Finally: Dyno charts of de-snorked 986S!!!
 

Greetings all,
I recently purchased my 2001 Boxster S (last week Wednesday), and could not wait to start playing around with it on my dynamometer. 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.

Since I own my own Dynapack Chassis dynamometer, and noticed some confusion in this board (yes, I have lurked for a while) in regard to if de-snorking produces any other benefit above an enhance intake roar, I took it upon my self to perform the following test. Each run was repeated to ensure credibility.

My bone stock S: red line
De-snorked (15 minuets later): violet line

http://i4.photobucket.com/albums/y14...norked986S.jpg

A 5 WHP GAIN!!!! In addition, almost 3 ft/lbs of torque

Finally some proof, and feel free to share this with our peer members. This is the most cost effective gain I have seen in a while!

On the dyno:

http://i4.photobucket.com/albums/y14...o/DSC01278.jpg

Left over "organ":

http://i4.photobucket.com/albums/y14...o/DSC01282.jpg


No tyre interface to introduce, variables like other cheaper intertia dynos. More data to come, as I try some interesting technology on the S...

You lucky son of a gun, how much did that dyno cost you? I presume thousands...
Im glad you did the dyno's, all you need to do now is test some other stuff like a cold air intake, or exhaust.

The unit set me back $61K, but worth every penny: more accurate and safer than inertial roller dynos. Since K&N is helping my race program this year, I will have to get a filter for the Boxster and test that too.

I design my own headers and exhaust systems for my race cars and many inline 4 vehicles, and will soon embark on making some for my S. When I spent some time studying the undercarriage earlier today, I noticed that the factory exhaust system is in dire need of some improved breathing! More ponies to come!!

Thats a lot of money. But if you design your own exhaust systems and headers, Id suggest making short equal length headers and gradually make your way to the longer "racing" style headers. That way we can see if there is a linear form to flow vs backpressure needs and where the optimal points are.

You are amazing, Jonathan. There is so much power in header tuning, it is mind boggling. I have data on your suggestion, and found out that high performance engines hate back pressure, but require fuel and ignition optimization for improved efficiency and power: the main reasons my simply reducing BP sometime results in power loss. I look forward doing some primary length tests on each bank using a true "burns-style" merge collector.

There's also the scavaging effects of the right length of pipe.

It'll be fun to see what you learn while playing with the car and the dyno.

Very true, Blue. You can also enhance that with pipe ID steps, and preventing reversion at the flange helps a bunch as well. Despite what I see in the market for the boxsters, a long primary tube may prove to be a best bet due to the relatively low peak power RPM of the boxster engine. Most units I design for 9800+ rpm engines have primary lengths that hover in the 20 inch range.

Do you do any modeling with software tools? Wave, GT-Power? You can get close to optimal much faster with some well designed models.

Bisimoto-

Welcome to the board and thank you. I think alot of us have been waiting for a true engineer and enthusiast to come along and do a few things right. Theres no doubt that the factory 3.2 is a somewhat detuned motor to keep the Porsche pecking order intact at the dealership, but it would seem that the key to coaxing more power out of the 3.2 lies in DME tuning, not just bolt on bits to help the motor breathe better.

I am very interested in finding the right headers (preferably with integral high flow (200 cell ideally) cats and 2nd cat deletes. On a motor of this expense, I'm not sure I trust running any of the higher flow filters or intakes due to the increased amount of grit that gets by, by figure a de-snorked stock intake. Now if someone can make a fantastic map to flash into the DME to take advantage of this and 93 octane fuel (or better) I think that would be a real winner.

Good luck to you and keep us posted.

Patrick

I just looked on caymanclub.com for desnorking.

I'm still not sure what it is. All I got is that there is an extra air restriction on the car somewhere.


Can anyone explain what it is briefly?

Never mind, guys. I found an amazing guide here.


http://www.caymanclub.net/reviews/showproduct.php?product=28&cat=4




This guy has a Boxster S 987 so this applies directly to us.


