Why I Re-Snorked my 987 S

[Kevin the Slow]

Yup, I Re-Snorked my 987 S... Here's the tale,

Last night after I left work, I drove to Greenwich CT. to play Power Ball. With the jackpot at 340 million, I figured it could be worth the drive of 40-50 minutes.

At 9:30pm, I hit the Sport button, set PASM to "Normal," turned on the V-1 and away I went. With no traffic to speak of, a "brisk" drive and a short time later, I'm on Arch Street and the Lottery store I go to has run out of tickets.

Bummed but Determined, I locate another place a few blocks away and they have a line of over 75 people @ 10:30pm and the last ticket they can sell is at 11:00pm...and I'm going to buy several hundred dollars worth of tickets, so I'll never get served in time. They tell me they can start selling tickets at 4:30am, so I tell them I'll be back and they insure me they have enough tickets on hand to take care of me in the morning.

When I get back in the car, the low-fuel warning comes on. I cycle through the OBC and it shows that for this trip, all highway except for 3-4 blocks, my average MPG was 10.6!

10.6, that's way less than the Pepper loaner I drove last week. I guess I hadn't ever really paid attention to my MPG before, just my MPH :)

Anyway, I fill the tank and reset the OBC for the trip home...MPG is even less on the return trip, 10.3 MPG!

So, I decide this is the perfect time for an experiment.

I took a nap, awoke at 3:30am and Re-Snorked. I then reset the OBC and drove back to CT. over the exact same route in the Sport Mode w/ PASM on "Normal." My OBC reading... 20.8 MPG!

This has got to be a mistake! I get my Lottery tickets, reset the OBC and drive the exact same route back home...20.9 MPG!

I admit it, De-Snorking the 987 S had a negative result. Although the sound was incredible, to cut my gas mileage in half is not worth the audible pleasure I derived from being Snorkless.

The sound of the Re-Snorked Boxster is definately different, although I'm still running without the intake restrictor plate I'm not sure if this makes much of a difference in the sound.

I didn't have OBC on my 986, so I never measured the MPG on her after I De-Snorked and K&N'd. I did compare my gas consumption to that of other Boxsters when we were on drives, but I was always in the same range of mileage as other, Snorked Boxsters. Would someone with a De-Snorked 986 w/ OBC share their mileage results?

Kevin - wearing my flame retardant suit...

P.S., Don't waste your money, I already bought the winning Power Ball ticket! :D

[tmc]

Wow, very interesting.

But wtf? Why would allowing more air to the engine hurt fuel economy?

[PorscheFan]

I have seen an article about air flow to the engine. People think if they take out some kind of air duct will make engine suck in more air. But this air duct is purposely there to direct air into engine. Without it , less air will flow into the engine. I think this may prove it.

[MNBoxster]

Hi,

I think your Evidence is purely anecdotal and your Cause and Effect totally circumstantial. There is waay too much mysticism surrounding this totally innocuous length of tubing.

The snorkel is a Noise Abatement Device to comply with Noise Abatement Laws prevelant through Europe. Porsche leaves it on ROW models to prevent the cost of redesigning the intake.

I de-snorkled my Boxster 3 mos. ago and haven't seen even a 0.1% drop in my MPG. In fact, we took a Sunday Drive through the Wisc. Backroads last weekend to see the Color and I got 30.1MPG on the Expressway getting there (on Cruise Control - 65MPH) and 26.9MPG through the twisties (although we weren't pushing it, we were averaging 55+ MPH).

I've read it was to prevent water from entering the engine in the rain and this is a bunch of Bull! You'd have to drive through Katrina before this device would serve this purpose. The Boxster Engine draws in so much air, that any water getting in the Intake and travelling to the Plenum is so diluted as to be more akin to very moist air. The Filter will trap most of it and the quantity of Air moving through it will pick-up the water mostly as a mist.

