boxster exhaust too quiet?
 

So my friend drove my 987 the other day and actually stalled it three times, exclaiming, "its so quiet." Now, I have not stalled my little jalopy, but will attest that compared to the 986 S's, Cayman S and 911's I've driven, my 987 is pretty quiet.

I think I choked not having the sport exhaust installed at the dealer at the time of purchase and unfortunately, can't spring for a whole new exhaust right now (although I'd quickly swap out the tips for something S-like). But, anyone know a little trick that can pulled on the stock exhaust to get a bit more bark out it?

Haha...the whole "its too quiet" was used when my dad stalled my car several times when he first drove it. Can you desnorkel a 987? I personally love the quiet approach of German exhuast compared to those tin cans on rice rockets and those American cars that all sound the same.

I agree, look into modifying the intake if possible (desnorkle or switch to high flow). It would probably be more noticable being right behind you anyway. Should make a nice growl for you.

Yeah, this might help turn on your Check Engine Light too!

I am not aware of a Porsche Sport Exhaust option for the 987. Are you sure about this?

De-Snorkling wouldn't effect the Check Engine Light, but adding a cone filter might. Just wanted to clarify that De-Snorkling is ok to do. :rolleyes:

I haven't seen any posts on a 987 intake or a CEL problem... I know some of the 986's did have that problem.

Too quiet? That's an easy fix.

Just get under it with a drill and a 1/4 inch bit and drill you some holes in your muffler. About a dozen will do real fine.

Then she'll make some noise and you'll know the engine is runnin'.

I prefer the 1/2" bit it really gives the rear bumper that black smoked look! :p

The only individual that I've read about who desnorkeled his 987 (an S)subsequently resnorkeled when his mpg was dramatically reduced. As 987 owners running 91 in CA will attest, range is not the Boxster's strong suit...not sure I'd personally reduce it further to get more exhaust noise.

I'd agree with bmussatti...from what I know, there is no sport exhaust yet available...sport tips yes, but I don't think that will improve the noise.

Hi,

I seriously doubt that CEL's or lower MPG was caused by desnorkelling. It's only function is to reduce Intake Noise to comply with European Noise Abatement Ordinances.

There's a lot of Urban Myth surrounding this innocuous ABS Tube.

It does not allow Cooler Air to enter the Engine, the difference isn't significant enough to alter the Engine performance.

It does not allow more air to enter the Intake because the Throttle Body controls this, so the DME does not demand more Fuel consumption.

It cannot trigger a CEL because nothing is affected by it's presence or absence except Sound Waves. Removing it may jostle a component or two (especially something as sensitive as a Hot Film MAF) causing them to trigger a CEL, but that's a function of one's removal technique rather than the absence of the Snorkle itself.

All reports to the contrary are TOTALLY Anecdotal, and people are seeing Cause & Effect where there simply is none...

Happy Motoring!... Jim'99

MN,

You may be right in your dismissal of reports on the negative impacts of desnorkeling as urban myth and anecdotal, but generally speaking I'd value the input of someone who actually has a 987 and desnorkeled versus the theorizing of a 986 owner.

The owner I'm referencing is from PPBB. His comments are below and the whole thread can be found by searching their archives with "987" and "snorkel" using the "AND" search-qualifier.

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?

Subsequent post:[/

The intake of the 987 is like the one on the 986 SE, very closed and shaped. I think that I was actually allowing less air to get into the engine based on the recessed position of the air box opening where the Snorkel tube attached.

If the engine was getting that much less air, it would use more fuel to get the job done (I have no engineering degree and I'm a lawyer so take it easy on my scientific analysis )

Anyway, the instantaneous increase in the MPG is staggering to me. Although the test conditions were not perfect, I did keep many things the same;

The outside temps on both the De-Snorked and Re-Snorked run were within approximately 10 degrees of each other, cooler on the Re-Snorked run,

The trip took about the same amount of time, my top speed on both trips was about the same and I did not, knowingly, change my driving habits for the experimental run,

I listened to Heather Headly on both trips, I love her music and just and just got the CD,

I did not eat or drink between the runs,

I had no passenger on either trip,

I the De-Snorked trip up was taken with less than 1/2 tank of gas, while
the De-Snorked trip home was with a full tank, which might explain the slight
variation in the MPG, 10.6 - 10.3, on the De-Snorked runs,

I also add that the Re-Snorked trip up started with the needle just under
the "F" and upon arriving home, I still had more than 3/4 of a tank,

Top-up on both trips, no ac, no fog lights, and seat heaters used at any point.

It seems too dramatic to just be coincidence to me.

