Originally Posted by Jeremias06
Installed an ROE supercharger and have +20 long terms at idle when first start the engine but after engine warms up they go to +10. On both banks. I have no vacuum leaks. Spark plugs look great according to ROE.
I dont have a ROE setup, but with most any obd2 car tuned properly you should only be hovering near zero on LTFT ideally in a perfect world. This obviously isn't always possible but the closer to zero the better. Its more than likely because
you have increased airflow in the intake just at idle and in general due to the blower being on the threshold of building boost almost instantly.
The LTFT being that far out is an major indication that the ecu is obviously correcting for something that isnt what it expects according to the fuel mapping tables that are currently on the ecu and that its been happening constantly.
Basically the ecu wants something and adjusts but the sensors report back data and the ecu compares and finds its not getting what it thinks it should. This drops into STFT and if this continues for a while without improvements there for long enough it gets committed to LTFTs.
I believe.... 20-25 percent on most (not all) obd2 is like the upper limit before it can just go into limp mode on some cars. I cant say the same for the viper because i've not been down that road fully myself so take that bit with a grain of salt.
Honestly, retune if you can to correct this issue, ultimately you want the LTFTs to be there for a safety net for adjustment when things are off slightly and if you are almost already maxed out this isnt going to give you that "cushion" because you're already right up against the edge on LTFTs.
Also you might check into the bypass valve on the blower if it has one (it should) and adjust if possible? This is obviously an overall adjustment across the board, but i would think that you're shoving more air in at startup due to the nature of the setup and bypassing this a bit more might help but i cant say how much that would affect you once fully warmed up. Something to think about maybe.