This question came up in a conversation a friend and i where having. Has anyone made a performance chip for a scion yet? Ive also heard that instead off buying a performance chip you can just send your stock one out to get reprogrammed. Anyone with information on this?

No. Not currently at least.

read this post http://www.scionlife.com/forums/viewtopic.php?t=5628 it talks about the intake dyno at first but then it talks about why the ECU is stupid and needs a custom reprograming

also jet chip makes the v-module for the echo(same engine) but the stock ECU will catch the upgrade after a few days and put everything back to stock(that is why it is stupid it is a looping ECU, ((the terminator, it learns)), anyways a couple companies are testing the ecu upgrade and trying to get a chip for us, that is where we will get the best BANG for the BUCK.

unichip would probably do something if there was interest. a lot people seem to be happy with them as a company.

unichip would probably do something if there was interest. a lot people seem to be happy with them as a company. i agree, if you find a chip company that will do it, go ahead, when i get my xb i will even give up my box for the experiment, but that will have to wait for a while.(plus they have to be on the east coast)

the stock computer is not stupid. much of that thread is filled with misinformation.

the most a chip could do for you is make a couple more horsepower with the downside of requiring that you use 93 octane gas instead of 87.

thats certainly a valid option.

but there is nothing stupid about the stock ecu, and no miracles to be performed by an ECU change.

some quick facts about how modern car ECUs work:

They operate in two modes, open and closed loop.

Cosed loop operation happens most of the time, idling, driving around slowly. In this mode the computer compares the MAF sensor readings to O2 sensor readings after combustion, and the computer adjusts constantly to ensure optimum air/fuel ratio settings.

When you floor it and get into higher rpms, the competer reverts to static maps for fuel vaules, since sensors don't react fast enough to perform closed loop at these times. However, correction factors learned from closed loop operation still modify these static maps.

so, what can an aftermarket chip do that is useful? It can change those stock open loop static fuel/timing maps, and either run leaner or with more timing advance to make more power. This will cause a need for higher octane gas to prevent pre-ignition.


I wouldn't expect more than 2 or 3 horsepower. In fact a lot of modern ECU systems automatically adapt for higher octane gas on their own using knock sensors.

aftermarket ECUs become more valuable when ou start making extensive modifications, which cause the stock static maps to become more and more invalid. Cold air intakes can often really screw things up, by causing the MASS sensor to no longer report correctly. In fact, often times cold air intakes make their higher power numbers not from better flow, but from faking out the mass air sensor and causing the car to run leaner.

Cold air intakes can often really screw things up, by causing the MASS sensor to no longer report correctly. In fact, often times cold air intakes make their higher power numbers not from better flow, but from faking out the mass air sensor and causing the car to run leaner.

then why does the factory offer a cold air intake for the cars?

((the terminator, it learns

lol,... terminator... my cpu is a neural net processor... a learning computer.

Arnold calls Gateway computers (http://www.studentfreestuff.com/celebrity_prank_calls/ArnoldSchwarzeneggerPranksCallsGateway.mp3)

listen to the last line about his computer... hahaha

jackmott, I'll have to disagree with some of what you said.

The ECU can advance the timing a little to take advantage of higher octane gas but not much and even if it advanced it as far as possible without detonation it would not make more power. More advance does not allways = more power. The engine has to "need" the advance to make more power. Too much advance = negative work on the crankshaft. The correct amount of ignition advance is the least amount of advance possible before torque starts to drop.

The MAF does not lean the engine by tricking the ECU, it just tells the ECU how much air is flowing past it and MAF sensors are very quick and accurate. The ECU adds fuel to match the air flow. If the engine is so efficent at getting air in and out that the MAF readings are off the OEM fuel/ignition maps, THAT can cause some real problems, otherwise the engine will only lean out if the ECU runs out of injector duty cycle because the airflow through the engine is too great The O2 sensors fine tune the mixture from the input from the TPS and MAF.

Aftermarket performance chips just narrow down and optimize the fuel/ignition maps. Depending on the OEM maps your gains can vary, some cars (make/model) show more gains than other cars (make/model) depending on the quality of the base line maps. How much effort did Toyota spend on getting these fuel/ignition curves as optimal as possible? I would guess they are pretty good (108hp from a NA 1.5L is pretty good) and an aftermarket chip will show little gains, unlike my old '88 Chevy blazer that showed significant gains with a simple chip change.

Open loop just disables the O2 correction. The ECU still requires TPS and MAF input to look up the fuel/ignition advance curves. This only happens at full throttle or if there is a sensor malfunction (limp home mode, "check engine" light on).

I agree with you that the ECU is not stupid, it fine tunes the fuel and ignition maps to suit the engines running conditions as it runs down the road. It cannot sense a modifiation and reset things to stock.... It just regulates fuel/ignition to the maps set up and what the sensors tell it.

I call the ECU "stupid" because it doesn't think the way I do (I guess I'm prejudiced against OEM ECUs)!!!
ken