De Snorkeled! Does it negatively effect HP or torque?

[Pianohawk]

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.

[sickbananas]

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

[Lil bastard]

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!

[chaudanova]

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...

[backman_z]

I was ambivalent about it, until I spoke with Jaay (whose posts are all over this forum). So I removed the snorkel. I agree with what he told me: “Just look at the snorkel.” There is a very significant narrowing at the end closest to the side air vent. I just got the snorkel and traced the inside of both ends as best I could, just to take a look. Without getting out my protractor and brushing up on my geometry, I would guess that there is about a 40-50% reduction in size from the large end compared to the small end.

Now, how many people spend all lots of cash to increase the diameter of the air intake system in order to improve airflow. You cannot convince me that the small end of the snorkel does not constrict airflow, even if only a little.

Did I notice a difference in performance? Not sure. I like to think I did, but it could all be in my head… in any case, I'm keeping it out.

[yimmy149]

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

[Tranlm]

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.

Originally Posted by backman_z

I was ambivalent about it, until I spoke with Jaay (whose posts are all over this forum). So I removed the snorkel. I agree with what he told me: “Just look at the snorkel.” There is a very significant narrowing at the end closest to the side air vent. I just got the snorkel and traced the inside of both ends as best I could, just to take a look. Without getting out my protractor and brushing up on my geometry, I would guess that there is about a 40-50% reduction in size from the large end compared to the small end.

Now, how many people spend all lots of cash to increase the diameter of the air intake system in order to improve airflow. You cannot convince me that the small end of the snorkel does not constrict airflow, even if only a little.

Did I notice a difference in performance? Not sure. I like to think I did, but it could all be in my head… in any case, I'm keeping it out.

[DonQ]

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.

[Jaak]

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.

[Steve Tinker]

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....

[dsisco]

Im getting my Ecu reflashed tommorow on the dyno,

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

thanks guys