Originally posted by Porschefile
It's generally accepted that running over 80% duty cycle on most injectors for long periods of time will wear them out very quickly. This can cause abnormal failures like failing stuck open (can flood the cylinders) for example. [/B]
Dead on, and it can also cause them to stick closed(either completely or partially). Problem most people face pushing duty cycles is combining that with insane fuel pressure using rising rate regulators with absurd ratios(like 12:1) Pushing those limits is both potentially dangerous to the motor, but also to the car and yourself(fire/explosion).
85%DC is the fail safe. Most good tuners wont push 80% without stepping up one size and then tuning down, as long as fuel atomization isn't compromised at low speeds/no boost..
For street tuning ability, i've used components referred to as EIC(extra injector controller) or SIC(supplemental injector controller). VERY similar to what RUF used on the CTR as stated above. It allows stock drivability and fuel consumption with the stock injectors, but as boost kicks in, the EIC/SIC automatically references your trigger signal/injector signal and adds fuel accordingly through a second set of injectors based on a programmable table you input via PC.
for those who want more power, but can't quite fork the cash for a complete standalone it's a good option to look into. Still need to control timing; and good programmable boost sensing DIS can handle that for the most part. The EIC I love using the most is by 034 Motorsports.
weblink here: http://www.034motorsport.com/product_info.php?cPath=22&products_id=71
Probably old news to most. Good news to some