De-snorkeled my Box 5 minutes max

[ChefCarnivore]

Thanks for the post. I always wondered what desnorkeling meant. I like the sound the car makes now. If it improves performance I'm not sure.

[mptoledo]

The sound after desnorkling is pretty cool, especially at the 3000k range and up. I have read 100's of post in numerous threads and it seems the mpg loss mostly comes from people changing their driving habits to here the new sound of their engines. I have only seen 1 guy who claims his mileage went to 10mpg on a 40 mile trip. I consider that post worthless and without merit as there is no way you will drop 40% to 50% in mileage.

I still haven't seen any concrete data, just opinions. For now I will keep it off as the sound is pretty cool. I do monitor my MPG on every fill up and will report my findings.

[mptoledo]

Ok, I found this post on here from a guy who dyno'd his 2001 "s".
He found a 5.3 hp gain and 2.7 torque gain.

He owns his own dyno and has great credentials. " I am an engineer, tuner and enthusiast, and have designed parts for NSXs, S2000s, and even factory supported FWD drag race teams. My race program involved many secured world records...but I digress."
Finally: Dyno charts of de-snorked 986S!!!

Now, the dyno doesn't test the car under true driving conditions and wind speeds @ 50mph. So take the info as you want. I am still searching for the truth, as I know its out there! Most the claims of loss of mpg came from the 987 not the 986.
exerpt "Wow..this is so sad...so much happened on the board while I spent more time beating my poor S on the dyno today. I have repeated the results on 17...yes 17 passes with and without the "snork". The data remains the same. For what it is worth, this mod produces 4.6~5.5whp at high rpms. Whew!"


I am not trying to blindly support my decision. If i am wrong I would be the first to admit it. I just don't take some other guys response of "it felt like i loss power" as a scientific conclusion.

[JFP in PA]

Sorry, but I still don’t buy it for multiple reasons. Interestingly, he ran his tests on a hub design dyno that is well known for always giving considerably higher readings (10-12% are not uncommon) than conventional roller units in side by side runs. I know the manufacturer claims this is because it’s unique design which “eliminates the “roller effect”, but at the end of the day, the rollers are in much wider use. In any case, while I am not going to challenge the veracity of his test; I can tell you that two different cars that I watched being tested showed a slight, but measurable drop in HP and Torque when tested on the rollers. When combined with consistent comments that multiple cars saw lower gas mileage with it out, but recovered the mileage when it was reinstalled; I think you are “tilting at windmills” here……………

[mptoledo]

Originally Posted by JFP in PA

Sorry, but I still don’t buy it for multiple reasons. Interestingly, he ran his tests on a hub design dyno that is well known for always giving considerably higher readings (10-12% are not uncommon) than conventional roller units in side by side runs. I know the manufacturer claims this is because it’s unique design which “eliminates the “roller effect”, but at the end of the day, the rollers are in much wider use. In any case, while I am not going to challenge the veracity of his test; I can tell you that two different cars that I watched being tested showed a slight, but measurable drop in HP and Torque when tested on the rollers. When combined with consistent comments that multiple cars saw lower gas mileage with it out, but recovered the mileage when it was reinstalled; I think you are “tilting at windmills” here……………

Again, I am still in the wait and see camp. I check my MPG after every fill up. I do like the sound with it off. Even using an inferior dyno, it should give a consistent before and after reading even if they are both high. Enough of that. As I said in the OP, HP and torque gains(if any)are negligible and aren't the reason I did this.

I am glad you brought up the MPG issue, as to me that is way more important than any small gains or losses in hp or torque. I will definitely keep an eye on them over time and report my findings, as unscientific as they may be. I still think most people rev up and wind out through the gears more to hear the noise, which makes sense why they would see lower mpg.

[JFP in PA]

OK, I went and looked up one of the guys that ran the test I watched on the rollers and he sent me the following data on multiple runs, with and without the baffle;

***18 Jul Stock no mods ***
RF-001 258.31 bhp 220.54 ft/lb
RF-002 258.21 bhp 221.92
RF-003 258.44 bhp 221.03

********* 18 Jul De-Snorked runs *****
RF-004 256.95 bhp 217.82 ft/lb
RF-005 256.17 bhp 218.46
RF-006 255.95 bhp 218.91
RF-007 256.19 bhp 220.00

Doesn’t look very promising on the performance side, but it was noisier……

I have no idea about the source of the MPG change, so you could be correct in that it results from "too much right foot"..........

[Boxtaboy]

I agree with JFP, in that I think desnorking does make you lose a little power. I was desnorked for a year, and always noticed that at highway speeds over 60+mph, it always felt like I had less power with the snork out. My personal layman's theory is that the snork was designed with the curved, trumpeted opening (which sits closer to the grille opening) to better facilitate airflow into the airbox, giving it a smoother and less turbulent flow into the airbox. With the snork out, there is a void in that area that includes all these waffled edges at the rear section which cannot help airflow into the airbox. Couple that with the fact that the remaining opening after pulling out the snork leaves a straight edge whereas the snork used to have a curved opening, and the flow must be worse than before, IMO.

