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Lap Dog
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Discussion Starter · #1 ·
I drove 170 miles in 5 F weather this morning and my 325 felt a lot faster. 70-90 mph in 5.5 seconds (4-th gear) - not bad for a wimpy 2.5 ltr. I was reading on one of the Miata forums that every 4 degrees difference in intake air temperature bumps up HP by ~ 1%. Does anyone have facts/links to substantiate that?
 

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I like cookies.
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I don't have an hard facts, but my engine always seems more responsive and stronger in cold weather...

Even sounds better...
 

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Lap Dog
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Discussion Starter · #4 ·
Plaz said:
Okay, so that's a downside for SoCal. :lmao:
Yep! I'd be sleeping during the day and driving at night if I were living in SoCal :)
 

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•••••••
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brave1heart said:
Yep! I'd be sleeping during the day and driving at night if I were living in SoCal :)
If it wasn't for the whole pesky job and family thing, I'd be doing just that. :D
 

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Lap Dog
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Discussion Starter · #6 ·
Plaz said:
If it wasn't for the whole pesky job and family thing, I'd be doing just that. :D
:lmao: :lmao: :lmao: :lmao:
 

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brave1heart said:
I drove 170 miles in 5 F weather this morning and my 325 felt a lot faster. 70-90 mph in 5.5 seconds (4-th gear) - not bad for a wimpy 2.5 ltr. I was reading on one of the Miata forums that every 4 degrees difference in intake air temperature bumps up HP by ~ 1%. Does anyone have facts/links to substantiate that?
Colder air is more dense hence more air is allowed into the combustion chamber giving more HP.
 

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buyme///M5 said:
Ya, cold air compresses easier :dunno:
I never said that. Colder air is more dense meaning more oxygen per unit volume of air means more power. Remember an engine is just a giant air pump. The more air you can get into and out of the engine the more power you can create. Why else do superchargers and turbos exist?
 

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Bruce said:
I never said that. Colder air is more dense meaning more oxygen per unit volume of air means more power. Remember an engine is just a giant air pump. The more air you can get into and out of the engine the more power you can create. Why else do superchargers and turbos exist?
No, sorry if you misunderstood, but that's just what I said :dunno:
 

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Exit Flagger
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cold air burns has less mouisture. engines love cold air.

i remember being 16 and driving my parents taurus and always loving the fall & winter months.........it felt like I was in a mustang. :D
 

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M Mad
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It is called density altitude. Aior density is a combination of pressure and temperature.

Somewhere online there is a HP calculator that you plug in temp and altitiude and stock HP (which is corrected to "standarad conditions" ) and it gives you the approximate HP in those conditions.

As was pointed out, engines are air pumps, they move air in. The use oxygen, the more oxygen, the more power. You can increase the oxygen by several means.

Increase the pressure - supercharginig in all its forms does this.

Decrease the temp - like CAIs do, and for supercharged engiens, intercoolers do this.

Add oxygen - Nitrous does this. Nitrous breaks downin the engine to make additional oxygen.
 
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