M104-AMG

iTrader: (8)

I have the following mods on stock turbos, stock intercooler, and stock airbox:

1) Efini Y-pipe (replaced all gaskets w/new updated metal gaskets)
2) gutted stock down-pipe
3) Greddy/Trust CAT-back muffler
4) M2 Stage III ECU
5) boost pattern of 12-10-12 with an occasional 13 spike

Since I just popped/blew my motor (95K miles),;

do I need to upgrade injectors on the next engine, even if I have a M2 Stage III ECU, or just keep it stock (550/850) ?

If I need to upgrade, and since this is both a street and AutoX car, which would be best setup:

1) stock setup (550cc primaries / 850cc secondaries);
2) upgraded secondaries (550/1300 or 550/1200)
3) upgrade all (850/850)

Again, this is with a M2 Stage III ECU, so I don't want to run too rich and have carbon build-up let alone very poor gas mileage.

Thanks in advance,
:-) neil

FD3RotorTurbo

iTrader: (1)

i would go with 4- 850's. you can pick some up for around $100 and all you have to do is shave off 2mm off the primary fuel rail. i have the same setup and i can run 15psi no problem.

poss

iTrader: (5)

With a stock based ecu, you have to run stock sized injectors. You can buy a SAFC to run larger injectors on a stock ecu, but at that price point, you might as well get a pfc.

M104-AMG

iTrader: (8)

Does that mean I cannot run 850cc injectors with my M2 Stage III ECU ? Or only 1200cc and 1300cc injectors are not supported ?

Will I be running too rich with (4) 850cc injectors and a M2 Stage III ECU ?

TIA,
:-) neil

Mahjik

iTrader: (1)

ISUposs is correct.

Unless you add an additional controller, you cannot safely enlarge your injectors with any rechipped ECU (unless it's already been programmed for the larger injectors).

M104-AMG

iTrader: (8)

Ugh.

I guess I should just install a boost-controller. What should I set one to with a M2 Stage III ECU ? 13 psi ?

BTW: what is the stock secondary size ?

:-) neil

Mahjik

iTrader: (1)

Stock secondary injectors are 850cc's.

You should be able to run up to 13PSI on the M2 without a problem. I've read about people running more, but I wouldn't necessarily recommend it.

The problem with using larger injectors without reprogramming the ECU, is that the ECU will think it's using a different sized injector. If the ECU thinks it's using the stock 850cc and its using them at 50%, how much more fuel will you be dumping in using 1300cc injectors at 50%? Quite a bit more so it requires tuning.