MYTH BUSTERS - Air Intake Temps
NEWS
 

  1. Welcome to Kia Optima Forum General discussion forum for Kia Optima

    Welcome to Kia Optima Forum - a website dedicated to all things Kia Optima.

    You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, Join Kia Optima Forum today!
     
+ Reply to Thread
Page 1 of 4 123 ... LastLast
Results 1 to 10 of 34

Thread: MYTH BUSTERS - Air Intake Temps

  1. #1
    Learner's Permit
    Join Date
    Dec 2011
    Posts
    196

    MYTH BUSTERS - Air Intake Temps

    Ok, so I wanted to get to the bottom of the CAI/Short Pipe Intake/Factory Box debate on intake air temps. In short, I wanted to know if I would be sucking in hot air with the Injen Intake set up since it pulls air in around the eng compartment and is not a true CAI. While I appreciate it alleviates some flow restriction, I did not want to offset that improvement by sucking in air if the air was significantly hotter than through the OEM snorkel or some other CAI method. While I don’t know what gains are to be had by the reduction of flow restrictions offered by the Injen set-up, I struggle to believe it is on the order of 15HP. Dyno readings on turbo/IC engines will be all over the map depending on whether the hood was open, heat soak was in play, what carpet blower they used to cool the IC and radiator, etc. Until formal charts are released with the conditions noted, we can only speculate.

    Also in question is how much the IC will pull heat out. The amount of heat any given IC removes is a function of its soaked temp, the delta T between itself and the air flowing over it, and the flow speed. The hotter the air blowing through it is, in comparison to the outside air, the faster is can remove it. What is for certain is that an IC can only remove a portion of the heat coming in, and if you put hotter air in it hotter air will come out. An IC will not output air at a constant temp while you vary the input temp. In short, hotter air in means hotter air out, though it’s not a one to one relationship. Thus, you want the coldest air coming in your air filter.
    This study does not track air temp coming out of the IC, although it could be measured directly or with a Torque app. The reason I didn’t, or haven’t yet, is because the intake air temp does not react quickly due to the IC’s thermal capacitance and heat soak effects. It is much harder to compare effects of changes by tracking the air temp coming out of the IC unless you control lots of conditions such as idle time, time driving at X speed, the IC’s steady state temp, etc. In fact, I have seen the intake temp coming out of the IC take several minutes to cool down driving at 50 mph+ after idling only minute. For this reason, and knowing the hotter air coming in leads to hotter air coming out, I chose this first study to focus on air coming in.
    The set up for baseline measurements is shown here, where I have a TC in the snorkel intake, one outside the air box (motor compartment ambient air), one inside the air box behind the air filter, and another outside the passenger window to take ambient temps. Data was logged with a 4 channel data acquisition unit sampling at 10 Hz.
    MYTH BUSTERS - Air Intake Temps-imag0095.jpg




    In the second test, I removed the snorkel to simulate what the air being pulled in the filter would be if it were the Injen set-up. The TC used in the first test to measure the snorkel temp was now used as a second measurement of eng compartment temp. Here’s the two results graphed. The results are alarming to me.

    MYTH BUSTERS - Air Intake Temps-oem-air-temp-study.jpgMYTH BUSTERS - Air Intake Temps-instake-temp-study-no-snorkel.jpg

    In summary, snorkel does a great job of keeping the intake temps low. The average temp increase was 6 degrees for 25 minutes of mixed driving. Had I not idled so long in the beginning, it more realistically would be about 4 degrees.
    The open box test did not fare so well. The average air temp rose to 26 degrees, about 20-22 degrees higher than without the snorkel. If you sat at idle (as in before a race as a red light, for example), the intake air you get to start the race off with is 45 degrees higher than outside! It takes a minute of average driving to bring it down to pre-idle temps. You better believe you IC is soaked with heat now after pumping in air at idle that’s 45 degrees hotter than with a snorkel! If you drove on a the highway, flushing out all the engine heat with cooler air still leaves you sucking in air that is at best 10 degrees hotter and it takes about 5 minutes of this to get to this point. Even more interesting is that the intake air temp in the air box shoots UP at WOT. So the heat your IC is taking out of the charged air is ejected right back in to the air intake box. So the effect of flushing out the eng compartment with cool air is negated by the recirculation of heat back into the air box.

    If we use the standard estimate for HP change due to air temp change, Delta HP = HP *1(-sqrt(T1/T2)), where T1 is the original temp in Rankin, and T2 is the new temp in Rankin), then not considering the IC effects we are losing an average HP of 7 horsepower sucking in the hot air. This is average, not peak. We can speculate how much of the extra heat the IC would take out but two things are certain. One, it won’t take it all out and hardly any of it until you reach some kind of speed, and Two: Your IC will be soaked so hot during idle you’ll never recover from the lost power until to drive at speed for a while.
    I am sure many out there will reject this study, but I’d like to see someone refute it. My conclusion is a true CAI is in order for out turbo charged / IC engines, and in the real world the Injen intake or others like it do not likely offset the loss of power due to air temps with their improved flow characteristics. So I cannot recommend it, especially for several hundreds of dollars.
    Thanks, hope you enjoyed my Sat afternoon project!

