Thanks for the video Michael. Interesting that the Max Flow mufflers actually make a little more HP than the Super Cup ones! I've already got those same Fabspeed headers with 200 cell catalysts, so if I get the itch for more power, replacing my CircuitWerks mid pipes and stock muffler would be the next step.

Nice work Ike. Your idea is similar to how Porsche runs their GT4 Cayman race cars... dual intakes running to the rear window vents.

Only potential downside of your design is the intake temps. Have you read the temps in the trunk during normal operation?

Solid work!

Thanks for the props!

The intake temps are an issue with the rad expansion tank in there. Here's a chart from this morning. Ambient temp was 78deg. These measurements are from the OEM IAT sensor. You can see a pretty quick climb, this was start to finish on a 13 min drive. I should have charted water temps too but they never exceeded 185. More work to be done! Maybe I'll go ahead and install the water air intercoolers now lol.

Another subjective thing I can say about the performance difference is how freely the engine revs now in neutral. My very first reaction after I pushed my tune was shock over the difference there.

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Can you help me know where you found your larger throttle body? I can’t find the correct one and don’t have a part number to reference. I have the ipd plenum but can’t find the cable throttle body needed to bolt up to it. :D

I'll add my 2 cents here. I have a 2001 Boxster S with a Fabspeed catback exhaust and a "mystery" tune that came with the car when I bought it 8 years ago. I only know it was tuned because the local Porsche dealer said it was not factory. I bought the intake kit from ESC (IDP plenum, 74mm TB and hose) and "though" I felt more midrange punch. Granted, the throttle response feels sharper but numbers don't lie. According to the dyno, I lost a few hp and lb-ft. A gigantic waste of money it seems.

NECRO thread, but i'll take a shot.

all the info is in the provided dynos, but i do not think they have been interpreted properly.

first of all, there are three passes - stock, exhaust, exhaust+intake. both exhaust and exhaust+intake improve over stock throughout the curve.

exhaust+intake also has higher peak torque and HP over just exhaust (ie at higher rpm) however exhaust looks to have much more midrange over exhaust+intake. they say it's not the peak power that matters but rather total area under the curve. but that depends on how you drive - keep it over 5k rpms and exhaust+intake is outperforming everything else.

further, exhaust was performed with a tune while stock and exhaust+intake were not. this becomes very obvious when looking at the afr curves at the bottom of the dyno - exhaust runs leaner and for longer compared to either stock or exhaust+intake. ie, the tune looks to run an afr of 12.5 vs 12 when the ecu transitions to open loop. apply the same tune to stock and exhaust+intake and i think you will see exhaust loose the midrange advantage. until then it's an apples to oranges comparison.

is the 987 plenum 3D printed yet?

There is some great info and discussion in this long running thread.
From everything I have read here, elsewhere and my own findings I conclude the following.
On the intake side the biggest restriction is the standard airbox which has a tortuous and choked path for the airflow.
Replace with a 987 airbox or some other sealed system and that should help.
As for a larger throttle body and plenum, all I have read does not lead me to believe these are of any benefit and indeed seem to result in a power loss low down in the rev range.
Why is this? Well my thoughts are as follows.
From what I understand the electronic throttle body works by receiving a single from the DME that dictates how much it needs to open based on throttle position, load, engine speed etc.
If you have a larger throttle body then it just opens less (once it has calibrated it self).
As the throttle body is a larger diameter then although the air mass flow is the same as the standard smaller one the air velocity slows down which results in reduced cylinder fill at lower revs hence lower torque/power.
I know the intake neck after the plenum is unchanged so the air velocity in theory could return to normal but it won’t as it has decelerated too much to be clawed back in time.
When the revs climb the air velocity increases sufficiently to overcome this deficit and full cylinder fill is again achieved and possibly a small hp gain at very high revs.
Just my thoughts.

Nitro, I think you may be right, but…
I know a tech very close to one of the major engine rebuilding firms.
He has an early 4.0 rebuild in a 996. I’ve ridden in the car and it runs pretty well. He says he has modified nothing. No tune (or bigger intake AFAIK.)
It would seem the ECM is able to adapt pretty well.