MJH78

right now I have my timing bumped 1.5 degrees all the way around (running 91 octane), on top of the base sniper tune. Weather around here right now is 95-100 and pretty humid. does anyone know if doing anything to the timing based on these weather conditions will help the motor run a little stronger? Everything runs fine, but of course this heat seems to drain a little of the liveliness out of the engine.

devongarver

thats a good question, im curious as well, cliffyk, whats your take on this?

vanquish

If anything you are going to have to pull timing when it gets warmer out. If you have your timing at the limit for cold weather there is a very good chance you'll get pinging when it gets hot outside.

devongarver

that was my initial thought...

MJH78

can you explain why you would need to pull timing in hotter weather? Just trying to understand..

devongarver

I was relating it to the fact that heat-soak from a blower meant i needed to pull a bit of timing out, as i would get detonation otherwise. This could be fixed with a bit higher octane, but cooling the boost was what i really needed. This is just how i was thinking about it anyway.

MJH78

I guess it makes sense. my thought, now that I think about it more, is that warm air being less dense than cooler air has less oxygen in it, thus will "burn up" quicker. if your timing is too advanced, you'll get complete combustion earlier than you would if the air were cooler. obviously combustion that occurs too soon can cause loss of power and pinging, etc. not sure if I'm right or wrong there though.

cliffyk

The PCM will take care of most ambient conditions, however there are combining factors that we humans have to help it out with--one of which is that when ambient temps get friggin' HOT we need to back things off a bit, especially if we pushed them hard in the cooler weather.

In the "fall/winter/spring", one of the two seasons we have here, I run 2.5° Global Spark Adder and 2.0° on all of the RPM based ranges. When HOT comes (it was 102°F in the shade Sunday) I have to back off the Global to 2.0°; and the low RPM range to 1.0°, and the mid and high ranges to 1.5°--YMMV...

H0SS302

I dont understand how you run those values. I was pinking like an SOB when I did that in the winter.

devongarver

Just out of curiousity, do you have any other performance mods than what is listed in your sig? Just seems like you have some really good numbers if thats all, im impressed!