Do Heat Exchanger Fans make it worse and actually reduce cooling?

Today we deep dive into some testing of cooling fans on the Heat Exchanger. Some say it makes cooling worse, others say it enhances cooling. Either way we're going to find out :)
-- Video Chapters --
00:00 - Intro
03:36 - How we're going to capture and gauge performance of the fans
05:14 - Building the temperature monitoring and logging device
07:41 - Installing temperature monitoring equipment
08:39 - Gathering temp info
10:28 - Sensor accuracy
13:53 - How the data was collected, conditions and driving
17:31 - Idle data
10:55 - Idle, WOT dig pull, coast down cruise data
25:41 - Cruise entire course data
28:58 - Summary of data and conclusion
29:57 - Huge flaw with this fan setup
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[@glendonallingham]

You are a wizard, love the test, shroud test gets my vote

[@MalcolmV8]

OK appreciate the feedback :)

[@AbrahamPerez-lq1ie]

Thanks for all that data. Made my decision easier.

[@MalcolmV8]

Glad you liked it.

[@Wings65288]

What a badass vid. I searched high and low for something like this when contemplating fans. Had fans on my car last season and noticed zero difference. When I had to replace my heat exchanger I ended up yanking both fans off my Whipple Cobra. Awesome vid thanks!

[@MalcolmV8]

Thanks man, and the data shows you didn't miss out on much of anything. At least not with the way those fans are setup.

[@trevorchichester8550]

So grateful to you guys for taking the time to do this! I started down the rabbit hole of research and I was amazed by how little data there was compared to unvalidated rumors. I feel selfish asking but I would absolutely love a test with the shroud.

[@MalcolmV8]

You're very welcome and yes the shrouded test has been in motion as well as some other testing yet to be shown. It had a bit of a break over the winter but once the FL heat sets in again we'll be back on this.

[@trevorchichester8550]

@@MalcolmV8 nice! Can't wait! Definitely subscribed and I'm gonna share this.

[@markrosario8800]

Wow, excellent job with all the testing. It had to be a lot of work. I'm viewing this much after you tested this, so your efforts are appreciated!

[@MalcolmV8]

Glad you liked it. We have more testing and work done and will post additional videos on it when I get some time.

[@racequad9]

Dang, that is discouraging. I thought for sure fans would help a lot more than the numbers you showed - especially for the idle test. I would absolutely like to see you test the fans with a custom built shroud or something to block those huge gaps and actually force more air through the HE. As always, thank you for all the work and test you do to provide these videos.

[@MalcolmV8]

I agree, I was disappointed and didn't want to believe it lol, but months of testing over and over said the same thing every time. Maybe the shroud fixes it? You're welcome on the testing, glad you enjoyed.

[@racequad9]

@@MalcolmV8 I just thought of something, would some sort of smoke test be possible if you remove the HE from the car and put it in fish tank or something and have it run to see where air is being pulled from?

[@MalcolmV8]

@@racequad9 I like the way you think but I don't even have to do that. Fans pull air from the path of least resistance and from 30+ years of playing with cars and heating issues I can tell you 100% the fans are sucking air in the from the sides. Pulling air through a radiator or heater core causes resistance to flow so the fan needs to be sealed up to really suck it through. Otherwise it'll just pull the bulk of the air it wants through the gaps and sides where it can.

[@racequad9]

@@MalcolmV8 Ah I gotcha. That makes sense for sure.

[@MalcolmV8]

@@racequad9 None the less I may look at doing some sort of demonstration that can quantify the changes as I enjoy hard facts and data over much else as I'm sure you can tell lol.

[@e.rivera6219]

Vote for shroud test!!! Awesome info and vid!!👍👍

[@MalcolmV8]

I appreciate the feedback and vote :)

[@nate4718]

Love the videos keep um coming, any real world data with a killer chiller? I live in FL and car currently has one, but have never tested to see if it’s making a big difference or robbing me of precious AC.

