 Ring and pinion gears., Gear ratios. |
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| Keith914 |
 May 29 2017, 08:24 AM
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Member  Group: Members Posts: 248 Joined: 29-April 16 From: Laguna Beach, California 92651 Member No.: 19,948 Region Association: Southern California  |
What are the practical (including cost) options to change the ring and pinion gears to "lengthen" all the gears so as to optimize a more powerful engine?
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| rick 918-S |
May 30 2017, 06:26 AM
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Hey nice rack! -Celette Group: Members Posts: 21,239 Joined: 30-December 02 From: Now in Superior WI Member No.: 43 Region Association: Northstar Region 
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Don't forget that part of the cooling on an air cooled engine is fan speed. You want to run the RPM's up a little higher. specially on hills or hotter days. Water cooled engines on the other hand are a different machine. With 255/50/16 rear tires and an HB 5th gear I run the freeway about 2800 RPM's at 80-85 and lots of torque to pull hills or stay in 5th at 2000 RPM's. I use 1st gear to get the car rolling because its easier on the clutch disc but never abuse the gear. I have a custom length 901 case. If I explode it, it will a setback to get the car back on the road
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| Mark Henry |
May 30 2017, 10:33 AM
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#3
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
QUOTE(rick 918-S @ May 30 2017, 08:26 AM)  Don't forget that part of the cooling on an air cooled engine is fan speed. You want to run the RPM's up a little higher. specially on hills or hotter days. (IMG:style_emoticons/default/agree.gif) Six or T4 you should always be doing 3000rpm or more. Never lug an air cooled engine, really an air/oil cooled engine, as they are highly dependent on airflow both from the fan and through the cooler. That's why for me a HA gear (.624 ratio when flipped for 5th ) is a better choice than the H (.594) for highway driving in 5th with stock OD tires. |
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Posts in this topic
Keith914 Ring and pinion gears. May 29 2017, 08:24 AM
Perry Kiehl IIRC there weren't options on R&P only gea... May 29 2017, 09:18 AM forrestkhaag A one-day-newbie to gears with a more powerful en... May 29 2017, 09:33 AM Mark Henry Most Porsche gearing changes are through the gears... May 29 2017, 09:38 AM Mark Henry What is a more powerful engine? A /6? V8?
The 901... May 29 2017, 09:46 AM forrestkhaag My early read is that it is as much an issue of th... May 29 2017, 09:52 AM Steve AFAIK the 901 gear box only supports a 7:31 ring a... May 29 2017, 10:15 AM Steve :bump:
For added Gear Calculator link in above po... May 29 2017, 12:11 PM Dave_Darling If you have a 915 gearbox, there were a couple dif... May 29 2017, 12:30 PM
Chris914n6
The easier way to go is tires with a larger overa... May 29 2017, 04:00 PM Montreal914 What about the 7:27 R&P from the Sportomatic?
... May 29 2017, 12:33 PM Steve Wouldn't you want a higher ring & pinion t... May 29 2017, 01:35 PM Montreal914
Wouldn't you want a higher ring & pinion ... May 29 2017, 02:07 PM Steve
Wouldn't you want a higher ring & pinion... May 29 2017, 08:43 PM Montreal914
[quote name='Montreal914' post='2490876' date='Ma... May 29 2017, 11:47 PM Perry Kiehl I thought the '73 stock gearing worked pretty ... May 30 2017, 05:41 AM Mark Henry A healthy 3.0 can start in 2nd no problem on every... May 30 2017, 05:56 AM Steve Good point Rick. Even though my speedo says 80 mp... May 30 2017, 07:49 AM Keith914 Thanks for all your responses. I hope to have my c... May 30 2017, 08:40 AM Steve
Thanks for all your responses. I hope to have my ... May 30 2017, 08:51 AM |
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