So far as directing the Air to the Engine, again Aaaaannnnnhhhh! The Engine will draw all the Air it needs and the capacity of the Intake and the Filter exceeds the demand of the Engine.

I also own a Lotus Esprit which has it's sole intake in roughly the same position as the Boxsters (although a few inches higher). I have driven it through torrential rains and never had a problem, nor have any other Esprit Owners I know (and I know most of them - Nationwide). And this car, because of the Turbo draws at least 4 times the Air a Boxster does.

I'm not so much trying to disprove your theory as alerting you that the problem you experienced lies elsewhere. It may have been a BrainFart by the ECU (DME in Porsche Parlance), a faulty MAS, a stuck Vac valve or the like, but it certainly wasn't the lack of a snorkel.

Happy Motoring!...Jim'99

Edited October 20, 2005 by MNBoxster

[Skibum]

I totally agree with MN Boxster.

I have no decrease in gas mileage.

[Stefan]

There has been speculation that the temperature of the air going into the intake of a desnorked car is higher. That would explain a difference in MPG. And the difference would probably depend on the speed you are driving, how hot the outside air temp is, humidity, etc.

But Kevin knew I was going to say that ;)

[Kevin the Slow]

      I think your Evidence is purely anecdotal and your Cause and Effect totally circumstantial.  There is waay too much mysticism surrounding this totally innocuous length of tubing.

Hey, I WANT to be wrong on this!

I had my 986 De-Snorked for over 30K miles and never saw a loss of MPG. I think I was the first to De-Snork a 987, which I posted here, and I loved the sound. It is clear that on both the 986 and the 987, the presence of the Snorkel does reduce sound, heck, I've been saying that for years. But, It also appears that the 987 Snorkel may impact more than just sound…

I think the issue may be in the design of the intake area of the 987. There are many more angles and the air box appears to sit further back in the intake area than it does on the 986, which may factor into my results. The air that rushes into the 987 intake area may not be directed as effectively into the air box as it was on the 986, thus the assistance provided by the Snorkel tube in directing air into the engine may be more on the 987 than on the 986.

I intend to do a Re-Snorked drive this weekend, then do a Re-De-Snorked run back to compare the results again. If the results are less dramatic than the 10 MPG gain I experienced, and I mean MUCH less dramatic, I would Re-De-Snork without a doubt. But if they are consistent, a 50% loss of MPG, I'd be crazy not to leave the Snork in place.

Have any other 987 owners De-Snorked? If so, please tell what your MPG results have been.

Kevin

[Rolando]

      I think your Evidence is purely anecdotal and your Cause and Effect totally circumstantial.  There is waay too much mysticism surrounding this totally innocuous length of tubing.

Hey, I WANT to be wrong on this!

I had my 986 De-Snorked for over 30K miles and never saw a loss of MPG. I think I was the first to De-Snork a 987, which I posted here, and I loved the sound. It is clear that on both the 986 and the 987, the presence of the Snorkel does reduce sound, heck, I've been saying that for years. But, It also appears that the 987 Snorkel may impact more than just sound…

I think the issue may be in the design of the intake area of the 987. There are many more angles and the air box appears to sit further back in the intake area than it does on the 986, which may factor into my results. The air that rushes into the 987 intake area may not be directed as effectively into the air box as it was on the 986, thus the assistance provided by the Snorkel tube in directing air into the engine may be more on the 987 than on the 986.

I intend to do a Re-Snorked drive this weekend, then do a Re-De-Snorked run back to compare the results again. If the results are less dramatic than the 10 MPG gain I experienced, and I mean MUCH less dramatic, I would Re-De-Snork without a doubt. But if they are consistent, a 50% loss of MPG, I'd be crazy not to leave the Snork in place.

Have any other 987 owners De-Snorked? If so, please tell what your MPG results have been.

