Note: Had to break this up into two seperate posts because I had too many links.
Let's be honest here, filter socks look gay.
Nuff said.
Everyone wants open throttles. Mmm... Open throttles.
But even so, I wasn't willing to sacrifice my engine sucking up rocks for the sake of looks. My car is a daily after all, so the option of running no filters isn't cool.
Whilst searching for a replacement to gay socks, I found that Jubiride make a filter screen that you insert between the trumpet and the throttle body that block large objects from being inhaled:
But to me, ~$75 seemed a bit over-the-top for what essentially is a piece of metal mesh sandwiched between some rubber, and something that doesn't filter anything. Hence, I made my own for substantially cheaper, and which also have the added benefit of filtering, not just stopping rocks and larger objects. If you just want a screen, then just don't include the foam filter layer. What could be easier?
I originally stole this idea from Clug4AG to see how easy it could be done, it works quite well. Well enough for me to wonder why more people don't use this as an alternative to socks. I also wanted to reinterpret that guide because he uses the intake gasket as part of it, whereas my throttle set-up has the trumpets detachable and separate to the intake gasket, and I didn't feel like replacing the OEM intake gasket every time I went to replace the filter foam.
Inspiration from Club4AG:
I recommend you read through my guide before doing it, as I've given a few tips along the way which will make your life easier, and mean you don't have to trial-and-error it as I did.
Tools needed:
- Scalpel (can buy cheap ones from officeworks. Highly recommended, makes life easier)
- Pair of scissors
- Ball-point pen (any colour will do, I found that black was the easiest to work with though)
- White permanent paint marker (Officeworks)
- The two bolts that hold the trumpets onto the throttle body
- A single trumpet to use for templates
The paint marker I used, for reference:
Materials needed:
- Air filter oil (I got mine off eBay for cheap)
- Zip lock / glad bag
- A sheet of thin rubber (mine is 1mm thick, you can use whatever you want though, but to me any thicker seemed like overkill). I bought it in a meter-long strip which was more than required, but it's nice to have some spare to allow for fuck-ups. This applies to all materials you'll use (foam, metal screen).
- A sheet of foam (I didn't want anything super restrictive & dense, I got foam that you can see through when you hold it up to light. It's around 12/13mm thick. Obviously keep in mind that when you bolt down the trumpet the foam will be compacted slightly but once again use your own judgement as to what would be the best foam for your application. Don't get that yellow foam that you find in seats and cushions, you know the one I mean, it's far too dense and will restrict airflow like a motherfucker, but that's just my opinion)
- Metal mesh screen, somewhat like the consistency of fly-screen.
As a note, I found that Clarke Rubber was a one-stop-shop for the foam and rubber. They have heaps of different types of rubber and foam in all manner of thicknesses for your browsing pleasure. The metal screen I found in my local Mitre 10, but Iām sure Bunnings / another hardware store would have something similar.
The consistency of the mesh I used:
The thickness of my foam:
The Process
Step 1: Using your ball-point pen, the strip of rubber and one of your trumpets, trace an outline of the mounting surface. Be sure to include the bolt holes, the hole for the adjusting screw if applicable, and the hole for the intake. Repeat this template 9 times, as you will need 2 for each throttle + 1 extra to use to make templates using the white paint pen that you can get paint all over then throw away (saves getting paint on one of your trumpets).
TIP: Try and use a ball-point pen that you can take the flexible ink barrel / chamber out of. I found that I couldn't get the pen into the bolt holes to trace the shape because the pen was solid and wouldn't bend, but because the ink barrel is bendable it allowed me to get into the tighter holes.
Step 2: Cut one rubber template out on it's own. You'll be using this to make final cuts and measurements until you are happy enough with it's shape to replicate the cuts for the foam & metal screen pieces and to ensure it fits hellaflush. I found that when cutting out the various holes it worked best if I cut outside the line by a small amount, say 1mm, to make sure it didn't impede on airflow or bolts, as illustrated below. Use scissors to cut out the intake hole and the scalpel to cut the smaller holes.
TIP: I found the easiest way to cut the holes was to bend the template in half and make a cut in the intake hole, enough to fit the scissors through, then cutting straight to the edge, then following the circle around. For the bolt holes I found that I had to make small individual cuts with the scalpel, taking it out each time, rather than cutting it in one hit, if that makes sense.