That being said, ultimately, after putting the snork back in, and feeling like the power had come back at speed, I still really disliked having the snork back in place because there is a remarkable difference in the way the car sounds with the snork back in.... it was just too quiet for my liking, and I soon was back at pulling that snork out. This time, however, after pulling out the snork, I took a dremel to the remaining straight edged opening at the rear section, and sanded it into a curved opening to simulate the curved opening of the snork (and then vacumed out the sanded out bits prior to putting it back together). You can't see it too well in the crappy picture I took at the time, but I now have a curved opening into the airbox. Not sure if it helps or not, but I do love the sound of the car desnorked, and if it means a 2hp loss as JFP shows, so be it...at least I can hear the sweet growl of the intake while I'm going slower, and getting less mileage.

Desnorked and dremeled remaining opening:

[DANMKII]

Originally Posted by mptoledo

I have read 100's of post in numerous threads and it seems the mpg loss mostly comes from people changing their driving habits to here the new sound of their engines.

Hm- that makes ALOT of sense. Personally, I know I would get lower mpg from trying to hear the intake.

I've been reading this thread with some interest because I tried to de snorkle my '99 Boxster following the instructions you have posted here and couldn't get the snorkle to budge. I wiggled it and at one point had both feet on the car pulling on it but it wouldn't move an inch so I gave up. My mechanic wants me to put in a cold air intake system and he says it should come out if the intake system is to work correctly. All the reading I've done on the pros and cons are as varied as the experiences of the drivers. Some say an HP increase some say not, some say better sound some say your fuel system regulator will eventually compensate for the change and the sound goes back to normal. Although everything I've read about the snorkle goes along with the Swedes getting a knot in their shorts over the noise, and I'm no expert on air induction, it would seem to me that the tube shape of the snorkle would have an effect on air turbulance as the air is forced down the tunnel of it. It may even have the effect of increasing PSI on air entering the air filter box. It would be interesting to really see something definitive on this topic because although it has been widely discussed there doesn't seem to be any agreement on its benefits or drawbacks.

[sd_boxster]

Since a bunch of you have desnorked Boxsters that have the cup - has anyone ever found it full of debris? Seems like a question that bears asking...

Originally Posted by sd_boxster

Since a bunch of you have desnorked Boxsters that have the cup - has anyone ever found it full of debris? Seems like a question that bears asking...

There was nothing but dust in the tray when I got mine out. The second time around I grabbed the tray and the snorkle came out so easy I was amazed. I had pulled on the snorkle itself the first time and it wouldn't dislodge. What I've noticed is the car sounds more mellow, there's an intake noise that is missing but the upside is my gas mileage appears to have increased by one mpg. Combination around town and freeway I'm up from 22 and change mpg to 23 and change mpg and on a freeway cruise to Sacramento my freeway miles where up to 26 mpg. also up one mpg. :dance:

[JTP]

The Boxster's unique location for the intake may have an effect on HP losses or gains many have claimed. Unlike a front engined vehicle where the intake system can take advantage of the high pressure area naturally provided by forward motion, the Boxster's side mounted opening creates a low pressure at the intake opening as the vehicle moves forward. I suspect the snorkel places the intake opening at a point closer to the moving air than if the snorkel is removed. This would force more air into the intake system than with the snorkel removed. You can feel this effect easily by driving your car at 60 MPH and opening the window slightly. There is an immediate drop in pressure that you can feel in your ears. The area behind the grill feels the same drop in pressure. The higher pressure that exists at the opening of the intake dictates how much air is ingested into the engine. The odd shape of the intake area, with the snorkel removed, may cause areas of low pressure due to Bernoulli Effect of the moving fluid past the opening providing less air pressure at the intake opening. For this reason, it is possible the engine is getting less air with the snorkel removed.

I read the tuner's thread about the 17 runs he did, and on a stationary vehicle his claims may be correct but may not be correct on a moving vehicle due to the unique nature of the intake opening. A desnorkeled Boxster with a scoop on the side may give better results.

[Boxtaboy]

Originally Posted by sd_boxster

Since a bunch of you have desnorked Boxsters that have the cup - has anyone ever found it full of debris? Seems like a question that bears asking...

I've had my snork out for a year, and no extra debris in the air filter with the snork out. There's always some dust and small leaf remnants in there regardless of whether the snork is in or out.

[SoCalKen]

2 things that come to mind,
1: How long does it take for the computer to recalibrate to the new flow? could this affect a "before and after" dyno if done right away? The reaon I ask this is I have read about some modifications that raise the MPG but after about a week of driving the computer remaps and the MPG then below the original MPG.
2: Is it possible that the space behind the grill and the leading ege of the snorkel is big enough to slow the velocity of the flow just enough to allow some debris (water?) with weight to fall into the tray rather than a constant high velocity flow going straight into the filter.
Hmmm, makes ya wonder,
Ken

[t2-bxtrs]

well i guess after much debate and everything else.... it is what, what it is .. gain or no gain.. it's just more sound (noise) !
so to each his own... if you're happy with it (do it at your own risk) if not ... so be it!