|
|
|
|
| Author |
|
|
Registered User
|
What Ratio 5th gear for 915 with 7:31
I have 915 trans with 7:31 R&P. Going to use 25% for Auto cross. What ratio 5th should I put to drive at freeway speeds for long drives to wine country.
|
||
10-21-2015, 09:18 PM
|
|
|
Registered
Join Date: Apr 2005
Location: outta here
Posts: 53,169
|
Tallest one you can find. TL (31:22) is the tallest one that comes to mind.
JR |
||
|
10-22-2015, 05:47 AM
|
|
|
Registered
Join Date: Mar 2001
Location: Marysville Wa.
Posts: 22,431
|
1976 912E used a 21/29 = 0.72.
__________________
https://www.instagram.com/johnwalker8704 8009 103rd pl ne Marysville Wa 98270 206 637 4071 |
||
|
10-22-2015, 06:24 AM
|
|
|
gearhead
Join Date: Nov 2007
Location: Loverland, CO
Posts: 23,539
|
It should already have a TL or TM in it. You want to stick with a factory gear. There are taller gears in the aftermarket but race gears are too noisy for a long highway cruise.
__________________
1974 914 Bumble Bee 2009 Outback XT 2008 Cayman S shop test Mule 1996 WRX V-limited 450/1000 |
||
|
10-22-2015, 06:39 AM
|
|
|
Registered
Join Date: Jan 2009
Location: Marietta, Ga (Atlanta)
Posts: 2,970
|
Quote:
Amen to that, put a .63 Powerhaus 5th gearset into my 915/70 8:31 with a 3.6 motor. It cruised along great on the highway with nice "overdrive" feel. However the noise and whine drove me nuts! Went back to stock 5th gear. Have since acquired a new factory TL 29:21 5th gearset but have not installed it yet, I'm sure it will make me happy!
__________________
'80SC Widebody 3.6 transplant Anthracite "The Rocket" Long gone but still miss them all: '77 911 Targa, '72 BMW 3.0CS Coupe(finest car I ever had!) '71 911T Coupe White, '70 911T Coupe Blue '68 911 Coupe Orange, '68 911L Soft Window Targa |
||
|
10-22-2015, 07:09 AM
|
|
|
Registered
Join Date: May 2014
Posts: 216
|
I put a taller 5th in mine after going from an 8:31 to a 7:31 for auto-x and took it back out less than a year later. I don't recall the details because it was 15 years ago that this happened, but I know that I really didn't like it. I was doing some track days so that might have had something to do with it. With the 7:31 the stock 915 gearing on 16" Wheels seems to end up at about 10mph per 500 RPM
__________________
1971 911T British Racing Green 3.2L 2013 981 Boxster S Aqua Blue/Grey 2014 981 Cayman S Agate Grey/Black enjoyed and passed along: 1990 964 C2, 2007 C4S Cabriolet, 1997 986, 1958 356 A |
||
|
10-22-2015, 07:18 AM
|
|
|
