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Old November 27th, 2019, 08:23
Mishimoto Mishimoto is offline
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Mishimoto R&D: XJ Performance Fan Shroud

Hey everybody,

My name is Steve and I work for Mishimoto Automotive. If you're not familiar with us, we make cooling products for a huge variety of vehicles, including a radiator, and now a fan shroud, for the XJ.

We wanted to share our R&D behind our new fan shroud and hear what you all think! Also, if anybody can get us in touch with whomever sets up sponsorships for the forums, we'd like to pay for our membership, but haven't gotten a response to our PMs or emails.

Check out the R&D below and let us know what you think.

Thanks,
-Steve

Constant Stride Ė Fan Shroud R&D, Part 1: Production


Driving off the beaten path is a constant stride. Every throttle input and steering angle change is carefully calculated to overcome the obstacles in front of you. All it takes to break that stride is one misstep. A coolant temp gauge climbing into the red or a wisp of steam from under the hood is enough to take your focus off those obstacles and lock it on your dash. Suddenly, the challenge becomes cooling down your vehicle instead of making it to the end of the trail.

Overheating is an all-too-common occurrence for many Jeep XJ Cherokee owners. Off-roading is also an exercise in low-speed driving and for the XJís outdated engine fan, itís an exercise in futility. When the XJís 4.0L engine is churning at a pace just above idle, the archaic engine fan is barely moving air through the radiator. Low fan and road speeds, coupled with the extremely high load of crawling up a steep grade leads to rising coolant temps. The only way to move more air through the radiator with the stock fan is to increase the engine speed or road speedóboth could be disastrous in an off-road situation.


One solution is to ditch the mechanical engine fan and substitute electric fans that spin at a constant rate regardless of engine speed. An even better solution would be to enclose those electric fans in a shroud that tightly hugs the back of the radiator. A well-designed shroud ensures that air is only pulled through the radiator and not from the hot engine bay. But thereís a challenge specific to the XJ that makes building a fan shroud like this problematic: space.

The XJís 4.0L inline-six engine is nearly three feet long from the bellhousing to the front of the crank, and itís longitudinally mounted (front-to-back). That leaves little room in the engine bay to mount fans. Less than four inches exists from the shroud mounting points to the front of the engine, to be exact. With our 10-inch fans measuring 2.36 inches deep, we had just under two inches to work with.

To make the most of the scarce space, we decided to keep our fan shroud in the spirit of the XJ, simple but effective. Two electric fans will take the place of the mechanical fan, while a third acts as the A/C fan. The shroud itself will be made up of a flat sheet of aluminum that attaches to the stock shroudís mounting points. A small lip at the bottom of the shroud will close off the gap between the shroud and the radiator to improve efficiency.

...Continue Reading>>>
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Old November 27th, 2019, 12:28
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Anak Anak is offline
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Re: Mishimoto R&D: XJ Performance Fan Shroud

Awesome to see the support!


I have put in a message for the Board of Directors to see about getting you the answers you want. Being the holiday season I can't say exactly when someone will get back to you. And this place is a living example of the Pareto Principle.


Could you tell us more about the fan controller? I see that is one of the options, but I don't see any pics or details about its operation.


I see there is a jumper for the '97-'01 models. What can you tell us about wiring in earlier models?


How many amps draw for the whole system? Under "Specs" I see 13.08 amps, but is that for one fan or for all three? Note that some of us have our charging systems pretty well maxed out, what with additional lighting, ARB fridges, winches and who knows what all other new electronic gadgets that no one was thinking of when these vehicles first came out. An upgraded charging system is a fairly common need in our world.



For what one person's opinion is worth, I would suggest you rename your product to include the fans in the name. At first glance, looking at the page from which to purchase this, I had a WTF moment when I thought a relatively simple piece of aluminum sheet metal was priced higher than an aluminum radiator. Stepping back and seeing that this also includes the fans resolved that issue in my mind, but it might create an initial negative impression that could put off some folks.
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Old November 27th, 2019, 13:06
Mishimoto Mishimoto is offline
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Re: Mishimoto R&D: XJ Performance Fan Shroud

Quote:
Originally Posted by Anak View Post
Awesome to see the support!


I have put in a message for the Board of Directors to see about getting you the answers you want. Being the holiday season I can't say exactly when someone will get back to you. And this place is a living example of the Pareto Principle.


Could you tell us more about the fan controller? I see that is one of the options, but I don't see any pics or details about its operation.


