View Single Post
blacklotus99 blacklotus99 is offline
Registered User
Join Date: Nov 2006
Location: Sydney, Australia
Posts: 204
The 915 was developed for the 2.4 in 72 as the 901 was seen to be at the end of its useful life due to the increased power of the 2.4 and 2.7 cars. Also the dog leg 1st shift pattern was seen as antiquated and may hinder sales in the future.

Also at this time porsche knew the 2.7RS and other more powerful versions were coming so they needed a new gearbox that could reliably take up to 300hp in the 2.8 RSR.

The prototype engines for the 930 were developed initially using the 2.7 and 915 and put out 280hp. They decided eventually to reduce the boost to 0.8 bar, increase displacement to 3.0 using the al. case for improved off boost torque and develop a version of the 4 speed box from the Carrera RSR amongst others. This basic 4 speed gearbox had been tested to be reliable at well over 600hp. The 915 5 speed was not seen to be reliable enough to go in to the the flagship production car given the expected power output and likely further development of the 930 in to the future.

The G50 5 speed replaced the 915 in MY87. Im not sure why it wasnt put in to 930 until MY89. Perhaps others know that story.
'75 turbo
'75 Carrera (Euro)
'71 Alfa 1300 GT Junior
Old 02-18-2010, 07:16 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)