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Year, engine, modifications, etc.
Generally speaking open element is less restrictive but on a lower HP, smog engine I'd really doubt it would be noticeable since that's not likely the low point in the system
M
id use the dual snorkel in hopes of cooler air.
Open elements dont do much except make noise unless youre engines air needs exceeds the stocker.
Most new cars all have cold air stock...get a kick out of guys tossing them and installing the ricer hot air systems. Little OT but had to barf that out.
Dual snorkel. If open cleaner would have been better (for those engines), GM could have saved money on air cleaner cost. And they LOVE to save money....
when comparing a filter that grabs hot air from 6 inches away to an open air filter that uses the same hot air its kind of a moot point isnt it? I mean 40+ years later and the answer still not being obvious should sat something right? that Said, because im a gluten for punishment I and converting from an open element to a dual intake CAI myself to prove to myself theres no great difference for a street car.
Last edited by augiedoggy; Jan 15, 2021 at 11:58 PM.
CV67 makes a good point.
Neither will be the best, because they both pull hot air.
If you're after every bit of power you can get, a cold air system is going to be best.
I'm considering building one and will post the project when I do it.
Guess it matters what op is talking about..my 79 dual snorkel attached to ducts to outside air is not same as dual snorkel in engine.
also if preheat is needed which i assume is why there is a snorkel at all?
Last edited by interpon; Jan 18, 2021 at 10:44 AM.
If you are speaking of the L-82 78-80 dual snorkel with the front airbox.....it is hands down the best thing to bolt onto a C3 Vette small block.....it is also the ugliest.
The L-82 unit moved plenty of air and it was much cooler than inside the engine compartment......
Myself...I have an 11" K&N open filter top deal that fits up in the L-88 airbox......I can see it through the back of the scoop.....it is not sealed but that is for another day.
Simple physics - ultimately, power is directly proportional to the mass of air moving through the engine, assuming that the fuel induction system can maintain a proper or at least constant fuel to air mass ratio and all else is equal, e.g. volumetric efficiency. If the air outside the car is 80 F and under the hood it's 110 F, the the density and therefore mass of the air, assuming constant pressure, decreases by about 5%. This would come off the gross hp and thus off the rear wheels. From that then, it is better to pull air in from outside the engine. Also, and admittedly just conjecturing here, it seems that under the hood the airflow is more turbulent than at the inlets for the snorkels which direct the airflow into the intake and at speed. It seems then that ramming air into the air ducts to the snorkels would actually help to drive air in vs letting the engine do all the work to draw it in. So, perhaps some more benefit.
It would be a great experiment to make multiple runs randomly switching back and forth between snorkel and under hood to find out.
If you are speaking of the L-82 78-80 dual snorkel with the front airbox.....it is hands down the best thing to bolt onto a C3 Vette small block.....it is also the ugliest.
The L-82 unit moved plenty of air and it was much cooler than inside the engine compartment......
Myself...I have an 11" K&N open filter top deal that fits up in the L-88 airbox......I can see it through the back of the scoop.....it is not sealed but that is for another day.
Jebby
Last week, I had my first time ever backfire through the carb, air filter fire. I've owned, repaired, modified 75+ cars over 50+ years from total pos's to factory muscle cars. I had a K&N filter top years ago when they first became popular. I soon replaced it with a full metal top, because of the possibility of it catching fire and burning my hood. So, the car backfired and the paper filter caught fire. The metal top of the open filter saved my hood. I was able to put the fire out quickly with a extinguisher. No damage except for the paper element.
So, though remote, there is a chance that the K&N filter top could catch fire.
