Cold Air Induction Box

CorkSport is proud to announce that we are expanding our Cold Air Induction Box product line to include an Air Box for the COBB SF Intake system as well as our current development of cold air boxes for the 2010 Mazdaspeed3 and 2010 Mazda3.

In our testing of this product we wanted to define:

  • Where the cold and hot air fronts exist in the engine compartment and what differential can be expected between these areas.
  • Where high and low pressure areas exist which direct requirements for sealing off areas to ensure the coldest air temperatures into the filter.

To achieve these results, we determined that extensive pressure drop testing under dynamic conditions was not possible while delivering a box that retails under $100. A well planned design of experiment which measured temperatures in the engine compartment, airbox and surrounding areas would give us not only the hard numbers we needed to show results, but also some intuition as to where the various pressure zones exist and how that effects movement of hot and cold air in the vicinity of the filter. What we found is that the various pressure zones in the engine compartment can create barriers preventing the intake from drawing hot air.

Our testing utilized a MSD DashHawk OBD2 Datalogging system and an Innovate TC-4 Four Channel Thermocouple Logger to measure Inlet Air Temperatures, Boost Air Temperatures, Ambient Air Temperature and two channels of thermocouple inside the box and directly outside the box in the hot engine compartment. The ambient air temperature on this day was about 64F. Earlier in the day we tested the short ram intake without our box and found intake air temps were 2-8 degrees lower than the engine compartment temperature.

Testing these variables on our cold air box design we saw a huge benefit – over 30 degree difference between the engine compartment and the interior of the box. By time of this testing, the engine compartment had a chance to heat soak and the hot air in the engine compartment 10-15 degrees higher. Despite this increase in temperature, our average temperature differential was now in the 25-28 degree range and inlet air temperatures were down 8-12 degrees dependent on volume of airflow past the sensor – obviously in traffic you’re going to get some level of heatsoak in the inlet system, MAF Housing, etc. – but that cools off quickly when 64 degree ambient air temperatures blast past at the rate of an office cubicle of volume per minute.

Some may ask, why is your box not enclosed or better sealed within the engine compartment? In the course of our testing seal off surfaces, we found areas – such as the gap under the box – are either a source of cool air or have a pressure effect that prevents hot air from entering into them. Some of these, such as the seams on the box, were beneficial to seal off, some provide relatively cool air, but others were completely inconclusive. Bottom line, there are a number of areas which may appear to allow hot air into the box, but testing proved otherwise.

The end result is a series of boxes which use a overhanging lid with seal strip along the mating surface, silicone seal at the filter port and contoured front edges which align with the headlight assembly. These systems promote filter temperatures roughly equivalent to ambient air temperature and 8-12 degree inlet air temperatures drops compared to similar intake systems without the box. Note: As we did not test at all possible outside air temperatures, extremely hot or extremely cold ambient temperatures may show some variation from these results, but the effects should be minimal.

If you have any questions or suggestions of further tests or concerns you may have with the CorkSport Power Series Intake System or CorkSport Cold Air Induction Systems, feel free to post comments to this blog so we may update the details and content.


19 Replies to “Cold Air Induction Box”

  1. Looks like a nice product. A couple questions: Does the box reduce induction noise trasmitted into the cabin? Also, several people have broken the factory bracket under the battery that the COBB SF bracket attaches to ($55 +). This is due to the lack of a good flex point and is the Achilles’ heal of the COBB system. Any chance of a redesign that utilizes the factory airbox mounting points? Thanks!

  2. We will most likely be offering up a pair of lugs that will bolt into the bottom of the box and pick up those factory mount isolators for people who have broken brackets or simply want to help isolate their existing COBB intake and not tie a moving engine to the chassis through the intake bracket. No indication on when we’ll have that available but I’m going to knock a pair of them out on the lathe fairly soon. These will be an additional product and will not be included with the cold air box assembly as we’re doing our best to keep the price down across the board. For people who need and/or want this addition, those parts will be available separately.

  3. Hey great work! Not sure if you’re testing on an auto or stick, but I noticed that the auto’s have their cooler behind the lower left-side grill just above the fog light (I have the 5 door S with a manny). The manual has a dumby grill there instead. It is a chamber heavily isolated from the engine compartment, and could serve a cold-air intake well. I could send a picture if I’m not communicating the location well. One could easily order an Auto replacement grille and have a steady rush of cold air (unless it’s 103 like it was here in Temecula 42 days ago. Have fun.

  4. Yeah these are available now for the Speed3 and Speed6, neither of which have automatic transmissions, but thanks so much for the heads up on the Mazda3 trans cooler location. I’ll have to work on that to make sure that there is no induction of the heat off of that cooler into the cold air box or blocking of the cooler outlet by the air box. The Speed3 version is available for the CorkSport Short Ram Intake and the COBB Short Ram Intake.

  5. Yeah the location probably wouldn’t work as well with the auto unless the box was above the cooler. But for the manual tranny owners it might be great. I would just buy an oem auto side grill and let in the air. Stoked to see the SRI available now!

  6. Why don’t you fully close the box and then add another ram pipe all the way to the bumper / fender area to route cold air in there. Boet I’ve done all the testing I know! 50 different tests on a load dyno.

  7. i have just ordered one of your cold airboxes and I have read this thread and you did not answer a guys question on if they reduced induction noise and other noises. Can you let me know if I will still get the sound I am expecting with your new short ram air intake for my 06 mps 6 i really want that noise as it is non exsistant at the moment

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