Kevin

<{POST_SNAPBACK}>

I de-snorkeled my 986 the same weekend I bought it so I don't know if my MPG is what it should be (I am at about 20 or less mpg including freeway and stop-go traffic) I also removed the foam from the filter ... it may be my perception but after doing it, the car seems to respond better (there should be more air flow withoult the foam and particles would not go though)

I am interested in the results of your test even if it is a 987. -Good luck

[mee]

There has been speculation that the temperature of the air going into the intake of a desnorked car is higher.  That would explain a difference in MPG.  And the difference would probably depend on the speed you are driving, how hot the outside air temp is, humidity, etc.

But Kevin knew I was going to say that ;)

<{POST_SNAPBACK}>

There can be no difference in temperature, snorked or not. The system is completely sealed to the point where the snork attaches. Neither case breathes engine compartment air. The PCNA guy who was quoted that the desnorked did or whatever must not know much about Boxsters.

I cannot imagine any statistically significant temperature difference in heat picked up by a plastic snork or a rubber surround (assuming some sunshine or warming effect getting behind the grill. Only minor differences in turbulence and restriction of the snork (and sound).

Finally, from a thermodynamics point of view, I believe any additional heat taken in by the engine improves efficiency. It's just not good from a HP point of view due to the air density. I'm too lazy to look up the formula.

The only rational reason for getting worse MPG without a snork is that you wind that flat six out to redline every chance you get to hear that wonderful sound. I have heard that desnorking adds HP just bordering on being statistically significant.

[adsach]

Kevin - You may want to run through a full tank of gas de-snorked and look at the pump mileage rather than the OBC mileage.

PS. - I thought of our 2003 fall group drive up Mt Equinox (in your 986) when I went leaf peeping in VT last weekend. http://blueturban.com/auto/photos_d1.html

PPS. - I picked up a friend from Brooklyn up at the Rhinecliff AMTRAC station and did a drive through Duchess county yesterday. The foliage is at peak right now. He was blown away by the train ride along the Hudson followed by a Boxster ride along mountain roads to nowhere. My friend used the word 'Magical'.

We took a drive up the Taconic today and I asked if he wanted top up for the freeway - He said no way!, he doesn't get to ride in a convertible every day and definitely wanted to enjoy the experience top down even in the brisk weather. I DO get to drive a convertible almost every day and I couldn't agree more. These cars really are 'magical'.

[Kevin the Slow]

The only rational reason for getting worse MPG without a snork is that you wind that flat six out to redline every chance you get to hear that wonderful sound.  I have heard that desnorking adds HP just bordering on being statistically significant.

<{POST_SNAPBACK}>

That has never been a problem for me, I wind it out all the time...even w/ the Snork in place.

I'll know more this weekend. My plan is a 100+ mile drive with the Snork in place and then make the return trip over the same route with the Snork removed. Any other suggestions on variables to watch for and how to remove them?

[Kevin the Slow]

That was a great run! I missed you guys last year, I thought you had moved back west.

[RandallNeighbour]

One thing you might try to do is to top off the fuel tank before you leave and check fuel economy the old fashion way. Also, determine cruising speed limits for yourself so you can match them both ways.

[tmc]

Kevin,

How did you de-snorkel the car so that you could re-snorkel it without buying extra parts?

I ask because the de-snorkeling directions I've seen both have you breaking things or dremeling things or whatnot.

Thanks

tmc

[Kevin the Slow]

Kevin,

How did you de-snorkel the car so that you could re-snorkel it without buying extra parts?

<{POST_SNAPBACK}>

No broken parts on the De-Snork of the 986 or the 987. On the 986, occasionally the edge of the vent frame or a louver will break, but they are fixable w/ epoxy or inexpensive to replace.

On my 987, I removed the restrictor plate, so I ground down the pins to install an inner mesh. You can do the De-Snork w/o doing any grinding. Both Charles Atlas (who posted his instructions here) and Mark from NY did it w/o damaging anything.

I’m hoping to get to do another comparison run this weekend to confirm or disprove my MPG results.

Kevin