Of course you'll get worse MPG because you'll be listening to the engine hahaha

I know he says he didn't change his driving habits, but he also said it sounds great meaning he's hitting the gas! Too each his own......if someone wants more noise typically they could careless about MPG. I hope nobody bought a boxster for it's great MPG.

Usually less air doesn't mean more fuel to compensate. Less air means less fuel. Most computers have a set a/f ratio and when it starts to get less air it won't run rich to over-compensate... it will simply add less fuel and result in a loss of power.

[QUOTE=SD987]MN,

You may be right in your dismissal of reports on the negative impacts of desnorkeling as urban myth and anecdotal, but generally speaking I'd value the input of someone who actually has a 987 and desnorkeled versus the theorizing of a 986 owner.

The owner I'm referencing is from PPBB. His comments are below and the whole thread can be found by searching their archives with "987" and "snorkel" using the "AND" search-qualifier.

Hi,

First off, not too appreciative of the slight that because I don't own a 987 somehow my knowledge of the Car, and it's workings, is less accurate, but whatever...

Second, I read those posts on the other Board and dismissed them the first time. The Lister's experiment is not controlled in ANY way. Reversing a Trip is not the same Trip - You go Up the Mountain and get X MPG, now you descend taking the same road, same speed - MPG improves - Valid..??

He goes on to speculate that he's allowing less Air into the Engine. Not at all true because the Engine DRAWS in the Air it needs, there is no RAM effect necessary or else how do you rev the Engine in a stationary position? But, even if he were correct, how does that consume more Gas as the MAF sensor would detect less Air and signal the DME to CUT the Fuel supply, not increase it?

Did he maintan the same shift points, speed? - he only admits to thinking he did so. Did he hit the same number of Stop Signs (for the same period) or the same number of Stop Lights? Was he on level ground the entire trip? Did he operate the OBC correctly? He admits to a Temp and Weight difference which squewed his comparison, although I admit not 10 MPG worth. He seems to infer that the Car was recently serviced as he had use of a Loaner, was the Battery disconnected during this Service or the DME reset? It could have been in Memory Acquisition for the initial trip(s). None of this is detailed in his Report.

Just explain to me exactly what mechanism is at play here to cause this variation, how it could happen, and you may convert me. Otherwise, my explanation is the much more credible of the two, whether I own a 987 or not. I'm not even heavily disputing his variation in MPG, only that the Snorkle, or lack of it, was somehow the cause.

You wanna believe this guy and his Methodology, OK, that's your right, but don't profer it here as FACT that others may act upon. And don't arbitrarily impune my knowledge and experience just because you're willing to be led down the proverbial path without any examination of the facts. I don't know which is sillier, his assertion, or your believing it...

Happy Motoring!... Jim'99

OK, let's get some lively discussion going about the below (or above) suggestion to use a "High Flow" and its potential effect on the CEL! Looks like we have covered the de-snorkel debate/topic pretty well!

My personal experiece with the Evo Cone setup ruined 2 MAF's. It sounded sweet though!

Since then I've had the newer MAF from the 04+ cars and software update. I have read that these newer stlye MAF's won't go bad, but I'm not going to chance it again. My local mechanic, a Master Technician for Porsche, told me every car he's replaced the MAF on had a K&N stlye filter.

Obviously your 987 would have the newer style MAF.

I don't think he intended for you to take it quite so harshly and certainly I don't think that it is an affront to your depth of knowledge. Throwing paragraphs at him in defense is a little over the top. ;)

You have a lot of knowledge and you want to share it, that's fantastic, but sometimes you can be a bit overwhelming in your demonstration of that knowledge. Even the most knowledgeable of experts can be questioned, y'know?

Sometimes anecdotal evidence is all we have to go on. This guy's experience showed that he got a 50% reduction in gas mileage when desnorkeled. It may not be very scientific, but neither are your anecdotal claims that a strut tower bar improves handling yet you continue to defend those.

This 987 owner stands by his claims; they warrant discussion.

Hello Tommy
 

That's why I love my new exhaust.

Magnaflow.

KRZ

Hi,

Actually, I think he did. Using upper case in Internet Courtesy is akin to shouting and there were no emoticons to indicate otherwise. Most people would have taken it the way I did.

Thank you for your compliment on my knowledge, but that's merely a discovery and retention of fact - I did not invent this stuff - those are the really smart People! Most of what I learned was passed on to me and has stood the test of time if nothing else. But, I am always ready and willing to be challenged. If I'm incorrect, I want to know it and I also want to learn, so no problem there. If you feel I'm overwhelming, point taken. Read my posts and avoid looking for inferences and other meaning and maybe it won't seem so overwhelming.

