[natedog7700]

An idea of how much HP is gained for X amount of temperature drop? I took my car out tonight and it feels so much faster i totally forgot how much of a difference the weather makes. Humidity 31% and 59 degrees. Last time i drove the car was 56% humidity and 75 degrees.

[natedog7700]

Anyone?

[MooreBoost]

Originally Posted by Car Throttle

For example at an equivalent pressure of 14.7 PSI, changing temperature from 85F to 32F can change the density of air by almost 11% (increase). Theoretically in this circumstance, an engine would be able to make 11% more power.

Googled and found this.

[dyezak]

Too many variables. If it's 90F and you are limited to 89o fuel and detonating at 17psi, it's completely different than 90F on e85 with a clean tune at 23psi.

[WTF?]

Well, he did say it was his same car. I think it is safe to say that they are pretty close to the same circumstances. I think everybody knows that under two completely different situations, two completely different cars run completely different.......

[mike@x-ph.com]

Originally Posted by MooreBoost

Googled and found this.

This is assuming boost is constant which is not true.

DME does not target a set PSI, it targets load tables (and a lot more boost related tables).

PSI will change on a stock car all the time based on a lot of factors

[Sgop335]

Originally Posted by natedog7700

An idea of how much HP is gained for X amount of temperature drop? I took my car out tonight and it feels so much faster i totally forgot how much of a difference the weather makes. Humidity 31% and 59 degrees. Last time i drove the car was 56% humidity and 75 degrees.

Mikey is right. Boost target reduces with lower iats and vice versa so power is about the same. However at low iat, timing drops may be absent rezultung in faster

[CoffeeBean]

Yep on our cars it changes. In the summer I'll hit 18-19 psi, but the winter only 15-16. I had a Celica Alltrac manually set at 15 psi and it was so much faster in cold weather.

[RVA_MR2]

what about if you're running with jb4? doesn't it target a set psi?

[mike@x-ph.com]

Originally Posted by RVA_MR2

what about if you're running with jb4? doesn't it target a set psi?

When you are using a piggyback PSI is set ... If everything else is constant, car will make more power in colder a climate

[ASBSECU E93]

For N/A cars - cold weather is commonly referred to as 'Hurt Feelings Weather' when they race against turbo cars...