A few things here. Don't make a very costly mistake just putting a Cobb tune on this car. If you have these 890cc injectors on them then I have to assume the car is already tuned to some degree. If you had those injectors in the car without a tune I doubt it would run for long beyond idle. If you want to use the Cobb you must have a tuner make you a tune to go with your mods. There is no choice on this.
In terms of tuning those injectors that will not be an issue for a good tuner to do. They are big injectors for a stock turbo and you will NEVER max them out however they are still within range to run properly for you so leaning out the car should be a no brainer for your tuner. Keep in mind that under WOT depending on the fuel and tune you may see some black fuel smoke. Many tunes run low 10:1 AFR which is just barely above visible smoke ratios. Any dip into the 9:1 AFR range and you will definitely see smoke. This typically occurs during shifts or rolling onto the throttle (known as tip-in) this can also be adjusted in your ECU to compensate for the larger injectors.
Be careful out there and keep an eye on those oil levels!
Originally Posted by BoosterRooster
Whats up guys, just got my 05 STi and it came with some mods. I wanted stock but couldnt pass up the deal i got. Everything is mostly suspension upgrades but it also has aps TBE, APS cold air intake, 890 cc injectors. Im assuming the fuel pump has been upgraded but not sure. My AP is on its way should be here tomorrow and was wondering something. My fuel seem a little large for a stock turbo and i can tell its running rich, Will a good tuner be able to control this or should I go ahead and get a bigger turbo before its tuned? Or is there anything else I can do to help keep it from running so rich?? I know i need to tune it asap so any info would be great, prolly wont have the money to get a bigger turbo for at least a couple months.