Agreed, anecdotal evidence can be a good thing, it leads to further exploration and confirmation, but lacking this, it must always be viewed with some skepticism, maybe even much skepticism.

So far as my claims for the Strut Braces, there is some degree anecdotalism in my claims, but not totally. I took a couple pieces of kitchen string and attached one end to a Stud on each Strut Tower. I joined the Strings in the middle with a Glue Stick sufficient that they would withstand a little tension. Then I ran the Car 3 times on a twisty road with left and right handers and some off-camber surface. The string broke each time. After installing the Front Brace, I used the String setup again, 3 runs on the same road, same weight, speed. The string did not break once proving that the Towers do indeed move in opposition.

Also, I ran a favorite stretch of road, same weight, speed, tire pressure and noted at what speed the Car broke loose. After adding each Brace, I ran it again in duplicate conditions (identical to the degree allowed by Quantum Physics which states that no two events can ever be the exact same), and was able to increase my speed by 7MPH, then 12 MPH respectively. Add to this that virtually everyone who has done the install has confirmed my claims. This is somewhat more empirical than simple Feel. And, you can do the same thing and you will get the same results - it is repeatable!

There were any number of reasons why the Lister experienced a 50% reduction in MPG, independent of the action of removing the Snorkle, including the possibility that he didn't experience a reduction at all, but only thought he did because of some factor which he didn't account for.

As I stated, the only function of the Snorkle is to reduce Noise. The Intake System of the 986/987 are identical in the way they function (though not truly identical). Many 986 Owners and 987 Owners have sucessfully de-snorkled with no ill effects. This further leads me to believe that the Lister was mistaken and merely concluded an invalid Cause & Effect...

Happy Motoring!... Jim'99

I agree, I have a hard time following anecdotal evidence, but pretty much any experiment can be shown to have deficiencies.

For instance, your string test doesn't prove that the strut tower brace didn't instead transfer the forces along a different plane/axis than that which the string was tensioned in; that tieing the tops of the towers together didn't force them to move in other ways. It also doesn't show that the strut towers were prevented from compressing, which would slacken the string. As for the speed at which you were able to take the turn, short of actually running the car through that turn repeatedly, with and without the strut tower bar until the car actually DID lose control and spin out, you can't say that the improvement wasn't simply due to improved driver confidence--you never actually proved when the limits of handling and adhesion were reached, with or without the bar.

With your experience, and with your demonstrable ability to find flaws in an experiment, I'm sure you know how easy it is for one to trick oneself into believing one's own hypotheses. Skepticism is a good response to that.

(don't get me wrong though--I'm still interested in getting a strut tower bar, not trying to *prove* you wrong on that, just showing skepticism).

I have no plans on desnorkeling my car because I don't see how it will add any benefit, but you're right, I have no idea whether or not to believe that it would detrimentally affect performance.

Hi,

I take your point(s). But, the String Test did prove that the Towers did move on the same axis that the Brace occupied. Was there additional movement, maybe some, but minimal due to the undercarriage bracing and Radius Arms. The Towers tend to move perpendicular to the Fore/Aft axis of the Car (Side-to-Side) in response to Camber changes of the individual Struts as they respond to bumps and surface variations in the Road. Compressing of the Struts would not slacken the Strings as the Strut Mounting Studs are fixed.

So far as Handling is concerned, it's not truly necessary to run the Car to the point where it breaks loose, any threshold will do. The Road and Tight curve in question is 0.5 mi. down the street I live on - Mississippi River Blvd. This road is the 'Coast' Road along the East Bank of the River and so mimics the meandering of the River itself. I have driven this curve twice daily for a total of 29 years and the last 10 consistently. I know at what speed the Car's Rear End starts to get squirelly and raised this threshold by 7 & 12 MPH respectively by adding the Braces. These speeds would more than makeup for any Experimental error, at least to the point where one could definitely confirm that the Car could now go faster through this stretch. If anyone wants to start a collection for a few accelerometers, I could be more precise.

Defintely agree that proving a Hypothesis can lead to false results, but, while my Data is not precise, nonetheless, the theory was proved...

Happy Motoring!... Jim'99

The "drill into it" suggestion was not too far off the mark. Have a look at my post at

http://www.ppbb.com/boards/ppbbphp/showflat.php?Cat=&Board=ARCHIVES&Number=1085350&pa ge=&view=&sb=&o=&fpart=all&vc=1
and
http://www.986forum.com/forums/showthread.php?t=5059

These posts should give you something to think about. I wasn't prepared to spend big $$ on a minor improvement in sound that resulted in no HP increase. Some of the aftermarkets systems are just way too loud. I was also not prepared to bypass the cat, as the boxster is a convirtable and i would have to cop all the ill fumes at traffic lights.

