Anyone know the best intake temperature for optimal HP?? I know that the hotter the air is the better the fuel burns and the cooler the air is the more HP is gained, but there must be a point at which the air is too cold for optimal combustion and HP. It is starting to get pretty cold here (some snow) and just thought that I would get this one taken care of.:D

Probably somewhere just before the air starts to turn to liquid. :) Though the termal shock at such temperatures might be dangerous for your engine.

37*F in the desert on the way to the dragstrip brought my V-8 car into a beast! Very noticeable power increase. Modified motors are more susceptible to temp change.

Cold, dense air is good for horsepower. Nitrous accomplishes this too, at a superconducted rate. (proper terminology?) IN other words, if the air temperature and humidity are at a good level...let's say a damp foggy night...a car's engine will perform better than oh, I don't know, 115*F sunny day in Palm Springs.


NASCAR's optimum engine temperature for horspower is 210*F. Every engine is different...so our Scooby's could like it at a higher temp. Funny thing is, once my car is warmed up, the temp gauge never moves up or down. :confused:


/more rambling Skylab™ /more rambling

Humidity is a huge factor in this as well, assuming low humidty you can get super horsepower from low temps, the intake on the race car that I am building in the Formala SAE club we are getting temps below freezing through the throttle body (methonal fuel)

COLD! I do enjoy living near the beach, at sea level... especially on coold summer nights with no humidity... apparently the car likes the cold sea breeze too?:)

In general:
Dry is good - fewer unburnable water molecules displacing desirable oxygen molecules
Cold is good - air is denser, meaning more oxygen molecules per cc of air
Sea Level / high barometric pressure is good - again, air is denser than at higher altitudes

To get a quantative idea of how each of these affects horsepower, plug some numbers into this:
http://rshelq.home.sprynet.com/calc_hp.htm

That is a really cool link! I wonder, though, if it is more applicable to a N/A engine in terms of the effect altitude and barometric pressure has?
Doesn't a modern turbo engine's ecu to compensate (to some extent) to changes in altitude by increasing boost as the air gets less dense?
Thanks again for the neat-o link:alien: