Injector duty cycle? Fast 87.8 on Turbo 408

Pretty much a newb on injector data/sizing

Got a couple questions that might be easier for someone little more advanced to answer. Been tuning camed vehicles with injector swaps but always found correct injector data with no problem. Have a friend with a Texas speed 408, Boost reference 1.1 FPR 58psi base pressure and BW S475. Just swapped from On3 turbo to S475 so still in middle of retuning the whole VE table. He bought Fast 87.8Lb injectors which nobody really had true injector data cause they don't offer data themselves.

1st question. If the injector data isn't 100% spot on can the duty cycle be off and misleading? At 10psi and 6500-7krpm (cause hes manually shifting it instead of letting pcm shift it at commanded 6krpm) starting to hit 100-110% Duty Cycle. Starts to lean out a hair when this happens but haven't ever hit this high of rpm before so the VE data hasn't been touched this high before just interpolated from the old turbo setup.

2nd question. Is 87lb Injectors too small for a 408 on 10-14psi? Or should he have went bigger from the get go?

Just relooked at the tune and the Injector flow rate vs vacuum is lower than what I remember seeing on the tune I've found searching the net for correct data. It should be higher than 42.6-46.6 correct? I've revised the tune so many times maybe that's part of the problem and Duty Cycle being misleading.

Mainly worried if these injectors are too small or not for such a big motor on boost. If not then Ill continue searching for better data.

Get injectors with good data otherwise everything could be incorrect.

If the flow rate is only at 42-46lbs is that because you are using the double stoich method??

GEN 3 computers should be able to plug in 80+ lb/hr injector info just fine into the tune.

No. I did a lot of searching and believe I only found 1 or 2 people using these injectors to get data from. I'm trying to find the original tunes I took the data from. I thought I remember the flow rate being higher in the tune but I might have grabbed an older tune of this truck at some point and not reset the flow rate vs kpa. Theres no true data for these injectors unless we send them off to get flow bench tested for the proper data. Like I mentioned I'm still a newb at setting up injector data from scratch. Especially on injectors that the manufacture doesn't offer any data themselves.

http://www.hptuners.com/forum/showth...85-lb-hr-30857

Further down one of the txt data it does mention hes scalled them down 50% due to using a gto pcm. Should I double the flow rate since this is a 3rd gen pcm?

Also being a boost reference fuel pressure regulator all the flow rate column should be the same across the board if I remember reading correct. Think maybe I started with bad data being the only tunes I've found are ls2 or ls3 pcm's

the 04 pcm is the same as the 03 silverado with low resolution in the VE table? im tuning a lq4 with 60lbs injectors 58psi boost reff regulator and i haven?t pass the 52% DC by 7psi of boost on this smaller injectors but the resolution in my VE is crap 10kpa each cell instead 5kpa

Yes we are running 2bar at the moment and resolution does the same as yours. Then even looking at the 3bar os available on his pcm is even worse on resolution but he hasn't upgraded to 3bar map yet.

thats why i let this bit"h on 2Bar i saw that the VE ist worst in 3Bar and I dont think im gonna pass 16psi of boost so 2Bar its just fine by me the iddle tuning is the worst part of it,