B'more 1.8tQMS

I was just wondering what people thought about upgrading injectors. My car is Upsolute chipped and it's mapped for stock injectors but I was wondering if it would do any harm to upgrade to the APR 1+ sized ones. Theoretically, even at the same ignition timing and boost levels it should provide better performance, right? Are they plug and play with the current ECU? Any pointers would be helpful.
Thanks,
Dave

Shaun

The injectors will be providing more fuel than the ECU is aware of and you will run rich. Mixing and matching is a bad idea. It's just not that simple.

SP (oenophile)

Bigger injectors utilizes the programs that are designed to release the fuel at shorter interval as opposed to the programming for stock injectors. Therefore, the fuel curve is different.

nexlvl, Dean@Evil U.

If you run the car with the current setup, it'll run rich. The ECU will assume x amount of fuel and h amout of air when really you'll be putting in x+ amount of fuel and the same h amount of air. Eventually it'll throw a code because your O2 sensors won't know what to do. If you spend the money to upgrade to bigger injectors, you might as well spend the money on the new chip so that you can get the most out of them.

sj audi

it will hurt.

Shaun

Yep. The car won't run right and you could potential damage the catalysts (among other things).

nexlvl, Dean@Evil U.

not to mention gumming up the O2 sensors and (eventually) the valve seats.

AggregatVier

...compensate for the extra fuel by cutting the injection time - but only within about +/- 9%. Over or under that and you'll get a CEL. You'd have to increase flow with a bigger turbo to get any additional benefit over stock and that would primarily show up in the upper RPM ranges. There are some adaptation channels you could play with to increase fuel on acceleration and at higher RPM's but it's not for those without the proper test equipment.