Great vid. I was actually just about to share it when I saw this thread

Couple ideas for additional vids:

• We've had some discussions on here on if just simply blocking the Helmholz resonator in a base C2 Carrera would have any performance increase. Love to see if you guys can do a test on that. The conventional wisdom is: no it does not. Just sounds better. However, one caveat is the base C2 does not have a Helmolz actuator flap like the C2S does in Sport Mode. Its permanently open. I've wondered if the fact its always open creates some intake turbulence that robs some power.
• What effect does an aftermarket tune have on a 997.1.
• What effect does adding the factory Sport Mode module to a base C2 997 have on performance. You can install this for around $1k. The module is only $50 but you need to pay $895 for the software upgrade from Porsche to activate it and then the dealer needs to flash it.

Keep it up and excited to see more!!

 

No need to test sport versus normal on a dyno. Unless the dealer-added sport mode is drastically different than the factory-installed one, sport mode does not add horsepower or torque. Its primary function is to change the throttle mapping and shift points so the engine responds to the gas pedal differently, the exhaust sounds different and the transmission shifts more aggressively. It is not a re-tune and does nothing for engine output.

 

Great video! I was about to post it on here as well. I am going through the same process on my 997.1 and have bought a bunch of performance parts waiting to be installed.

Some thoughts

1. It would be really useful to see if the intake & IPD mods make a better difference with a custom software tune rather than just an ECU reset.
2. I wish you had used the Evolution Motorsports intake rather than the K&N, as that seems the most promising.
3. Really looking forward to the exhaust comparison. I'm hoping for Muffler only, then muffler & 200 cell, then muffler, 200 cell & headers.
4. I hope you will also do the full Intake & exhaust with engine tune for the grand finale.

Keep it up, we are watching!

 

Makes sense. Those open air intakes are notorious for heat soaking. The IPD/GT3 TB would only work when you open up the car more; delete the cats and add free flowing headers. Cost vs HP gain is not even worth it.

 

Just a thought here. The video reports a 15HP decrease after the K&N CAI is added to the IPD plenum + GT3 TB. OBD analysis showed that this was due to a drop in the AFR. The K&N CAI looks like it's the 57-7000 (can anyone confirm?). If so, that intake was actually designed for the 996 (1999-05), which means I doubt it would have been tested extensively on a 997, if at all. I could not find a 997 CAI on the K&N website.

So here's the issue - the MAF measures the linear velocity of the air passing through, not the actual volumetric flow rate. The MAF is "calibrated" against the stock intake cross-sectional area. If the K&N CAI's diameter at the MAF site happens to be larger than the stock pipe's diameter, this would cause the MAF to have an artificially LOW reading. (Does anyone know?) This would then explain why the video reported a drop in the air-to-fuel ratio, which was thought to retard the engine timing and reduce HP across the board.

 

Mass Air Flow sensor measures mass. Otherwise, at high altitudes, engine would be running rich. All things equal, more velocity results in more mass/sec passing through

 

Yep, that's why it's called a MAF (Mass Air Flow) Sensor. The 996 and 997 intake angle and geometry are identical so the K&N is fully compatible with a 997.1 NA car, but not a 987.2 - throttle body intake position and angle are different.

However, the K&N is probably the worst OD the CAI to test because of the very curvy intake piping. They should have run this with a Fabspeed J-pipe or Y-pipe or and evolution Motorsports one, all of which are better than the K&N. But the other issue is you can't reproduce actual airflow volume and temperature on a stationary car with fans blowing on it, so the air available for a stationary dyno test is always going to be hotter than the air available in a moving vehicle, especially a fast moving one which is where the less restrictive intake will have the largest benefit.

 

Right, but if you change the diameter or flow characteristics of the pipe that the MAF is mounted in, it can change some of the assumptions that the MAF is calculating against. This has been an issue with other 997 mods, which have required ECU reprogramming to compensate for the different MAF readings caused by a larger tube diameter. The K&N filter doesn't use the stock MAF location. I have no idea if it's the same diameter. I also wonder if there may be turbulence where the MAF is mounted in the K&N (since it's mounted very near where the pipe opens up into the cone filter.) Or maybe the MAF isn't an issue at all, but how then do we account for the drop in the AFR noted by the folks in the video?

This is also true. At the same time, I seem to remember that they recorded intake air temperature in the video. It also may be that the air temperature for the CAI trial was high enough to affect engine timing. I believe it was 39C = 102F.