# optimal intake air temperature
**URL:** https://forums.speedlife.net/t/optimal-intake-air-temperature/86833
**Category:** SON240sx Automotive
**Created:** [June 29, 2005, 9:40pm UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833 "2005-06-29T21:40:15Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@alesserfate](https://forums.speedlife.net/u/alesserfate)
#### Post date: [June 29, 2005, 9:40pm UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/1 "2005-06-29T21:40:15Z")
hey guys, there are various ways to cool the air that goes into your engine, intercoolers, nitrogen cooling, heat exchangers, all of them try to achieve the cold in the air, whats the OPTIMAL (duh, it means most appropriate to achieveve highest performance) air temperature to make your engine perform at its best, anybody know ?
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### Author:  [@Sven](https://forums.speedlife.net/u/Sven)
#### Post date: [June 29, 2005, 9:56pm UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/2 "2005-06-29T21:56:59Z")
The colder the air the denser it is.
The denser it is the more oxygen there is.
The more oxygen there is the more fuel you can dump it and the bigger the bang will be.
Compressing air (with a turbo or super charger) makes it hot.
Nitrus gets around this problem because it has a very high oxygen density compared to regular air. So you get way more oxygen but no temp increase. (In fact since the Nitrus is stored compressed, it should be much colder then ambient).
Intercoolers ARE heat exchangers.
Nitrus cooling is a way to cool down overheating intercoolers. (If you are talking about what I think you are talking about. That is, you spray something like Nitrus onto an intercooler.)
Optimally you would want the air to be at absolute zero (well maybe not could cause some fuel problems). It’s a little tricky to get it that cold though. So realistically you’d want it to be close as possible to ambient after compression. The bigger the intercooler you use however … the more air between the compressor and the cylinders and that means lag. So optimally it depends on a lot of things.
Again you are going to have to be a million times more specific if you want any useful information.
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### Author:  [@alesserfate](https://forums.speedlife.net/u/alesserfate)
#### Post date: [June 29, 2005, 10:12pm UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/3 "2005-06-29T22:12:21Z")
cool, awsome, so absolute zero is 0 on the kelvin temp scale which is -273C ? does that mean it wont hurt the performance engine if the air that goes into it is as cold as 5C ?
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### Author:  [@Sven](https://forums.speedlife.net/u/Sven)
#### Post date: [June 29, 2005, 10:23pm UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/4 "2005-06-29T22:23:17Z")
Like I said within reason the colder the air the better.
It will help performance not hinder it. 5 degrees would be great. -5 would be even better. Make sense?
I don’t know exactly where you are going with this though … how are you going to choose which temperature your intake air is at ?
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### Author:  [@alesserfate](https://forums.speedlife.net/u/alesserfate)
#### Post date: [June 29, 2005, 10:25pm UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/5 "2005-06-29T22:25:07Z")
> [@Sven](#):
>
> I don’t know exactly where you are going with this though … how are you going to choose which temperature your intake air is at ?
mwahahaha, you’ll see sooner or later, my ultimate forced induction system, thanks for helping me out =D im sure i’ll have more questions on this along my journey to boosted future lol
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### Author:  [@Racer\_XTREME](https://forums.speedlife.net/u/Racer_XTREME)
#### Post date: [June 30, 2005, 5:25am UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/6 "2005-06-30T05:25:32Z")
There is a lot more to it than just the cooler the better.
… if you are running a charged air system, way more comes into play, you need to deal with efficencey. You could make the largest IC in the world, it would cool the air a lot, but the pressure drop would be enormous, your turbo would top out at like 4psi and you would have so much lag you’d never reach it.
… do you get that?
Personally, id rather run hotter air into the engine, if i can get faster throttle respones and 0 boost lag, … but people are different.
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### Author:  [@Pavel](https://forums.speedlife.net/u/Pavel)
#### Post date: [June 30, 2005, 7:03am UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/7 "2005-06-30T07:03:26Z")
> [@Racer X](#):
>
> Personally, id rather run hotter air into the engine, if i can get faster throttle respones and 0 boost lag, … but people are different.
By 0 boost lag do you mean you’re at full boost at idle? sweet!
Just so you know, the air temperature makes a HUGE difference in HP. Therefore your idea of running slightly faster response may not be THAT good. At the race track, the rpm range keeps the car in full boost anyway. Didn’t we have this discussion with ADAM before?
