RotaryGeek

ok so i am looking to boost my car. i deliver pizzas so i drive A LOT. im only going to push like 4 or 5 pounds till this other job comes through and i don't want to wait for boost. so im giong to only use an fmu right now. i see all these fmu's that say like 10.1 or 12.1 . i realize these mean something important, but i don't know what they mean. someone help me out. don't bother telling me to lose the fmu cuz there is better out there. i already know that, but im only going to be using this for maybe two months. or till i can afford to get a chipped ecu and wideband and laptop. whichever comes first.

tranceminister

Basically a 10:1 ratio would mean for every 1lb. of boost pressure, the FMU will add 10lbs. of fuel pressure (psi). A 12:1 ratio would be, every 1lb. of pressure the FMU will add 12psi fuel pressure.

Sikocivic

If you are going to use an FMU I would suggest a better fuel pump too. I added an inline pump when I ran an FMU because the stock could not keep the pressure up to what I needed. At 5lbs of boost you are trying to push about 100PSI of fuel through the injecters.

Guy-Fast

yup fmu on stock pump=blown motor

fmu's require a fuel pump upgrade plain and simple to work.Hence why kits that use fmu's sell upgraded pumps with them

Briman2021

Not to hijack, but what kind of fuel pump would you recommend?? this is for a 97 civic ex w/ d16y8 running 7lbs of boost.

Jmunk

A walbro 190 i'm sure would work good.

-SKUM-

What is the stock fuel pump rating in a 90 crx Si? Ive herd rumors that is 190LPH.