Fender Vents

[theholycow]

Originally Posted by Old Crows

I've seen a number of cars ... no rhyme or reason to it... that have factory installed fender liner vents. It would appear to be a good idea to help extract the air out of the compartment.

They're mainly decorative.
http://www.msnbc.msn.com/id/22453076

[Old Crows]

Originally Posted by theholycow

They're mainly decorative.
http://www.msnbc.msn.com/id/22453076

I'd partially agree. The vents described in the article are largely deco items. Sort like the 'port holes' on my old man's Roadmaster!

The vents I'm thinking of are actually in the wheel well.... ahead of the front tire.... directly in the splash guards. More effective in that location as its a huge low pressure area...

[Lug_Nut]

Damn right! And that's where the intercooler on my diesels are located. A few simple 1/2 long pieces of poly tubing and longer fender liner mounting screws have opened up all this low pressure area to pull air through the intercooler, yet doesn't pack up with snow in the winter, doesn't fling road dirt and grime into the fins, provides more air flow than a vent insert and costs under $2.
Before the spacer installation the air through the intercooler was quite restricted. It had to pass up over the plastic wheel liner, squeezing between the liner and fender and finally out through a gap into the engine bay.

[GasSavers_Merc]

Originally Posted by Old Crows

I'd partially agree. The vents described in the article are largely deco items. Sort like the 'port holes' on my old man's Roadmaster!

Most are just for decoration, but there are some truly functional ones out there. To clear things up, there are probably 3 reasons for having a vent on the fenders, Reducing high pressure areas that can cause drag, cooling and for looks. Here are a few examples of side vents, alternatives to and fro...

The New 2009 Nissan GTR does have a functional fender vent. Being a sports car with quite a bit of downforce, it has quite a slippery shape. These vents probably help pull high pressure air from the rear of the front tire. This would give some exit for the air entering the engine bay and air cooling the front brakes. It would probably drop some lift created by the natural effect this area produces:

Now, would it be effective on a car that does not require as much cooling? A car such as an econo box? Probably, but I would think that a simpler approach would be something like that on the Honda Insight: More than likely, this fender design does the same thing by letting high pressure air escape the rear of the front wheels(Edit: Although it would probably do nothing for cooling). It's probably designed like this because of packaging as well. I would think this would be advantageous on most cars, but you could simply avoid this all together by blocking off the front wheels and diverting air away from the front wheels.

The vents I'm thinking of are actually in the wheel well.... ahead of the front tire.... directly in the splash guards. More effective in that location as its a huge low pressure area...

The vents you have in mind are those used mainly for cooling. The front end is designed as a high pressure area for the main purpose of cooling. You would need a low pressure area to take advantage of the cooling. it's more likely designed for a secondary cooling unit, such as a oil cooler or a intercooler:

[Old Crows]

Originally Posted by Lug_Nut

Damn right! And that's where the intercooler on my diesels are located. A few simple 1/2 long pieces of poly tubing and longer fender liner mounting screws have opened up all this low pressure area to pull air through the intercooler, yet doesn't pack up with snow in the winter, doesn't fling road dirt and grime into the fins, provides more air flow than a vent insert and costs under $2.
Before the spacer installation the air through the intercooler was quite restricted. It had to pass up over the plastic wheel liner, squeezing between the liner and fender and finally out through a gap into the engine bay.

Exactly! I've no clue where the air went without the splash guard venting. Clearly better to pass the air flow to the LP area in front of the tire.

[Old Crows]

Originally Posted by Merc

The vents you have in mind are those used mainly for cooling. The front end is designed as a high pressure area for the main purpose of cooling. You would need a low pressure area to take advantage of the cooling. it's more likely designed for a secondary cooling unit, such as a oil cooler or a intercooler:

Thanks Merc! What car is this vent on???

[GasSavers_Merc]

This is on a 1989-1994 Nissan 240SX. It is a modifed piece that came from the 1990-1991 Nissan 300ZX TT used to help cool an intercooler installed inside the left side of the bumper.