(X*4*Y)/1200
X= BPW and Y=Engine RPM.
TBI IDC (%) = [4 * IPW (ms) * RPM]/1200
Wrong calculation was started here in 2007:
http://www.fullsizechevy.com/forum/g...lse-width.html
Comes out correct to 1project2many TBI helper and all other math...
Printable View
(X*4*Y)/1200
X= BPW and Y=Engine RPM.
TBI IDC (%) = [4 * IPW (ms) * RPM]/1200
Wrong calculation was started here in 2007:
http://www.fullsizechevy.com/forum/g...lse-width.html
Comes out correct to 1project2many TBI helper and all other math...
Ok, so to simplify = X * Y / 300
My $0E shows X*Y/600, HHMMMMMM, I might need more pressure after all.
:rolleye:
You know your better at math then me... :thumbsup:
But you got a lot of injectors too! They fire same as TBI right? Here's MPFI
MPFI IDC (%) = [2 * IPW (ms) * RPM]/1200
Try out my new spreadsheet calculator, put your math skills to good use and read this thread too, here's direct link to spreadsheet:
http://www.gearhead-efi.com/Fuel-Inj...ll=1#post20070
I'll take a look at it. Yes they fire just like regular TBI, just alternate opposite of each other.
EDIT: Looks pretty good Mark, you're right that first page is a lot to take in. Only recommendation I have is to label the '7247 stuff as "$0D/$0E". Oh and yes I need more pressure.:thumbsup:
I moved these fuel pressure posts here Greg...
There's some polishing to do, thanks for the mask names on sheets. It's a lot of info, but all you have to fill in is White Boxs first set. Last st are optional calculations.
Were you happening to run up to 49% IDC on the old one?
I would have to fire up the laptop, and check a log, but I am pretty sure I was hitting around 38% (would really be around 80%) and IPW would not go higher than 4.2ms, which is fine at 4K rpm but not at 6K.
I am really super lost in this thread and its all 99% over my head. But did I read something right, saying that the injector duty cycle % display in the 0D ADX is wrong?
So far everything I've checked is only half... try this!
Tried that ADX and if it is correct, then I am going well over 100% DC when in PE and hammering on it. I saw the DC go up to 119.02% on a recored log when I was hammering on it. TPS 73%, MAP 90, 4000 RPM, and in PE. WB AFR was still at 12.6, so it wasnt going lean, but I cant speak for weather the injectors were going static.
Are you 100% sure it is displaying the correct DC %?
Exact same time data sample on the normal adx was 59.51% DC
Sorry, for got you were MPFI, change the 4 to a 2 in conversion.
TBI IDC (%) = [4 * IPW (ms) * RPM]/1200
MPFI IDC (%) = [2 * IPW (ms) * RPM]/1200
I'd say good and remember one of your logs at 61%.
So although different format it looks like the origanal was accurate for MPFI.
http://wiki.openoffice.org/wiki/Docu...ROUND_function : It specifies number of places to ROUND, if you still care.
I have read and reread this thread trying get a better understanding of the info needed to use the TBI calculator Mark created.
What is bsfc? And how do I know what the value is?
Also in the calculator it gives bpc.
If using the calculated values to tune a $42 tune is that the same as bpw?
BSFC = Brake Specific Fuel Consumption
For N/A engines this is generally between .45 and .50, Supercharged engines between .50 and .60 and turbocharged engines between .55 and .65.