratio, a flipped 3rd (N) is a .793 ratio. You want a smaller number, thus a flipped N will give you a shorter gear. A flipped H is .594 and a flipped HB is .613. The H series are the easiest, most straight forward and cheapest (about $500 or less) way to get taller gearing in 5th.
|
|
|
|
Posts in this topic
ottox914 trans gearing ?'s Dec 31 2008, 10:37 AM
J P Stein I have a GA mainshaft & gear F/S in the classi... Dec 31 2008, 11:10 AM sww914 The ZD 5th gear in the 914-4 trannies is the highe... Dec 31 2008, 11:40 AM ottox914 Thanks for all the replies:
JP: I'm trying t... Dec 31 2008, 03:17 PM
J P Stein
Thanks for all the replies:
JP: I'm trying ... Dec 31 2008, 04:04 PM r_towle I think you cannot flip an H gear onto the 5th gea... Dec 31 2008, 03:27 PM Dr Evil
I think you cannot flip an H gear onto the 5th ge... Dec 31 2008, 05:23 PM race914 Here's the '901 gear flip chart'
T... Dec 31 2008, 05:43 PM |
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 15th January 2026 - 10:25 AM |
Invision Power Board
v9.1.4 © 2026 IPS, Inc.