I'm glad that I didn't have it on.,
Simple physics - ultimately, power is directly proportional to the mass of air moving through the engine, assuming that the fuel induction system can maintain a proper or at least constant fuel to air mass ratio and all else is equal, e.g. volumetric efficiency. If the air outside the car is 80 F and under the hood it's 110 F, the the density and therefore mass of the air, assuming constant pressure, decreases by about 5%. This would come off the gross hp and thus off the rear wheels. From that then, it is better to pull air in from outside the engine. Also, and admittedly just conjecturing here, it seems that under the hood the airflow is more turbulent than at the inlets for the snorkels which direct the airflow into the intake and at speed. It seems then that ramming air into the air ducts to the snorkels would actually help to drive air in vs letting the engine do all the work to draw it in. So, perhaps some more benefit.
It would be a great experiment to make multiple runs randomly switching back and forth between snorkel and under hood to find out.
see link in post 3 ..done on temperature study including L82 full throttle second snorkel opening...and yes L82 79..surprisingly hot in engine compartment..ugly..maybe but does hide other uglier stuff on mine
Video also of full throttle actuation
Last edited by interpon; Jan 16, 2021 at 11:35 AM.
Simple physics - ultimately, power is directly proportional to the mass of air moving through the engine, assuming that the fuel induction system can maintain a proper or at least constant fuel to air mass ratio and all else is equal, e.g. volumetric efficiency. If the air outside the car is 80 F and under the hood it's 110 F, the the density and therefore mass of the air, assuming constant pressure, decreases by about 5%. This would come off the gross hp and thus off the rear wheels. From that then, it is better to pull air in from outside the engine. Also, and admittedly just conjecturing here, it seems that under the hood the airflow is more turbulent than at the inlets for the snorkels which direct the airflow into the intake and at speed. It seems then that ramming air into the air ducts to the snorkels would actually help to drive air in vs letting the engine do all the work to draw it in. So, perhaps some more benefit.
It would be a great experiment to make multiple runs randomly switching back and forth between snorkel and under hood to find out.
I do believe there is at least one thread where folks here experimented with this as well as mounting pressure temp sensors to determine the effectiveness of the cold air charge..
I do believe there is at least one thread where folks here experimented with this as well as mounting pressure temp sensors to determine the effectiveness of the cold air charge..
temp i put in post 3 link..have not seen pressure study but would love to see
Not trying to hijack or anything here but while this topic is in discussion I might as well ask here. I have purchased this dual snorkel air cleaner to put on my 74 and am considering cutting out the now sealed dual hood scoops and using them for forced CAI.. does anyone have any thoughts on this and why it might be a bad idea? I dont drive the car in the rain but figured I could incorporate some form of drains to prevent that from being an issue.
Last edited by augiedoggy; Jan 16, 2021 at 12:47 PM.
I think that is a great idea!
I would not worry about water ingestion unless you submerge the car. It would take extremely large quantities of water to hydro lock the engine.
Think about airplanes with piston engines in rain going 150 mph or more. They don't have an issue and ingest a whole lot more water during rain than your car ever will.
So those NACA scoops are currently non-functional? If you hook up the CAI to them opening the hood may be a challenge. Then closing the hood making sure the hose does not come into contact with the exhaust manifolds or belts/pulleys and cause issues there.
Might want to see if you can get the air from the wheel wells, which would require some cutting.
Or you could run it back to the wall in front of the wiper tray and tap in there. That's where I got the additional cold air for mine. Benefit is you get a little ram rise there too. The base of the windshield is a high pressure area.
Not trying to hijack or anything here but while this topic is in discussion I might as well ask here. I have purchased this dual snorkel air cleaner to put on my 74 and am considering cutting out the now sealed dual hood scoops and using them for forced CAI.. does anyone have any thoughts on this and why it might be a bad idea? I dont drive the car in the rain but figured I could incorporate some form of drains to prevent that from being an issue.
Last edited by REELAV8R; Jan 16, 2021 at 03:23 PM.
I would tend to say just the opposite. There is a greater difference in the street driven car since it averages slower speeds and sits idling at lights allowing for under hood temps to rise to a greater degree than a vehicle moving at high speeds.
because im a gluten for punishment I and converting from an open element to a dual intake CAI myself to prove to myself theres no great difference for a street car.
