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HP Tuners Help

General Tuning Discussion

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419 LS3 Camshaft Ported Heads Fast Intake Heads 102mm Throttle Body. Will Not Idle or start with out Being on the Pedal not Shure what Look at or What to Change

idle base setpoint set it to 1000rpm for start you can lower it later if you want

make your overspeed -10 and underspeed +10 this will make it choppy but you can change it later

idle spark advance in gear/in park set them 18-22 maybe higher you can use a single value across the tables

high low octane table use the same spark advance value in the idle area of the table from 0-1200rpm, it might help with the surging if you use the same value in the low load area from 0-revlimiter

adjust the ve table if you haven't already

and the most important tables to tune for your throttle are under idle/airflow and i cant really help you with this part as i dont really know much about adjusting the iac or electronic throttles but check base running airflow, iac steps vs effective area,throttle cracker, throttle follower, etc area scaler

When you fit a decent cam to an LS engine there are a few key areas you need to change. As Fahad mentioned above, you need to start by setting a realistic idle speed to suit your cam size. Normally I'll end up around 800-850 rpm hot even with an aggressive cam. One of the issues with a big cam is that the dbw throttle is limited in the stock cal as to how far it can open and this is usually not sufficient for the engine to idle, particularly when cold. From memory the max opening in the scanner is 27% so if the engine is stalling and you're hitting that then you need to deal with this. Often tuners drill a hole through the butterfly but you don't need to do this. Instead you can adjust the 'percentage max' parameter under the idle airflow tab (Sorry I don't have my PC notebook in front of me so I can't give you the exact name of the parameter).

You'll also need to adjust the base running airflow table (think of this like a feed forward table for dbw opening position to achieve idle), and of course your VE table to get your fuel delivery right.