996 TT what do the side air intakes do?

I did do a quick search (honest! c: ) and the reason I asked is I was in the dealer a few months ago and the service lady said the vents were there to cool the turbos. So i'm assuming she meant there are oil rads in there and it cools the oil leading to the turbos? I can't see air flowing over them is gonna do much :?: or is she talking out of her rectal passage? :hand:

The side intakes draw air in and over the cars intercoolers, the air then exits through the vents in the sides of the rear bumper. Hope this helps Rick

Cool, so she was right. thanks Rick

OK, so now we've established she knows about cars... 8) :useless: :thumb:

Well strictly speaking she isn't right. The intercoolers are not the turbo, they are radiators that the hot, pressurised air pass through to lower the air temp thus condensing it and making it less liable to pre-ignite the charge and increase power. It's possible (not having examined it in detail) that some the air after passing through the intercoolers is then channelled over the turbos to keep air flowing over them and reducing their heat in a rear engined scenario. However, compared to the answer I'd have expected, thumbs up to her!!! She didn't say they were extra cup holders.

Think she meant the vents cooled her turbo's :?:

Does she have nice Turbos? On a serious note, how do you get your signature picture down to 80x80 pixels and it look ok? I've tried several attempts but my picture looks like it was taken by a 'Brownie' camera. :?: BTW I think you mean heat exchangers as rads typically have water in them, or are these coolers also in the water circuit? Polite answers please Ray :bandit:

The turbo intercoolers are air/air radiators on a 996... So cold exterior air from the side vents blows over the fins to cool down the intake air that passes through the core after being heated by the turbo (from pressurisation and proximity to hot exhaust gases)

That's it Wattie, yes when you do work on a compressible gas it generates heat as the molecoles are agitated - put your hand over a hand pump and you'll see. Any help on getting a decent picture? Ray :bandit:

The vents are there to increase volumetric efficiency. Previous posts explain how this is achieved.

Bingo.....a very important point outlined here!! The cooled air (from the intercoolers via the aforementioned vents by said lady!) with be greater in volume as the air density changes when cooled!! So its not only the temperature thats is a factor here. The two issues combined make the difference. .....god im almost talking myself into some uprated intercoolers here hehe.

The sole purpose of an intercooler is precisely to increase the density of the air entering the cylinders - as the bottle-neck on engine power output is the mass of air that you can get into the cylinder in 1/400 th of a second (@ 6,000 rpm). The colder the air is, the heavier it is, but the turbo heats it up - hence the need for an intercooler. There is almost no limit to how much fuel you can get into the cylinders in the time available (even at 18,000 rpm in a bike or F1 engine), but it will only burn if there is around 14 x as much air as fuel in the cylinder when the spark plug fires. Lesson over... :coat:

The lower slit vents aren't there for the air to exit through, they are designed to create a low pressure area to promote the flow of air into the top intakes. Without them the top intakes didn't gulp enough air to be effective.

If you were to bolt on bigger intercoolers, would this make a noticeable difference to power?

I wouldnt say noticable but it would be guaranteed to increase power. The standard units are quite efficient to start with. but always room for improvement. Im sure there will be comparisons on the net somewhere. When I start modding my car, this will be one of the first areas I will pay attention to.