Fastmax

I am getting ready to fire my 5.7 TBI that I built for the first time. I have tuned my LT1 and my TPI before, but this is my first venture into TBI.
The build is a mild 5.7 with 9.5 to 1 comp, ported swirlies, a summit 204/214 flat tappet cam, the ultimate TBI mods and LT1 exhaust manifolds with 3" single all the way back.
What I am wondering is that in addition to these items I installed an 18 PSI spring in the regulator and am deleting the EGR. Can someone guide me as to what sort of initial changes I should make to the factory BIN file in order to get close so I am not either drowning it out or starving it for fuel during my first fire up and run in?
Thanks
Roy

Brandon2350

If its bored you might want to add the additional cylinder volume... id fire it up and do some datalogging....this will give you a quick baseline to get your idle roughed in.

Fastmax

Well the problem is on initial fire up, especially with a flat tappet cam, I just wont be able to focus on datalogging. Busy setting timing, looking for leaks, checking RPM, etc.
I was concerned about the change in fuel pressure affecting the effective injector sizing and having to adjust for it. But I dont see anything in $42 that I equate to things I am familiar with such as a base pulse multiplier or injector size. Is there no adjustment for changing injector sizing?
Thanks
Roy

RBob

iTrader: (1)

This is used:

LD2B4: FCB 135 ; BPW const for EGR off,

There is a table of value at $324 for when EGR is active.

It is the displacement and injector flow rate rolled into one value:

; Val = 1461.5 * (VOL/RATE)
; VOL = Vol of 1 Cylinder in liters
; RATE = Injector flow in gms/sec

RBob.

Fastmax

Unless I am doing the math wrong (and that is certainly a possibility) using 5.7 litre and a 55 lb per hour injector the value that I come up with that should be in BPW constant for EGR off is 150. However the number the factory has in there is 135.
Upping the pressure to 18 PSI changes the injector to 68 lb hr, and changes the answer I get for the value to 121. Which leaves me having no idea what I should change it to, if at all at this stage....
Roy

RBob

iTrader: (1)

The early and most used 5.7l TBI injectors are 61 #/hr at 13 psi fuel pressure.

RBob.

Fastmax

Aha! Thank you sir!
Roy