Our second feature on the Porsche 997 C2 project car is live on our YouTube channel. I'd heard so many conflicting things about intake mods so thought id test some myself as accurately and scientifically as possible.

Who else has back to back tested intake mods and on which NA models? I know it will be different on each engine, so results are only valid for my exact engine model.

 

Really nice professional presentation, typical Aussie, no BS approach, I'm looking forward to the next installment!

 

Really excellent video! Well done! This is awesome. We need a lot more data like this. Something to balance all the heaps of BS from vendors..

Would be very interested to see something like this for 997.2

 

Great work there ,,good to see a non biased professional test ,,the data dose not lie , well done Andrew

 

Subscribed

 

I think the wisdom from the internet is that the cats are the biggest restriction - it will be interesting to see if they can prove this in the next installment

 

Brilliant!

 

That’s a great video! Thanks for putting that together. The IPD results were surprising.

I am really interested in an exhaust video. Would it be possible for you to compare center muffler replacements like Billy Boat versus a bypass type like Fabspeed? Maybe do a dyno run with and without a Gundo hack? Performance cats, too, of course. Ah, the possibilities are endless.

 

Great video, and it really confirmed what I have been thinking about not only with my 997, but most modern NA cars in general: there is very little untapped power in these cars.

Those were a little surprising to me as well. I was actually beginning to believe that if I were to do any performance mod, it would be the IPD plenum and GT3 throttle body. PCA did a video with TPC Racing recently which seemed to indicate that not only does the IPD plenum improve performance, but that it does it across the entire power band where it could be felt the most.

 

Great vid, guys. It was informative and fair. Looking forward to see the next test series to see if there’s any net improvement as a package when combined with a complete exhaust.

 

Great video and info, thanks for the research and effort! As a owner of a 997.1 with the 3.6 I have been considering these options myself. Just last night I decided if I change anything it will be for sound/pleasure only and not performance. You have just reinforced that!

Can't wait for the exhaust test.

 

I was also surprised by the results. I would love to see if any of these intake mods combined with exhaust mods. That would be a LONG dyno day

 

Great presentation. The hot air intake mod is proven !

 

it’s only proven on a dyno where the car is not moving. I have modified my deck lid to get within 9 degrees of ambient.

https://rennlist.com/forums/997-foru...-deck-lid.html

 

Interesting video. Some comments.

With each change they really should have reset the DME by disconnecting the battery for 10 minutes and then done those "warm-up" dyno runs. This might have resulted in different and more accurate results as it takes the DME longer to adapt to changes if not reset first, so these dyno runs were probably done without the DME fully adapting to each change. Typed this before watching the rest of the video and glad they finally decided to reset the DME.

I'm not surprised by the results of the K&N panel filter increasing horsepower. They flow more air and if the ECU can maintain the proper fuel trims for that increased air, you end up with more power. It's one of the reasons I run a filter like this in pretty much all my cars. Properly maintained without over oiling, they filter just fine and don't contaminate the MAF sensors.

I was initially a little surprised by the ipd plenum and GT throttle body. I wish they had tested the normal diameter plenum and not the larger one as going from a smaller inlet pipe to a larger inlet pipe actually reduces the air velocity, so although the larger opening can flow more air, the air is actually moving slower. This is why in my wife's car I installed just the standard 3.8L ipd plenum that works with the nromal S throttle body and didn't go larger.

The full K&N also isn't the best CAI to test. As you can see, the tube has a 90 degree bend in it and sitting on a dyno where it can't get fresh air in through the engine lid can skew the results. They should test an Evolution Motorsports intake that actually draws air through the openings in the decklid and has a much cleaner air path from the inlet to the throttle body, or a Fabspeed setup. Of those 3, I believe the K&N to be the worst. I do find it odd that the DME was over-richening the mixture when running the K&N intake. The computer should really be trying to keep the AFR at the same number and it shouldn't be ending up overly rich like it did on the dyno run. This may be from them not resettng the DME after the change so the car was still trying to adapt to the increased air flow and had over-richened the mixture initially to do that.

I'm interested to see the exhaust mods, but those by themselves probably won't show much. Once they add the intake mods back on with an higher flowing exhaust, I think that's when they'll see some decent numbers. After they do that I want to see the new dragstrip time more than the dyno results as the CAI will still get hampered by the car being stationary. Wish they'd also use the normal ipd plenum and not the larger one to keep the intake air velocity higher.

For anyone who hasn't seen the MAF number testing done by gasongasoff, he did a pretty scientific study using MAF and fuel trim numbers using the stock airbox vs a Fabspeed CAI and this one was done on a 997.2 - Rennlist thread - https://rennlist.com/forums/997-foru...surements.html