Cold Weather=More power. Why?

[s2d4]

Originally Posted by Suberman

So, how much extra power is produced and at what temperature does this imaginary power show up?

This would be why your fuel economy improves in winter. Not.

@Fast_Freddy, you guys would get along like a house on fire.

[n2oinferno]

[humfrz]

Originally Posted by Suberman

...........
For our highly tuned engines cold intake air can make no discernible difference in power output. I am happy for anyone to show this to be wrong by dyno or other means: increase in too speed observed or quicker acceleration times.

So, Suberman, are you saying that an aftermarket CAI for the FR-S/BRZ is a waste of money .. ??

humfrz

[SpeedR]

Originally Posted by Suberman

So, how much extra power is produced and at what temperature does this imaginary power show up?

This would be why your fuel economy improves in winter. Not.

If cooler air dose not mater whats the point of an intercooler?

I am sorry but you appear to have no idea what your talking about.

[Rayme]

It makes more power. All engines make more power with colder air as the computer dumps more fuel to keep the air fuel ratio.

[ZDan]

Originally Posted by Suberman

So, how much extra power is produced and at what temperature does this imaginary power show up?
This would be why your fuel economy improves in winter. Not.

There are a few reasons why cars get worse mileage in the winter, one being winter fuel formulations having less energy content, another being that colder/denser air creates more aerodynamic drag.

Another secondary effect is that since colder air *does* give more power, then at a given cruise speed, you'll have a smaller throttle opening to make the same power. This gives greater losses as the engine has to do a tiny bit more work to draw the air past the smaller throttle opening.

Believe it or not, there is a HOT air intake mod for mid-90s Honda VX cars that improves fuel efficiency for this reason (wider throttle opening required for a given speed/power setting)!


That said, I would guess that most CAI mods for this car won't necessarily improve performance much, if at all. That has been the case with a lot of S2000 intake mods...

[WolfpackS2k]

Good lord, isn't basic chemistry a requirement for high school graduation? Questions like the OP's make we weep.

[Suberman]

Originally Posted by SpeedR

If cooler air dose not mater whats the point of an intercooler?

I am sorry but you appear to have no idea what your talking about.

The intercooler cools the intake charge after it has been compressed by the supercharger. That's why. I do know what I'm talking about. You apparently do not. But now you know a little more than you did before.

[Suberman]

Originally Posted by WolfpackS2k

Good lord, isn't basic chemistry a requirement for high school graduation? Questions like the OP's make we weep.

Well, it would be simple if stochiometric ratio is all that was at play here but because the engine controls are now very sophisticated that isn't all that's involved.

Zdan's covered all the bases I think. His post is the most useful answer in this thread. That's just IMHO of course.

[Suberman]

Originally Posted by Rayme

It makes more power. All engines make more power with colder air as the computer dumps more fuel to keep the air fuel ratio.

Well, no, see that's the point. That's the easy answer and probably incorrect if the bmep is limited by a knock sensor system.

It's torque that matters, bmep at its highest level. Power is just a multiple of bmep. Mind you, bmep is a calculated number but it represents real force.

If colder air results in more fuel being added then superficially higher bmep should result. However, the engine can't take more bmep than the detonation limit allows. Since the knock sensor operates at peak bmep already and at all temperatures then colder air can't make more power. The ECU retards ignition (or reduces boost) so the supposed more powerful air fuel mixture develops exactly the same bmep as the thinner air fuel mixture at higher temperatures.

It seems simple to figure out but it actually gets quite complicated.

[Suberman]

Originally Posted by humfrz

So, Suberman, are you saying that an aftermarket CAI for the FR-S/BRZ is a waste of money .. ??

humfrz

Yes I am. The only economically sensible power modification to make to this engine is supercharging. Because of fuel economy considerations factory engine builders just don't leave free hp on the table any longer. An extra 4 or 5 hp at peak rpm just isn't relevant, assuming that's what these CAI actually achieve, which is doubtful. You never use that "extra" power. "Free flow" exhausts aren't worth the money either for similar reasons although at least you might get useable improvement in peak torque from one of those, but only with a lot more noise.

I don't think the chassis design will be able to use much extra torque without considerable driving skills.

At a minimum I'd also fit much better tires and an easily adjustable rear roll bar. Of course you'd need to know how to adjust that roll bar so were back to driving skills again. Fun car but tricky handling.

[Rayme]

Originally Posted by Suberman

Well, no, see that's the point. That's the easy answer and probably incorrect if the bmep is limited by a knock sensor system.

It's torque that matters, bmep at its highest level. Power is just a multiple of bmep. Mind you, bmep is a calculated number but it represents real force.

If colder air results in more fuel being added then superficially higher bmep should result. However, the engine can't take more bmep than the detonation limit allows. Since the knock sensor operates at peak bmep already and at all temperatures then colder air can't make more power. The ECU retards ignition (or reduces boost) so the supposed more powerful air fuel mixture develops exactly the same bmep as the thinner air fuel mixture at higher temperatures.

It seems simple to figure out but it actually gets quite complicated.

Say it in simpler terms, are you saying the ecu pulls timing when it sucks in colder air? Are you saying the ecu doesn't use the colder air charge to extract more power out of it?

It sounds like if you are saying is true, the opposite also should be, the warmer the air intake, the more ignition timing it advances then, right?

EDIT:
You know what, fuck it, you're just a troll on here. You go one about the car's handling again (which seems to be the only thing coming out of your mouth) in this thread which has nothing to do with making more power in colder weather anyway.

[SpeedR]

Originally Posted by Suberman

The intercooler cools the intake charge after it has been compressed by the supercharger. That's why. I do know what I'm talking about. You apparently do not. But now you know a little more than you did before.

And why would you bother if colder air dose not make more power?

and now were done troll

[1086]

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did it work yet?