I see there is a jumper for the '97-'01 models. What can you tell us about wiring in earlier models?


How many amps draw for the whole system? Under "Specs" I see 13.08 amps, but is that for one fan or for all three? Note that some of us have our charging systems pretty well maxed out, what with additional lighting, ARB fridges, winches and who knows what all other new electronic gadgets that no one was thinking of when these vehicles first came out. An upgraded charging system is a fairly common need in our world.



For what one person's opinion is worth, I would suggest you rename your product to include the fans in the name. At first glance, looking at the page from which to purchase this, I had a WTF moment when I thought a relatively simple piece of aluminum sheet metal was priced higher than an aluminum radiator. Stepping back and seeing that this also includes the fans resolved that issue in my mind, but it might create an initial negative impression that could put off some folks.

Thank you for the help with the vendor subscription - I know this isn't everybody's day job, so I understand it can take some time.

To answer your questions:

We use this controller (https://www.mishimoto.com/adjustable...oller-kit.html), but include both the NPT and the probe-style sensors. It's a single-speed, thermostatic controller that triggers the fans at any temp between 150*F and 240*F, it also includes a manual bypass that you can hook up to a switch to turn the fans on whenever needed. If you want to use the probe sensor, you just slip it in between the fins on the radiator; the NPT sensor just requires any 1/8" NPT port into a coolant galley, or we also sell adapters to splice the sensor into a coolant hose (https://www.mishimoto.com/catalogsea...sult/?q=MMWHS-). We wanted to make this an add-on in case anybody wanted to use a manual switch, progressive controller, or already had another controller installed. We include the installation of the fan controller in our installation video as well (https://www.youtube.com/watch?v=RdPzPNRmkBU), so you can see how to wire it up.

The jumper for the A/C fan is only needed for the 1997-2001 models as Jeep changed the plug type for those years. The early models are a direct plug-and-play with the connector attached to the A/C fan, but we still include the jumper with every order, just in case. The other two fans can be run off the controller or a switch as mentioned above.

I've updated the current ratings on the page to reflect the entire system. Each fan pulls 13.08 amps at startup, so if all three start at the same time, it will draw 39.24 amps. Once started, each fan pulls 6.8 amps for a total draw of 20.4 amps.

I will also pass on your concern with the product title. It's always a fun line to walk making descriptive titles that don't take up your entire screen, especially when most people are browsing from their phones

Hope this answers your questions, feel free to let me know if you have any more or if I can clarify anything more.

Thanks!
-Steve
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Old November 27th, 2019, 18:44
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techno1154 techno1154 is offline
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Re: Mishimoto R&D: XJ Performance Fan Shroud

On the web site the fans are listed at 950 CFM each. Through the years, several manufactures have offered the triple 10" fans with and without shroud. They have all seem to have failed in real life daily driving. I assume they were also 950 CFM each for a total of 2850 CFM.

Towards the end of 2004 I have been running dual Derale 13" fans for a total of 4000 CFM. I have not had problems with them. In regular stop and go traffic in Florida. One fan is enough to keep the temperature in check. With the AC on, both fans are needed. Although I have driven my XJ to more than half of the states at highway speeds I am yet to encounter any long hard hills in near 100 degrees. I do not know how the fans will cope with that high an ambient temperature. I say all that to say 2850 CFM may not be enough unless there rest of the cooling system is at its peak efficiency.

I guess the triple fans paired to your radiator may be cable of keeping high temperatures at bay. Personally, I would feel a lot more comfortable with about 4000 CFM. This is not based on any scientific evaluation just real life daily driving.
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1996 XJ; 4.0L; AW4; NP231; SYE; D30 and D44; ECTED; 4.10 gears; 30X9.5 -15 BFG/AT/KO; 3" lift; Rusty's LCA; JKS ADJ UCA; Kevins ADJ Track bar; Drawtite Front Receiver; Dual Electric Fans; Dual Battaries.
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Old November 27th, 2019, 20:00
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Anak Anak is offline
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Re: Mishimoto R&D: XJ Performance Fan Shroud

Quote:
Originally Posted by Mishimoto View Post

I will also pass on your concern with the product title. It's always a fun line to walk making descriptive titles that don't take up your entire screen, especially when most people are browsing from their phones
Perhaps just come up with a marketing name for the package. Something like a "Triple Threat Fan System."

Or list it as a fan set.

A shroud just seems like such a simple thing. Best if you can get the prospective customer past that point.