  2. Remove Advertisements
    Optima Forums
    Advertisements
     

  3. #2
    Super Moderator NilVlrod's Avatar
    Join Date
    Apr 2011
    Location
    West Deer, PA
    Posts
    2,355
    Model
    2011 Optima SX
    wow, that was informative.
    Now I really want to build a front mount IC with the air intake going in front of the battery so it pulls in cold air. But I need pipe...

  4. #3
    Experience Norm1's Avatar
    Join Date
    Nov 2011
    Location
    Tacoma WA
    Posts
    713
    Good job.

    I've got no dog in the fight but wouldn't the snorkel bring in some cold air into the short pipe intake filter area?
    especially while not at idle.......


    2012 SWP/Beige EX, Tech/Premium, Spoiler, De/Rebadged, LED tails, 35% Tinted, 4,750K Low/High/Fogs, CHMSL Flasher, Sport Pedals, Catch Can, Mud Guards, 20mm RSB, Front Strut Bar, Custom LED DRLs, Cupholder LEDs, K&N Air Filter.

  5. #4
    Learner's Permit
    Join Date
    Dec 2011
    Posts
    196
    Quote Originally Posted by Norm1 View Post
    Good job.

    I've got no dog in the fight but wouldn't the snorkel bring in some cold air into the short pipe intake filter area?
    especially while not at idle.......
    At idle, none. While driving, it wouldn't take in more air than without but it would direct some to the vicinity of the conical filter. However, there's three things you have to realize. One, your mixing the air coming out of the snorkel with the entire eng compartment volume which dilutes it significantly. Secondly, the snorkel is not a ram air intake. It's gasket sealed all around it when the hood is closed and air is sucked into it, not pushed in, as one may think. If you don't believe me, check it out for yourself. See if you can find the entry path for the air into the snorkel.
    Third, I argue that pulling in so much heat while idling is perhaps the biggest issue of all, driving heat soak. We have an undersized IC, that much is obvious if you watch the boosted intake temp in Torque while farting around town.

  6. #5
    Learner's Permit
    Join Date
    Dec 2011
    Posts
    196
    Quote Originally Posted by NilVlrod View Post
    wow, that was informative.
    Now I really want to build a front mount IC with the air intake going in front of the battery so it pulls in cold air. But I need pipe...
    +1. That would be a sweet set up. Perhaps even move the battery to the trunk somewhere and really open things up.

  7. #6
    01/2012 ROTM securityguy's Avatar
    Join Date
    Jun 2011
    Location
    Northern Virginia
    Posts
    2,434
    Sorry Cad, but with all due respect, I did a test a month or so ago comparing the intake temps of the stock airbox and then performed an actual Injen CAI installation. I used a very reputable OBDII gauge and took readings directly from the ECU sensors that monitor temps. The Injen actually performed BETTER than the stock airbox as you can see from the data I supplied in another link. I commend you on your testing but just because what you have done "appears" scientific it does not provide real-world performance data while the car is actually being driven under various conditions as I performed in my testing. You will gain very LITTLE by moving the filter to the front of the battery but knock your socks off if you want to:smile:

    See post # 46 in the link below:

    Aeroforce Interceptor Gauge & Group Buy
    Last edited by securityguy; 01-28-2012 at 05:41 PM.
    2011 Optima SX Ebony Black (June 9, 2011 Build date)
    Premium & Technology Packages
    Sport Wheels, Mud Guards & Body Side Molding
    Roadruns Custom Grill
    Injen Cold Air Intake with K&N filtered BOV Exhaust
    Saikou Michi Custom PCV Oil Catch Can
    Luxon Strut Tower Brace
    3M Clear Bra Protection with full Carbon window tint
    Continental Extreme Contact DWS High Performance All-Season Tires
    De-badged
    WeatherTech Digital Fit Floor Mats
    LED Super White License Plate Bulbs

  8. #7
    Learner's Permit
    Join Date
    Dec 2011
    Posts
    196
    Securityguy, I saw your post of two snapshots in time using your torque app or any other OBDII scan. If you want to elaborate on the back ground of the data such as what the IC temps and conditions of the car were for each run (what everything steady state and equal before each reading, etc...), I would be happy to consider it and why it is immune to higher intake temps. All I have shown is you in fact are sucking in hotter air, and your IC will be soaked faster and hotter than without the INJEN. If these factors don't affect your car, that's great. Let's dig in some more and see if we can figure out why. If your data appears complete and valid, I am willing to pop off a hose at the TB and put a TC into the intake itself and we can see just what the IC is doing to our air.