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### Author:  [@Racer\_XTREME](https://forums.speedlife.net/u/Racer_XTREME)
#### Post date: [June 30, 2005, 8:02am UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/8 "2005-06-30T08:02:09Z")
full boost at idle sounds good to me, … thats why im building an ALS.
But besides the point,
Yes while racing generally you have high RPM’s keeping the turbo spooling, and obviously lower intake temps make a large difference in power.
BUT, with a huge IC you have a huge pressure drop, your turbo is working much harder than it needs to, and because of that it will slow down faster, so sure at 4000rpm you have boost, but at 3800rpm you’ve lost it, race cars also rev fast, and loose rev fast. So if your full boost above 4000rpm youd need to shift at redline or above, (assuming he hasnt changed his redline) just to not loose power.
Race cars are built to run at high revs always, his car probably wont be, and with a huge pressure drop across a massive cooler will add problems to the cars driveabilty.
The best thing is to find different ways to cool the air, there are much more effecient ways to coolar charged air then a front mount intercooler, but they have different problems.
Where i work, for every high boost high power car we have to design a cooler for, we design a water to air charge air cooler thes extremely effiecent, but it weigh more.
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### Author:  [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)
#### Post date: [June 30, 2005, 2:54pm UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/9 "2005-06-30T14:54:14Z")
The best setup from what I’ve seen
Air To Air intercooler that is decently sized
Insulated cold pipe (i would think not hot pipe though as it would retain heat, possibly right near the turbo where ambient air is hotter than air being expelled from the turbino)
Water To Air Intercooler after the air to air cooler with a small rad for the cooler on either driver or passenger side.
CO2 spray on the intercooler and the air to air rad
Intake manifold gasket insulator from hondata
Vented hood to pull as much air from the engine bay as possible
problem is even with 100% efficiency the charge temp would still be only ambient temp. So CO2 is really the only way to bring it down, and unfortuantly that is something that needs to be refilled all the time like nitrous so its gay
WRX makes 35 more ft lbs of TQ between -10degrees and 20 degrees so Paul from neetronics says so its HUGE, about 1 ft lb per degree
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### Author:  [@Racer\_XTREME](https://forums.speedlife.net/u/Racer_XTREME)
#### Post date: [July 5, 2005, 6:56am UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/10 "2005-07-05T06:56:26Z")
> [@Sasha (Turbo)](#):
>
> The best setup from what I’ve seen
>
> Air To Air intercooler that is decently sized
> Insulated cold pipe (i would think not hot pipe though as it would retain heat, possibly right near the turbo where ambient air is hotter than air being expelled from the turbino)
> Water To Air Intercooler after the air to air cooler with a small rad for the cooler on either driver or passenger side.
> CO2 spray on the intercooler and the air to air rad
> Intake manifold gasket insulator from hondata
> Vented hood to pull as much air from the engine bay as possible
>
> problem is even with 100% efficiency the charge temp would still be only ambient temp. So CO2 is really the only way to bring it down, and unfortuantly that is something that needs to be refilled all the time like nitrous so its gay
>
> WRX makes 35 more ft lbs of TQ between -10degrees and 20 degrees so Paul from neetronics says so its HUGE, about 1 ft lb per degree
I agree that would be a great setup, with fast spool up times too.
Very similar to what i want to do, minus the air to air, the CO2, and the intake manifold gasket.
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### Author:  [@system](https://forums.speedlife.net/u/system)
#### Post date: [July 5, 2005, 8:19am UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/11 "2005-07-05T08:19:54Z")
Anyone know how effective those intercooler spray kits are?
The ones that have a small water reservoir and spray a mist over the intercooler. Water evaporating, cooling down intercooler, lower air temp going to cold pipe.
Stock STi has one of these doesn’t it?
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### Author:  [@DTS](https://forums.speedlife.net/u/DTS)
#### Post date: [July 5, 2005, 8:35am UTC](https://forums.speedlife.net/t/optimal-intake-air-temperature/86833/12 "2005-07-05T08:35:17Z")
> [@Racer X](#):
>
> full boost at idle sounds good to me, … thats why im building an ALS.
before you build your 2 step rev limiter you should probobally understand how they work
because they run at 4000 rpm not 800rpm :roll: