Hey everyone,

I got myself an 07 coupe just about a month ago and I have been having so much fun it’s unexplainable. So since I just got the car I’ve been brake boosting, redlining, you name it, so I real have a feel for what my launch and speed is like. It’s just started to get super hot where I live, approaching 100 degrees on some days and the humidity is quite high. Now I was showing my friend the car and when I brake boosted and launched, I could tell my car did not feel quite the same from launch. I have fairly new sport tires and usually when I brake boost my tires will make some noise with just a little spin, and off I go, however when I did this the other day, my tires did not spin at all and I could tell it was slower off the line. Is this usual when it starts getting hot outside? I would even wait later in the day when it was still 90° or so and I still felt a slight power loss at launch. Just wondering if this is normal and you guys experience this too?

 

G/Z's seem to have heat soak issues in general. When the coolant temps get higher, they tend to start pulling timing.
Last weekend I went on a long drive with a bunch of guys through some fun canyons roads (back roads in Santa Clarita & hwy 33). It was hot, though not as hot as it was this weekend. I run a scangauge 2 OBD readout, so I can monitor engine vitals (coolant temp, battery voltage, timing, etc.). When I'm running the car hard (long hills, tight sections, and one spot where we were going MUCH faster than the speed limit) is when the water temp starts climbing (above 206* typically, highest I saw was 213*) is when I can feel and watch the ECM pulling timing. I don't know if this is when the VQ's start to knock or if its just programmed into the ECU to begin pulling timing based on the higher water temp. I was running 91 + a fair amount of Boostane, my octane should have been around 95. Other drivers and myself all make a point to open our hoods when we stop (either to regroup or lunch stop) to let everything cool off as much as we can. I'm considering adding a coolant swirl pot in the near future to help with cooling.
Remember, hot air is less dense than cold air, so the air is less dense just to begin with on hotter days. Higher humidity only adds to this.

 

That happens with any car. Hot air = less power from the engine. Plus hot tires means more grip, so harder to break traction.