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VRA National President
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Decided to go for a backroad jaunt tonight to get the juices flowin (I meant the bike but I guess that goes for me too... :))

Charlotte just LOVES the cold weather. My dad and I have discussed the notion many of times. Maybe the sound carries differently in cold air but I could swear she had an extra 10 horse. The colder the weather, the harder and faster she wants it. I was floggin it on some of these back roads and the acceleration was **** near intimidating tonight.

Do ya think there's any truth to a bike having more power in the cold or is it all just perception?

On a side note, I took my girlfriend's Aero 750 out direclty after just to stretch its legs a little and man, what a dog! With stock pipes and air, it has no balls whatsoever. It felt like I was running it with a banana stuck in the pipe. Fine for her but I'm spoiled now. :)
 

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the "fun" guy
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I think you have a good point Slicks. I've noticed that my bike runs really well in colder weather...which makes me wonder if it's running a little rich perhaps?

Anyway...we all know that HEAT KILLS.....so with the rides I have taken in the cold weather here I can feel a difference in how it performs. I wish I could say the same for me in colder weather. ;)
 

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AZ's Official Mechanic
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you guys already know your rear cylinders run rich so with the cold weather your front is running a bit leaner and the rear is prob. just right. also with the cold air its burning the mixture more complete so its making a bit more HP/TQ. my bike picked up 5 or so MPG since its gotten "cold" here in phoenix. just shows im rich in the summer.
 

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the "fun" guy
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QKENUF4U....I appreciate the explanation. Makes perfect sense.


By the way...I thought most people in Phoenix were running a bit "RICH". LOL :):):)
 

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Official BTK Forum Pot Stirrer
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it also has to do with the density of the air. Cold air is more dense than hot air you get more air to compress in the cylinder, which makes for a more volatile mixture at ignition.

I've been out three times in the past few days, lucky me with our terrible wet weather, but anyway Robin really loves the cold air and responds very well!
 

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re

i'm with spok-cold air is dense,get more in the cylinder and get a bigger pop
everything runs better in the cold-i have had 10lb bags of ice my manifold
many times at the track :grin:
 

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Colder air means denser air, which means more oxygen, which means a leaner mixture. Remember, lean is mean. The key to tuning for power is, running as lean as possible with the highest advance of igniton timing. To far lean or to far rich equates to less power and detonation. Finding the fine line in between results in optimum performance.
I think most of us tune slightly on the rich side which is always safe. That being said, better performance is achieved in colder denser air. Happy Motoring!,

*you guys are die-hards riding in the cold. It`s in the freakin twenties up here in NY.
 

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Cold air = more dense air = more oxygen - all true. FI should be able to compensate for the temperature of the air by sending more fuel which will add more power. For carburated engine, it may run leaner.

Besides the air being more dense, there is another consideration of the cold temperature. Thermodynamics states that the effieicney of the heat engine is inversely proportional to the temperature of the heat sink. In other words, if the temperature where the heat is being rejected (e.g., exhaust gaes being sent out throught the pipe to the atmosphere) is lower, the efficiency of the engine will increase. That is why power plants actually can generate more electricity during winter time than summer time except that they need more electricity during the summer months than winter months.
 

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I miss you, Deron
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Well, it wasn't cold here today. Mid-40s and sunny, and I just got back from a ride. Yay!! Best Christmas present I could ever get. :D It's gorgeous today, and the ride was spectacular. Hardly any cars on the street and no cops in sight, so I went a lot faster than I normally would. It's supposed to be even nicer tomorrow.

Life is good.
 

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Official BTK Forum Pot Stirrer
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Slicks said:
Ok, compared to the average bear, I think I'm fairly smart but I'm beginning to feel dumber and dumber by the post .... :)
No worries there slick, just keep an eye out for ranger rick as I go get me my pic-a-nic basket
 

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ppark said:
Cold air = more dense air = more oxygen - all true. FI should be able to compensate for the temperature of the air by sending more fuel which will add more power. For carburated engine, it may run leaner.

Besides the air being more dense, there is another consideration of the cold temperature. Thermodynamics states that the effieicney of the heat engine is inversely proportional to the temperature of the heat sink. In other words, if the temperature where the heat is being rejected (e.g., exhaust gaes being sent out throught the pipe to the atmosphere) is lower, the efficiency of the engine will increase. That is why power plants actually can generate more electricity during winter time than summer time except that they need more electricity during the summer months than winter months.
This is true. Besides the more HP the engine is putting out, the road temps are lower and the tires have less bite. Thats the problem most drag racers have racing at night. More HP and less traction. Be careful and don't take the twisty's with the same throttle.

Ride safe and long.
 

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RIP Deron Harden :-(
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Slicks said:
Ok, compared to the average bear, I think I'm fairly smart but I'm beginning to feel dumber and dumber by the post .... :)
i'm with you slicks
 

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Yeah Slicks,i think you're right. My ole 1500 Vulcan seems to run a "lil" quicker in the cold than the warm. It could be though I'm twisting the grip a bit more than normal trying to get to where i'm going. I found out its just as cold at 70 mph as it is at 40 mph!! So you're right,they do seem to run with a lil more power when its cold! See ya, Kenny in North Carolina.....
 
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