[@MalcolmV8]

@@nate4718 I ran a killer chiller on the Zinc about 10 years ago. I never did get all the kinks worked out. I didn't like the reduced cabin cooling and then after it killed two A/C compressors I just abandoned it. Ironically I ended up just removing A/C from the zinc all together lol. Perhaps I will revisit it some day but honestly IC and HE's have come such a long way I'm not sure it's worth the loss in cabin A/C.

[@nate4718]

@@MalcolmV8 gotcha I couldn’t tell you what version chiller I have but so far no issues with AC “yet”. I’m up in Clearwater if you ever want to do testing/comparison with my 03

[@MalcolmV8]

@@nate4718 very cool. If it works, it works. Probably no reason to mess with it.

[@stoodiss]

Thank you for all your content. It's hard work provided to us hard-core Cobra guys for free. I'm subscribed and always watching. Thanks again

[@MalcolmV8]

You're very welcome and glad you enjoy the content. I enjoy making it so glad its useful :)

[@vicecityperformance9564]

Great stuff malcolm, fans are definitely not needed. You should do a test with a much larger heat exchager to see if that added capacity actually makes a big difference

[@MalcolmV8]

Thanks man. That is on my todo list along with a few other things :)

[@JCDriller]

@@MalcolmV8 awesome, I think this is the real question. Smaller fans with a drop in heat exchanger vs no fans with a giant HE requiring a aftermarket crash bar. Thanks so much for doing all this!

[@zaccam3233]

Great video. Love the info. Looks like I didn't miss out on much not getting fans on my heat exchanger from vmp. I'll put that money tword some tires.

[@MalcolmV8]

@@zaccam3233 Thanks, glad you enjoyed the video. I'd agree a better use of the money in this case.

[@ishyne22]

Thank you for your hard work.

[@MalcolmV8]

Glad you liked it.

[@RS-nc2fs]

amazing info! thanks for putting in the time and effort into your videos really cool stuff! curious about the fan shroud as well.

[@MalcolmV8]

Definitely takes a lot of time to figure it all out, thanks for the feedback and other vote for the shroud.

[@guevoncito6265]

Great video. Love the data centric approach to answer the questions that so many people love to debate. I replaced my dual fan heat exchanger with a much larger capacity DOB Titanic without fans. No regrets at all. I also have an IC coolant sensor right after the heat exchanger....and a flow meter similar to yours. Also, my radiator fan pulls so much air through the front grille that paper sticks to the face of the heat exchanger just like the demo videos of the heat exchangers with fans. So, despite not having fans mounted, the airflow is still going over the heat exchanger and providing *some* cooling effect.

[@MalcolmV8]

Great feed back & info, thanks for sharing.

[@SC32V95Cobra]

Thanks for the investment in all the time to compile this data! I'm guessing you're correct about the fan mounting being poor with respect to fan effectiveness and I would love to see the difference between the current mounting setup in this video and a well shrouded setup no doubt. Keep up the good work!

[@MalcolmV8]

It's currently in testing and a new video been made with exactly that :)

[@MrTitans1989]

Great video thanks for putting in the effort to educate me and make my decision easier 👍🏻👍🏻

[@MalcolmV8]

Glad it was helpful and you liked it :)

[@majeedlx]

Very interesting results and thank you for the video and hard work . I can’t wait for the next video with shroud

[@MalcolmV8]

You are very welcome. Sounds like another vote for fan shroud lol

[@AwesomeFinish]

Yes! Build the shroud, I really want to see if it helps.

[@MalcolmV8]

Thanks, I appreciate the vote :)

[@danterakin]

Enjoyed this video a lot! I did put fans but my sole purpose was to cool the intercooler system off between 1/4 runs but never for regular driving or runs.

[@MalcolmV8]

Good info, did you buy any chance get some data before and after the fan install?