Thank you for clarifying the amp draw and the controller. I may be down for one of these systems, complete with radiator. Plans call for a stroker, and I intend to upgrade the cooling system at that time.
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Old November 27th, 2019, 22:41
Veeb0rg Veeb0rg is offline
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Re: Mishimoto R&D: XJ Performance Fan Shroud

Where does the temp sensor the fan controller get installed? I love the idea of this but have always heard that for daily driving a triple fan set (really a dual fan with the a/c fan) isn't sufficient to handle stop and go traffic/sitting.
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Old November 29th, 2019, 10:06
Mishimoto Mishimoto is offline
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Re: Mishimoto R&D: XJ Performance Fan Shroud

Quote:
Originally Posted by techno1154 View Post
On the web site the fans are listed at 950 CFM each. Through the years, several manufactures have offered the triple 10" fans with and without shroud. They have all seem to have failed in real life daily driving. I assume they were also 950 CFM each for a total of 2850 CFM.

Towards the end of 2004 I have been running dual Derale 13" fans for a total of 4000 CFM. I have not had problems with them. In regular stop and go traffic in Florida. One fan is enough to keep the temperature in check. With the AC on, both fans are needed. Although I have driven my XJ to more than half of the states at highway speeds I am yet to encounter any long hard hills in near 100 degrees. I do not know how the fans will cope with that high an ambient temperature. I say all that to say 2850 CFM may not be enough unless there rest of the cooling system is at its peak efficiency.

I guess the triple fans paired to your radiator may be cable of keeping high temperatures at bay. Personally, I would feel a lot more comfortable with about 4000 CFM. This is not based on any scientific evaluation just real life daily driving.
Quote:
Originally Posted by Veeb0rg View Post
Where does the temp sensor the fan controller get installed? I love the idea of this but have always heard that for daily driving a triple fan set (really a dual fan with the a/c fan) isn't sufficient to handle stop and go traffic/sitting.
Thanks for the feedback! We do have these fans running on a volunteer truck here in DE/PA and they have not had any problems with overheating in traffic, but that is with our radiator installed as well. We definitely recommend that the rest of the cooling system is kept up with including making sure your thermostat is opening when it should be and the coolant is kept clean. Also, CFM matters, but a well designed fan shroud also makes a big difference. While our testing showed a 41% increase in flow over the stock fan, it also showed that the fans pulled air through much more of the radiator. We're confident that these fans are enough to keep your XJ cool in high ambient temps and traffic.

@Veeb0rg we include two sensors with the controller, one is a probe that you simply insert into the fins of your radiator, the other is an NPT sensor that requires either an NPT port into the engine's coolant galley (there are sometimes unused ports with plugs in them on the engine) or you can purchase an in-line adapter for your coolant hoses to install the sensor (https://www.mishimoto.com/catalogsearch/result/?q=MMWHS)

Quote:
Originally Posted by Anak View Post
Perhaps just come up with a marketing name for the package. Something like a "Triple Threat Fan System."

Or list it as a fan set.

A shroud just seems like such a simple thing. Best if you can get the prospective customer past that point.

Thank you for clarifying the amp draw and the controller. I may be down for one of these systems, complete with radiator. Plans call for a stroker, and I intend to upgrade the cooling system at that time.
Thanks! Our marketing department is big on being consistent across our site, so the best I could do is add "kit" to the end of the product title

Thanks,
-Steve
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Old November 30th, 2019, 09:18
Black1990jeep Black1990jeep is offline
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Re: Mishimoto R&D: XJ Performance Fan Shroud

You should have the fan set tested in hot weather on a slow rock crawl up hill. That is the real proof test. Perhaps Death Valley at 115 F. Of course that will have to wait till summer, but maybe some folks in the southern hemisphere can test for you this December?

Also you could disable one fan, and see how only two fans do for cooling. That would give us an idea of how much margin there is in cooling capacity. So run a test with one or even two fans switched off and see how she does. If turning off one fan does not result in a temperature rise, that would be a good thing to show. If two fans cant cool the jeep safely in moderate weather, on the highway, then three fans probably are marginal.

You want to test the snot out of this in hot weather, slow crawling, i.e. high engine load, perhaps with one fan off, or blocked. You need worst case testing.
You dont want to sell a boat load of these systems to find that this summer customers are overheating on trails, as that would be bad for them, and your company. You need to test them to the limit prior to offering them for sale.

I wish you the best in this endeavor.
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