maf and throttle body diameter

[The Radium King]

it's the 987/cayman that has the long-neck plenum. the 997 is shown in the link to pedro's site below and is quite stubby. i think the 987/cayman have the long neck to distance the throttle body from the resonance flapper on the plenum, there to add more low rpm torque similar to the resonance tube on our cars. the problem with this is that that flapper is an obstacle to airflow at high rpm/airflow situations. it also must mess with the vacuum available, as the 987/cayman aos has two connections at the plenum.

[jaykay]

Yes you are right...I started to think out loud without checking first

This looks like a viable option to try!

[The Radium King]

it's kinda exciting; if we can get 10 hp for under $200 it becomes the best bank-for-buck mod currently available. twice as much hp as the under-drive pulley for the same price, almost as much hp as a $1000 tune or $2000 exhaust setup.

[jaykay]

I didn't know that there was a Carrera S throttle body at 76 mm and dedicated plenum. Thought there was just a 74mm and then the 82mm GT3 which would be too big I think.

Which one did the Planet 9 fellow use? 76 shouldn't hurt?? I think reducers are easy but a nice pipe from the tb to MAF may be trickier

It is very exciting!!! I was just going to put 996 stuff in there as a trial.

[Johnny Danger]

King,

Seriously, what is the likelihood that you will actually make one ? I'm on the fence about spending $1000 plus on the IPD set-up, and I would very much like to see if your design works. If, so, I'll be your first customer .

[The Radium King]

it's already been done by j.fro (see his posts earlier in the thread) i'm only fine-tuning his work by stating that the 997 plenum is a bit more advanced than the 996 (but interchangeable) and should produce better airflow, and that the pedro splitter is not required (hence lowering the price). and located some dynos to justify the work.

for me, the cayman throttle body is on it's way.

on my next parts order i'll get the 997 plenum (997 110 416 03; auto atlanta online parts diagrams are your friend when it comes to comparing parts and part numbers) and throttle body bolts. once they arrive i'll confirm diameters of the reducers and hose clamps required.

from what was posted by j.fro, and what is shown on the pedro board, the aos vent line appears to use different connectors so i'll have to confirm diameter and get some tubing for that.

i'll probably use some cheap 3" flexible duct to the maf housing until i get my new intake happening.

once everything is done i can post a list of parts required and my impressions of the end result (no dyno or anything). i'm slow, and shipping takes forever to my neck of the woods, so no results anytime soon ...

[jaykay]

Yes I am with you ....plus it's cold up here!

The driving season and mod season are co-incident

Yes I saw his post after mine. I had assumed that my 997 plenum suggestion wouldn't fit as he had gone 996

It looks like it has nice radii as you pointed out. Let us know about the diameters when you get the 997. The hardest part will getting the right silicon parts to fit nicely and look like factory quality

[Johnny Danger]

No worries King, the Dangermobile has been put away for the season as well. But, as Spring draws near, I'd love to be able to implement your design .