View Single Post
Old 04-07-2009, 11:32 AM   #10 (permalink)
Ritmusic2k
EcoModding Lurker
 
Ritmusic2k's Avatar
 
Join Date: Apr 2009
Location: Southern SoCal, California
Posts: 10

Carmen - '00 Saab 9-3 Viggen
90 day: 23.38 mpg (US)
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by theunchosen View Post
does yours have the turbocharger. I am going to assume yes?
Yep, all American-market 9-3s were turbocharged; the Viggen got an upgrade to a high-pressure Mitsubishi TD04.

Quote:
Originally Posted by theunchosen View Post
well either way what you can do is play with the ECU... If you get a programmable ECU you can set it to run your current HP(Maybe higher) and then you could set it to run lean-burn(injecting less fuel than it can burn). The really nice(expensive) ones allow you to switch on the fly...
Yep, this is how I intend to do the majority of my modifications; there's an amazing open-source community dedicated to cracking and modifying the Trionic engine management system. This is Saab's corporate name for their family of ECUs, which directly control boost, ignition, and fuel. In short, I can pull my ECU and use a special interface cable to reprogram it with the help of software developed by the community. This will allow me to build my own 'power tune' and 'economy tune'. Once Trionic 7 is completely reverse-engineered, it will allow for live-writing to the ECU without removing it from the car. Once this happens, I'll be able to install a carputer in my dashboard and run the appropriate software to load the maps I've created, so I can get the effective on-the-fly switching that's not available in the commercial Saab tuning market.

Until then, however, I'm forced to choose which program to run ahead of time, pulling my ECU each time I want to change it. I'll be installing a scangauge to assist in economical driving... but those functions will be able to be performed by the carputer once I have it up and running, so the scangauge is more of an intermediate step.

Quote:
Originally Posted by theunchosen View Post
With the Saab I don't know much about. . .I don't know anything about anything. . .how close your engine gets to knocking on a regular basis, but I would gamble it gets pretty close since its a low volume high output engine. It could cause problems, but I suspect your car is smart enough to relieve pressure if it detects pre-ignition or intense knock.
There's actually a ridiculous amount of headroom built into these engine blocks; as long as I use high enough octane (which is a real pain in the ass in California) and have a nice big intercooler, I should be safe. Saabs use a direct ignition system that actually uses the spark plugs themselves to detect engine knock (don't ask how; it's magic, I swear). It does so very well. This is a big reason to avoid piggyback ECU products that fool the system; modifying the ECU program directly leaves all knock sensing features intact.

Quote:
Originally Posted by Piwoslaw View Post
If you're close to your goal of 45mpg, then raise it 50mpg. Or even better, make your goal getting 45mpg not on the highway, but average.

Judging by your picture, Carmen has wide, low-profile tires on alloy wheels. Switching to slightly taller and narrower tires and pumping them to higher pressure (at least max psi minus 10%) would be a good start.
I guarantee you once I hit 45mpg, I'll set my next goal A major criterion for me is to make all my improvements in such a way that they do not limit my performance capabilities. So, Carmen's gonna need to keep the wide sticky tires. Down the road, it'd be feasible to own two full sets of tires, one for eco-cruising, once for, um... 'enthusiastic' driving. But before that, the majority of my mods are going to focus on software and aero.


Quote:
Originally Posted by Piwoslaw View Post
And when going to the store, take the bike
Whenever I can, I ride to work on an old Nishiki mountain bike that I converted into a commuter hybrid
__________________


  Reply With Quote