V8MiataMike

First of all I would say that the shear size of the Monster kit radiator plays a significant role in keeping the engine cool. Having the two small puller fans behind it also makes for a very good cooling system.

With that said, I was headed to a doctor's appointment on a late afternoon a couple of weeks ago in 95 degree heat with what seemed like 95% humidity. Had the A/C full blast although the top was down (helps a little a stops).

Halfway there I get into some real Atlanta traffic and sure enough, things are getting warmer when stopped. First time to see the temp gauge actually go above the center line! Once moving it would start coming back down. Finally I turn off the A/C but traffic is really bad. My assumption at this point is that once the heat soak really sets in, the two little fans just can't get the temp back down. Miata temp gauge hovered around 3/4 to 7/8 hot till I got to the parking lot. No signs of "overheat" when I lifted the hood to assess though.

I immediately began contemplating alternatives to the fan setup. I run the Ford Contour dual fan setup on my 67 Mustang which has worked really well. Looking at it and the space I have in the Miata, I went ahead and acquired another Contour fan. On high speed, this dual fan setup is supposed to draw around 3400 CFM.

Below is the comparison of the two fan setups.






The fan shroud depth is very shallow and after some trimming, literally covers the entire radiator. The radiator cooling section is 22 1/4 inch by 16 1/4 inch. The shroud is 24 inch by 16 inch. I trimmed off each side edge that would then overlap the side tanks by 1 inch each side which also let it slide into the hole so to speak so that the upper and lower shroud edges went up to the cooling fin surface. A 75 amp relay is used to power only (at the moment) the high speed circuit of the fans (not using low speed at this time) controlled by the stock Miata circuitry (adjustable radiator probe though, not the Miata temp sender on thermostat housing).

View from bottom:




View from top:




To my surprise, I was able to install this without removing the radiator. As always, it was in and out a few times before final install to tweak and adjust things and get them just right. The SN95 accessory drive I am sure made it possible. I am not sure if it will fit with the Fox body accessories.

Something else good about this setup is that Dorman (620-104) makes a new replacement part - the whole thing for around $110 - if I want to consider putting new parts in down the road.

Here in Atlanta, I will have another opportunity to "test" the cooling in 95/95 weather and traffic soon!


The air flow is significantly and very much noticeably higher now. Standing next to car you can feel the airflow coming from under the car.

jrmotorsports55

Very nice. I have Martin's upgraded fans and will be interested to see how they do.

Jason

MX-Brad

How long in stop 'n go traffic did it take till you started to see higher temps?

V8MiataMike

I think the ones I got from Martin were the upgraded fans as well.

Like I said, overall it did a remarkable job keeping it cool. The trip I believe stressed its abilities to the max.

About 2/3rds the way into the 45 minute trip. The last 1/3rd was mostly stop and not go... If I could have gotten moving for a few miles there at the end I think it may have recovered. It would start cooling down when in motion but while stopped it would start climbing again.

charchri4

Good to know about the contour set up. Looks like a great low buck solution.

jrmotorsports55

Yeah, those lines like the same fans I have.

tneyman

what brand of fan controller,do you recommend ,will a 65 amp,be ok,do the fans draw that much amps.

V8MiataMike

Right now I'm using an adjustable old school temp probe in the radiator that grounds the wire originally connected to (and grounded by) the Miata temp sensor. The original Miata fan output leads (+ and -) that powered the Miata fan now power a 75 amp Tyco relay. That relay provides the high amperage 12V to the contour fan.

The original Miata system is tied into the A/C system as well so when
I turn on the A/C the fans will run regardless of probe temp. It is working really well in terms of fan control.

I did however just buy a controller from Delta Current control. $80. Supposed to run a Taurus / Mark VIII fan (big time amp draw) for one of my other cars so I will see how that does.

Five-o-joe

Hi Mike. Would you mind posting a measurement of how much clearance you have between your radiator and the nearest accessory?

V8MiataMike

I have appx 2 1/4 inches between the water pump nub and the radiator "frame" area. It is appx 2 5/8 from the actual radiator core area (tube and fins). The next closest item is the power steering pump nub which is back another 1/4 inch.

tneyman

how did you mount fan shroud to radiator

V8MiataMike

There are 6 small holes in the shroud. One on each corner and one each on the top center and bottom center. I used those plastic pins (the kind used to attach a fan or trans cooler a radiator) to hold it in place that go through the core area.

The weight of the fans/shroud is actually carried by the lower lip of the shroud resting on the radiator cross piece at the bottom. The shroud is up against the tank walls and not touching the core itself (but very close!). If you look very carefully you can see the plastic pin circular head in the corner and center of the shroud in the picture from above.

movieboy4fun

V8MiataMike

Can you make a call on whether this setup cools better than your original "Martin" set up at a stop? I was going to try an electric WP just for fun in my project and follow charchri4's advice of " Go Big as you can" and go with a 27" x 19" 3 core Rad.

Thanks
Dean0

V8MiataMike

It absolutely does. The fans pull a significant more amount of air and the shroud ensures all that air flows through the entire radiator core area. At speed the fans and shroud continue to ensure the air flow across the entire core area.

But it is definitely a good idea to have the largest radiator core/cooling area possible. Go big for sure and the shroud and fans are in the go big spirit!

