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Do grille inserts affect airflow through the condenser and radiator?

TurboTJ

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Did a little math because people like @Jerry Bransford often like to say grill inserts are some sort of issue.

For the not faint at heart here it is. If the fan is flowing 2200cfm through the stock grill that requires about 0.2 psi of pressure drop. If you reduce the grill openings from 2" to 1.5" with the same fan speed you will reduce that flow to 1500 cfm. As the temperature increases the fan now spins faster. To increase the flow back to 2200cfm requires 0.5 psi drop total which takes about 50W or 0.07HP extra. This is the extra work required from your 190HP engine to make up for closing your grill up 1/2".

1/10 HP

Feel free to crunch the numbers yourself, please don't take my word for it. All I am suggesting is that some peoples opinion on the subject are a bit questionable regardless on who they are. My real world experience also happens to agree with the math. I personally wouldn't blame cooling system problems on the grill (even an angry grill).
Check out the comments regarding angry bird grills on Amazon. Nearly every one is about overheating. So arithmetic aside, grill inserts apparently really do cause problems.
 
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jazngab

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Grill inserts were one of the first things I bought when I got the Jeep. Just didn’t like the look of seeing the radiator or those two bars through the slots. That being said, I’m considering removing them. I’m still undecided.
 

alittleoff

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I run a perforated aluminum sheet behind the grille. And a 9.5ti in front of the grille. No cooling issues.
My main concern as with EJD, is insect intrusion.
 
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Brian Alcorn

Brian Alcorn

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Ok thanks everybody. I see them on lots of jeeps and kinda figured if it was an issue ppl wouldn't use em but had to ask the TJ people to be sure
 

Sundowner

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Ok thanks everybody. I see them on lots of jeeps and kinda figured if it was an issue ppl wouldn't use em but had to ask the TJ people to be sure
Well, until you define the "insert" that you've asked about, it's all conjecture. Thus far, several different grille-blocking things have been mentioned; thinking them to all be identical or analogous without defining them is inherently flawed. I would say that - based on what's been said thus far - you actually don't have an answer to your question, at this point.
 
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jazngab

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Well, until you define the "insert" that you've asked about, it's all conjecture. Thus far, several different grille-blocking things have been mentioned; thinking them to all be identical or analogous without defining them is inherently flawed. I would say that - based on what's been said thus far - you actually don't have an answer to your question, at this point.
When I’m referring to grill inserts I’m talking about these kind. Also, I forgot to mention I as well did not have any issues with them on. Although now I have a winch that sits up against my grill now.

DE8F01C7-B658-424E-9E40-57E9769C5DB8.png
 

TurboTJ

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I have an intercooler behind the grill with the A/C condenser behind that, with the radiator behind that. There is a winch and a couple of 6 inch lights in front of all of that. Seriously, I am amazed any air gets through all of that. My cooling test is the long hill (7 miles?) going north out of Bishop, CA. I can run that entire hill at full throttle (6 inches of turbo boost) with the A/C on, on a hot day without overheating.
 

89grand

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TJ's look near perfect from the factory, body wise. I've never wanted to alter the body in anyway. Sure, mine is lifted, but stock hood, stock grill, stock fenders, stock lights, no added chrome, no added blackness.
 
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Mr. Bills

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Well, until you define the "insert" that you've asked about, it's all conjecture. Thus far, several different grille-blocking things have been mentioned; thinking them to all be identical or analogous without defining them is inherently flawed. I would say that - based on what's been said thus far - you actually don't have an answer to your question, at this point.
How objectively intelligent-ish of you.
 
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Brian Alcorn

Brian Alcorn

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Cannot seem to locate the website but I believe they are of the one piece design
 

Sundowner

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How objectively intelligent-ish of you.
Well I realized in the first post that I had NO idea what the guy was talking about, and to a great extent, that hasn't changed...and that's not just because I'm an idiot.

Cannot seem to locate the website but I believe they are of the one piece design
Which means...?
 

Goatman

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June bug season where I live is pretty brutal on radiators. I once watched one wrestle his way through a perfectly good window screen.(the metal ones, not that plasticky crap) They act like a 12 ga. slug at highway speeds. A friend even had a windshield cracked by one. Go a mile or two away and they are few and far between. So I have been using 1/4" hardware cloth. Ugly as all ♨,but at least it isn't those "angry eyes crap those JK people seem to need.🤗
 

Mr. Bills

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@Brian Alcorn

The product you linked is for the JK and LJ and will not fit a TJ. https://underthesuninserts.com/

As for the two basic types of grille covers for TJ's, the grille insert or grille bug screen:

I would avoid grille inserts. They are gimmicky and will reduce airflow. Although some may differ, in my mind they are no better than angry eye grilles that scream mall crawler.

Grille bug screens have been used for decades on CJ's and YJ's. They are not particularly attractive but they serve a legitimate purpose if the bugs in your area are big enough and plentiful enough to cause damage. Bug screens will also reduce airflow, but in this case the reduced airflow is a trade-off in exchange for protection rather than grille inserts which reduce airflow in exchange for a fashion statement.

Other jeepers may have different opinions.
 
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