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

[Bisimoto]

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



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:



Left over "organ":




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.

[Bisimoto]

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.

[Bisimoto]

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.

[blue2000s]

Originally Posted by Bisimoto

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.

[porsche986spyder]

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.

[Stefan (Boston)]

Thanks for the great info. For most of us, it's not worth the cost of the dyno run. But it's good to know.

Did you alternate snork, no snork, snork, no snork, etc.? The reason I ask is that the DME does some weird ignition advancement/retardation compensation when it senses a change in air flow. I know that if I unplug my MAF, I get a noticeable increase in power.

Would you be willing to try the same thing with the stock air filter versus K&N?

[Bavarian Motorist]

Originally Posted by Stefan (Boston)

Thanks for the great info. For most of us, it's not worth the cost of the dyno run. But it's good to know.

Did you alternate snork, no snork, snork, no snork, etc.? The reason I ask is that the DME does some weird ignition advancement/retardation compensation when it senses a change in air flow. I know that if I unplug my MAF, I get a noticeable increase in power.

Would you be willing to try the same thing with the stock air filter versus K&N?

Huh...


That's interesting. I was wondering about that.

Will remove mine tomorrow, btw

[Bisimoto]

Originally Posted by Stefan (Boston)

Would you be willing to try the same thing with the stock air filter versus K&N?

Yes. My race team is sponsored by K&N. In the next couple of weeks, I will order a K&N filter from the factory for the S and post results as well.

Ed, I am willing and able to test the exhaust systems. I have also ordered a Porsche System Tester 2 to assist with my diagnosis during testing. Thanks for the kind words, and I will keep all informed of my data aquisition.