I have a simple qustion actually. Ihave an 83 t/a 305v8 with cowl induction. is there any down sides to keeping the cowl vent open all the time? I am just trying to find out if its a bad idea to allways have the hood scoop open and not have the car open it autmatically.

thank you
James

 

Think about rain, snow and other stuff going into your air cleaner. You want it closed when you are parked. You can hook a toggle (on off switch) up to the solenoid to open or close it when you want. I would put a fuse on the power side, maybe a 20 or 25 amp.

 

I have the power bulge hood, with no solenoid to open it, it's just open... It's "monsoon" season here, and the car runs ok...

Every now and then there is a bit of water on top of the air cleaner, no big deal.

Not sure if you have a standard single snorkle air cleaner, or if it's actually open in the rear to make use of the cowl induction...?

 

the cowl / ram-air induction has a solenoid to open and close a flap on the hood. This is hooked up to a plastic housing that goes into a special air cleaner lid with a hole in it. Water could go into your aircleaner if it was open all the time.

 

cool. if it wont hurt the car in preformance/gas mileage too bad or at all i think ill go the swich route.

Thanks

James

 

if your lid is like this, you will want the factory setup or switch to keep junk out

 

How about when using an open element air cleaner? My 82 T/A has the whole flap removed and the previous owner had an edlebrock signature series air filter on top of the carb he put in. It runs fine in the rain, but I do notice some water pooling on top of the intake mainfold, of course I do park facing downhill in my driveway (about 20 degrees, I know its fairly steep) so the water does run towards the front of the car.

Actually thinking about it some more, I never have really noticed any induction benifits, but when sitting in traffic, the fan seems to blow a whole lot of air out that cowl.

 

My friend has an open element cleaner on his 82 Trans Am with induction cowl hood and he's never had any problems with the weather. I also have an 82 with induction cowl hood and I don't have problems either.

Although I'm not running an open element filter, I replaced my air cleaner lid with the same the in the above picture and my car went noticeably quicker than before. Having the cowl ducting in place didn't make my car go any faster above having just the lid with the hole in the side.

I then went to a K&N air cleaner lid to allow air to flow more directly down into the carb. My car lives outside in the weather and not even with rain have I personally had a problem with water getting into the wrong places.

Hope that helps.

 

I'm not sure that you would need a fuse that big. I measured 5.6 amps being drawn by the solenoid when I used the cowl ducting. I didn't measure the initial current draw though which is usually higher of course, but perhaps 10A might be enough.

 

what does the cord actually plug into thats on the cowl piece. from the solenoid. i could never figure this out! i know the other is ground.

 

It makes contact to the oil pressure sending unit, and several other sensors like the throttle kicker relay I think. When all the sensors reach a certian operating condition the flap opens. Disconecting the 1 power wire at the cowl will not hurt anything. I just taped mine off and hooked up an on / off switch. I had water in my aircleaner with the car parked and the flap open once after a heavy rain.

There is a air filter in there. Think of a lid that just covers the airfilter but is not big enough to cover the entire housing. Then attach a full size lid ontop of it. What you see in the hole is the smaller lid with a aircleaner underneath.

 

HMM, never seen a pic the carb version before, no air filter in the ducting? Of course I dont think the CFI I have collecting dust has one either.

I keep mine open, dident have any problems the year I drove like that. I did consider making some sort of plate to stop water from getting on the engine but figured it would trap water and start rusting the hood that was such a pain in the butt to find.

 

To get any positive pressure at the base of your windshield you need to be going at a decent speed, I'd say at least 30mph (you need velocity to get a pressure gradient in laminar fluid flow). So, if you're just putting around town or under light load there really isn't any advantage to having cowl induction so I wouldn't leave it open all the time if it works automatically.

 

At low speed it vents heat, sounds cool too.