I'm upgrading to 440cc injectors from 310cc. all of my fuel maps are tuned for the 310's. does anyone know of a mathematical formula to adjust the fuel maps to account for the bigger injectors and maintain the afr's that were achieved when tuned with the 310's? for example: if I'm adding 20% fuel with the 310's, can I multiply that 20% by a value that corresponds with the bigger injector in order to achieve a flow rate close to the one that's achieved by te 310's?

to much math for me. 310's wont handle 10-12 psi?

barely handles 10. it's not the injectors. it's the stock ecu that's the problem.

cuz i would think the injectors should feed that much boost. but our ecu is a pain in the ___. is it throwing the tune or what? if so, get an ecu from a 02 or up echo depending on your car year, it wont learn. i need one bad. but anyone, youd probabaly have to figure out the flow rate for both injectors at 100% then find what that rate would be at whatever your flowing right now. then like you said, tune the emange to run the same % rate, but youll prob have to run slightly higher if your 310's arent feeding enough.

I'm upgrading to 440cc injectors from 310cc. all of my fuel maps are tuned for the 310's. does anyone know of a mathematical formula to adjust the fuel maps to account for the bigger injectors and maintain the afr's that were achieved when tuned with the 310's? for example: if I'm adding 20% fuel with the 310's, can I multiply that 20% by a value that corresponds with the bigger injector in order to achieve a flow rate close to the one that's achieved by te 310's?
I believe you have the Ultimate now correct? if so, there is a way to scale the map by just typing in injector size, its that easy. But you still need to get it re-tuned because that is just a rough starting point. There shouldnt be a problem driving the car around keeping it outta boost. If I were you I would go right to 550cc injectors. You have a built motor and with that turbo you will have to run a lot of boost to get the numbers you want. Unless you have a return fuel system with a 1:1 FPR then id go with 550's. We sell drop in 550's for the tC and im going to run those as well when i drop in my motor this month. Then im slapping a t3/4 47 trim turbo on it. We will be making a manifold for that turbo to go on my car, if you are interested and enough people gain interest we may produce it.

ok....got the 440cc injectors. Ultimate cannot scale back the bigger injectors at idle under closed loop stock ecu control. im running hella rich at idle. this is bull since i called greddy before ordering the injectors to make sure that i got the biggest size that ultimate could handle. greddy said on numerous occasions that ultimate is capable of handling injectors 150% OVER stock... meaning that to be 460cc max on the xA. WTF!!!!!!!!!!!! Additionally, the greddy turbo wastegate cracks at about 6-7psi and I maxed out at 12.5 psi with the AEM boost controller.... I could live with 12.5 for the time being but I can't live with the car not idling correctly. too damn frustrating....should just get an EVO.

that's weird man, we are running the ultimate on our tC with 900cc injectors and got it to idle fine, although it is a different vehicle all together, it well exceeds that 150% mark.

Also, you boost sylinoid may not be as efficient as when it was new, mine did the same back when i was injection water-meth before the turbo. The water meth corroded the noid and at 90% duty cycle I was hitting only 9psi. Replaced it and now at only 24% duty cycle im there.

Where do you live? consider bringing it here to tune, many have made long road trips to do just that