I have a Radix on my 2005 GMC Serria with a 3.00 pulley and other mods. I live in Maine and drive the truck year round. It recently has been 30-20 degrees outside and I've noticed the engine starting to ping at full throttle. I had it tuned about a month ago and it was fine, but this colder weather seems to be the cause. A couple of days ago in the morning on the way to work it was pinging and was 26 degrees out, then later during lunch break it was 35 degrees out and the truck didn't ping.I was wondering if anyone else has exsperienced this before too?

 

check your boost gauge. Cold weather is gonna cause the boost to rise some. Timing set for your current boost level may be to advanced for the colder weather boost levels. Check the boost gauge.

 

Alright thanks!

 

Colder air is denser, that is it contains more air molecules in a given cubic foot of volume. More air means more O2 and this can create a lean condition causing knock. Your tune may be too lean or have too much timing advance for the colder denser air. You should get your tuner to have a look at it and take some logs. They will likely have to richen it up a little or pull some timing or a combination of both. If you are running a MAF it may adjust for the colder conditions over time but if your tune is near the limit it may need to be revised.

 

When you notice this, is it running from the same initial start-up when you left home that morning? I mean the first time you cold start it in the morning, even after its reached full operating temps. I've noticed that mine runs differently if I drive it from the initial cold start versus turning it off for a few minutes after its reached its operating temps, like when getting gas. Hope that makes sense.

 

Thanks for the info guys! It will do it in the cold weather after it has be restarted as you were asking. I will have the tuner turn back the timeing. Thanks again!

 

I've noticed up to 1.5psi more on average from warm days(80's) to cold days(high 20's). I've also noticed that my AFR starts to rise a little bit in the upper rpms on cold days. This is probably caused because the MAF maxes out earlier on cold days and not having enough fuel programmed in the PE table once the MAF maxes.

I think Mort hit it pretty good.