[@danterakin]

@@MalcolmV8 I did not get before and after data but my finger in the water test proved it worked. After the run the water would be considerably warm but not to the point it was too hot to touch. After 10-15mins of having the fans on (pump was wired to turn on with fans too), the water felt like it was room temp. But I got many negative comments from folks when I did 3 fans on my Afco stating I am making it worst and less functional. My IAT2s were always excellent and never concerning (average temp 105-110°). But check this out, my fans would only be on when I would hit my switch meaning that 99% of the time, the fans were off. They were literally there for my cooldowns at the track. That would’ve been a cool and quick test for you to just have them off and see if the fans create a blockage because for me, it did not. Peep my old setup: instagram.com/p/BL4eDQ2hiou/?igshid=MzRlODBiNWFlZA==

[@tae8455]

Great info, I say build the shroud and retest...

[@MalcolmV8]

Thanks man, I appreciate the vote and feedback.

[@zd302gt]

Interesting find! Love all the data! Maybe pull the fans off and add some foam tape to seal them to the heat exchanger and retest. Before you go through the trouble with building a full shroud and changing the mounting.

[@MalcolmV8]

I thought about that but even then the fans would only be sucking through that one spot. A shroud would ensure the fans are pulling across the entire core. I figure if we want to improve the fans let’s do it right :)

[@SomeDude365]

Great test and data. One of the things I heard, mainly from the few road racers, in regards to fans impeding cooling is during sustained high speeds, like at a proper road racing circuit where the average mph is over 100mph and there are straighaways where 150mph can be reached. The argument is that the speed of the air going through the HE is at that point faster than the speed at which the fans are able to move/extract air/heat so that's where you are really losing out......that's going to be much harder to test as you obviously don't want to be testing that on the street. But it would be interesting to know. In addition to building a shroud and seeing if there's any improvement there (there HAS to be) it would also be cool if you could test the infamous GT500 HE with fans/no fans as that is kind of the gold standard on these cars. Who knows.....the larger surface area with the attached fans may yield a better result.

[@MalcolmV8]

That actually was a GT500 HE from AFCO. It seemed pointless testing the tiny stock sized 03 Cobra HE. Agreed the only real way to test sustained 100 to 150 mph sessions would be on a race track. I would think there’s no need for HE fans at those speeds there should be an abundance of air you could duct to the HE for premium cooling.

[@fstcbra]

Can't wait for trunk tank results vs the front tank

[@handlebarmoustache6136]

Thanks for the effort you put into the testing. It shows that some of these manufacturers are just pushing propaganda gimmicks in their products, and then doubling down on it again and again. Question… do the latest gen Shelbys, hellcats, and factory blown vettes, Camaros, and caddies use fans on their Hx? For that matter, do any factory blown late model cars use fans?

[@MalcolmV8]

No problem glad to do it and glad people enjoy it. Good question on all new cars. I haven't researched every single new late model to have an answer but OEMs usually have to find the balance between performance and cost so they can't be looked at as a bench mark, but certainly a good guide of what they've found works.

[@roninthedestroyer8958]

Excellent work

[@MalcolmV8]

Cheers. Glad you liked it :)

[@roninthedestroyer8958]

@@MalcolmV8 think about my question i posted

[@jplperformance9073]

Thank you for your testing, wow

[@MalcolmV8]

Anytime, glad you like it :)

[@Coyote9smilespergallon]

Very impressive! I could’ve figured out the sensors, but making the bungs himself and that little temp reading computer was slick as fuck!! And I appreciate his efforts!

[@MalcolmV8]

I appreciate the feedback. Currently more options in testing so there will be some follow up videos to this.

[@Chalomonn]

Great vid Malcolm!! We appreciate it!! Do you happen to have a part number for your intercooler pump?

[@MalcolmV8]

You're welcome and I'm glad you liked it. I do believe the part # is E2512A.

[@Chalomonn]

@MalcolmV8 great, thanks bud!

