Premium gas as required by the manufacturers is 91 octane. 93 octance is not available in all states, so APR for instance has a 93 program and a 91 program. I assume Michael has 93 available.

Also it does not take another hour and a half for a reflash. That’s just for the original install of the modified ECU.

curisu
There are plenty of penny pinching VW/Audi folks.:) However, there are so many established chip tuners with prices as low as $300 that it never seems worthwhile.

dont you already have to run premium in that audi? i thought most turbo/gasoline engines you had too to run premium gas to stop detonation.maybe thats why your mileage is better because a lot of turbo cars will retard the timing if you dont run premium.sounds like the engineers really detuned that motor for emissions or reliability purposes if premium wasn’t recommended to start with.

I thought so too – I think the european engineers think all American drivers are idiotic and purposefully detune their high-compression/forced-induction cars to run on 87. My wife’s mother’s Volvo C70 has a turbo 5cyl that *recommends* using 87 octane. Blew my mind when I read it on the fuel cap.

I believe that the bulk of the fuel savings come from properly scaled injectors vs voltage latency (so the ECU better knows how much fuel is squirting), a properly leaned-out map that makes safe power (tending towards the magic 12.5-13.3 AFR), and more efficient end-to-end setup (intake/exhaust). A healthy respect for the new-found power is also a boon as you probably won’t stomp it at every light. ;)

That being said, I wouldn’t describe ECU tuning in the Evo/Subaru world “simpler” by any stretch of the imagination. For instance, the most recent customized ECU images coming from the community (well, okay, a *very* small subset) provides some pretty nifty features like a knock/detonation indicator that blinks your CEL, a quickly switchable “valet” mode that reduces the rev-limit to something you preset (2200 rpm out-of-the-box), and the more application specific modifications to control how the 3 diffs work in conjunction with each other. One current release has software-based NLTS (no-lift-to-shift) available; folks in the forums are bragging about getting 0.3 secs off their ETs.

There is an amazing depth still to be found in the stock ECUs. “Finicky and sensitive” is more an aspect of how early an adopter you want to be. My Evo is a daily-driver that I hand-tuned. I’ve learned to wait a couple weeks for bugs to be worked out of the newer releases before flashing my ECU. 99% of the time, after the growing pains are dealt with, the ECU is as stable as if Mitsubishi engineers wrote and tested the software themselves.

I do agree with you to the extent that the average car enthusiast is not likely to want to get deep into the guts of ECU tuning. The ROI for that time spent is, well, not profitable. Given that the VW/Audi/Porsche markets aren’t likely to be filled with penny-pinching, garage-based tuners like the Japanese import markets, I’m not surprised that OSS/FOSS projects aren’t available to tune those marks. And I’m equally unsurprised that big tuning houses turn to well-known (and expensive) 3rd party ECU’s to do finely-grained tuning. Those ECUs are beautifully documented and allow such a breadth of custom code to be run that it would be a joy to work with something like a Motronic, and consequently, fun things like switching AFR maps on the fly for power vs efficiency is very straightforward with them. Getting it integrated with the CC stalk or other stock instrumentation is probably a quick thing for them; the hardest part was probably the UI/UE decisions (i.e., how long to hold the Set/Accel before entering map-change mode, etc.).

Regarding DIY chip tuning like EcuFlash or Enginuity, VW AG’s Motronic engine management programming may be far more complex, fickle and sensitive compared to the EVO and Subaru’s EMS systems.
Motronic is deeply integrated into the car and controls nearly everything. For example, APR has the option to let you switch between octane maps, boost maps and valet mode through the cruise control stalk. I’d be afraid to mess with it myself…

That being said (or maybe due to the fact), there is a grassroots movement to allow the owner to do exactly what APR does at home, in their garages, and on open stretches of road. Open-source and/or free-software solutions like EcuFlash (Evo/DSM) or Enginuity (Subaru) give the home-wrench the ability to reflash their ECUs thousands of times. What you save in initial costs (a couple hundred dollars), you have to make up in testing time, fuel, and the invariable risk that you will damage something in the process. It definitely is not for everyone, but for the OCD guy who likes to muck about with *everything* in your car, it’s definitely the most involving solution. I’ve learned more about turbo-charged applications as they relate to combustion engines than I ever thought I would, and I honestly thought it was a blast. Case in point, it’s common knowledge that a freer flowing exhaust will increase horsepower on a turbo-charged car. Most anyone that spends time in an enthusiasts’ forum will glean that it “reduces backpressure” allowing “quicker spool”, etc. When you’re the guy tuning your car, you get an almost visceral sense of the drop in back pressure. You can watch the boost spike hit earlier and more predictably, and then you can really tune for some serious high-end HP or try to flatten that torque curve out with changes to ignition timing. I think I have something 40mb of logs from the stock-to-exhaust tune process. More when I installed my home-fab cold-air intake. It was just fun. Period.

On the other hand, if you can afford a 911 turbo, the opportunity cost of self-tuning is way too high to justify spending dozens, maybe hundreds of hours fine-tuning VANOS and fuel maps. If you make $150/hr (what I calculate to be the baseline income to afford to run a $150k sports car), and you spend 50-100 hours to tune your ride, you end up costing yourself $7500-$15000 to get it “just right.” Probably not worth it unless the experience itself is what you’re seeking ;).