Tuning Bigger Injectors Help

[BrianC98Z28]

Im trying to iron out a friends bolton/dry nitrous setup. We put Lucas/Delphi 37lb injectors in it since we were maxing the stock injectors. Ive read and read and understand that naturally you have to change the IFR and Ive done that according to the spreadsheats. My Question is is that the only thing you have to change or do you need to adjust or do you need to do anything else such as B4003 and B4004??? Any help is appreciated. Thanks.


Brian

[BowlingSS]

I think that is the only table you need to change. I would do some logging to make sure nothing else has changed.

Bill
:beer:

[mr.prick]

be sure of your fuel pressure when you change the IFR table
with the spreadsheet, it must be right or you could end
up chasing your tail.
then you can use BEN factor to
fine tune the IFR table.

[BowlingSS]

be sure of your fuel pressure when you change the IFR table
with the spreadsheet, it must be right or you could end
up chasing your tail.
then you can use BEN factor to
fine tune the IFR table.

Do you have a map of your IFR/Ben or is there one in EFILive?

Thanks,
Bill

[mr.prick]

data = BEN
column = RPM
row = MANVAC

[dfe1]

Make sure you know the fuel pressure at which your injectors are rated. Most are rated at 3 bar (43.5 psi). If you're working with a 4-bar (58 psi) fuel system, you have to compute injector flow at that pressure and use that in your IFR table.

[TAQuickness]

Of the injector tables, {B3701} would be the next most important IFR table ({B4001} being the most). Unfortunately, most injector vendors do not supply a off-set table specific to the application.

[BrianC98Z28]

TAQuickness off the table b3701 what would need to be adjusted there?? Sorry for questions but just trying to take it all in as ive just recently focussed on the whole tuning thing.

[BowlingSS]

data = BEN
column = RPM
row = MANVAC

Do you have a screen shot of that MAP?
Thanks,
Bill:cheers:

[hquick]

This topic interests me also as I recently swapped my 19lb/hr for 42lb/hr.

[Wasted Income]

I've got a set of 60 lb/hr Siemens coming...subscribing.

[mr.prick]

here is a link to a spreadsheet, it has a page for the IFR table.
http://forum.efilive.com/showpost.php?p=53885&postcount=2

[jetblast]

i went from 28lb to 42's, got great fuel economy/drivability by encreasing the b4001/ifr table by 65%, decreased the b3701/injpwva, b4702/injvc, b4003/mininjpw, b4004/defminpw, and b4005/smallpadj by 5%,, also decreased b3201/intfp by 2% for better crank/start-.

[BowlingSS]

i went from 28lb to 42's, got great fuel economy/drivability by encreasing the b4001/ifr table by 65%, decreased the b3701/injpwva, b4702/injvc, b4003/mininjpw, b4004/defminpw, and b4005/smallpadj by 5%,, also decreased b3201/intfp by 2% for better crank/start-.

Why did you pick 5% and 2% for the tables?

Bill
:cheers:

[jetblast]

2% was just enough decrease to get a high energy crank, the other tables it was just trial and error, but basically i figured the squirt is now bigger so you need less small pulsewidth control. and forgot, i also decreased b4006/smpwt by 5%. i'm new to tuning, and only been doing it since i got my gto back in 04, read a bunch of different sources, from books to mags, mags to books a few times over, and some ls1tech also. do you thinks those values are way off?