I will not even bother putting a wire mesh because I don't smoke and no one who drives my car will smoke.



Thank you, Bisimoto, for bringing this great idea to my attention, and most of all, thanks for proving that it is worth it :)

This would have been good to know before I installed my TrueFlow. I could have done them together at the same time. Is there a how-to section in here showing how to do it yourself. The one this last guy posted doesn't even actually de-snorkle, it just shows how to remove the retaining ring around the snorkle and then they put it back together with a mesh overlay. :cheers:

The mesh will also help keep "leaves" out and other stuff that flies up from the road like other peoples cigaret buds. :cheers:

He accually removed a restrictor plate thats in front of the intake.

Not worth the 2 dollars to me!!!


Just kidding.

Now where are all the critical comments from forum members who have said emphatically that desnorkeling will not increase HP at all and it's all about making the intake a little louder?

Lurking now, aren't you?

Oh yes, that too. But left the snorkle on the 987.

Now I am confused. So there is a snorkel somewhere also? Do you know where it is?

When people always referred to "de-snorkle" I thought they were talking about the intake tube that contains the little extra noise/silencer box that sticks out from the tube just before the throtle body. I had no idea there was another "snorkle" shaped device in front of the air box, that one could remove fronm the outside. I think many others were thinking of the C.A.I. tubbing also. I'm deffinately going to remove this "snorkle" part now. :cheers:

How come the 986 doesn't have this restrictor plate in front of it to begin with and the 987 does?

If you are referring to that guide I posted, the author said that Porsche added it for the 987 because of the cigarette incident...

You can see it in that list you posted. The guy did not remove it for some reason. He only removed the restrictor plate and retaining ring. Not sure why he stopped there. Look at the part sitting next to the dyno in the picture below in the original post. That's the SNORKLE part. It's just shown sitting straight up instead of the way you would normally see it inside the vent area. Hope this helps. :cheers:

Thanks. My final noob question on this matter (hopefully) is can it be removed from the vent or only from the engine?


:)

That's funny, because I heard that was the reason for the CUP shaped part. :cheers:

I wonder if the shape of the snorkle tube being a long smooth part leading up to the intake had some type of airflow/aerodynamics pupose. Therefore it would have been better to test it on the dyno with a fan blowing on the intake vent to simulate the car moving forward, since it was sitting still when you did the before and after test. Just a thought to consider for future testing. :cheers:

From what I've heard it can be done from the outside on both 987 & 986 models. Still wish someone would direct me to the how-to post on removing the SNORKLE part. I know someone recenlty just yanked on it and it came right out after some effort. But I want to make sure I don't break anything, so I'm not recomending that way. :cheers:

No, I do not blue, since the software is only as good as the engineers who designed it. In addition, my experience dictates that most exhaust modifications defy logic and the dyno is a key component to finding hidden power.

Many premier race teams use their own software, as well. I have many algorithms in my arsenal that I keep top secret, and those equations will point me in the right direction and allow me to get to my goal fairly quickly. If the is a market for such advanced headers for the Boxster, I may even pursue it. Only time will tell.

This board is great! Thanks for the kind words, and warm welcome everyone.

http://www.ppbb.com/boards/ppbbphp/showflat.php?Cat=&Board=ARCHIVES&Number=820409&For um=ARCHIVES&Words=10min&Match=Entire



Here is a good guide on how to remove the snorkel.



So removing this little thing will really make that much of a difference. Nice.



EDIT: For you, porsche986spyder :cheers:

I did use a fan in 2 areas: the front for the heat exhanger/radiator, and the rear driver's side vent, but only to provide cool air. A single cylinder in our P-car engines demands air at 2000RPMs that none of my industrial grade fans can generate. As a matter of fact, a NACA duct (superior to our Porsche side vents) is only efficient as a ram at above 200mph.

2 weeks ago i performed a test using a fully radiused intake pipe on single cylinder induction tubes, and gained 12whp on a 320whp engine. Infusing such technology in our induction may prove benefitial, but the factory ram tube, incorporated with the "deflection cup" is a restriction, and hence, the power gains seen in the upper RPM range.

