A new take on snokels

Originally Posted by Allen K. Littlefield

This snork mod talk has me thinking, (always a bad sign) that what if a trumpet/funnel snork was fashioned and replaced the original. Would that not a certain amount of ram effect (poor mans supercharger) into the intake thus increasing performance, at least a little bit? I notice that the stock snork seems to get larger as it enters the intake manifold which is the opposite of what I am suggesting. Also if the new Boxster/Cayman animals have a larger air vents there must be a valid reason, more cooling air perhaps? Is there a larger or should I say, more open replacement for the vent cover on earlier models? You understand I mean less metal around the opening cover and more sreen area? Any of you engineer types have any thoughts on this, Jim etc.?

AKL

I'm not sure the effect is going to be overwhelming, I'm just trying to tweak my intake to match my lower restriction exhaust. The so called "cold air intakes" breathe from under the hood, where's the cold air in that formula? I prefer to keep the outside air sealed from the engine compartment. I may mod the snorkel, if I do I may take a different path than the one posted..

[Allen K. Littlefield]

Originally Posted by DrRoentgen

I'm not sure the effect is going to be overwhelming, I'm just trying to tweak my intake to match my lower restriction exhaust. The so called "cold air intakes" breathe from under the hood, where's the cold air in that formula? I prefer to keep the outside air sealed from the engine compartment. I may mod the snorkel, if I do I may take a different path than the one posted..

Dr. R, the evo intake closes the chamber off so only outside air (cool air) enters the cone filter. I am not so sure if this is good or not because I don't know if the opening around the stock intake area allows for some air flow over the engine and cutting it off may contribute to high engine temps. Again, the more experienced here should chime in. Cooler intake air and a cool engine are both goals that are hard in a mid-engine car. I have also seen air scoops that would tend to ram more air into the intake. I think cooling air comes in the right side vent, over and down and out the bottom so the scoops would work on the right side too. Again, I am new to this and am learning so my info. may not be totally accurate but that gives others with more knowledge to post corrections. What ever the case, have fun with your car.

AKL

Originally Posted by Allen K. Littlefield

Dr. R, the evo intake closes the chamber off so only outside air (cool air) enters the cone filter. I am not so sure if this is good or not because I don't know if the opening around the stock intake area allows for some air flow over the engine and cutting it off may contribute to high engine temps. Again, the more experienced here should chime in. Cooler intake air and a cool engine are both goals that are hard in a mid-engine car. I have also seen air scoops that would tend to ram more air into the intake. I think cooling air comes in the right side vent, over and down and out the bottom so the scoops would work on the right side too. Again, I am new to this and am learning so my info. may not be totally accurate but that gives others with more knowledge to post corrections. What ever the case, have fun with your car.

AKL

AKL,

I'm always learning as well, the sealed evo intake makes much more sense. I had read some corroborating information regarding the engine temps and de snorkeling. I'm hoping someone will post and comment on the following:

Does the snorkel taper accelerate the airflow?

Would shortening the length provide an advantage over just leaving the snorkel out?

If you shorten the length should the outer lip be enlarged and blended into the new end?

I worked on the car as a hobby all winter long in my own shop. I have enjoyed the car since the first day I drove it and improved it each year with whatever it has needed. Fact is I was so effective in my approach to perfecting my Boxster that I was awarded with a ticket this past weekend...

RE: Ram air

Doesn't take effect until triple digit speeds. Although the intake tract length can be tuned for a certain harmonic.


RE: Snork length and taper


According to velocity stack wisdom, the longer length helps out low end while a shorter is better for hp up top. The reverse taper of the snork actually slows down air velocity within the snork since the air has to expand, but I've seen this design before soo?

[2000SoCalBoxsterS]

Yes. The right side air vent is for engine compartment cooling and the left side vent is for the engine intake. As to the snorkle, I believe that desnorkling would only serve to slow down air flow and give it a lack of direction. Air direction to the air filter and air velosity will be better with the snorkle. You've got to believe that the Porsche engineers knew what they were doing and put it there for a purpose. That being said, I do believe that that purpose can be enhanced with a FabSpeed or EVO Cone shaped Cold Air Intake system.

I was at the Porsche dealer a few days ago and I was looking at the new Boxster's, I was curious about the larger vent on the 987 so I knelt down and looked inside the driver side vent. I was surprised to see that it looked more restrictive than the 986 vents. The larger vent appears to be mostly for styling. When you look into the vent most of it is closed off by black plastic leaving only a small opening for air to pass through to the engine air filter.

[insite]

here's an engineering take on this:

1. because there is an air filter directly following the snorkel, any tuned effect due to the length of the tube is negated when the air flow is interrupted by the filter.

2. the tube is designed with a trumpeted end to act as a venturi. it will actually flow more air than a non-trumpeted design of slightly larger cross-sectional area.

3. the tube cross-section grows as it gets closer to the airbox. the primary purpose of this tube is to suck cold air at a reasonable velocity and expand the cross-sectional area of the charge to roughly match the cross sectional area of the air filter. the idea is this: rather than have a stream of air hit a small section in the center of the air filter, static friction from the filter can be reduced by using the entire filter. if the air flow is expanded to hit the entire filter at once, resistance to flow is minimized and filter efficiency is maximized.

4. the cup on the end of the tube was an afterthought designed to prevent rain water from entering the motor. reports of hydrolock caused this modification. removal mayl negate the purpose. it should be noted that the hydro-lock modification also included a drain in the airbox; it is my personal feeling that the cup on the end does nothing and the drain in the box does everything.

5. i believe that the snorkel was designed to work best without the cup on the end. i bet a dyno will show that the snorkel in place without the cup yields a more positive result than no snorkel at all. them engineers is smart.