I am considering getting a plenum for one or both of my P-cars. Have a 09'C2S with some mods and a new 11'CTT with a sharkwerks bypass pipes on the way. I want to put the plenum on one of the cars and if I really like it will put it on the other car. For the CTT its $200 cheaper and very easy to install, whereas the 911 will be costly for installation.

Which car should I do first?

Which car will I feel more of a difference?

 

I didn't notice much of anything on my 04 CTT. It did help with the annoying hesitation with small throttle tip-in inputs, but that's about it. Didn't notice anything at the dragstrip.

 

Thanks for your feedback. Wow drag racing a cayenne. You think their is any differnce putting a plenum on a NA engine compared to a TT engine?

 

I don't know.

 

one less part to break...

 

Look at the factory design... on the 996/997 motors the plenum is a T-shape which is pretty poor for airflow, this is why the IPD plenum makes more sense on that motor. For the Cayenne V8 motors, the stock plenum is already Y-shaped which means the IPD one is not as much of an improvement. FYI

 

Just to add another FYI...

http://www.egmcartech.com/2009/10/10...cayenne-turbo/

 

The M64 block is probably the single most developed engine in Porsche's flat-6 repertoire. The plenum in those cars work by equalizing flow between both banks. As the engine runs the "on/off" status of the valves across each bank create pulses and slows flow. A T shape plenum system allows slowed air traveling from the bank that is closed to travel to be redirected to the other side. A Y shaped plenum does not allow this to happen as flow is directed to only one side.

At low RPMs, this pulse effect is much greater. At higher RPMs, the flow redirection is not as significant as the duration of the banks closing is much shorter.

Here is a close up of a GT3 cup car. It absorbs pulses from either side, without using a soft Y curve in its design.



Testing of larger bore T shaped plenums have shown similar gains when matched with an appropriate throttle body.


This is my understanding of how the airflow is directed in a flat 6 engine. If there is someone with contrary facts, please correct me.

 

bbywu:

What are your thoughts with these (IPD) on 997.1TT along with a GT3 throttle body and a Werks 1 Carbon Y Pipe?

I have been considering doing this with new IC's as my next upgrade to my 565HP/550TQ in conjunction a new flash to bump up to the 650HP package. I'm looking to remove a bit of the Turbo lag. Currently running Tubi race exhaust.

Thanks

 

Not a lot of experience with CMS products. Do they have a dyno with your setup? I guess the only way to show lag reduction is to map throttle and boost.