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Discussion Starter #1 (Edited)
Does anyone know what the volumetric effieciency of our 2.5 mzr's are? in a COMPLETELY STOCK environment?

if you dont know what volumetric efficiency is dont bother posting!


i'm guessing it is probably around 70-75%. if anyone knows let me know!

also did everyone know that you can actually attain ~140% volumetric efficiency purely NA!


but in seriousness, I would like to know what the VE is of the 2.5mzr,
 

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I was wondering when jmaister was gonna come in here!
 

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cold air as in denser air doesn't really plan a true role until the air is under 60degrees F
So you're saying an engine sucking in 60 degree air doesn't make any more power than an engine sucking in 160 degree air everything else being equal????? I think I might have to disagree with you there.
 

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Discussion Starter #8
no not saying that at all, just saying there isn't true butt dyno ( what you can feel ) difference between lets say.. 60 and 65. or 75.. any person who is pulling 160 degree iat on an NA has problems.

below 60 is when air really gets denser
 

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no not saying that at all, just saying there isn't true butt dyno ( what you can feel ) difference between lets say.. 60 and 65. or 75.. any person who is pulling 160 degree iat on an NA has problems.

But aren't a lot of short ram intake systems pulling in a lot of engine heat underhood? I'd think 160 degree air temps underhood are pretty common. On hotter days probably not uncommon to see temps well above 160 degrees. No?
 

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Discussion Starter #11
But aren't a lot of short ram intake systems pulling in a lot of engine heat underhood? I'd think 160 degree air temps underhood are pretty common. On hotter days probably not uncommon to see temps well above 160 degrees. No?
I would say no. If that were the case and there was no air movement under the hood and it was a constant 150-160+ then how the hell would the engine keep from overheating?
 

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No offense, but I'd say there is too much guessing in here.
share your wisdom please. guessing is good, better than your useless comment.


as to SRI, well now, whatever is made for the 2.5 is all POS. They dont even provide MAF read outs, tells you how much they know. This isnt carb days boys.

You gotta use your brain.

I would say no. If that were the case and there was no air movement under the hood and it was a constant 150-160+ then how the hell would the engine keep from overheating?
90 degrees F thereabout idling, and 75 ish while accelerating, also pending outside temp(is it within reach as well). It will effect knock sensor, fuel trim, and spark timing if the temp is higher than optimal.

with a proper cold air, you could bring the IAT down to 58 or less.

Still, the calculator puzzles me abit. It must have included turbo engine as well. But then its a different animal, cant just use one equation for that.
 

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you should test the effectiveness of said radiator and fans when it is 160 degrees constantly all around it.. I say overheat.. but who knows.
Well you have to think about where the coolant temps are at when the engine is at operating temp. Most cars typically like to keep the coolant temps in the 170-200 range. That is the happy place for engine coolant temps in many engines and the car will try to keep the coolant at those temps by use of the thermostat and fan. The radiator keeps coolant temps in check by ambient airflow over the radiator. If sufficient airflow isn't taking place (stop n go traffic for instance) or if the coolant is getting hotter than normal for any reason the electric fan will kick on. Some fans are two stage meaning they have a low and a high setting that works off an automatic temp switch. Other cars have one big fan and then a smaller backup fan (usually called an auxillary fan) to back up the big fan when needed. Alot of fans are a "pull type" meaning they are pulling outside ambient air into and around the radiator to cool the coolant. Other fans are a "push type" that blow air onto the radiator. If the air blowing onto the radiator is cooler than the coolant it will cool down the coolant.
 

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I wonder how much these short ram intake systems raise the air temp that is entering the intake tract compared to the sealed oem airbox that is pulling cool air down low far away from the engine? Short ram intakes breath better than the stock intake, but unfortunately they are just breathing hotter air which negates the power gains one would think.
 

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Discussion Starter #20
my guess is that it isn't too hot probably in the high 90's esp when the car is moving quickly the air temps shouldn't be hotter then 100. * shouldn't * but im not underhood temp expert
 
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