  9. #8
    01/2012 ROTM securityguy's Avatar
    Join Date
    Jun 2011
    Location
    Northern Virginia
    Posts
    2,434
    Cad, based on recommendations from forum members, I measured seven different parameters both before and after. I am not using a phone app but a highly reliable ODBII scan gauge that takes real-time data from the ECU and displays it digitally. The gauge was set for taking readings from the ECU every 100ms. I set the gauge to read four parameters: IAT, Ambient Temp, Boost and Coolant Temp. The only time that the temps increased for the Injen beyond stock was at a 5 minute idle which I never encounter in real world driving. I am open to digging into this further too and commend you for taking a Saturday to do your test. Unless you have actual parts and can do a true before and after test as I did, your data is a good read at best and still leaves unanswered questions. By doing pre-install and post-install runs and measurements, I can only assume that my data is about as accurate as you'll get in trying to determine the efficiency of the Injen or any intake for that matter. Open to ideas and to taking additional measurements as my intake is fully installed and will not be returning to stock as I am thrilled with the unit and the performance:smile:

    Each day was sunny with average humidity. I did my best to duplicate the exact scenario for each run. Same stretch of highway and traveling at the same speeds for each measurement.
    Last edited by securityguy; 01-28-2012 at 06:04 PM.
    2011 Optima SX Ebony Black (June 9, 2011 Build date)
    Premium & Technology Packages
    Sport Wheels, Mud Guards & Body Side Molding
    Roadruns Custom Grill
    Injen Cold Air Intake with K&N filtered BOV Exhaust
    Saikou Michi Custom PCV Oil Catch Can
    Luxon Strut Tower Brace
    3M Clear Bra Protection with full Carbon window tint
    Continental Extreme Contact DWS High Performance All-Season Tires
    De-badged
    WeatherTech Digital Fit Floor Mats
    LED Super White License Plate Bulbs

  10. #9
    Learner's Permit
    Join Date
    Dec 2011
    Posts
    196
    SG, I am glad you're happy with your intake and am happy for you. And I know you did a comparison at some point. I thought it difficult to believe the air wasn't hotter after seeing your data and decided to see in real time for myself what I would measure in my car. The data I present shows what it shows, clear for all to see in real-time with actual air temp measurements, and it shows the engine compartment is hot and the air getting pulled into the engine is hotter if it's not from outside the compartment. This is not a function of what kind of air intake you have, it's a function of where you pull in the air. You suggest either the Injen intake somehow lowers the temp of the intake air, or that the IC pulls it all out back out no matter what you throw in. This defies heat transfer principles, so I accept your input and experience and will do a run sometime with a TC in the throttlebody next to the intake air temp sensor. This would show the air temp going into the engine in relation to the intake air temp. What do you think?

  11. #10
    03/2012 ROTM SickBmw's Avatar
    Join Date
    Dec 2011
    Location
    Chatsworth, CA
    Posts
    20,019
    Year
    2015
    Make
    KIA
    Model
    K900
    Trim
    VIP Package
    I'll tell you something, if there's 1 thing I learned coming to the forum it's that if somebody has already made a mod on their car you can't argue with them to try and tell them that it's not right even if what you're saying is right.. Cadima what you have posted shows scientific proof of what you are saying, and I can recognize that what you're saying makes perfect sense!

    This has been an ongoing argument on many different vehicles on several different forums. My opinion on the matter is that a car manufacturer does several months of testing or longer in designing an intake system to make sure that it performs in the proper way. Many aftermarket companies will design aftermarket intake systems that look nicer and make more sound but do you really believe for 50 or 100 bucks that it's going to outperform the factory intake system??

  12. Remove Advertisements
    Optima Forums
    Advertisements
     

Similar Threads

  1. Turbo Cold Air Intake
    By PJE08302010 in forum Optima Engine and Technical Discussion
    Replies: 19
    Last Post: 11-04-2012, 04:08 PM
  2. KN Typhoon Air Intake
    By Troy Brah in forum Optima Engine and Technical Discussion
    Replies: 43
    Last Post: 10-21-2011, 12:43 PM
  3. 2011 Kia Optima K5 cold air intake?
    By OptimaKing in forum Optima Engine and Technical Discussion
    Replies: 11
    Last Post: 10-06-2011, 06:45 PM
  4. Variable Intake System
    By Optima Prima in forum Optima Engine and Technical Discussion
    Replies: 2
    Last Post: 07-29-2011, 08:50 AM
  5. Changing the air intake on the Optima
    By optimasprime in forum Optima Engine and Technical Discussion
    Replies: 13
    Last Post: 08-19-2010, 05:44 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Powered by vBadvanced CMPS v4.1.2