Re: Re: Open Element Air Cleaners: Some temperature

From: Bruce Bridges (
Date: Mon Jun 22 1998 - 12:18:22 EDT

Sounds like a neat setup. Are you going to post some pics too?
At 11:39 AM 6/22/98 -0400, you wrote:
>>Scott Wrote:
>> This weekend I picked-up a very cool gadget from a local Radio
>> Shack. The Shack sells an "Auto/RV Thermometer" for $15. It
>> is about the size of a pack of gum and comes with a 6-foot
>> lead and termperature sensor.
>> The temp is displayed on an LCD display down to the tenth
>> of a degree. I mounted the thermometer on my driver side mirror
>> with the included adhesive (put her right on the glass, next to the
>> top of the mirror housing). I then snaked the temperature lead
>> under the hood and into my Mopar Performance open element
>> air cleaner.
>> Here is what I found:
>> Driving down the Interstate tonight, I found that when I was
>> cruising at 65 mph, the temperature of the air going into
>> the throttle body is 35 to 40 degrees HOTTER than the
>> ambient air measured at the mirror. Yes, cruising down the highway
>> gives a difference of 35 to 40 degress. The temp outside tonight
>> varied from 72 to 75 degrees as I cruised along the Interstate.
>> The temps in the air cleaner were around 110 to 115 F. <==< =:^0
>> When I got into town and went from stoplight to stoplight, it
>> got even worse. I was seeing air cleaner temps around 120F. <==<
>> YIKES!!!!!
>> These open element air cleaners are sucking tons of hot air from
>> under the hood.
>> I did notice once neat thing: I started the truck after it sat for a
>> while and drove off at a reasonable pace. The temp in the air
>> cleaner wasn't that much higher than outside air. I then
>> watched the coolant temp guage on the dash climb to
>> operating temp. Boom!!! The air cleaner temp started to climb
>> rapidly. It's not the engine block giving off all that heat, it's
>> the hot air coming from the radiator. We're sucking
>> in air that has been heated by the radiator. Ugh!
>> I even tested cruising as fast as 80mph on the Interstate. This
>> doesn't help the air temps in the air cleaner. In fact, it hurts.
>> At higher speeds, the temp is guaranteed to hang around 120F
>> when the outside temp is in the low 70s.
>> I challenge all Dak owners with to purchase the same "Auto/RV"
>> thermometer from a local Radio Shack and report their results.
>> Mount that baby on your mirror and guide the "measuring part"
>> under your hood. Post the results.
>> My next test will be to local the "measuring part" near where the
>> factory air box got its fresh air supply (near the front,
>> passenger-side corner of the engine compartment) before I removed it.
>> I am very suprised at these numbers. Especially at high speeds. I
>> think we're going to have to scrap the open element air cleaners.
>> Raising the air temp by 40 degrees *can't* be helping our
>> performance.
>> - -Scott
>> p.s. If you kick on the A/C, that's good for another 8 degrees of
>> heat going into your open element A/C. Sigh... :^(
> I found the same thing when I did that. My reading was
>110 degrees for the open element and 89 degrees for my ram air.
>Don't scrap your open air. This weekend I hooked up my ram air
>to my open air element. Runs great but no track measurements yet.
>All I did was bought a 8' pc of aluminum dryer vent hose the kind
>that you can expand to 8' even though when you buy it it's only
>4' long. It's aluminum not vinyl. Anyway stretched it out to
>8' then cut a 2.5" slot in about 5-6' of it. I then took it
>and wrapped the slotted portion around the air cleaner making a
>complete circle with the non slotted end ducting down to my old
>ram air connection to the left of the radiator right through
>the rubber splash boot. So far works great sucking cold air.
>The aluminum dryer vent is stiff so you can bend it pretty tight
>around the air filter (I have the MP performance air cleaner, lid
>measures 13.25") although if you have a true 14" air filter it
>probably won't work due to fire wall clearance. I'll try to post
>some pics in the next couple of days.
>Mike Catlin

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