An introduction from an unlikely hypermiler
 

Hello all!

I just sorta wrote down everything I'd want to say in my vehicle description, so I'm just going to repeat it here:


Carmen is an aspiring Jekyl-and-Hyde. She's a sports car, and she knows how to drink like one. I'm often quite economically-minded. My goal, therefore, is to get her to achieve significantly improved fuel economy upon request, without having to permanently sacrifice an ounce of performance.

Carmen is a 2000 Saab 9-3 Viggen that I picked up this past October. She's a demon and I love driving her, whether it be a four-hour jaunt to Vegas or a quick trip to the store. Ultimately, I have simultaneous urges in divergent directions. That is to say, I intend to wring every last scrap of available power out of her, but I also intend to wring every last calorie of energy from the fuel she burns and convert it into motion.

My endgame is to have a car that produces in the neighborhood of 300 horsepower, but can reliably return over 45mpg highway when prompted to do so.

I know this is anathema to much of the spirit of this forum's membership, but I want to prove to myself and to others that a car doesn't have to give up one strength for another. I hope to make a few friends here, and am really looking forward to learning as much as possible about all this.

haha, just so long as you don't tell them about the inspiration to go from 0-60 quickly they won't know.

I'm likewise playing with the idea. I have a motorcycle engine that I am going to drop into my Del Sol to make twin engined AWD, when summer gets here and my load lightens.

There are still alot of things that might be able to be done.

Although. . . I am going to have to confess I do not know much about the Viggen. Saab is. . .outside my range of contact. They are pretty rare here in TN. Guess they don't sit well with us. . .?

WIKIPEDIA here I come

<edit> So. . .I couldn't find a very good data review of the car and Wiki came up dry. I am familiar with the car now that I have seen a picture. . .I wish my car were named after a fighter-bomber. There are still alot of options without sacrificing HP. Weight reduction is one that gains in all directions. Heavier wheels to lighter ones and taking stuff out of the trunk are pretty entry level.

If you really wanna get down to it. . .strip everything body-wise off and replace it with Carbon fiber or Fiberglass. Although, thats a serious PITA you save some weight. While you are at it you might be able to find more aero friendly pieces specifically maybe fenders, bumpers and hoods.

Oh, and I am the forum troll!

</edit>

The Viggen was, for lack of a better description, Saab's "M3". It was produced between 1999 and 2002. Total worldwide production over the entire model run was around 3,000 vehicles. So, within the enthusiast community, they're sort of the holy grail of modern Saabs.

EDIT: here's a wikipedia link for you - http://en.wikipedia.org/wiki/Saab_9-3#Viggen

One of the biggest draws to Saabs is the fact that they're already a great platform for 'no compromises'. In fact, I'm already not too far away from my ultimate goals... In present configuration Carmen makes roughly 240hp, and I can get 40mpg out of her on the highway.

On that note, I screwed up when filling out my profile info in the garage, and I accidentally typed the Highway EPA number in the Combined EPA field, so the graph and sig image are both underrepresenting my actual mileage achievement...and the graphs aren't updating after correcting the mistake and adding more entries in my fuel log. Anyone have a tip for me about forcing a graph update or deleting a vehicle so I can start correctly from scratch?

Ritmusic2k -

Welcome to EM!

Hit the reload button a few times and it should be recalculated correctly. You can always edit your garage entry to change any of the EPA information.

Whenever I do a fuel log entry, I need to do a reload for the graph to reflect the new entry. You can also edit any of your fuel log entries if you make a mistake.

CarloSW2

cfg83, thanks for the tip! When I went home everything was fine; I think my computer at work must've cached the image.

Now that I am equipped with the vastness of information available on the internets regarding the 9-3 Jet fighter, does yours have the turbocharger. I am going to assume yes?

I love the Viggen! I almost got a 2002 Viggen convertible last fall, but the dealer was screwing with the price. Had I gotten the Viggen I probably would have been boosting too much and getting bad mileage.

Good Luck on the horsepower and MPGs.

well either way what you can do is play with the ECU. If you have a turbo great, but that kills the idea of adding one for HP gains, but it saves you some coin. 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.

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.

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.

And when going to the store, take the bike :)

Yep, all American-market 9-3s were turbocharged; the Viggen got an upgrade to a high-pressure Mitsubishi TD04.

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.

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.

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.


Whenever I can, I ride to work on an old Nishiki mountain bike that I converted into a commuter hybrid :)