| ...but for the sake of discussion: If the outside air is 70 degrees F (530Rankine), it might heat up to 160 F (620R) by the time it actually enters the combustion chamber (these temperature values are purely hypothetical). Hot air is less dense than cool air, so there is actually less oxygen entering the combustion chamber due to the rise in air temp. Because CF is less heat-conductive it won't get as hot as the stock aluminum manifold, and has lower thermal conductivity, so it won't bleed off as much heat into the intake air. So if the new manifold could cause a 20 degree drop in air temp entering the chamber (140F, 600R), and assuming everything else is equal, the new air density will be inversely proportional to the new air temp. After some manipulation of the Ideal Gas Law, and assuming everything else about the engine stays the same, there would be about a 3.33% increase in Horsepower, from 160F to 140F. I don't know how hot the intake air actually gets on an N/A, so these numbers might not be close to the real world at all. Basically, you take the original intake temp (in Rankine scale, which is Fahrenheit + 460) divided by new intake temp (R), and that tells you what percentage of the original power you'd make. For an N/A, 7hp probably isn't worth the cost of a custom manifold. But you could always get better flow characteristics and increase intake pressure to make it worthwhile. The Corvette C5R has CF manifolds, as do a LOT of serious racecars...like all F1 cars. It's the only way to go when you're spending millions of dollars to lose a 10th of a second around the track. On a 900hp F1 engine, 3% really means something. Hope this helps. Anyone out there who sees a mistake, let me know...I hate giving bad/incorrect info ;)
----------------------------------------------------------- "I love you all...I love you more than life itself...but you're all fu*king mad" - Ozzy Osbourne "Funk you very much" - George Clinton 
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20:24:31 01/09/03
