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

[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.

[Bisimoto]

Originally Posted by blue2000s

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.

[blue2000s]

Originally Posted by Bisimoto

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.

[Cloudsurfer]

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

[Bisimoto]

Originally Posted by blue2000s

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

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.