Well I just finished installing my fjo wideband unit on my 99 ls. I was releved that my car was running a little on the rich side. At full throttle my a/f ratio was right in the area of 11.2 to 11.5 range. Now my question is if I increse the boost 2 psi, approximatley what would my a/f ratio be ??? I am currently using the greddy kit with the pos blue box for fuel management, and boosting @ 8 psi with my timing about 1-2 degrees retarded. If I do increase the boost how much further should my timing be set back??? Any suggestions would be helpful...

 

anyone???

 

It depends on what your fuel map is set for at that load and rpm.

Bottoz

 

I am not exactly sure what greddys fuel map is on the blue box. However I can tell u that the a/f ratio was in the low 11s fom the time the car is floored at 3k rpms all the way to redline. This tells me I could possibly add a pound or to of boost to level out the mixture. I just wanted to see if anyone knew what the approx. a/f ratio would be before I actually raised the boost pressure.

 

the "fuel map" on the blue box is 12psi (fp) for every 1psi (boost), raising the boost a little might lean it out a little but @ the same time it's going to increase fuel pressure w/the extra boost so it won't lean out that much might want to try 10:1 disc or something in the box

 

Any suggestions about how much further to retard the timing??? How about any guestimates on what the air/fuel ratio would be at 10 psi??? It was in the low 11s at 8 psi...

 

the blue box acts like an fmu raising fp? I always thought it messed with the map voltage? How does it increase fp through the ecu? maybe im thinking of another kit...I know the civic si kit doesn't come w/ a rising rate fmu

 

The kit for an ls does not come with a rising rate fmu. I think 94dxt was suggesting a rising rate fmu with a more aggressive fuel disc. Correct me if I am wrong...