[@bobgodd]

Very well done.

[@screamineaton]

Very interesting test. I had always assumed you wouldnt see a change while driving. But sitting in a stop light i thought you would see a difference with fans. I can see maybe a change with a full shroud at sitting still test but you may not see much difference anyways as fluid temps are not much above ambient. Bet you would see better results with outside temps in the 40s or less.

[@MalcolmV8]

Oh yes for sure, in the cooler temps the results become much more pronounced but nobody has cooling issues when it's in the 40s and most people can't even hookup then and put the power down. But yes cooler air, even in the 50s and 60s makes a huge difference for the superchargers. Heck even in the 70s I see such cooler IATs.

[@zd302gt]

I like the Rob Dahm inspired “tuning” B roll at the 9:15 mark. 😉

[@MalcolmV8]

Oh it is? lol I'll have to check it out. I didn't even realize lol

[@chiefrino6890]

Amazing test as always!

[@MalcolmV8]

Thanks, glad you liked it.

[@nocturnalcustoms376]

Loved the video, but I think you guys might be missing a critical benefit in your tests (at least for a car that sees track use) I’ve been eying a fan setup or my impala, mainly because of the burnout box. At idle, the blower isn’t generating much heat anyway as air is being bypassed. At WOT during a pull, you’re getting natural airflow. Either way, it doesn’t seem like a fan would be much benefit in either scenario. In the burnout box though,you’re hitting boost/making heat but with zero airflow. On my impala, IAT2’s spike pretty high during the burnout and depending on how quickly I stage, they don’t fully recover before the start of the pass. I’m hoping a fan setup will keep my IAT2’s down during the burnout and give me a lower starting point at the launch. I plan on using a puller so airflow isn’t obstructed during the pass. I’d love to see if you guys could test it before I get around to it, maybe save me some time since you already have a fan setup to use 😂. As many others mentioned, also curious about the shroud.

[@adamcarrasco2669]

Thats a great video and a lot of useful information. My question is since the I.A.T temps versus the water temps are 25 to 30 degree difference do you think an increase in the intercooler water pump flow would help it cool further?

[@MalcolmV8]

Yes increases in water flow show increases in cooling. That's why for this test I was running a Stewart EMP pump which was the most powerful I could get my hands on.

[@MrSpdjunky]

I'm going to add more to this now that I have a lot more experience with my car. I currently use the car for drag and drive type events. Cruising or driving 30-60 miles, then 3 back to back passes. Everytime a pass is made with the blower spinning 24-25k rpm going down the strip, yes the heat exchanger is going to cool some, but it cant keep up maintaining the temp on a return road or back in the staging lanes. Large fans on a poorly shrouded heat exchanger, that that is inadequately sized for larger hp builds, will have minimal dwell time(the time the water passes by the fans) to cool giving minimal gains. The larger the heat exchanger, the better it will work. Likewise, the larger the offset when adding fans. When, a viewer looks at this, they have to consider how hard they push their combination. A few stops and back to 45 mph for 1/2 a mile to another stop is not the same as some city driving or drag strip racing that can thoroughly raise the water temps throughout the whole system very quickly and take forever to cool back down. I'm personally planning a 6" wide heat exchanger with fans and an adequate shroud on a pwm controller. As this video shows, fans arent really needed after so much mph. When judging how much of a cooling system you need for the blower, it really needs to be based off of power/blower rpm, and how it will be driven. With wide open roads with minimal stops, you can get by with a lot less of a system.

[@BIGEVILRACING]

Very useful info. Ill be ripping mine out and save weight

[@MOHSY10]

Thanks man amazing data Look like the hear exchanger not doing the job! Have you considered that maybe there is issue with the H/ex ??

[@MalcolmV8]

Yes in prior videos I replaced the HE with a brand new unit. I flow tested it and then cut off the barbs and upgraded them from 3/4" to 1" ID for max flow. I'm getting the best possible cooling from that HE.

