stupid fmu question
 

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.

Re: stupid fmu question
 

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.

Re: stupid fmu question
 

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.

Re: stupid fmu question
 

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

Re: stupid fmu question
 

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.

Re: stupid fmu question
 

A walbro 190 i'm sure would work good.

Re: stupid fmu question
 

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