Temperature seems to effect my blitz controller. My current blitz ratio setting shows 1.2bar on my greddy boost guage when the weather is cold/cool, but drops to show only 1.1bar when its warm/hot. I don't mind as it is almost like a safety feature, (hot weather and it gives less boost, cold weather and it gives more).

Anybody done any runs in the winter and in the summer to compare power output?

I have turned my boost down to 16psi, so round 1.1 bar today. already iv noticed that my air temps are about 10oC less than at 1.3bar max, 1.2bar sustained.

My car is a lot slower on hot days. It will only boost to 0.8bar most of the time. On a cold day it will boost to 1.2-1.3. And I have a mechanical boost controller.

I have a HKS EBC,and from winter to now summer I had to increase the percentage by quite some before i ended up running at my desired 1.0 bar boost...It works by percentage, I believe I ran at 42 in winter while now i am at 54!!

Definitely a better intercooler will reduce the difference!!
I ran last summer on standard IC and my car was dead, now with the fmic is not so noticeable the difference, but enought to be felt!

Is a Pace WMIC ( or SMIC ?mounted in the same place as orginal) any better than the standard intercooler in this weather?

yup. Not as good as the Pro Alloy FMIC though.

Whittler raises one of the most valid points here guys. As all ya techno guys are missing the bigger picture. That is, in the ecu's map, high intake temps call for reduced boost, reduced ignition advance (it retards), and maybe even addition fueling to act as a coolant, thus causing a less than perfect burn.

Of course all of you have made valid points, and if the ecu was still trying to run at full bore then these are the things we'd be talking about.

I hope no-one misunderstands me as you are all correct, Im just pointing out the the number one reason why we want ACT's (ait charge temps) low is to take full of advantage of the ecu's fuel and ignition mapping !!! As the ecu and the person who wrote the map, knew everything you guy's are saying hence the ecu's decision to alter the fueling, timing etc due to the lack of "density" in the air charge !!

Then after that has been acheived of course we want dense charge entering the engine as this has the effect of increasing the capacity for the same given volume at the same given boost pressure.

Similar effect is true with normally aspirated, cold air is denser.... More air + addtional fuel = more power

Defo more noticable generally on turbo engines !!! Remeber it's not an explosion in the engine that creates our torque (and BHP), in fact an explosion is in fact detonation. It is the burn of fuel in the fuel/air mix that creates heat. That heat in turn causes the air to expand forcing the piston down. So it's obvious that the denser the air, the more air we have to expand, this is why turbo'd engines are so power full, as the boost is already trying to expand before we've even super heated it to create that agrresive exspansion to send the piston downwards on it's power stroke !!