Injector sizes and issues

[Gunni]

So IԚ´m at home calculating some excel file to make it easier to calculate injector sizes required for this and that HP and so on,

to my amazement and this has been noted before,
that the stock 325i injectors ( 14,2lbs , 149cc)
Duty Cycle HP at 0.45 BSFC
0,75_______142,0
0,80_______151,5
0,85_______160,9
0,90_______170,4
0,95_______179,9
1,00_______189,3

So how is it possible to get more then 190hp???
Note : 0.45 BSFC is about as light as possible,
Anyone have some info to shed some light on this?

[GermanGorilla]

Hi,

Gunni- strange things these Injectors !!!

The BMW S54 M3 engine is about on the limit with the CSL mods.

Yet many and including some so called 'respected' Tuning Companies
allege that a Re-Map of the ECU, the so called 'Flash' will return
380 BHP from the Stock arrangement with their Re-Map for several
hundred pounds.

The problem is, that without changing the stock S54 M3 Injectors
its impossible.

Same on the S50B32 Evo engine, and so on.

So, unless the correctly rated Injectors are specified and fitted in any Modified Engine that allegedly makes serious gains over stock, then
all claims can be taken with a pinch of salt.

The revearse is the same, ie, to high and problems ensue with fueling,
spark and so on.

Biggest giveaway on an alleged 'Tuned' engine is what type injectors
is it running.

Regards,

The Gorilla.

[gcorky]

adjusting fuel pressure will alter the flow to a degree will it not?

[DaveD]

i think this thread was done a couple of weeks ago

http://www.e30zone.net/modules.php?name ... highlight=

[Gunni]

Yes,
like so

(Square root of New pressure / Old pressure ) x injector size,

for instance for the 149cc injectors at new 4bar pressure

sq of 4 / 3 x injector size = sq of 1.33 = 1,153 x 149cc = 171cc or 16,3lbs
Duty HP
0,75 -163,0
0,80 -173,9
0,85 -184,7
0,90 -195,6
0,95 -206,5
1,00 -217,3


This is still at VERY low 0,45 BSFC,

[surj]

hi all had this problem last month im slowey put my 2.7 back together with a few tweaks aswell of course with the mods i know i need to uprate the injectors as stock ones are crap alot of people use the m30 injectors say off the 3.5 but i went to my local bm breakers which is midland bm and asksed chris for some advise he then said m30 injectors are off old hence injectors are probaly worn out etc then he advised me to go for 2.8i injectors off the e39 5 series i dont know if its a suitable upgrade (does anyone know) but they do look a far better injector