Quote Originally Posted by only_1 View Post
After the headers I have a Magnaflow Y Pipe, and Flowmaster catback. All 3" mandrel. I ran an exhaust back pressure gage at the header and its readings are flat. The exhaust isn't limiting me right now at all.
Air filter I have a 3" tall 14" diameter round open element.
I don't know timing as I had paid someone to tune it. He said he set it at 19 degrees across the board. I am hoping he was not serious, though I think he was.
Base timing is still 0.
Yeah it is running lean. The tuner dropped the fuel pressure down to stock tbi. He didn't like the increased fuel pressure it had when I brought it in.
I hope that is a joke too.
L31 typically needs 12* from 0-1,200 rpm @ 100 kpa, 16* to 1,600, 24* by 2,400 and 28-32* timing by 3,400 rpm. That cam should idle good around 25* of timing. Limit cruise timing to about 42* and get that 42* by 50 kpa and below and 2,400 rpm and above.