Diablosport Forums

On a 5.7L Magnum what is the optimum spark timing on cylinder #1. Is say running spark up at 25*-27* too much?

I recently tried adding a little spark to come up from 18* on cyl1. I added a couple of degrees, got the spark on cyl1 up to like 21, 22 and 24 at various rpms on a WOT pull. Very little timing got pulled, so I gradually added a little more and achieved getting the spark on cyl 1 up to around 25*-26* through a good portion of the rpm ranges on a WOT pull.

At the same time I added some fuel, on the order of 5% to quench some knocking that was occuring (I was getting like 2.5* of timing removed). After the fuel was added....I'm back down to 0* timing removed and the spark is advanced by like 5*, 4* and 3* across the rpm ranges.

Is this ok and does this make sense or should I back it off?

Log attached.

Is that one of the "Tuna's" tunes? Why would you mess with Johan's tune? It is still clean if you did. I have also found those timing numbers to be the "sweet spot" if you got fuel to make that happen. My CMR tuner apparently likes those numbers also, because the data log of my last dyno run with 100 octane alternative fuel shows a 27 degree timing number at the top. The curve of the RPM after the DIG looks different with your AWD, very cool...NICE!