Thanks for the suggestion...great minds think alike!

Thanks man! :D

I know the engineers who designed it. Ricardo knows what they're doing and GT suite is an off-shoot of them. It's an open ended code so you need to input alot of parameters to get an accurate model.

Wow! Thant's amazing. Thanks for all the info. Sounds like you know what your doing for sure. Please keep us posted with any more dyno test you do with other mods. :D

Ram air vent ducts???
 

So what is your opinion of these "Ram" air vent ducts? I've seen 2 designs and was thinking of buying them before I de-snorkle my car. Any thoughts as to if these would realy work/help any more?
http://i5.photobucket.com/albums/y15...eFlash/381.jpg
http://i5.photobucket.com/albums/y15...eFlash/405.jpg

This is much appreciated Bisimoto! I hope you can get us a few mod dynos in the future as well. :cheers:

I am going to do this on the week end and remove both the restrictor plate and snorkel.


I'll report back w/ some test results.

Hi,

Just caught this thread - see: http://www.pca.org/tech/tech_qa_question.asp?id={5628EC8F-3626-40D2-8AE0-E9F524E0718F} . I'm still not totally convinced, I think there's an error in the methodology. That's an approx. 6 CHP gain, and I'm just not convinced this part robs 6 HP. I can hold a thermometer in my hand and watch the Mercury rise, that doesn't mean I've made the room any warmer, or conversely, that I have cooled the room when I release the thermometer. There's no reason for Porsche to do it...

Happy Motoring!... Jim'99

I'm not sure if the thermometer analogy conceptually applies here.

Bisimoto!!

Welcome to the board! You are definitely the kind of Boxster guy we need on here.

I would love to drop by your place and test my engine. There are some great roads through the hills in Hacienda hts. I have transplanted a 3.4l 996 carrera engine in my car. I have revo software, the K&N intake and a somewhat screwed up set of headers, 200 cell cats and muffler from a shop in Maryland that was supposed to be designed for the swap. Alas, the exhaust system sounds really great, but there are fitment issues with suspension. I would love to see what you come up with for the 3.2 engine exhaust wise. The 3.4 and 3.2 are (almost) the same engine.

If you need/want a guinea pig for exhaust system work, I would be happy to volunteer!!

BTW nice work on the desnorkleing. I did this a long time ago, and decided it was worth it just for the sound. Glad to see it does add a bit of torque.

Monte

I agree. I look at the dyno results. I think it speaks for itself. By the way the link the other guy posted by PCA says he thinks by doing this we are removing the cooler air from the outside!?! Makes no sence, all we are doing is removing something that is restricting the air flow, not REMOVING the air flow all together, nor are we re-directing it from some place else, like from the inside of the engine. It will still pull the air from the outside! Look how close the opening is to the vents. :cheers:

Hi,

Dyno results can be funny and not always verifiable or repeatable. The Lister must admit this if he's the kind of engineer, he seems to be.

So many variables must be exactly the same on each run for any results to be meaningful, especially since you're claiming a very small % gain of overall power (1.9%). Some, but not all include: Ambient Temp, Barometric pressure, Fuel flow, Octane, Alternator Output, each line of code in the DME operating w/o fault on each run, Engine Temp, Tranny Temp, Bearing Temp, and on and on.

For example, an Alternator (whose power draw is variable and not constant) alone can draw as much as 4-30 crank HP because of the inefficiencies in a Belt & Pulley system, so if it was filling demand on the 1st run, but not the 2nd, this alone could account for the variance seen.

The best method is to do multiple runs exactly duplicating the conditions of all previous runs and then averaging the results. Then, you reverse it, put the snorkel back on and see if you consistently achieve the previous Baseline numbers over an average of multiple runs. If these results aren't duplicated to within a pretty narrow degree, there is some variable not being accounted for.

Just because you get a graph from a single run which supports your theory, isn't in, and of, itself proof of anything...

Happy Motoring!... Jim'99