De Snorkeled! Does it negatively effect HP or torque?
 

Just de snorkeled my 99 porsche boxster. The difference in sound is great! One question, does it negatively effect HP or torque at all? If you've de snorkeled your boxster feel free to take a minute and describe the effects...your experience will be useful to those who are researching this simple mod.

de-snorkle
 

On my 2000 S it def. did nothing negative. Awesome sound and better response. Generally a better feel. Recommend this mod. to all.

There has never been any quantitative data released on de-snorkeling. All the info. is, to-date, just anecdotal.

The snorkel's intended purpose is to meet noise abatement laws in some countries, especially Switzerland and it was included in models for all markets (since the legislative environment is always changing).

My personal opinion is that it neither positively or negatively affects performance, but greatly improves the intake sound of the motor. My car is de-snorkelled.

Plus, if you're careful and don't damage it on removal, it is totally reversable. So there really is no downside to trying it.

Cheers!

Bisimoto had a thread where he dyno'd before and after the desnorkeling. It gained power. Runs were on a dynapack...

Thread is here on 986forum...

Isn't there increased risk of cigarette ingestion after de-snorkeling?

I don't smoke so I'm not worried. But I HIGHLY doubt it. Regarding the potential negative effects of de-snorkeling Pedro (http://www.pedrosgarage.com/Site/Technolab.html) told me:

"There are no cons on the '99.
It's a great mod.
Just pull out the snorkel.
No need to add mesh.
I de-snorkeled mine in 1998.
No issue with MPGs either.
Happy Boxstering,
Pedro"

Nope, there is absolutely no increased risk of a cigarette or other large particle getting into the engine if you remove the snork, cause as you see below, there's a mesh screen in the intake right before the MAF.

http://i42.tinypic.com/jh4vae.jpg

I don't smoke either - but my radiator cavities seem to fill with butts quickly.

Getting a butt into the engine wasn't what I was worried about. If someone flicks a still-lit butt and it ends up ontop of a paper filter having massive amounts of oxygen pulled through it, it will catch the filter on fire.

I know the stock filter has foam on top of the paper, not sure if that would help or not.

-james

Thinking about this, the diameter of the snorkel from one end to the other should not really matter. In dealing with fluids, there are two things to distinguish between: flow speed and flow rate. Flow speed is just the instantaneous speed of a molecule of fluid (in this case, air). Flow rate is the amount of fluid passing a cross-sectional area given a unit of time. Flow rate is what we're interested in if we want more horsepower, torque, etc.

Though the snorkel does converge in, I don't think removing it would do anything to increase the flow rate of the air. You have to remember that the end where the snorkel connected is same diameter as that end of the snorkel. So, even if you do remove it, the size of the hole for the air to be sucked in is still the same.

Thing is, the snorkel tube itself was not put in for the purpose of blocking out cig butts...the protruding lip on the painted air vent housing was put there to redirect objects over and behind the intake, so taking the snork tube out will not increase the risk of a cig butt going into the air filter housing. In fact, I have seen cig butts in the foam portion of the air filter even in cars WITH the snork still in place. If a cig butt is going to get in there, it will get in there regardless if the snork is in or not.

I've had my snork out for years without issues. I even took a dremel to the section left after pulling the snork out to smooth out and widen the hole since I didn't like the hard edges left in the opening after pulling the snork out. The sound is terrific, and my filter hasn't caught fire. :)

I don't have any dyno evidence but something that was interesting to me none the less. I have a 2004 special edition which had slightly more power than the standard 2004 Boxster S from the factory. My understanding is the extra horsepower was basically achieved by an intake change and an ECU re-flash from the factory.

I compared my intake to one from a friends older Boxster S and indeed mine was pretty drastically different. However, one other thing that was interesting was my snorkle was massively larger than his was. I've not been able to compare a "standard" 2004 Boxster S to mine yet, but if it's the same situation it might lead one to believe a de-snorkle could have some slight added hp benefit.

Anyone got a picture of a snorkle off a standard 2004 Boxster S? I'll take a picture of mine and post it.

Worth a thousand words?
 

desnorkle an 04S
 

quite interesting.. a year ago i've put up this question if it was possible to do this on an 04S and i don't think anyone had done so, or just did not post a reply.
reason was, i attempted to do it on my 04S and no amount of wiggling the plastic grill after taking off the one screw, did not budge and i was afraid to break the part..
i hope you could shed light on this?
thanks for sharing.

I did my 2004 S. I remember it being a bit scary to get it to come loose though.

De-snorkling coupled with building a hi flow air intake = deep, amazing sound.

De-snork flow
 

Lets leave out intake tract acoustics and ECU response to airflow changes which affect performance. Assuming that these that these factors are not affected by de-snorking, we now basically left with flow considerations. A normal Boxster engine has to draw air in like a pump. Flow losses upstream of the engine will reduce the flow rate at a given rpm. Fluid energy is lossed by having to make through obstacles. Air flow is a tricky thing; one has to test what is an obstacle in combination with everything else.

Generally section changes, area reductions, sharp edges surface friction all give rise to losses in steady state pipe flow. The flow loss reduction or lack there of, with respect to a de-snork comes down to the flow losses associated with the snork (area restriction; the cup is a sharp edge vs. the sharp edge you are left with upon its removal. I would guess that the huge intake area increase would just beat out the losses associated with the air box sharp edge....but one has to test.

