Thats pretty much the question. What are the biggest injectors on stock pcm with a racetronix fuel setup. And why can you only go so big with injectors on a stock pcm?
thanks,
Tony

 

if you change the injector size you have to have the pcm tune to udjust the injector conastants table to let the pcm know what the flow rate per hour is.

you can put 96# but yoy better know haw to tune the pcm real well so it will idle right and not wash the rings out. the bigger you go the more tweaking it takes. but the pcm will have to be tuned.

 

with your current mods you will not benefit from larger injectors. but it wont hurt either. if you planning on doing a heads cam pretty soon then yes later you will need them, but if you have no plans for that, then the money can be better spent elsewhere.

 

I believe that Siemens is making a real nice 60# High Impedance injector. I've been told that they are very crisp at low PW's so they will idle fine. I haven't tried any yet but the Turbo Buick guys love them.

Steve

 

The Siemens 60s or Siemens 57s both work well.

 

I understand that bigger injectors is a wate with my current mods, but my future plans are a 383 stock heads with ptk 76 air-water kit. Far future plans include afr heads etc... .
So could i put some 94 lb low impedance injectors with a impedance convertor for te stock pcm??
Within te next year i plan on 550-600rwhp...within 5-7 years i plan on 850-950rwhhp so the injectors i am buying i would like to keep through this whole evolution.
any thoughts?

 

Sure you can run Low Impedance with a converter box. However, If your spending all that dough on the turbo stuff you may want to consider a DFI system so that you can tune for boost. Stock PCM's can work, but everything seems to get more and more compromised as boost goes up. I believe a DFI will run either High or Low impedance injectors.

Steve