408 First start up

[Lahmer_52]

We just got done getting my brothers 408 LS put in the car and looking for some advice on the initial tune to start the car up and get rings seated. He added FIC 42# injectors so not sure how much that will change the initial tune on the VE table that was running the LS9 cammed 5.3 that was in there before. the 408 has ported 243 heads and a 238/251 .675 lift cam breathing through an LS6 intake. any advice on how much to add or take away from VE table would be greatly appreciated. Attached is the tune file that was running the 5.3 previously with the updated injector data.

Thanks for looking

[5FDP]

That file is using both MAF and VE, so just doing something to the VE isn't going to do what you think it will when it's using a blended mode still.

Honestly just start it, it should run and idle but won't be exactly right.

There is no way to predict what exactly it will require as far as fueling and idle airflow to keep it running good. If you have to use your foot to keep it alive during the first start so be it. That will just fine to get a heat cycle in the motor.

[charcoal03silvy]

As 5FDP said... hard to make arbitrary changes for a brand new setup. Trial and error is the name of the game. Whatever you think it may want for idle, go a little further. Worst case is the idle hangs and you can back off a tad. Don't worry about nailing the idle down till the VE and MAF models are dialed in.