Another Drew

<center><img src="http://pictureposter.audiworld.com/AudiWorldPics/2000/ahlfog2.jpg"></center><p>
Has anyone looked at how much the passenger side foglights block cool air from going to the intercooler? When you look at just the lens of the foglights, it doesn't look like the foglights would block much of the air going to the intercooler but if you remove the grill, you'll see that the foglight housing reaches deep into the IC ducting. Not only does the foglight block the IC, so does the towhook. The ducting on the driver's side looks decent, but the passenger side is pretty lame.

So, for the summer and the track, I'm going to take them out. I'm getting a second set of the lower grills and use a piece of grill to cover the empty foglight holes like this picture.

You can feel how hot the ICs get, so any cooling in going to be better.

I rarely use the foglights so I won't miss them much.<p>Andrew Lee
00 S4
APR chip
MTM catback
18X8.5 Fikse FM/5
Alcon B type/rotors (very soon!!)
Vortrag coilovers (soon too!)

Todd W

The outlet is more critical.

Todd W

KevinH

Either do that mod or wait for somebody to come out with an RS4 type of bumper. Did you order the inserts already? How much?

Another Drew

You're talking about the pop-out grills, right? I ordered them. Here's the part numbers:

8D0-807-345-L-GRU left grill $20.30
8D0-807-346-L-GRU right " " $20.30<p>Andrew Lee
00 S4
APR chip
MTM catback
18X8.5 Fikse FM/5
Alcon B type/rotors (very soon!!)
Vortrag coilovers (soon too!)

Another Drew

I don't see why the outlet would be more critical than the inlet. I would have figured that both are important.

Thanks,<p>Andrew Lee
00 S4
APR chip
MTM catback
18X8.5 Fikse FM/5
Alcon B type/rotors (very soon!!)
Vortrag coilovers (soon too!)

Todd W

First off, only half of the IC core is hollow - the rest is solid. 2nd, you can't push air through it at 30, 60, 90mph, etc. The air needs to slow down. You slow it down by letting the flow spread out from a small inlet to a large volume duct.

Once the air has passed through the IC, now all you care about is getting it out of the way so that more air can pass through the IC. If you try to speed it up, then you will build up pressure that will keep air from flowing through the IC. Therefore, you want to draw it out with an outlet the same size as the core, which is larger than the X-flow area of the core. The air will expand again, helping to evacuate it.

If the air does not flow through an adequate outlet, then more air at the inlet will only increase the pressure, not really improve the flow, and heat up the air that is trapped behind the IC. Now you will have a pocket of hot compressed air conducting heat back into the IC.

If the inlet is larger than the core, then you run into more problems with backflow within the inlet.

Todd W

Tristan

Not sure it helped.. but the idea was awesome I thought. At the track you drive differently, so let us know about the street.
Tristan

Another Drew

<p>Andrew Lee
00 S4
APR chip
MTM catback
18X8.5 Fikse FM/5
Alcon B type/rotors (very soon!!)
Vortrag coilovers (soon too!)

NASA racer

They had a camera inside the front wheel well and there were big cooling ducts, presumable from the front bumber. I wish they'd change to this front bumper to stop intercoolers venting into wheel wells.

https://www.audiworld.com/news/00/00archive.shtml