How much does cold weather boost Power/Torque?

[tim]

The difference in power between riding during the day at around 15-20 degC, then riding at night around 0-5degC has been really noticeable over the last couple of days.

Just wondering, has anyone ever done a dyno test to find out what the figures are? My bum dyno thinks it's around 10-15kW? I definitely like my engine more when it's really cold

[Screamin TE]

Im not sure if you would get a considerable gain. Cold air just aids in giving a more complete combustion as colder air is more dense, so effectively there is more in there. In a general round about sort of way.

[metaltriumph]

i definately ride faster in the cold.







Usually to get back inside quicker...

[Phil]

My bum dyno thinks it's around 10-15kW?

Is it tested to NATA standards - with a reading like that I'm guessing not

[Glen]

We did a dyno day at Flywheels a while back and the difference between the start of the day when it was cooler and less humid and the end of the day when it was bloody hot seemed like about 10hp onthe ZX10's that were there

[Wattie]

We did a dyno day at Flywheels a while back and the difference between the start of the day when it was cooler and less humid and the end of the day when it was bloody hot seemed like about 10hp onthe ZX10's that were there

nothing to do with the lack of Oxygen in the dyno room at the end of the day also??

[Wattie]

Just be thankfull it is Fuel injected, otherwise we'd need Gos in here to explain when is the best time of year and best hight to re-jet your carbies to.

[Gosling1]

.....Just be thankfull it is Fuel injected, otherwise we'd need Gos in here to explain when is the best time of year and best hight to re-jet your carbies to. .....

yeh mate, don't forget you need to stop at Braidwood on the way to the coast and re-jet your bike for MAXIMUM HORSIES !!



10-15kW from the cold weather ?? not on your nellie mate. You will definitely feel a better response from the motor though with colder, denser air being combusted, but not that much extra hp. I reckon there may be a couple of ponies in it, at the max.

[Kermit]

10-15kw gain in cold weather highly unlikely unless your bike is running boost, with cold weather you tend to get 1-2 psi of boost creep.

A few kw gain at most, in a N/A machine in the cold.

[Blurr]

yep as Gos said it is just better response.

The extra sharpness from the throttle makes you think you have more ponies.

Still it is fun . My little CBR250RRRRRRRRR used to do mad wheelies in the cold weather

[Kawawog]

Yeah mine blows me away in the really cool weather..Like previously said the throttle response is crisp as and its even harder to keep that front wheel down!! Last winter i smashed the throttle hard one night in first gear at 60kph and it just broke traction and started wheelspinning.. So much for kawasaki's traction control system on the 08-09m, did fark all.. It kept spinning hardcore until i backed off

[oldman]

?????????/

[oldman]

Further proof that dense includes me .

[oldman]

Cold air is more dense, (kind of like most of this forums members), so is cool gasoline as it becomes smaller when it is cool. So logically you have increased the amount of oxygen and fuel in the combustion chamber so more power even on a carby bike. If you have EFI with temp or oxygen sensors even better. I have no proof just basic physics. Have a JIm Beam and a cold brew and even the most mentally challenged will understand.

[s man]

Your on the right track oldman..
If you engine runs better cold then its tune is out of whack.
Cooler means more air which means leaner mixture. Your bike is leaning out a little when cold.
For those with EFI bikes, the computer will always punch more fuel in when cold.
That doesnt happen with carbs.