[@MOHSY10]

Tell you something I know it's very rare but it happened with a friend, it was double pass h/e. we found it by accident , the divider inside the h/e tank not sealed properly . Good luck Can't wait to see the shroud results Thank you

[@MalcolmV8]

@@MOHSY10 I've seen that too but I have a total of 3 of these HEs here. All three perform on par with each other so I think it's functionally OK... or all three are leaking the same lol :)

[@AndrewBaker302]

But couldn't the fans be wired to a switch to run in the pits, between runs at the strip? Along with the fluid pump? Seems like they would be handy there

[@MalcolmV8]

Someone else asked that and yes you can wire it that way and I considered testing that but with around 30 amp draw on the EMP pump and the dual fan draw the battery wouldn't last very long at all.

[@modlist6129]

Informative video like always Malcolm. What do you think about using fans only when the the car is off ? Let’s say for example you are letting the car cool off and you manually turn on both the fans and intercooler pump together meanwhile you are cooling off the car for the next run?

[@racequad9]

This is why I was hoping the idle test would show a bigger benefit for the fans. I didn't think fans would make a difference while the car was moving, but I for sure thought they would help for idle and when the car was off (would need to add a manual switch). But as Malcolm mentioned, the gaps in the back is probably why they're not cooling as they should, the fans are just pulling air from the gaps around them rather than pulling air from the front through the HE.

[@MalcolmV8]

I had someone else ask me about how the fans performed with the car off but I don't have an answer for that as all my tests had the engine running as you can see. It did occur to me to maybe test that but with the EMP pump pulling 30 amps and the fans pulling around 10 or 15 amps (I need to go validate exact number) I'd barely be able to run them before the battery is dead so it didn't seem like a viable test at the time. I'm assuming guys who do this at the track and let it run have a smaller water pump and possible smaller fans or single fan?

[@GTCOLE281]

@@MalcolmV8 they sit there with a fat battery charger on there! Lol with a 1000ft extension cord 😅

[@MalcolmV8]

@@GTCOLE281 oh heck OK lol. Good to know. I've seen guys doing that with trans coolers and other things, guess it makes sense they'd do that as well 😂

[@modlist6129]

@@MalcolmV8 I figured the same as well it would drain the battery real fast specially a big pump and dual fans all at once.

[@roninthedestroyer8958]

I have a 2014 Shelby GT 500 stock what if you added a small heat exchanger to the cool side out of the stock heat exchanger. So it can get cool down again. Instead of replacing the stock heat exchanger with a bigger and thicker radiator.

[@MalcolmV8]

I’ve seen people try stuff like that. Even saw dual heat exchangers stacked. I’ve never heard anything good from it. I believe your best bet is a good working setup. I have other tests in the world and more content on the topic to come. You can get some updates and see what’s coming from time to time on my social media.

[@KenMileyJr]

Excellent video, thanks Malcolm! Question, do you have your intercooler brick flange trimmed for the IAT2 sensor? I'm told it will show higher if you don't trim the flange.

[@MalcolmV8]

I don’t recall the flange been in the way but I’d have to go back and look at pics. Either way doesn’t matter as I now have the VMP core and it doesn’t have the flange like the stock core.

[@TripleJ_01]

Have too look at the whole system. Hopefully not too hard to understand. On the air side you want air temp into blower as close to outside ambient as possible. The underhood inlet is crushing the efficiency and overall performance. Why make the blower run hotter for no reason? Try a test with nothing changed but a cold air inlet (best) or a shrouded filter. There’s a reason you never see an OEM vehicle with an open underhood air filter. On the coolant side, one way to see how efficient the HX is, is to add a thermocouple grid to the inlet face (say 4x4) so you can get an average air temp and compare that to the coolant inlet. You want as great of a difference as you can get (ie outside ambient temp or close will yield the greatest efficiency. If the inlet air temp is very close to the coolant inlet it will be hard to get any heat transfer. Also coolant temp in and out of the HX is roughly the same as the coolant in and out of the IC brick. If you know the formulas and density/specific heat tables - you can calculate the heat rejection from each device, since you have coolant flow rate. IC brick heat rejection = HX heat rejection. Heat rejection on the airside will always equal coolant side heat rejection. You’d need a supercharger outlet air temp pre intercooler to calculate the airside IC brick rejection but it’s probably unnecessary.

