doing a street tune on my ITR engined EG hatch, reativey new to mapping but not to cars,
im a qualified mechanic so no real need for noob talk.

anyhow vtec is set to 6k rpm, its ok in say first and 2nd gear but if i pull up onto vtec in any higher gear under heavey load it wil start to break up and bog down just before vtec.
it also runs very rich while this is happening too.

can someone help with what the maps should be doing around vtec, as in changes in ignition etc.

all the ignition system seems fine, dizzy and cap, plugs and leads all ok,

fuel pressure maybe??

im running apexi power fc by the way(not great i know) has s2s2 cams,buddyclub header, magnus intake manifold and a few other bits,

any hep is much appreciated!!

 

how rich are you at vtec crossover?

 

Have you tried to lower the VTEC crossover point?

I don't know much about the APEX power FC, but if you're running rich before crossover, maybe lean it out for that RPM range.

 

hitting high 10s low 11s, once it stops stuttering it leans back out.

tried leaning it out but didnt hep much.

iv just been out at it and its not as bad since i dropped the fuel pressure a bit, no gauge on it at the min cos the last one broke but its not at anything too far off anyway.

i would still like to know what way the mapa should change around vtec crossover????

 

you're gonna definitely have to set fuel pressure. get a gauge and set that before continuing.