We had our first major cold front of the season come through last night, the temp went from over 80 degrees yesterday to right at 40 degrees this morning with low humidity.

Took the SRT-4 for a short run this morning and I swear it was running quicker. Anybody know if there is a formula of some sort to factor in temp/humidity for a quarter mile run?

 

I believe so, air is cooler , it runs better.......cooler air going in intercooler and turbo and all that good stuff. I know what your talking about because it was pretty cool this morning here in Michigan on my way to school, probably mid 30's and it ran pretty good i must say!! [sm=smiley20.gif]

 

It definately runs better cold. You should try it on a 20 degree or less day. You'd swear there was another 25-40hp at the wheels. Try a car magazine website, maby Hot Rod mag, or Car and Driver......maby submit it as a tech question.

 

I think there are some advanced formulas that take into account the inlet (intake) air temp. and density using the mass flow rate... but these are pretty advance formulas... being and engineer, most engineers round numbers anyway... so you can theoretically (sp) calculate it, but the math involved would be rather tedious... but I'll have to check some references when I get home, I might be wrong... (don't tell anyone - hehe)

 

for a quick fix... try this...

http://wahiduddin.net/calc/calc_hp_dp.htm

 

That's what I was looking for, thanks!!!!

 

An engine will run much better when it is colder and you will have max performance because the air is more dense when it is cold. Standard temperature is 59 degrees. When the temperature is 59 degrees your engine will run its best that it can. If it is colder then 59 then your turbo benefits even more and engine performance wont change a whole lot. The key temperature is 59 degrees though.

 

My Shelby Z was wicked in the cold, it gained tons of power since the intercooler is right next to the radiator and I think they were even touching causing heat sink into the intercooler. It would often times peg the 15 PSI boost gauge on a below freezing evening.

 

where did you get that?? I am not doubting, I've just never heard that before though...

 

I am a pilot and you have to know about performance of the engine, the standard temperature is 59F degrees or 15C and the standard atmospheric pressure is 29.92 Hg. At these ideal conditions that is when your engine will perform its best that it can. Another thing, on hotter days if you live for instance at a place where it is sea level, the density altitude will be higher so your engine might think it is performing at a higher altitude then it really is thus, decreasing your engine's performance.