stock ECU really that crappy?

AZ-Scoob · 03-03-2004, 12:13 AM

Everything I have read about the stock ECU has lead me to believe that it is so amazingly crappy it cannot even compensate for the most basic modifications.(or are the stock parameters that narrow?)I have never seen an OBDII computer that cannot easily and quickly adjust for increased airflow or control ignition well enough to prevent knock, after all one parameter of OBDII is self tuning. All the factory computers I have watched active readings on have been able to keep the timing advanced as much as possible to increase efficency, and pull just enough timing to keep knock in check, then bump it up again as soon as no knock is detected anymore, or to add or pull fuel according to the o2 readings to maintain proper A/F/R.
I never tested my ECUtec, and havent had the chance to log a stocker, but everybody seems to say that the cars run super lean with even minor increases in air or boost levels. so what gives? do these things have the automotive equivalant of Pong?

Kobiyashi · 03-03-2004, 10:39 PM

To answer your question, no; the stock ecu is correctly made and works great, and yes the h4 is VERY knock prone. With no EGT or Wideband O2 sensor the ECU has no clue what to do to remove this when you start modding items, nor could it. The CAI also change the MAF readings so it confuses the ECU even more. The reason other cars gain HP due the CAI is because it leans the car out, the WRX is already leaned as much as it should be in stock form, after some BPU's it can be leaned out more.

-kobi

nixstur · 03-04-2004, 12:37 PM

Ha! I think the 04 ECUs( in both the STi and the WRX ) are pretty weak. Some of the first US STis came with detonation problems( an option I'm sure the owners don't recall asking for ) and the regular 04s have some open/closed loop switching issues that made the UTEC look bad. Subaru may be doing this on purpose for fuel efficiency, emissions, or to make it harder on tuners, but the result is that the ECU is starting to get a bad a rap as their transmissions... Just my personal opinion, though.

AZ-Scoob · 03-04-2004, 09:04 PM

cool, this is exactly the kind of replies I was looking for! guy at work has a stock 02, going to plug into the data link and see how it reacts to airflow changes, and changes in fuel demandas far as getting power out of other cars by leaning them out, thats not always true. the Mitsubishi computers actually increase the injector pulse length in response to increased airflow. tested it out with a CAI on an Eclipse GSX, had 3/4 of the open element filter blocked off (had approx. the same volume readings as when it had the stock intake system and air filter) pulled off the restrictor, and within 30 seconds the short trim levels adjusted for the increase in airflow. 2 minutes after that the long trim adjusted itself to bring the short trim back down to zero, allowing an immidiate adjustment to be made again should the need arise. the EGT's stayed solid, no knock detected at all. I think the Scooby puter doesnt have that kind of adaptability.
will let you know my findings of the tests!

nixstur · 03-04-2004, 10:45 PM

Keep us posted... So we can save up for an EVO... Ha!

AZ-Scoob · 03-05-2004, 12:11 AM

I was going to buy an evo, then I figured I did not want to bring my job home every night. besides the Suby has a MUCH better fit and finish quality. like comparing a lexus to a.....Lancer! I felt that the WRX was a much better platform overall. and the clutches dont crap the bed in 1000 miles like the EVO's do if launched agressively.and our tires last longer than 12k before they are bald!