Can anybody tell me if you retune the stock ECU, would it still pass smog? What i mean is, would it change any of the smog checked items' values to where it wouldn't pass smog? I was recently thinking of getting someone to tune it to see what kind of extra power i could free up (probably not much). Any intelligent info is appreciated.

 

What type of piggyback are you going to use?

 

none...it's the stock ECU...on a few other types of cars...it has yielded higher hp #'s when tuned over a tuned piggyback...I am thinking about trying (well, someone else since i am electronically retarded) with the tC

 

If SMOG is for emission checks, and u tune for N/A, wich is to get the leanest possible without getting EGTs too high, then that means u are actually emission friendly, since u are not dumping more fuel, but using less. Isn't it like that?

 

i don't know...that's y i'm asking...but in a smog check, there are about 35 different output levels that they check the legality of...thanx for the input though

 

i dont think you can tune/flash new toyota ecu's. you will need a piggyback or standalone.

 

Generally, we'd gain a little power by leaning out the fuel curve at wide-open-throttle, known as "open loop" mode.

Problem is, though, at anything less than WOT, the engine is running in "closed-loop", in which the motor is balancing signals from the MAF sensor on the intake and the A/F ratio sensor right on the exhaust manifold.... in order to figure out the perfect balance of air, fuel, and ignition timing for best instantaneous power and fuel economy.

We cannot effectively modify these closed loop settings... partially because no one's cracked the ECU encoding, and partially because the ECU is an active learner, and will shoot to override any changes you make anyway.

Smog tests are done at idle and at a set RPM (2500 ?), both of which are closed-loop, so essentially, a piggyback's effect on emissions is limited and variable.


Your best bet is a CamCon from PowerEnterprises. This is one of the extremely few piggybacks that can adjust ignition timing as well as the fuel map for a toyota. There is only one fuel/ignition map you can use, but you have the ability to simply turn the unit off, and the car won't even recognize it's there.

Therefore... race time, turn it on... after the race, turn it off.... And just like that, you go from a good power gain at WOT back to stock closed-loop settings for best fuel economy. The ECU won't try to learn anything (it doesn't learn open-loop settings), and you're not struggling to retune it every few drives since you don't floor for every second of the motor's useage.

 

nice, thanx for the very informative...info sensei. I appreciate it

 

Not a problem! Any other questions, just let me know!