I know when turbo is installed you need a FMU. What about before turbo? When is the time to invest in a FMU? What 'bolt-ons' can you bolt-on until this is finally needed? I have the SRI, Cat-back, RRM IM, as you can see in my sig. How much futher can I go with the add-ons, before I need a FMU?

Thanks

 

You don't need an FMU until you are actually straining the stock system. This means turbo or heavily modified NA, ie. not just bolt-ons.

 

Pretty much if you buy every N/A mod (including cam, high compression pistons, etc etc) then you "might"... But even then, most just get larger injectors, Walbro, and a AFR.

 

Future add-ons
RRM Cam
RRM TB
RRM P&P Head

So no FMU would be needed for these until I purchase and install the turbo?

 

FMU really isnt needed until turbo but I wouldnt go with a fmu. I would go with a piggyback ecu and a wideband. much nicer set-up but a tad more expensive.

 

Correct.

 

from what i understand, a FMU only works on boost as the one made by Vortech Superchargers and is useless otherwise. An adjustable fuel pressure regulator, on the other hand, can be installed pre-turbo and follows the advice above where it doesn't do much until you have the necessary mods.

 

FMU senses boost, and gives you a set amount of more pressure to the fuel rail, giving you a much richer condition. The limitations of NA will never require an "set ratio fmu" but rather would benefit from a rising rate, ajustible FPR (fuel pressure regulator) stabalizing your fuel pressure and providing more along wot.