RomRaider

hi everyone, i have some problems on idle with my roots supercharger, i placed the icv pre s/c and post the maf, i put check valve in the icv hose to prevent boost leak when i floor the throttle, the throttle body placed after the s/c and i use cheap bov and use it as a bypass valve.

i have tried to put the icv post the s/c and it idle fine with valve to resist boost while idling, but i think if i put it before the s/c it will bring the iat down when idling, but this setup bring me some problem when i adjust the idle map, i have tried many time changing the IACV and ISR table, everytime i reach the target rpm for couple minute it pull the ignition timing about 10 degree from the ignition base and it consume more fuel and bring up the engine load, the afr seems fine about 14-ish but the fuel consumption is bad, on the logger there is a IACV_AlphaN and i have no clue about this, i have tried messing up with AlphaN IACV and the TPS Compensation but no change.

the engine is m52b25 came without o2 sensor, -373 ecu updated to ms41.2, can someone help me?

i will upload the log tomorrow

sorry for my bad english

here is my log,

the first one (log28) is using stock m52b25 IACV and ISR setup but I raise the rpm target from 700 to 750
and the second one (log22) is adjusted IACV, ISR and disabled STFT

For this setup, as you're not using the stock clutch based on what i can see in the picture, you're going to want both the MAF and the throttle body before the blower

ok i see, but is there any other way to adjust the idle? if no I will put the icv hose like before

and I'm curious what caused the ignition retard on idle? somehow on the adjusted log, I can reach the target rpm but the timing always dropped

i have an update on this issue, everytime the ECT passes 85 celsius it will drop the ignition timing, after I turn my fan on until the temp below 85c the ignition timing become normal again, the only table that have those value is the muffler flap table, i have zeroed out the table to try my luck, but still the same

I need some help to figure out which table would affect this behavior