Cut inside the line, about 1mm in:
This is what you should remove:
This is what you should be left with:
What it will probably look like first time (thus, requiring a trim):
What you should end up with, to ensure that it doesn't impede airflow:
Step 3: Using the mounting bolts, mock up the template on the trumpet to see if you've done a good job cutting it out and that all the mounting holes line up, the template doesn't interfere with any airflow through the middle, and that it sits flat. I used pencils in this photo because I couldn't be bothered going out to my car and getting the two bolts, but anything that fits through the bolt holes will do to mock it up into place. Don't eyeball it, chances are when you actually have the bolts through them, it won't be square and will impede on airflow. Best practice, yo.
Step 4: Now cut out the rest of the rubber templates. The reason I say to only cut out one first is now that you've mocked up one, you know roughly how much to cut out around the holes to make sure the rest fit flush if need be, rather than cutting them all out first, then having to go back and re-cut them all. Once this is done, separate them into four piles of two. That's your "gasket" component sorted for all four throttles, let's move onto filtering.
Rubber "gasket" components completed. (The other pair were still on the trumpet at the time this photo was taken):
Step 5: Take your white paint pen, the one throwaway rubber template, and your sheet of foam, and trace out the shape onto the foam. You will need this piece at least four times, one for each throttle. This part is a bit of a bitch because foam isn't the easiest stuff to write on. I found that it worked best if I only lightly pressed onto the foam, rather than trying to press really hard, as the foam shape will distort if you do this, and you won't get a nice clean outline. Remember that you only need to mark the overall shape of the trumpet and the bolt holes, you obviously won't need to cut a hole in the middle as you'll be leaving this in place to filter the air.
TIP: As you can see in the photo further down, I made spares. I managed to get the initial set, plus two sets of four for replacements for later on down the track, out of my cut of foam. This filter element is the only piece you should need to regularly change, much like any air filter. You don't have to make spares, but as I said above I had material left over, so figured I'd make more for when I changed the filters later on down the track whilst I was on a roll, rather than have to do it again later. But if you don't have enough foam, you will only need four initially to make a set.
Step 6: Cut out one foam piece around the outline. Only do one, for the same reasons as only cutting out one rubber piece initially, as said above. Guaranteed this will be the part where you will need to re-cut the piece, as foam is a real bitch to make it play nice. The foam pieces will look retarded and out of shape for some reason, every one I cut out did. Don't mind this for the moment.
TIP: Following the same principle as cutting outside the line for the rubber templates for the intake hole to make sure it doesn't restrict airflow, do this as well for these foam pieces, but inside the white line for this part. This is because the nibs on the white paint pens are huge and you will be left with a large amount of unsightly foam hanging over the ends if you follow the outside of the line, so you're allowing for this tolerance when cutting. This also means you won't have any nasty looking white paint on your shiny black filters.
Step 7: Mock up the shape on the trumpet. You will more than likely need to shave some off around the edges to make it sit nice and flush, with no bits overhanging over the sides. You don't have to be this pedantic, but I wanted them to look nice and hidden when they're bolted down.
TIP: Test for overhanging areas by putting the foam on a table, then placing the trumpet on top (as illustrated in the photo) then pushing it down, mimicking what it will be like when the trumpet is actually bolted down. This will make the foam squash outwards. Trim if needed.
Step 8: Cut out the holes that the bolts will go through. This part is a bit annoying because it's not easy to make a nice cut through the foam as it's not solid, but I found that the easiest way was to use scissors, and almost hollow out the hole. I made lots of small cuts, burrowing into the foam, then working the hole larger. Don't go too large though, as the holes are close to the edge. It's hard to describe, but I hope you get the general idea as to what I mean. The one consolation prize is that because the foam will expand as need be when you put the bolt's through, it doesn't have to be a great hole, just enough to fit the bolt through.
Not a great picture, but you can kinda see where the holes are:
Step 9: Test-fit the holes to see if the bolts will pass through. I once again used pencils, but don't be a lazy cunt like me. Use the bolts, as it's a more accurate representation. (The pencils are the same thickness as the bolts though. Jus' sayin) You may need to work the holes slightly bigger if it's difficult to get the pencil / bolt through the hole. Don't force it too much, as it'll more than likely tear. Repeat until you're happy with the holes.
Step 10: Mock up the pieces you've currently got for one throttle, IE grab the trumpet, two pieces of rubber and one filter. Run the bolt / pencils through all the holes to make sure they're all fitting together flush (as illustrated) and that everything is lining up with everything else. You, in theory, could stop here, but I don't trust the foam not to get sucked into the motor because it's too easy to tear in my opinion, hence the metal screen.