I have an S trim that I wanna put on my 94LT1 and I was wondering if an injector swap would be nessacery? the LS1 G TRim comes with in jectors so do need them for a 6-7psi S trim?

 

I'd go with the ford 42 # injectors with the lime green tops. They are on ebay and go pretty cheap. They are a good inkector. SVO 30's at a minimum.

 

Instead of buying injectors, you should start saving your money for the rebuild....
-Michael

 

24# SVO injectors will swap in without any computer tweeks, but you will be limited in the maximum power attainable. I was running out of fuel and fuel pressure (90 psi) when making 11 psi on a stock engine when running the SVO 24#ers

Upgraded to 30# SVO injectors and had to go with LT1 editor to let the computer know that it now had to deal with larger injectors. No computer issues.

Went whole hog ... 383 yada yada yada ... put in the SVO 42# injectors, but they are not quite as friendly as the smaller injectors, cold start richness, and not as good off idle response. Not a real big deal, just have to run it for a few seconds at 1500 rpm when starting cold. And I have to be a little careful giving it that pre shut off rev, if you slap the gas pedal for an instant it will often as not fall on its face for a split second. Big injector blues or something like that. Might just be a set up issue, but nothing I've done has changed very much with regards those 2 issues. Otherwise they are very good on the street. I run the SVO 42# at 52 psi fuel pressure and tell the computer they are 48# injectors. It works.


At the end of the day, I'd say use the 30# injector. User friendly and you can grow with them for a while.

Hope this helps

LWM

 

I run lucas 42# injectors, and after adjusting the injector constant, AND the injector offsets (which tells the PCM the delay of opening of the injector after current is applied) you can't tell the difference between them and stock. If you do these two right you shouldn't be able to tell the difference between ANY injector. For example I believe that around normal operating voltage the stock injectors have an offset of around 300 microsecs, whereas the Lucas injectors are 125 microsecs, and the very slow MSD 50# are closer to 1000 microsecs. Do you see now how important telling the PCM what the correct offset is? If you left the stock offsets in there and are running a different injector, the PCM is firing the injector early or late depending on which injector you have.

 

If running a FMU, I would suggest just using some Ford SVO #24 injectors, which can handle the higher fuel pressures and not have a tendency to lock up like the stockers. Also you will not have to worry about tuning the car like you would need to with a larger injector.

FMU's are not perfect, but will get the job done. Make sure and have a good quality fuel pump to deal with higher fuel pressures if sticking with the FMU and 24# injectors.. I used this setup with 8 PSI aftercooled no problems (stock engine with usual bolt onsS-trim, aftercooled).. 10 PSI, now that was a different story