I have drilled my exhaust to bypass internal chambers somewhat. Externally you cant pick any modification to the exhaust. Its louder but not by much. If i want it louder i can just increase the size of the holes.

Im suprised more people have not done this.

Post Hoc Ergo Propter Hoc.....

I think i'm just going to make an audio recording of the carrera GT at top speed and just play it through a loud speaker affixed to the rear of the car!

Thanks for all the posts and heated debate.

I was certain that the techquipement for the boxster listed a sports exhaust - maybe a brain fart!

You are correct.

There is a sports exhaust that operates to bypass chambers in the muffler at certain speeds and rpm (although most will hack it so its always open). There are 2 different types, the earlier (with the bypass pipes being external) and the later one (with most of the bypass plumbing in the muffler)

From what i heave read the porsche sports exhaust is much quieter than the aftermarket sports exhausts (but im sure someone can confirm this). Porsche exhaust, like everything porshe is also more expensive.

mach schnell, yes, Tequipment lists a PSE for the 986, NOT the 987. Interestingly though, the 2006 Order Guide for the 987 did list the PSE in the options section, but it was removed in a printing about 1 month later. I ordered it in my build, and then was told I can't get it. PCNA said the listing in the early printing was a typo. :(

bmussati - that is a bummer! Isn't funny how we have this amazingly perfect automobile, yet we still strive to change it and tweak it?! Is it the desire to be unique or the relentless pursuit for an evading sense of happiness??? :confused:

My "gut" tells me that Porsche pulled the PSE option for the 987 because they did not want to "steal any thunder" from the Carrera!! :( I don't have any proof, just a hunch.

The price for the PSE in the Boxster was $2,100. The Carrera gets $2,400. That's why I don't believe it was a typo...because it appears thay got the price correct!

With regard to de-snorkeling and loss of mpg, I find a 50% difference very hard to believe. If mpg's could be that significantly effected by a simple short tube of plastic I think we would be well on our way to solving the energy problems of the world and reducing gas consumption and prices. :confused:

With Regard to strut tower braces. At least on the S model they are a waste of money. Do you guys below to PCA? Do you ever use their Tech Q&A resources?

Strut braces do not make a difference on the Boxster S. There is enough metal going from one side to the other in very close to the strut towers. The factory built in the front strut brace concept in the car. Aftermarket ones are silly. Check out the GT3 Cup cars, they come from the factory looking just like the Boxster S with the same firewall between the front shock towers, and the same triangulated removable braces.

If you really want to improve handling you need to install a lower stress bar at the lower rear of the car on the subframe right behind the sway bar and above the triangualr shear plate. It attaches where the diagonals fasten to the shear plate.

de-CEL mod
 

Is it just me or has no-one else done the just as quick de-CEL mod? Seriously, taking OUT the CEL involves popping 2 covers off, taking out 2 screws, lifting up the cluster (pops out of clips) and turning the CEL bulb a quarter turn to remove. This can be done in 15 minutes, it's free, and you never have to look at that annoying CEL that turned on because of O2 sensors, MAF, etc.

Oh wait, I know someone is going to flame that I'm turning off a warning light that will tell me when something is wrong with the engine. Since 1996, when most cars added this annoying "feature" that is basically for the benefit of the dealerships, my CEL has never detected something that I couldn't feel or notice by driving. Often times, the CEL won't come on but the car will run terrible. Thus, MY CEL is my brain and seat of the pants. Also, I have an Autotel for when a car really does have a problem.

Just my 2 cents.

:dance:

Or just fix it properly. :rolleyes:

Ditto, it is that annoying CEL that actually motivates me so hard to fix whatever the issue and extinguish it with my Autel as soon as possible. I hate CEL with passion but killing the light will not do it for me... why not knowing a (potential) issue right away and fix it before it becomes a bigger issue?

I would have to agree. A marginal change in mph maybe, but 50%? Not buying it. Most likely there was some sort of computer computation that was thrown off. A snorkel pull is in no way going to dump twice as much fuel into the engine as a norm setup. The AF ratios and mapping simply wouldn’t allow it to happen.

You're responding to a post that's more than a decade old. :)

Ha ha! As are you! :cheers:

Seems there are a few of these these days!

What goes around comes around...
Sometimes it’s good to awaken these old threads though. There’s lots of wisdom to be found from members, some who may no longer be active. :)