the myth of cold air intake...

[tooter]

This is a fascinating exploration of cold air intakes and how they compare to a stock air box...

http://www.youtube.com/watch?feature...i2yo4UqPI&NR=1

[marcus]

subscribed.....

[tooter]

Another interesting off topic piece of information in that video concerned so called "heat soak".

Their underhood thermometer showed a rapid drop in temprature to ambient once the engine was started up and running. I noticed the same effect. When the hot engine is turned off and sitting for a while, the aluminium intake manifold runners would get blazing hot because of heat transfer from engine block. However, once you start up the engine, the temprature of the runners would rapidly drop because the continual rush of incoming air cooled them off. While that means that the initial incoming air is warmer upon startup, that effect does not last long especially when the vehicle is in motion.

[UberSilver]

Originally Posted by tooter

This is a fascinating exploration of cold air intakes and how they compare to a stock air box...

http://www.youtube.com/watch?feature...i2yo4UqPI&NR=1

I found out about 20 years back the CAI dont help HP. Because as a motorcycle mechanic I slowly began to relies that the Japanese cycle makers put a lot of time into air box design, and knew what they were doing!

Sometime in the early 90's we noticed adding pods to each carb was robbing HP. Around that same time the Japanese were going big on CAD design, as Honda released such classics as the 600F1. Then shortly Blasting us all with technology leaps with the F2.

I love Japan!

[tooter]

Originally Posted by UberSilver

I found out about 20 years back the CAI dont help HP. Because as a motorcycle mechanic I slowly began to relies that the Japanese cycle makers put a lot of time into air box design, and knew what they were doing!

Sometime in the early 90's we noticed adding pods to each carb was robbing HP. Around that same time the Japanese were going big on CAD design, as Honda released such classics as the 600F1. Then shortly Blasting us all with technology leaps with the F2.

I love Japan!

I do too.

Running computer flow models makes it possible to find the optimum resonance volumes @ rpm without hit and miss testing.

I've been reading up on air box design and just as there is a resonant correlation between manifold runners and plenum volume, there is also resonance dependent upon the volume of the air box.

[why?]

so this one proves a well sorted cai makes power. wheres the so called myth? Of course it takes these dunces three tries to actually get air that comes from outside the engine bay.

[cali yaris]

LOL. I like their show, but I don't think they are an example of unbiased testing. It often seems to me they are trying to "prove a conclusion".

[tooter]

Originally Posted by why?

so this one proves a well sorted cai makes power. wheres the so called myth? Of course it takes these dunces three tries to actually get air that comes from outside the engine bay.

You know, some of that 2% increase just might have been because of smoothed airflow within the extremely long ducting which looked to be about 4 to 5 feet long. Also of interest is the aftermarket drop in filters not making a noticeable difference. Anyways, I still like my made up intake because it sounds really cool.

[Yaristeve]

Originally Posted by tooter

You know, some of that 2% increase just might have been because of smoothed airflow within the extremely long ducting which looked to be about 4 to 5 feet long. Also of interest is the aftermarket drop in filters not making a noticeable difference. Anyways, I still like my made up intake because it sounds really cool.

Oh, I dunno. I tend to agree with Why? The rule of thumb is that you will get a 1 hp increase in power for every 10 degrees (Farenheit) drop in temperature. So the 3 hp increase seems to be within expectations (15*C drop is about 30*F drop) in spite of the accordian "intake" which probably wasn't that good for airflow.

[why?]

and smooth airflow is overrated, if not flat out a negative. That is why porting and polishing is left to large high hp engines.

It wouldn't surprise me if drop in filters did not make that much of a difference on near stock cars. Especially near stock hyper cars. It was interesting they didn't even try a car that was turboed from a n/a base.

I'm in 100% agreement with Garm. Someone gave them a premise, and they did everything they could to prove that right.

That is the only way anyone could mount anything aftermarket for an air intake in the back of an engine bay with a straight face.