Injector duty cycle too high for airflow?

[REDspydergst]

I need some comments opinions about my setup before I buy my next upgrade for my 2g.

I have a 2g with a pte 57 trim turbo flowing 48lb/min at 27-28psi with 1200cc injectors on e85. My injectors duty cycle is at 96-97 peak on e85. I feel that it is too high for the amount of boost im running. I checked for boost leaks n there were none. Compression is 150psi across the board. No exhaust leaks either. Im running a 255 wally.

what do you guys think about my injector duty cycle? is it too high for what im flowing? If I get a fuel pump that flows more would i notice a significant decrease on my injector duty cycle? Anyone here running a pte 57 trim? what are you flowing at what boost level?
oh by the way im running link.
Please let me know what you think. Thanks.

 

[snowborder714]

Upgrading to a larger fuel pump won't change IDC's. The only way to change that is to adjust target AFR (richer AFR will have higher IDC's than leaner AFR) or change out the injectors.

Those IDC numbers are higher than an ideal target of 85% max.

Do you have a log you could post so we could see if your airflow tuning is off (assuming you've got a logged wideband or MAP sensor)?

 

[mantega4g63]

is the 255 rewired with an afpr?

 

[REDspydergst]

I do not have a log at the time since they are all on my friends laptop. Yes I do have a zetronix wideband logged to link. My afr's are 11.5s. The original plan for my setup was to max out the 57 trim and I know it still has more juice in it because if I turn the boost up a little more it still flows more. I know this turbo is already at its efficiency level with the boost im running but I still want to the boost up. I know I should stick to the ideal target of 85% duty cycle but the tune seems real good. No knock at and AFR's dont lean out on high boost. Would I be better off buying larger injectors to obtain my goal of flowing 49lb- 50lb/min with that turbo? or should I just get both, injectors n a better pump?

Yes the pump is rewired.

 

[snowborder714]

You'll have to do a little digging to figure out how much airflow the pump can support at the boost level you plan on running to figure out if you need to upgrade the pump.
http://www.dsmtuners.com/forums/articles-tuning-ecu/366003-injector-fuel-pump-supported-airflow.html

You'll definitely need larger injectors.

Post a log when you get one in your hands.

 

[eclipsegsx1736]

In my experience, a single Walbro 255HP (rewired) will support equivalent to maxed-out 1000-1100cc injectors. You're almost certainly running out of fuel pump. If the problem is flow from the fuel pump, upgrading it will certainly lower your IDCs.

Maxing out your fuel pump is certainly something you want to avoid. When you go beyond the fuel pump's flow, there's the potential for air bubbles to accumulate in the fuel system. Even though your wideband gauge may indicate a safe AFR, there is potentially a significant percentage of combustion events that are way leaner than you want, and on E85 especially, this is a recipe for potential engine damage. Wideband sensors simply aren't nearly fast enough to pick this up.

Beau