Ok guys just a quick question. for every 2-3 degree decrease in intake temps what kind of power gains do you see? Just wondering https://www.nopistons.com/forums/pub...IR#>/smile.png

1hp per 10 degrees? Can't remember its been awhile..

Reducing air charge temps by 10 degrees will increase power by a minimum of 1%

aww gotta be more than that....right?

after installing the greddy fmic vspec there is a large notice in hp gains. even at the same boost levels.

yup



10-11 degrees cooler intake air charge equal 1% HP gain...

1% not 1 hp, that would make more sense..

yeah really its more like 1% min 2% max depending on your other mods. That is how sidewinder noticed such a gain with his FMIC, they cool 24-31 degrees on average depending on size...

So you guys are saying 1% power increase with nothing else changing? I was thinking the #'s could be more because the 10 degree decrease or whatever could allow you to turn up the boost a little, no?

Not to mention on boosted vehicles they spool faster too https://www.nopistons.com/forums/pub...DIR#>/wink.png

i wonder if theres a point at which you get no gains, or less gains

Good question! There prolly is a cap on cooling.

Thats only part of the equasion. Each 25 degree reduction requires 1 point less octane. Meaning you have more available octane = less detonation / preignition.

Where'd you guys hear about the 10 degrees equals 1% rule? I've never heard that one before.



For every degree lower in intake temp, it's one degree lower in exhaust temp.

Various engine building books. Info from Sparco, Greddy, Hks.

How about all the people who have cone filters sucking in air from the engine bay. Im not sure but i would estimate the air in the engine bay to be well over 250 degrees. Do the math.

Yeah, most of the gains from warm air intakes are from increased flow, not temp.

130-160 degrees under the hood depending on location.

well cold air is more dense, so you need more gas to run at the same mixture or cold = leaner, hot = richer

This is true. But nothing the ECU shoudnt detect and compensate for. Unless you have a carb.

the one percent is with all things being equall.. ie same air fuel ratio as before which with a denser charge will require more fuel. but with the cooler intake charge you can increase the timing a little which will move the torqe curve up the power band a little higher and thus make more hp. maybe even more than the 1-2%