2010 Camaro Supercharger Project - Need help with Injectors {B4001}

[mirage]

So I've read all over the forum about different ways to calculate injector data. I've seen numerous spreadsheets for GEN III vehicles, but either have completely missed it or do not understand how to setup the B4001 table for larger injectors. I'm replacing the stock injectors with Bosch short LS3/LS7 injectors that flow 72 @ 4 bar. The engine is completely stock with the exception of headers and exhaust. I've seen the spreadsheets that calculate MAP values from 0 - 80 kpa, but how do you map this to the LS3 B4001 table. The values start at 128 kpa and go to 640 kpa. I read that 400 kpa to ~500 kpa is the same 0 to 80 MAP range, but since this vehicle will be supercharged how do I handle the missing data. (Assuming the 0-80 MAP range is for NA cars)

{B4001} - Stock Injectors
Injector Flow Base (Grams/Second)
Delta MAP kPa Value
128 2.974609
144 3.198486
160 3.407959
176 3.604980
192 3.791992
208 3.969970
224 4.140625
240 4.304199
256 4.461914
272 4.614257
288 4.761718
304 4.904785
320 5.043701
336 5.178955
352 5.310790
368 5.439453
384 5.564941
400 5.687988
416 5.808105
432 5.926025
448 6.041503
464 6.154785
480 6.266113
496 6.375488
512 6.483154
528 6.588867
544 6.692870
560 6.795409
576 6.896484
592 6.995849
608 7.093993
624 7.190917
640 7.286376

[joecar]

LS1:
The scale goes 0-80kPa and is MANVAC which is BARO-MAP.
The pressure difference across an injector is FP+BARO-MAP = FP+MANVAC, where FP is rail gauge pressure which is 400 kPa (4 bar, 58 psi).
The IFR is calculated like this: IFR = R0*sqrt((400+MANVAC)/P0) where R0 is the flowrate rated at pressure P0.

LS3:
The scale goes 128-640kPa and is DELTAMAP which is the pressure difference across an injector.
The portion of the scale which is vacuum is 400-480kPa which maps directly to the LS1 0-80kPa scale (i.e. DELTAMAP = 400+MANVAC).
The portion of the scale below 400kPa is boost (300kPa is 1 bar boost, 200kPa is 2 bar boost, 100kPa is 3 bar boost).
The portion of the scale above 500kPa doesn't make sense (negative absolute pressure).
The IFR is calculated like this: IFR = R0*sqrt(DELTAMAP/P0) where R0 is the flowrate rated at pressure P0.

In both cases, factory rail gauge pressure is 58 psi (4 bar, 400 psi).


In the table you posted above, at 400kPa IFR is 5.688 g/s which is 45.32 lb/hr.

[mirage]

LS3:
The IFR is calculated like this: IFR = R0*sqrt(DELTAMAP/P0) where R0 is the flowrate rated at pressure P0.

In the table you posted above, at 400kPa IFR is 5.688 g/s which is 45 lb/hr.

Up to this point I follow, but I can't work the other direction and get it to work:
5.688 / .1255 = 45.3 Got that (just converting from g/s to lb/hr)

So if we assume R0 = 45, and P0 = 58 we should be able to come up with 5.688 at 400 kPa right?
IFR = R0*sqrt(DELTAMAP/P0)

IFR = 45 * SQRT(400 / 58) = 118.1758 <-- this is where I'm lost. Even if this is lb/hr then g/s would be 14.83106 obviously not 5.688??!!

What am I missing? It's got to be something simple...

[joecar]

...
I can't work the other direction and get it to work:
...

IFR = 45 * SQRT(400 / 58) = 118.1758 <-- this is where I'm lost. Even if this is lb/hr then g/s would be 14.83106 obviously not 5.688??!!

What am I missing? It's got to be something simple...

DELTAMAP and P0 must have the same units... you have to first convert P0 to kPa

58 psi = 400kPa...

so then IFR = 45 * sqrt(400/400) = 45 lb/hr

or IFR = 5.688 * sqrt(400/400) = 5.688 g/s

[mirage]

Yep just figured that out...

Thanks for your help... it's been killing me... NOW it's time to have some fun!

[joecar]

Your welcome...... let us how it goes.

[Tre-Cool]

isnt this a misnomer on the e38 anyway seeing as it limited to 8g/sec.

with those size injectors they'll all be above 8.

[mirage]

on the e38 anyway seeing as it limited to 8g/sec.

with those size injectors they'll all be above 8.

You are correct they will be way above 8g/sec so how do I configure for larger injectors if it is not via B4001?

[Tre-Cool]

like everyone else. via the vve table or maf tables.

just scale it back 15% see what your idle afr's are like and go from there.

[mirage]

I didn't realize there was a limit of 8g/s EFILive shows the maximum value as 15.9998. So I figured I could use up to the value which I was way under at the time.