Here’s a data point for the the air chair mechanics watching you tube Dyno runs that show CAI sucking hot air.

87 degree IATs with 79 degree ambient temp

8 degrees off. That’s about as good as it gets.

The car has a fabspeed competition dual cone intake with x51 dual snorkel deck lid.

I also have a LTT and third radiator. Cruising coolant temps are 170-172 degrees and oil temps are 195-200

 

so this reading was while you were cruising at 75mph? interesting. I am going to try that out on mine too. thanks for posting.

 

Would love to see your results- what’s the set up?

 

What were the readings before the modifications?

 

Some one with a stock one and a foxwell could do a reading real easily. 75 mph. ~80 degree day. Cruising throttle.

if I went full throttle iats actually would drop 2 degrees as the increased volume had better cooling.

 

2009 C2S 158k miles

Cool Rob, good stuff.

I am going to give that a try with my Durametric on my .2 C2S. I am very curious how Porsche got it down with the .2.

I want to point out to all, that RTL installed the x51 dual snorkel deck lid, which is a similar intake to the .2 cars. Rob, do I have this correct?

Peace
Bruce in Philly

 

The standard intakes on 997.2s are dual snorkel. I cut a hole in my deck lid where an X-51 is stamped out (both plastic and metal) with an air saw and installed the X-51 specific snorkel so my decklid is essentially OEM 997.1 X-51, if and only if airsaws are considered OEM.

 

Good data point. On my Cayenne Turbo S with CAI and a bunch of other mods, I see an 8-10 degree ambient to intake temp difference when I look at it on my p3 vent gauge. My 997 is supercharged and the intake air temp sensor is after the air is compressed, which adds heat just because compressing air does, so that one, although it has a CAI on it, doesn't matter here. I should check my wife's 997 which has a Evoms intake on it to see how it compares, but I'd really like to see data points from those running the stock airbox and whether those MAFs read intake air temp very close to ambient air temp. I bet there's a little bit of heat soak in the airbox assembly where it's at least a couple degrees higher than ambient even with the stock airbox and filter setup. In a modified car that needs more air (like most of mine) the increased air flow and velocity possible from the CAI outweigh the slightly warmer and less dense intake air.

 

please let us know

 

You may have already seen it, but I did a similar test a few years back, by swapping between a fabspeed CAI and the stock airbox. I have an 997.2S. This is what I wrote at the time:

One thing to know is that I have consistently observed (and recorded) the Intake temp and Ambient temp under various conditions. Here's what I can share:
- The stock airbox is not a 100% cold air intake (there are mesh panels that draw in engine air), but it does seem to draw in more ambient air than the Fabspeed (obviously).
- The "delta" temp (Intake temp minus Ambient temp) appears to be greater on the Fabspeed.
- At freeway speeds (65+MPH), the Fabspeed and Stock intake delta temps are basically equivalent (about 3-5*F).
- At lower speeds, the Fabspeed deltas are typically between +20-30*F, whereas the Stock deltas are more 10-15*F.

My measurements are in line with what has been reported here.

Original thread here:
https://rennlist.com/forums/997-foru...rements-2.html

 

I would bet money as soon as you hit the gas at low speeds IATs would come down and come in line with each other.

 

Cool data.

I'd like to see temp differences when running hard, specifically track speeds. And dyno sheets. All real life dyno I've seen, show the Fabspeed is mainly noise; which is fine! But I'd like power for the money. And to me, if temps are essentially the same, and power is essentially the same, I wouldn't feel justified in buying the "CAI"

Cw

 

Power comes from g/s density- More air more power. And the fabspeed has been proven to show higher g/s than stock.

 

So I live just outside of Los Angeles and it has been 100+ degrees everyday for a couple of weeks. Today in my area it is 100 degrees ambient temp exactly. I have the Evoms V-Flow intake. Not exactly the tightest air seal against the deck lid, but good enough.

Cruising at 75 mph on freeway that ambient temp was 100 degrees vs the intake temp range of 106-108 degrees. Engine compartment was another 8-10 degrees hotter ranging from 114-117 degrees. The engine compartment got up to 117-120 degrees after a few strong and repeated pulls to redline. Intake temp remained around 108 while engine compartment was 117-120 degrees.
Over all I am VERY happy with that.

For comparison I immediately took my 987 Cayman S out to do the same test and my Cayman has the Stock fully enclosed airbox. The results were almost identical with the Cayman even though it actually got a little hotter intake temps at 110 degrees at times vs engine compartment of 114.

At a stop light and idling, both the Evoms intake and the Completely stock fully enclosed Cayman S intake temps almost matched the engine compartment temps. Once the car got up to speed with good airflow the intake temps dropped dramatically.

This goes to show how important airflow is with either stock or CAI kits. This is also what bothers me about some of the bashing on CAI kits when on dynos. Most CAI Kit dyno videos I see have no high velocity cooling fans blowing directly into the engine and air intake as normal airflow would do when cruising at speed.

From my observation I saw no difference between a fully enclosed intake setup and CAI kit when cruising at speed or at a stop light.

One thing a lot of people do not mention is that the stock airbox will still be exactly the same temperature as the engine that surrounds it. That airbox will be 120 degrees if the engine compartment is 120 degrees, The outside air will still have to travel 3-4 feet throughout that hot 120 degree plastic airbox and then into the hot engine intake manifolds regardless how well it is sealed off from engine compartment air. Those 3-4 feet are still enough to increase air temps from ambient by the time it hits the cylinder walls and ignites. Just something to keep in mind.

 

Awesome so similar results! 8 degree delta! When the car is sitting still there isn’t enough volume for the intake tract to not heat soak so all intakes will have high iats then.