View Single Post
mysocal911 mysocal911 is online now
Registered
 
Join Date: Feb 2014
Location: Lomita, CA
Posts: 2,694
Quote:
Originally Posted by ClickClickBoom View Post
I think the imprecision in the system comes from the electromechanical/vacuum interface. Speed changes are relatively instantaneous, and vacuum and engine speed are not. Which I would gather they changed to the electronic type system.
Actually, the key problem with the vacuum actuator system is that it's an analog system design versus a digital system design as used
in the later Porsches. The analog design stored the desired speed as a capacitor's voltage. The later digital design stores the speed
as a digital value in a register. The latest Porsches starting with 996s don't use a separate module, but have the cruise control function
integrated with the electronic throttle body module.
__________________
Dave

Last edited by mysocal911; 02-28-2019 at 09:05 AM..
Old 02-28-2019, 08:49 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #28 (permalink)