Engines ... More power in the winter???
 

Hi,
After reading about turbos, superchargers, intercoolers, etc, something crossed my mind.

Turbos and superchargers blow compress the air flowing into the engine, the intercoolers cool the pressurized air.

Nature tells us that as the air temperature goes down the air compresses taking less space.
The outside temperature in the winter is lower than in the summer.

Adding all this together, an engine show have more power in the winter than in the summer because, the devices that enhance the performance combined with a low outside temp produce a bigger explosion.

And in principal this should happen also in natural aspirated engines but only so some extend, I think.

Taking this to extremes shouldn't a car have more power in the North Pole that in the Sahara desert??

If this is true when do the manufactures measure the power of the engines??

I'm not sure all this makes sense guys but can someone clarify this for me??

If this isn't true can anyone explain why???

Sure it's right.. and also cars perform better at night (more oxygen).. on my poor Bimmer I have to admit between Summer and Winter or day and night I don't notice much changes... but with small scooters usually you can feel the change a lot...

Well in theory yes that would work.
Manufacturers measure HP on an engine dyno in a building at room temperature.
The North Pole and Sahara would be drastically different for reasons such as air pressure and other varying reasons, In the dessert you need special breathers to keep sand out and in the North Pole you need an engine that will run at such extremely cold temperatures and the oil viscosity would be different so you would never be able to take an engine from such drastic opposites and expect it to work. But once you get the engine warm here in the normal parts of the world it wont be too noticeable like TT was saying.

Any Cold day will do! Cold Air is Denser than warm air. The denser the air you're getting into your engine, the more powerful the combustion and that = more power. Thus, the colder the air, the more power you'll get.

You are indeed correct about the effect of temperature.

The interesting point comes into play when you think about what altitude does to engine performance. The system least affected by altitude is turbo charged. My car is n/a. So regardless of temperature my car will have more hp at sea level then colorado. This is why many magazines state the elevation and temperature in their peformance test articles.

Beside the denser air at lower temperature, I think the temperature sensor in the intake will tell the engine management to give it a richer mixture.

Hehe, when I was younger I had a nice Malaguti Phantom, the original engine was dumped and I replaced everything with 90% Malossi parts and some Pinasco too.. of course also clutch and vario where racing items as the electronics... of course it was no more a 50 cc but 80 ;) and no idea about top speed.. the tacho had a max indicated speed of 100 km/h and it was easy to reach with also a passenger I tried a couple of time to top it with a car beside me to keep track of the speed, but never really dared to go above 115-120 km/h indicated on the car...
it was really a beast... every time you post about scooter I feel so sad thinking about "him"...

Here is a (crappy) pic :)

http://www.jabbasworld.net/photopost...83phantom3.jpg

I always notice a huge gain in the pick up and strength with which the engine pulls on a cold night compared to a warm summer day.
I sounds loads nicer aswell! Best conditions are a cold ambiant temperature and slightly over regular moisture in the air.
Standard induction systems usually show little difference between various conditions, as that is what they r designed to do, give reliable regular performance, but if u wack a k&n on wiv a heat shield and cold air feed, u will feel a big difference with the temperature change.

Yes, you're right. In effect you get natural intercooling.

As for how manufacturers test, it depends which standards organization they operate under. Anyway, all tests will have standard conditions they are required to be carried out under (likely close to ambient).

Yeah, on winter and at night your car goes faster.
It makes sence what you sad

:D

ya, but in Toronto now the cars are running so poorly because it takes 20+ minutes to get the car near proper operating temperature. Once you get there the cool air should help performance- but until then the car runs terribly.

I miss the days where you could hop in the car and drive without waiting 10 minutes for the windshield to defrost.

HAHA I don't feel sorry for all you that have to warm up your car. My garage is always at a perfect 60 degrees in the winter. :D

But for exemple those big engines, with more that 600Hp and 3 or 4 turbos how much to you think they can gain from this??

Anyone have a rough idea of how much Hp can a normal 2.0cc Turbo, intercooler , with 150HP (Manufactures reading) gain from temp drop pf lets say 10 or 20 degrees Celcius???

Thanks to all the replys.

I have no idea what the numbers are for a 2l turbo are, but I can tell you that my 5.7l n/a V8 showed a 22hp difference at the rear wheel.

The uncorrected summer number (on a 90F+ day) was 329rwhp (corrected to 334hp), and the winter number (on a 60F day) was 351rwhp (corrected to 335hp).

As can be seen from the corrected numbers, my engine puts out as close to 334rwhp as can be measured.. LOL :)

Is this one of the reasons why the manufactures test there pre-production cars in the snow so that they can measure the power gain from the low temp??
I say this because everytime a new car comes out there are photos on magazines from a few months ago that show them in the show.

I remember seeing a Porsche Carrera GT, and a seen today the new A-Class in the snow.