MRM331

Ducting the air in front of the radiator also makes a big difference. Any air that can slip around, under or over the radiator and into the engine bay raises the pressure in the engine bay lowering pressure difference between the front and back.

-Jason

MX-Brad

Speaking of which, do you still sell those radiator cowl covers? Would like to buy one if you do.

tneyman

I want to convert mine to sn95 set up,i am running the fox body set up,martins conversion,with the 11 inch fans on the front of the condenser,i live in phoenix,it wants to run hot,in the warmer months,i didn't know that I have to notch the frame,so the ac compressor will clear,are you using the mustang powersteering hoses,did you have to convert them,what did you do on ac hoses,any info would be helpful.

V8MiataMike

I used the stock Miata power steering hoses with a double flare fitting between the Miata high pressure hose and the Ford pump. I do not have a PS cooler at the moment and boy, the lines do get hot but I've had no issues.

I used the entire stock Miata A\C hose setup and actuallt bent/bolted the two Miata lines right onto the Ford A\C compressor.

topdownfun

While doing some recent radiator work ("while I was in there"...) I switched to the Contour fans. Mine is a '95 Miata using the SN95 accessories, including PS, AC, and even smog pump. After judicious trimming, the Contour dual fan assembly fits perfectly with "enough" clearance.In my swap I retained the Mustang's CCRM to run the fuel pump, A/C, and 2 speed fan relays. With the Contour fans, no extra controller was required, I used the Hi speed wire and the Lo speed wire from the CCRM plus a ground and that was it. Result is 2 fans on low speed and 2 fans on high speed. Clean installation, no more fan whine and no more pusher fans in the grill.



It's too early to tell how they handle the 100 degree temps of summer, but they have good reviews from the kids on the Mustang sites so I'm optimistic. In the meantime it's a clean install, and thanks to the OP for bringing it up.

TM

V8MiataMike

I have found it to be incredibly better. The amount of air moving through this shrouded radiator fan setup is miles ahead of un-shrouded fans in terms of air flow. It has to be even better compared to the pusher setup.

Nicely done using the CCRM. A real clean and factory engineered setup!

nnowa07

I also have the ford contour fans and an sn95 set up. I'm curious what wires you used from the CCRM? I'm using a MRM harness, and the only wires i have coming from my fans are the two from the plug at the bottom of the shroud- nothing from the fans. Do i buy those plugs separately? What do I plug in there? Do i need relays? A bit lost on the fan wiring... any help would be great! Thanks!

topdownfun

I don't have my wiring diagrams handy, so sorry if I add to the confusion. My fans operate with 2 fans on low and 2 on high, controlled by the CCRM, which has a high speed and a low speed wire coming out of it plus maybe ground. The way the fans get the low speed is by use of the resistor--there should be a resistor block on the corner of the shroud. The high speed wire goes directly to both fans from the CCRM, and the low speed wire from the CCRM first routes through the resistor before teeing into the high speed wire that goes to the fans. The other terminal on each fan is the ground. . So, on low speed, power goes from the CCRM to and through the resistor, then on the "high speed" wire to the fans. The CCRM's relays do their thing to make it all work. I didn't have a factory Contour fan harness and just made my own. So far, has worked perfectly, even in 100 degree weather, a/c on. (normal driving; I don't race).

MRM331

Hi Nick,
According to my records I kept the stock SN95 Mustang fan plug on your harness. This is a big pug with three heavy gauge wires running to it. This would have plugged into the Mustang single fan shroud. One of the wires in that plug is a ground and the other two are the high and low power wires. I'm not sure if a Contour fan shroud will integrate with that plug. What you should do is look on the Mustang Corral or other Mustang related forums for info on upgrading a 94/95 Mustang's fan to the Contour unit. Whatever they do is 100% applicable to your situation.

If the Contour fan only has a positive and negative lead you could simply cut off the Mustang plug from your harness, tie the high and low positive leads together and hook it up to the positive lead on the Contour fans and the negative lead to the negative. This will not give you a two stage setup but it will throw both fans on whether the SN95 computer wants high or low fans on, which will work fine.

As an aside, I think the Contour fans require a controller of some type to be actual two stage. Its a pretty antiquated and analog type of affair. I remember it going bad a few times on the Contours I've owed over the years and thinking it looked very 1950's at the time.

Good luck,
-Jason

nnowa07

Wiring isn't really my "A area" but I think I sort of get the gist. My issue is there are 3 plugs on the fan- 2 at the fan motors, one on the shroud with the resistor. Each plug has 2 wires (assuming a positive and a negative). I currently have a Ford fan plug wire (with the 3 wires coming out) going from the CCRM that MRM331 had installed into my harness. As he said in the post above, that includes the low speed fan, high speed, and ground wire. So my question is this:
Do I simply hook the negatives of the 3 plugs (2 fan plugs and resistor plug) to that ground, the low speed to the resistor plug +wire, and the high speed to the 2 fan +wires? Would that do the trick? Also any relays used? are they built into the CCRM or in my harness somewhere? Thanks for any help!
Here are a couple of pics- necessary or not.

nnowa07

Hey Jason, thanks for chiming in. It sounds like it is possible to get the wiring done so that the computer operates the fans in either high or low depending on which is desired. I'm hoping topdownfun will let me know if I'm on to something there. What do you think? Does my post above sound doable or am i missing something (wouldn't be surprised!). Any help is much appreciated- thanks again for the awesome looking wiring harness too!