Carbon intake Vs standard airbox power.

[bam_bam]

Ha. I love Wikipedians.

Ram air only really causes an 'effect' in well designed airboxes travelling through good air streams. Adding a CAF to your B7 does not create air ramming effect, it's a just a tube.

[docurley]

This is a good build right-up on a Ram Air setup on a V8 car, but just have a hunt around on the net will confirm the advantages of having a Ram Air system and hence why most car makers have the system fitted to there cars.

http://planetsoarer.com/BFI3/bfi3.htm

[JCviggen]

Ram air only really causes an 'effect' in well designed airboxes travelling through good air streams. Adding a CAF to your B7 does not create air ramming effect, it's a just a tube.

100%, absolutely true.

I have seen some actual RAM air effect at work on RS4s in Germany, and yes it works, but most of the gains are from 110 mph onwards. Not precisely useful anywhere but Germany. And they cost several grand to build...

[bam_bam]

This is a good build right-up on a Ram Air setup on a V8 car, but just have a hunt around on the net will confirm the advantages of having a Ram Air system and hence why most car makers have the system fitted to there cars.

http://planetsoarer.com/BFI3/bfi3.htm

That looks like a CAF to me (and a pretty good one), nothing to do with ram air.

[docurley]

This is a good build right-up on a Ram Air setup on a V8 car, but just have a hunt around on the net will confirm the advantages of having a Ram Air system and hence why most car makers have the system fitted to there cars.

http://planetsoarer.com/BFI3/bfi3.htm

That looks like a CAF to me (and a pretty good one), nothing to do with ram air.

Ram Air effect is caused by a sealed system to direct the air in to one location and this is what he did, mine for instance is the CAI fitted to the flap on the stock air box leading to the bottom grill and still using the stock snorkel behind the middle grill.

basically channeling the air in to a box unlike the open air filters just sitting in the air. If I added a CAI to that it would be just a cold air feed no Ram effect as the filter is not in a sealed unit (other than the CAI) so only allowing what the engine can suck in rather than ramming air in to the engine.

I hope that made sense

[docurley]

Just thought of another way to explain.


You travel in your car at say 70mph window shut and air con on, you breath normally because nothing is forcing air in to your lungs but you feel the chill as you breath. now open the window stick a funnel in your gob and stick you head out the window...... you lungs will have been forced to inflate (You will probably die Lol) but for those few seconds you will have felt Ram Air effect.

[bam_bam]

This is a good build right-up on a Ram Air setup on a V8 car, but just have a hunt around on the net will confirm the advantages of having a Ram Air system and hence why most car makers have the system fitted to there cars.

http://planetsoarer.com/BFI3/bfi3.htm

That looks like a CAF to me (and a pretty good one), nothing to do with ram air.

Ram Air effect is caused by a sealed system to direct the air in to one location and this is what he did...

There's a dirty big fucken headlight assembly in the way, that ain't directing the air to do sh1t.

basically channeling the air in to a box unlike the open air filters just sitting in the air. If I added a CAI to that it would be just a cold air feed no Ram effect as the filter is not in a sealed unit (other than the CAI) so only allowing what the engine can suck in rather than ramming air in to the engine.

I hope that made sense

It didn't. Just because the airbox is sealed from the under bonnet air doesn't automatically cause 'ram air effect', neither does just channelling air. The air box intake would need to be specially designed and exposed to clear air travelling at speed to give an 'effect', it would also need to have a pretty big frontal area. You've just got a tube at the front of your car...

[docurley]

There's a dirty big fucken headlight assembly in the way, that ain't directing the air to do sh1t.

Not the best and to be honest I cant see the whole setup

It didn't. Just because the airbox is sealed from the under bonnet air doesn't automatically cause 'ram air effect', neither does just channelling air. The air box intake would need to be specially designed and exposed to clear air travelling at speed to give an 'effect', it would also need to have a pretty big frontal area. You've just got a tube at the front of your car...

A tube with a funnel which takes up a large amount of the lower grill and yes speed is the key

[docurley]

[bam_bam]

It didn't. Just because the airbox is sealed from the under bonnet air doesn't automatically cause 'ram air effect', neither does just channelling air. The air box intake would need to be specially designed and exposed to clear air travelling at speed to give an 'effect', it would also need to have a pretty big frontal area. You've just got a tube at the front of your car...

A tube with a funnel which takes up a large amount of the lower grill and yes speed is the key

...and therein lay the problem. The tube. To work, the intake 'funnel' would need to be correctly designed AND directly attached to the intake plenum. You've got a couple of feet of tubing in the way which causes a backlock. Because air behaves like water under pressure, it means the air trying to get 'rammed' into your 'funnel' is actually just spilling out over the sides, the result, no ram air 'effect'.

[docurley]

Interesting, so I need to use the cars ducting and attach a tube to the end of that.

[bam_bam]

No. The tube needs to be eliminated. Without getting too technical, you'd need to correctly design the airbox intake/plenum for the desired application/cfm and THEN you'd need to subject that intake area to good air flow, like sticking up out of the bonnet or sommit. Even then, anything below 100MPH would be moot and without gains.

OR you could just live with knowing that you have a nice CAF on your car and forget about calling it a 'ram air' solution.

[docurley]

One second, is not the top snorkel a ram air feed

[bam_bam]

Depends on the shape, size, length and design of the snorkel. But if I were to guess, I'd just say it's just a snorkel, as the name would suggest.

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<sigh>
This one never goes away.

Ram air effect does exist however the effect for a road car is insignificant.

At speeds under 300mph (ish) air simply doesn't compress very easily.
If you put a funnel in an airflow not all the air that enters the cone of the funnel will exit via the spout. All that happens is the air spills out over the edge.

The only way you can increase intake air pressure is to slow the air down by increasing the volume of the intake airbox.

Ram air works on motorbikes more effectively as they are comparatively low displacement relative to the intake area.

If you want to go into the actual physics maths detail showing how ineffective it is then happy to oblige.