Yesterday I picked up the cowl air cleaner assembly off an 84 H.O. Formula (for $16 at the junk yard!). It has a solenoid mechanism to open/close the air flow - other than in rainy weather, is there a reason to have it closed? I'd like to take the flap inside it out for better flow. BTW, why didn't these parts come on TBI cars?

 

it **should** be fine without the flap, even in the rain, from they factory if you mashed it, the cowl opened. it should have some sort of baffle to keep the water out.

we never got anything from the factory, because the TBI cars were base cars, they got nothing fancy.

 

i have one on my car. it's hooked up to a switch. it's worth at least a tenth in the 1/4 mile to me.

you can run it without the flap. the two nipples in the bottom of the plenum are for water drainage. make sure you run hoses from them down and out of the engine compartment or you'll just draw hot underhood air into the plenum,

i cut a piece of screen and installed it in the hood opening to keep small debris out.

if you look at the factory setup, though, it doesn't have a lot of room for breathing. look at how small the opening in the top of the air cleaner is! also, if you go to a taller intake, you're screwed.

i think there's a better way.

if you look at the underside of your hood, you could create your own airbox by cutting a sheet of aluminum to fit on the support braces. then cut a hole in the sheet of aluminum just large enough to let the air cleaner element pass through. go to a 1-2" taller air cleaner element with the same diameter as the factory element and use one of the k&n xtreme air cleaner lids.

using the factory aircleaner, take a rubber gasket like the one on your firewall and run it around the aircleaner so it seals against the sheet of aluminum when the hood is closed.

this is the way they did it in the zl1 69 camaros. a much more effective cowl induction setup than the factory setup from the 83-84 trans ams, and it'd cost less than 50 bucks. as soon as i get my new intake on, i'm planning on doing it.

 

Check this out: http://www.hioutput.com/tech/air.html

 

The screen material that I have been using is from an HVAC return (not the louvered ones but the one with all the round holes drilled in it). The next time you are at the doctor, or any office with a drop down celing, look at the Ventilation you will see what I mean. This stuff is great for screening in the air inlet. It is about the same thickness as the block off plate, fairly ridgid, and the holes are the right size for the screws.

Not trying to be an A-hole (some things come naturally) but there was no Formula in 84. Formula was discontinued after 81 and did not reappear until 87.

 

Thanks for the great ideas! Until I found the stock setup, I had been thinking of how to make one, but hadn't figured out the best way to do it. Maybe once I've played with the factory piece (and it stops raining) I'll try that.

About the 84 formula comment, I don't mind at all. Constructive criticism isn't being an *******, its teaching. Now I've learned something new today.

 

Just got finished playing with the Formula. I have gotten an air cleaner off of an early 80's big Olds with a 307. The air cleaner came with the domed lid like the trucks, (useless for me because I have the cowl induction off an 84 TA), no silencer ring, and it has just enough drop on the base to clear the linkage. When I first tried the cleaner with out the air cleaner spacer the thing sat about 5mm too low and the curved air cleaner stud would not let the lid go down far enough to seat on the cleaner base. So rather than cut the old spacer, I made a new one out of the base of a 14" open air cleaner. It came from AutoZone, name brand of Specter (cheap). It just presses on the bottom of the Olds aircleaner. Tap it with a hammer to set the desired height, and you have a nice interference fit. Don't go overboard though, once it sets in place, it does not come apart (I tried!) You will need to cut a little out for the ThermAC connections and clearance for the IAT sensor. I also had to make a hole for the IAT, but since it is threaded (on the 88 anyway) all I had to do was undersize the hole slightly so that the threads would catch and screw it in place. The Olds unit does have an air baffle right at the snorkle opening, but bend it back and forth a few times and the welds will break.

Looks fairly stock, the cowl induction still mates up perfectly. Haven't been able to tell any SOTP difference in power, but I have noticed that the engine does not whistle as badly in the upper RPM range. It will be interesting to see what the milage does this week. I still need to get some ducting to mate the snorkle with the air inlet mounted on the radiator support. The new snorkle is about 2 inches away from the plastic inlet. Right now I am pretty sure that this set up flows much more than a Stock 305 TBI will ever need.