GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

Cabin Filter - New Pre Filter Option

yo_marc

Ready to race!
Location
New England
Instead of a real filter as the 1st-in-line, you could probably whip up something using house-screen, wire mesh, or something the consistency of 3M/scotch-brite squares. I've got some material around the house that is a washable charcoal mesh the same density and thickness as scotch-brite pads. Probably what I'd use if I am looking to get into this kind of mod. Easily cleanable and plenty breathable.

Actually come to think of it -- some paper (engine) air filters come with this sort of material as a pre-filter.
 

ITGUY

Autocross Newbie
Location
PA
This isn't a mod and it's not very time consuming for $20.00 bucks. This is replacing the existing air intake screen with one that is designed to hold a filter. and is sealed. This is great in keeping the hvac system clean of debris. I also replaced my cabin filter.
 

Sandman GTI

Drag Race Newbie
Location
Tennessee USA
Instead of a real filter as the 1st-in-line, you could probably whip up something using house-screen, wire mesh, or something the consistency of 3M/scotch-brite squares. I've got some material around the house that is a washable charcoal mesh the same density and thickness as scotch-brite pads. Probably what I'd use if I am looking to get into this kind of mod. Easily cleanable and plenty breathable.

Actually come to think of it -- some paper (engine) air filters come with this sort of material as a pre-filter.

You have a good idea.
The felt house filters they sell that you can cut to size would also work.
Does not have to be fine filter media as you are catching the big stuff here.

Good thought.
 

Sandman GTI

Drag Race Newbie
Location
Tennessee USA
Similarly, one wouldn't stack 2 filters on their house furnace either. It's hard on the blower motor. Who wants to replace a blower motor? It wasn't fun in my Saab hanging upside down in the passenger footwell. Probably isn't fun in the GTI either.

I am not a filter or blower expert but you have me thinking.
A clean filter should be able to pass more air than the blower can move.
In a well designed system the filter surface would be large enough to still pass enough air thru even if 50-70% full, maybe even a higher percentage clogged as this will protect the blower motor.
So with two new filters the drag on the blower should not be much.
If we run the system for 6 months, the car with 1 filter should pass as much air as the car with 2 filters. They both have filtered the same amount of air. The 1 main filter will be dirtier than the main filter on the 2 filter car. So at 6 months one car changes the $20 main filter while the other replaces the $4 filter. Maybe every other filter change now one would change the main filter in a dual filter car.

Also for thought.
Most cars use a squirrel cage blower. If you block off the intake, this blower should continue to spin with no extra load. A squirrel cage blower works well to flow air as needed in a car but is terrible at blowing with force or creating a vacuum. Again not an expert in detail but from hands on experience I think the blower will be ok. In fact with cleaner the air in the system it might last longer. It also might blow more air over time as squirrel cage fins can collect a lot of dirt and this will reduce efficiency.:D
 

ITGUY

Autocross Newbie
Location
PA
I used this Mann cabin filter I found part number FP26009





Sent from my LG-H900 using Tapatalk
 

bennybmn

Ready to race!
Location
Long Island
Instead of a real filter as the 1st-in-line, you could probably whip up something using house-screen, wire mesh, or something the consistency of 3M/scotch-brite squares. I've got some material around the house that is a washable charcoal mesh the same density and thickness as scotch-brite pads. Probably what I'd use if I am looking to get into this kind of mod. Easily cleanable and plenty breathable.

Actually come to think of it -- some paper (engine) air filters come with this sort of material as a pre-filter.

You have a good idea.
The felt house filters they sell that you can cut to size would also work.
Does not have to be fine filter media as you are catching the big stuff here.

Good thought.

Also for thought.
Most cars use a squirrel cage blower. If you block off the intake, this blower should continue to spin with no extra load. A squirrel cage blower works well to flow air as needed in a car but is terrible at blowing with force or creating a vacuum. Again not an expert in detail but from hands on experience I think the blower will be ok. In fact with cleaner the air in the system it might last longer. It also might blow more air over time as squirrel cage fins can collect a lot of dirt and this will reduce efficiency.:D

As long as the pre-filter isn't finer than the main filter you shouldn't add more restriction. It's really to "keep the wrenches out". And you're absolutely right about the blowers. You're just cutting down air flow.
 

The Fed

Old Guys Rule
Location
Florida
Here in Florida it doesn't matter. The cabin filter lasts about 15-18 months max before it starts to stink like dirty socks. At least that's how long the filter lasted in my MK5.
 
Top