Anyone know how much the Power / Torque / Boost changes as temperatures do..........?

J

 

J,

I saw on another thread that Stephen Done reckoned he had lost 13BHP during the last week due to a 10degree celcius temperature rise

Might be an idea to pop back to PE for an RR when the temps higher ... would be good to know.

Steve

 

BTTT....

Anyone else ?



J

 

You can work out the density change by some simple maths but there is a bit more to it than that every engine reacts slightly differently too, depending on a number of factors including the type of control system used ie MAF and/or MAP.

1% loss for every 10 deg F rise is a common yardstick used in the USA.

Andy

 

So this would roughly mean that for every 1.8 degrees that temperature changes on the Fahrenheit scale, temperature will change 1 degree on the Celsius scale.

Therefore 1 degree C means power goes down 0.556% i.e

Standard UK MY00 (218BHP) would loose 1.21BHP per degree C increase....

Ping you were right........

J

 

Just realised I loose..............

1.5BHP per degree C ...........

oh well 15 - 20BHP down for the summer

J

 

Ooops

Your math's a bit out !

10 deg F = 6.25 deg C

1%/6.25 = 0.16% power loss per deg C

Therefore to calc power loss from 5C day to 20C day on say 280 bhp.

280 x (20-5) x 0.16/100 = 6.72 bhp loss = 273.28

Andy

 

Hi Cosie,

Looked at it your way and would say you were more correct than me , but then would slighty disagree as the scale is a shifted constant...

I.e.

http://www.memphis-schools.k12.tn.us...apages/F2C.htm

So for every change in degree F this is 0.5556 degrees C. Therefore 10degrees F (1% power change) would equal 5.56 degrees C

or for every degree C, 0.0018% approx = half a bhp on my 270bhp Car

...

Oh well whatever................

It a bu**ger


J

 

School ? What's that ?

Your correct, I used 5/8 and it should be 5/9...Doh

So warm days aint so bad after all