Cold Air Intake Sound

[cdd]

Originally Posted by Mean Green

Most definitely makes a difference. I have seen the difference on the dyno. A 2-3 hp gain and double digit losses in torque. Here's some info. ISUPAGE; Performance Intake System Basics This second article has to do with a supercharger and a hot air intake, but pretty much the same difference. http://www.kennebell.net/techinfo/ge...AirWARNING.pdf
The stock airbox system is good until around 400 hp. Everybody has to make their own choice. Your system would probably be even better if you weren't sucking in hot engine air.

Clip from 1 of the articles;
It is, of course, your decision if you choose for your engine to suck in this hot underhood air with one of these over the counter or "custom" kits.
However, these things are not good for our superchargers and we not only don't recommend them, we are warning against the use of them. Look at
the facts. 10° of hotter air is equivalent to 1 psi of boost. That means the difference between the fenderwell ambient 70° system and the hot underhood
air temp can be an amazing 130° (200°-70°=130°) hotter. That 130° equates to about 13 psi of additional boost (13x10°=130°). So, you thought your
engine was only seeing the increased temperature of 100° from 10 psi boost (10x10°=100°).Wrong. It's 100°+130° or 230° plus the ambient. That's
the air temp of 23 psi boost! Surprised?Are you getting the picture yet?

Wow, 200* going into my intake. Maybe on a dyno under full boost with the hood closed and no fan in the front of the car. Never seen that on my car. I have a gauge the shows what the AIT(air intake temp) sensor sees sitting right in front of my face and the temp has never got that high or anywhere near that. Unless I am under boost the AIT sensor is no more the 14* above outside temp. On a turbo I would think that the compressor blades themselves (that this intake air flows through) would heat up the intake air from just the heat transfer through the turbo shaft even though we have 180* water/oil cooled bearings. Anybody ever took a thermal image or used an infrared thermometer to see the temp of the compressor blades? I don't believe everything I read without some proof. I have a Diablo that will data log sensors and tomorrow when it is mid 70* here in FL I will log at different speeds and also sitting still to see how long it takes for the temp to rise. I would try the same with the stock air box but don't have one so maybe someone else can do that.

[ChefTank]

to add my $.02.....


every cubic inch you add to airfuel volume you increase 10hp... this is a true and understood fact in the automotive industry (if not why bore anything?). my short ram (not hot air) is 3" and the factory system is 2.5" and necks to 1.78" at the end of the box. using rough math i can drive my car with my short ram and get the same whp# in 130 degree weather that the stock system gets at 30 degree weather.

why not? you said 10 degree's = 1hp




josh

[cdd]

Well, got home from work and took the car out. The current outside temp had dropped down to mid 60* so I am sure summer temps will increase under hood temp but this is the best I can do now. Cruising at 63mph, 2370rpm, outside temp 63.79*, ACT 77.19*. I pulled over into a parking lot and the ACT had got to 87*. I sat there idle for 5 minutes and the fan had cycled twice during that time and the ACT now showed 97*. For the next 5 minutes the fan ran continuously and the ACT got up to 111*. I then left the parking lot and within 1 minute the ACT temp was back down to 87*. I did not measure under hood temps but I would think it would be at least in the 180* range. The intercooler is absorbing the heat. Conclusion: Large fmi or w/i will do more for you than a cold air intake will.