[@04sneakysnake]

Definitely think the shroud needs some work, but I have a feeling a completely closed-off shroud might hurt at high speeds. I've seen some trick setups that have flaps/valves on the shroud so at speed they can bypass any high pressure air versus it getting caught up in the flow (and possible restriction) of the fans. Might be hard to fit on the tiny HE shroud, but I'd have to assume that's why there are those massive cutouts on the shroud as-is. Just a cheaper and inefficient method. 😋

[@MalcolmV8]

That would be an interesting setup with shroud flaps. I supposed if the shroud data showed blockage and lack of function at highway speeds something like that would make sense. Perhaps not an apples to apples comparison but it's worth pointing out when an engine is over heating and has subpar cooling and you add a shroud to the radiator with the fan it now cools like a monster at all speeds even on the highway. That makes me question will it really struggle to cool the HE on the highway with a shroud now? I don't really know. Sounds like we have another vote for shroud testing here :)

[@04sneakysnake]

@@MalcolmV8 Always in for more data!

[@banneddamn]

Id be interested in seeing a heat shield shroud around the filter so its not sucking hot engine bay air, then plumb a hose from the hole next to the fog light to feed the filter cooler outside air and see if any of that helps IATs

[@MalcolmV8]

I've played with that a lot over the years. In fact I built a custom 6" intake that ran from the throttle body to inside the fender. Temp sensors on the intake tube read lower as expected but after the air passes by the intercooler brick I get no difference at all. That brick will heat or cool air as needed. I even tried spraying water / methanol in the intake charge pipe and then tried 100 shot of nitrous. It made absolutely ZERO change to IAT2 temps.

[@josedelarosa6449]

I've got fanless on my GT500. These were bad about alternators going out and this would of advanced it more.

[@MalcolmV8]

Well seems you’re not missing much so that’s good.

[@jplperformance9073]

Yes please build a shroud

[@MalcolmV8]

This seems to be the majority vote :)

[@zd302gt]

If you wanted to increase your production quality, adding a lapel mic for your white board sessions would be nice. When you turn your head away from the camera to look at the white board you lose some voice clarity and magnitude. That room is inherently a little echo-y.

[@MalcolmV8]

I agree, I didn't think I'd need it indoors but after reviewing it later I noticed that too. Doh!! I noticed it was catching noises outside the room too which I wasn't expecting. I'll keep working at improving that. Thanks for pointing that out.

[@zd302gt]

@@MalcolmV8 Not a big deal at all, just like anything else in life, always room to improve. You guys are doing great!

[@MalcolmV8]

@@zd302gt thanks man, agreed. Always trying to improve.

[@justin.c_svt]

Well I guess it’s easy for me to say yeah go ahead build the shroud because I don’t have to do it lol

[@MalcolmV8]

😂

[@terryoconnor4208]

Thank you I for one appreciate your help and time .THANK YOU

[@MegaPartap]

Build the shroud

[@MalcolmV8]

Appreciate the feed back and vote :)

[@MrSpdjunky]

This testing was JT approved... 😂

[@MalcolmV8]

What's JT?

[@MrSpdjunky]

@@MalcolmV8 Tooley approved... 🤣🤣

[@Shaman-k2r]

Электровентилятор был создан чтоб охлаждать) Почему у вас не сработало, непонятно.

[@roninthedestroyer8958]

I don't think it's worth it

[@MalcolmV8]

I have some other configurations in testing with more to follow up on this.