Does anyone know how much extra hp your car is making when he weather getsa bit below the freezing point, compared to say a 75 degree day?

 

I knew this a while back but forgot. Reg, Im 90% sure its 1hp for every 5* drop.
SSC

 

I can not tell you the exact number but I can tell a big difference in performance when the temp is like -10C compared to like +5c.
If I had to pick a number it would be 20 to30hp. I know some people might laugh at it but I actually have been watching the chnege in temp/air and getting out there and testing the car. I have no real numbers or 1/4 timesbut from my experience it make a very big difference if your car is properly tuned.

My TPI responds very well to colder/denser air. There was an earlier article about the "Limits of the TPI" and someone there has all the numbers and times to prove this theory. On a colder night their TPI made a 1/4 mile pass one second quicker than on a warmer day. And they have done this pass several times to prove this.

Anyway, that is what I noticed about my car.

 

The old rule of thumb is 1% for every 11*F.

 

...............if the carb is jetted properly to compenste for the change in A/F ratio due to the change in temp. You'll want to change approx. 1 jet size for every 40* change in temp on most commonly available performance carbs. Colder you need to go richer, lener when you go hotter.

 

I ran my daily driver on the mti dynojet in Feb 00. The printout indicated a correction factor of .97 and an inlet airtemp of 65.5 degrees (I remember it was rainy). To my understanding thats 3percent high there just based on the cooler temp.

All i know is the tires dont hookup too well when its cold.