GS FONZy

iTrader: (6)

if i remove all O2s the car will go into open loop and stay there, ect...
will the safc be able to overide the ecu on fuel trims in open loop? will i have problems with the ecu fighting the safc for fuel control? i have read how many people have to reset ecu to keep it from altering fuel trims on there piggy back fuel controllers sytems.

JeffTsai

iTrader: (1)

Are you running boost? If not then your SAFC adjustments should not be enough to trigger the stock ecu to fight back. If you're running boost then the amount of fuel difference will cause the ECU to trigger a CEL and fight the settings on the SAFC. The way I solved my problem is by pulling out all 4 O2's. The car holds it's tune exactly how I set it and never changes. The only real downside that I'm seeing is that since the ECU is running 100% open loop...it does not adjust to atmospheric fluctuations such as extreme temperature changes. Here in Texas it's 70F one day and 100F+ the next. The other downside is that obviously you won't be able to pass state inspections, but we all know "someone" don't we?

KiPod

iTrader: (31)

If the car stays in open loop, is the computer able to adjust any ignition or cam timing? Or does it just stay in a safe steady tune?

morris

iTrader: (2)

I know the GS300 has issues with computer relearning but the GS400 doesnt seem to have the same issues. The other guys and I that are in ATL and running boost with an SAFC do not seem to have issues.

Also no CEL and no problem with emissions

GS FONZy

iTrader: (6)

do you still have your cats? are all your O2s still conected? how do you have your setup?

morris

iTrader: (2)

No cats and all O2 sensors are in. Stiill using stock manifolds but run straight through

GS FONZy

iTrader: (6)

So you are controlling your fuel SAFC, right? if that is the case than good news. The O2s don't overide anything
morris you da man in da 400 world.

JeffTsai

iTrader: (1)

It's all about tuning and how much more boost you're running. If you run just like 7-10psi or so and match the injectors correctly, then you should be able to tune within the ECU's acceptable parameters. The GS4/430 ecu is probably quite different compared to the programming in the GS3. The GS300 ecu is very very touchy and hard to tune in the ecu's range...especially at higher boost and rpm levels, stuff starts to get whacky.

morris

iTrader: (2)

Jeff that is true the local boosted guys with 300's do have ecu learing issues. IN fact Bing hooked up someothing that restes the ECU everytime he turns the car off.

The learing issue with the GS300 occurs with the SAFC and Mapecu as I understand it.

morris

iTrader: (2)

Oh and on my GS400 I have run from 8psi to 17 psi without ecu learing issues

Thats with 310's 370's and 440 injectors