I did this mod for sound; it is fanastic and I want more of it. If you are after a significant power go for an under drive pulley instead. I do get worse fuel economy because I am hard on the throttle enjoying the sound!

One day when I get around to it I will fabricate and post my solution to the de-snork sharp edge

That's exactly what I did. I didn't like the sharp edge left after pulling out the snork, so I took a dremel to the sharp edge, and ground it to a smooth curvature. I then vacuumed out all the stuff I ground down. Here's a blurry pic I took after it was done...
http://i50.tinypic.com/10h0d5g.jpg

Nice work! I didn't there was enough material there to shape a lip; I have 2000. Plus my plastic panelling is much tighter around the opening than yours. Huge losses can occur on sharp intake edges. Did you get a different sound out of it?

I was thinking about something a little more sneaky......I am betting someone here has probably done something similar already. I will post it up when I get it done.

Thx. Your intake opening should look exactly like mine, because mine's a 2001, and they didn't change it again until 2003.

You can definitely dremel down the sharp edge until it gets smooth. The sound is great, but I don't think dremeling the edge changes it much, the desnork itself adds a nice sound alone.

What I think would be interesting to do is to cut off the snork tube near the end where it meets the hole at the airbox and then either attach a curved trumpet like opening or fabricate one that will fit right into the hole as the original snork did. Short snork with a wide opening if you will...

You got it! This is what I was thinking of.......but it just a little sneaker than this!

If it works out I will let you know....I think you will like it a lot!

so i finally de-snorked ( i know, what took so long ) and since everyone always asks about before and after sound...

a totally unscientific, meaningless before and after. don't expect much with laptop speakers.

http://www.youtube.com/watch?v=WOzdnvW_oAA

This mod didn't please me. I tried the de-snork just to see what happened. Sounds much like when we used to take the air cleaner off of 60s and 70s cars. Trouble is that the sound gets bigger than the "go". Kinda like a little riceburner that has exhaust that sounds like 600 hp but still has no go.
To each his own........ Enjoy it if you lioke it, but I would not expect that you'll feel more HP. I didn't.

I De-Snorked mine today. I have a 98' and man was it a pane in the ass to get the vent off. In the process I was lucky enough to break one of those dame clips that are attached to the grill slits. The one I broke was the forward most to the front of the car. I reinstalled the deal and its a little more loose now but not that it will effect anything (I hope). I like the new sound of the engine now. Sounds great. AS for removing the vent I did research on it but it seems there is now easy way to get it off...I guess I'm lucky I only broke one clip :rolleyes:

I had issues too, but it was only because I didn't follow directions. I tried to remove the vent and the outer housing as one piece instead of pushing the slats free before removing the casing.

You know I tried that first, but I was sure I was going to break one of the slats with my large developed phalanges muscles :D

If you still have the broken clip you can repair it. If I remember correctly you can use actone to weld it back together, if tha doesn't work use CA glue. then get some 2 part epoxy to build around it for some extra support. of course put the epoxy in areas that won't interfere with reinstallation.
Ken

Reading all the hype about desnorkeling, I decided to try it out. It all came out really easily. My engine was pretty hot so the vent and snorkel was nice and pliable. Nothing broke and the snorkel itself came out easily too. If you are having a hard time with it try going on a drive and warm things up.

It sounds cool but I'll propably put it back on in the fall when it gets colder.

The main issue with airflow in engine intakes is usually not getting enough air.
If that was the case the all motors would just have huge intakes, throttle bodies and intake valves.

In the mid eighties engine designers learned that they could increase horsepower in certain ranges of engine RPM by tuning intake designs.
Air flowing into an engine is not like a water pipe flowing. The air in the intake is in a constant state of fluctuating pressure. Almost a vibration.
By tuning inlet length to a certain vibration frequency, You can increase intake pressure at that frequency. This can be compared to the resonators on a pipe organ.

Engine designers will often use this to fill in "flat spots"in the power delivery.

By removing the snorkel you could be creating dips in the power curve of your engine. This can be verified with a dyno chart showing dips at certain RPMs.
Then again, they also use these things to quiet induction noise. This might be done at the expense of proper flow.

So, if some one wants to do a proper dyno run with before and after charts, we might be able to see whats actually going on.

Otherwise, do it if you like the noise.
And remember louder doesn't always mean faster.

When I had my engine rebuilt (bought it that way), I had mine desnorkled as well as the resonator box removed. The wrench filled in the hole as well as smothed the filler so it was clean. I don't know what the car was before, but it does sound sweet now. The one upgrade I did that seems to make it better was the Sprint booster. The throttle respons is great and what I have noticed with two tanks of gas is an improvement in my gas milege. Close to 4 MPG/CDN better! I leave it in the sport mode.

I've de-snorkeled twice now and replaced back to standard twice...
Its just my butt dyno, but I seem to be missing something in the 3-4000 rpm mid range. Nothing wrong with the sound - it just seems that I'm not getting as much torque with the snorkel removed. So I put it back in!!
Maybe its senile decay setting in....

Im getting my Ecu reflashed tommorow on the dyno,

would it be a good idea to do this mod 1st?

thanks guys