Possible cam tuning question
Possible cam tuning question 
Staging Lane
Joined: Jan 2017
Posts: 67
Likes: 1
you can play with the idle overspeed\underspeed spark tables to create this lope sound.
So say you tell the PCM when the idle gets to 800, pull a bunch of timing. The idle RPM will begin to fall, then at 600, you put the timing back in, and the RPM will rise again until it reaches 800, and continue that cycle creating the bounce, or diesel sound.
So say you tell the PCM when the idle gets to 800, pull a bunch of timing. The idle RPM will begin to fall, then at 600, you put the timing back in, and the RPM will rise again until it reaches 800, and continue that cycle creating the bounce, or diesel sound.
Some of these ecms don't have all of the tables needed to do it. I know my OS doesn't, and I can't get my cam to sound like Sloppys 6.0 did, and mine is almost identical ( although I had mine together first )
you can make almost any multi-piston engine sound like it has a lope through tuning, artificially of course. Usually, you turn up the air-volume (which would normally raise the idle very high) then bring the idle back down by pulling fuel (run it lean, around 16.5:1 or leaner- sometimes the WB wont even show the a/f ratio). Reducing timing will also help un-smooth the idle.
The cam causes it when air reversed starves one cylinder and causes a slight pressure rise in the runner/manifold which feeds the next cylinder, giving a small event/misfire followed by a more normal event. Spread out over all the cylinders, it can be random order or sequential (sometimes the lope sounds very consistent and sometimes it sounds terrible).
I had a friend with a crappy V6 car once call me and ask for help. I arrived and it was loping like a race car. Bad IACV valve was pulling max air into the motor and the ECU must have had some fuel cap so it was running lean.
The cam causes it when air reversed starves one cylinder and causes a slight pressure rise in the runner/manifold which feeds the next cylinder, giving a small event/misfire followed by a more normal event. Spread out over all the cylinders, it can be random order or sequential (sometimes the lope sounds very consistent and sometimes it sounds terrible).
I had a friend with a crappy V6 car once call me and ask for help. I arrived and it was loping like a race car. Bad IACV valve was pulling max air into the motor and the ECU must have had some fuel cap so it was running lean.
That's easy to do.
Set everything in underspeed to 13 except 0 rpm, set everything in overspeed to -13 except 0 rpm. It'll sound like that. You can miss with the value accordingly to make it sound however u want. I'm referencing idle spark.
Set everything in underspeed to 13 except 0 rpm, set everything in overspeed to -13 except 0 rpm. It'll sound like that. You can miss with the value accordingly to make it sound however u want. I'm referencing idle spark.
