100% Duty Cycle Safe?

[dlc18]

So here is the set up:

Built B20 8.8:1
B16 head w/ Type R internals
Edlebrock Victor X Mani
GT3076R Turbo
Tubular Ex. Mani
1000cc Bosch
Walbro 255
Stock Fuel lines
AEM rail & reg (set to 30-32psi)
E85 fuel
s300
Boosting 26psi (boost cut 28psi)

Had the car tuned last late March, early April (in AZ), when the ambient temps where somewhere in the range of 85-95 degrees. The car ran great after the tune with 520whp and the injector duty cycle was around 85-90%. Did a project on the car and finally got it back together and running. Now it is January and the ambient temps are around 65-80 degrees when I drive it. Now with the colder weather, I am hitting my boost cut in 4th and 5th and maxing out my injectors to 100%. I am maxing out duty cycle around 6000rpm and 20+psi and my wideband is starting to lean out.

My tuner says that I can hit 100% duty and still be getting enough fuel. If i continue to climb in the RPMs (rev limit is 8300), the engine feels like it is misfiring (or detonating). My tuner also thinks that the cooler, denser air is not a factor.

My question is this: is the colder air/weather a factor? Do I need a totally different tune for the winter? Am I maxed out on my fuel pump? Is it safe to run the injectors at 100% duty cycle? Isn't there an air temp compensation built into the s300 for situations like this?

If all else fails, I am thinking that I need to upgrade the fuel pump, bump up the rail pressure, and retune. I have added a couple datalogs. Please let me know what anyone thinks. Thank you in advance.

[Spunkster]

Why is your fuel pressure so low?

If you were at 90% duty cycle in hot temps then you will be even closer to 100% duty cycle in cooler temps. Check your fuel presure when this is happening, and look at your wideband readings.

[dlc18]

That fuel pressure is what my tuner set it at. I think it is to get the most out of the Walbro 255 pump. Can that pump put out more at higher rail pressures, or do I need a different pump to raise the rail pressure?

If I retune it for the colder weather and run the duty cycle to 85-90%, will it adjust itself when the weather starts to warm up?

And is it safe to run at 100% duty cycle as long as I am not leaning out? Just seems like 100% is pushing it. And if you look at the datalog, it's not like it just creeps up to 100%. It pretty much shoots off the charts.

[Spunkster]

no calibration posted

[dlc18]

I have turned the settings in the boost by gear WAY down due to my lean condition. Other then that, this is my last tune settings.

[Spunkster]

YOu have the injector size set to 900 instead of 1000 and have an overallfuel trim added of 25%, this is probably why it is showing you are at 100 % duty cycle. I would recommend takign this back to the tuner to have them fix this. Also your fuel pressure is too low. The walbro 255 is a high presure pump and it is running below stock fuel pressure at this time. Fuel pressure should be between 45 and 50 psi.

[dlc18]

O.K. thank you for your time and help. I will be back with results.