Bigger injectors?

[beatrod]

Hi all. I have a an 84 svo motor. I have a stage 3 head from boport on its way with a 2.5 cam and a 50 trim turbo. I have a poorly ported upper intake that i will most likely be fixing and have been considering making my own lower intake using the factory lowers mounting flange and injector bosses. I have a megasquirt but im still working out the crank/cam sensors for sequential spark/fuel before it goes in. With that, it currently will have factory short block, stage 3 head with 2.5 cam, knockoff header (xspower), garrett stage 3 t04e 50 trimm .63, decent intercooler (not sure how efficient), factory TB, gutted upper, factory lower (possibly customized and made tubular), 3" exhaust, and to the meat of my question.. With an la3 without any piggy back, would it be doable to run say, 60# injectors until i get the megasquirt worked out? Has anyone ever tried anything similar? I tried looking but didnt seem to find much. I know the ecu doesnt know if you put bigger injectors on.. But my thinking is that with the increased air flow it will need more fuel to stay in stoichiometric or whatever it is. I also considered the VAM and the ecu telling it to fuel for x amount of air with a 35# so a 60# would make it FAR to rich.. But maybe i could tighten the spring in the VAM to compensate. Or offset the little slide tab so it will effectivly lie to the ecu.. Anyone ever done anything like that? I might just have to settle for waiting untill i get the megasquirt sensors worked out. But itd be cool to drive in the mean time😂 thanks all!

[Stinger]

The only way to do it is to pull the fuel pressure WAY down so the 60's flow similar to stock injectors, but that negates the benefit of larger injectors and the atomization is poor at such a low pressure. Otherwise you'll be getting nearly double the fuel under all conditions (pig rich/barely run).

So in this case you're better off sticking with the stock injectors and you just have to turn the boost down to 10psi or so in order to not run lean. It will likely make more power at 10psi than it did with the stock head/cam (last one I had on the dyno made 304hp at 12psi). I'd suggest having a wideband o2 setup installed in order to know the AFR so you can ensure it's safe (you'll need one with the MS ECU anyway).

[beatrod]

Yea i definitely dont want to drop fuel pressure.. Might well stay with what i have lol maybe a resistor in the valve voltage wire so its only sending half power to the ecu🤔 of course then theres the problem that all the higher it will get would be 2.5 volts return.. Idk. Il either think of something or i wont lol thanks stinger!

[beatrod]

Oh and i have the wideband already. Undecided on the aem i have on vs the innovate i have laying though.

[Stinger]

The AEM is better than the Innovate.

Half voltage = dead electronics.

[xr2300]

I have a ported setup also, but with a stock T3. My injectors flow 46#, but my EEC has a Moates chip with the tune for the injectors. A chip would be the simplest way to run larger injectors, but the best would be use the megasquirt ECU.

[beatrod]

Yea id rather just wait until i have the MS worked out lol i honestly considered looking into an on/off switch controlled by boost pressure or something and fashoning up some sort dual injector setup kinda like a methonal kit would act and adjust accordingly but once im that deep in tgeres no reason to not just change the ecu... I tend to have a work with what ya got mind set... But i already have the MS😂 one sensor is alot less work than rigging up some BS thats not gonna work right or even stay for that matter lol

[Stinger]

Is your MS even capable of sequential injection? I thought I remembered it being MS2 based?

[beatrod]

Pretty sure it is.. Its ms3x.. The guy had it running sequential with ls coils and all.. Guess il have to find out when i get it worked out🤣 if not, atleast il be able to tune it better than 1988's tech lol