Miata cooling system thread
07-25-2016, 12:42 PM
#601
Says the hundreds of kits sold and exactly zero issues reported 
Across this country, Canada, Europe, etc.... plenty of places with a lot more rainfall than where we are.
There are a couple spots in the engine bay you actually wouldn't want a vent directly over during a storm, so naturally we avoided those areas, and the template we provide means nobody will accidentally put the vents in the wrong place. We get the question about water probably once per week from someone who is guessing that is is an issue (as you are). We have a perfect record of it not being an issue for anybody.
Across this country, Canada, Europe, etc.... plenty of places with a lot more rainfall than where we are.There are a couple spots in the engine bay you actually wouldn't want a vent directly over during a storm, so naturally we avoided those areas, and the template we provide means nobody will accidentally put the vents in the wrong place. We get the question about water probably once per week from someone who is guessing that is is an issue (as you are). We have a perfect record of it not being an issue for anybody.
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07-25-2016, 12:58 PM
#604
For me it rests right up against the bottom of the intercooler. Small spacers had to be used to attach it to the front air dam.
Driver side, leading edge needed to be trimmed for piping (through fender) . Passenger side, same thing plus a slot for the pipe to pass back into the engine bay to throttle.
If this where plumbed conventionally, then another hole would be needed for the driver side. Over the top plumbed intercoolers will need no modification to the tray.
Cliffnotes:
Anything you need to do to a factory tray, you will do to this one, but it's not floppy and hole saws work well.
Driver side, leading edge needed to be trimmed for piping (through fender) . Passenger side, same thing plus a slot for the pipe to pass back into the engine bay to throttle.
If this where plumbed conventionally, then another hole would be needed for the driver side. Over the top plumbed intercoolers will need no modification to the tray.
Cliffnotes:
Anything you need to do to a factory tray, you will do to this one, but it's not floppy and hole saws work well.
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07-25-2016, 01:12 PM
#605
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Re downflow/crossflow
Probably the same reason most intercoolers are crossflow and not downflow like early FM. All packaging constraints being equal, crossflow on the wider dimension of a rectangular shaped heat exchanger would allow more time for the fluid to exchange heat for a given volumetric flow. It may also allow. for some configurations, a multi-pass operation like the trackspeed setup. If radiators where square, I'd imagine design would be trivial between the two.
Probably the same reason most intercoolers are crossflow and not downflow like early FM. All packaging constraints being equal, crossflow on the wider dimension of a rectangular shaped heat exchanger would allow more time for the fluid to exchange heat for a given volumetric flow. It may also allow. for some configurations, a multi-pass operation like the trackspeed setup. If radiators where square, I'd imagine design would be trivial between the two.
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07-25-2016, 02:09 PM
#606
Bingo. Longer tubes = more efficient. Triple pass is also slightly more efficient because forcing the water through only 1/3 of the radiator increases the velocity of the water through the tubes, which improves heat transfer between the radiator and the coolant. This is why all high-end hot-rod radiators are both crossflow and triple-pass.
The velocity thing makes perfect sense though -- and even single-pass cross-flow in a Miata configuration will have more velocity for a given flow rate than down-flow.
It also seems like you can improve the heat exchanger frontal area vs. tank frontal area ratio with crossflow?
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07-25-2016, 02:11 PM
#607
Says the hundreds of kits sold and exactly zero issues reported Across this country, Canada, Europe, etc.... plenty of places with a lot more rainfall than where we are.
There are a couple spots in the engine bay you actually wouldn't want a vent directly over during a storm, so naturally we avoided those areas, and the template we provide means nobody will accidentally put the vents in the wrong place. We get the question about water probably once per week from someone who is guessing that is is an issue (as you are). We have a perfect record of it not being an issue for anybody.
Across this country, Canada, Europe, etc.... plenty of places with a lot more rainfall than where we are.There are a couple spots in the engine bay you actually wouldn't want a vent directly over during a storm, so naturally we avoided those areas, and the template we provide means nobody will accidentally put the vents in the wrong place. We get the question about water probably once per week from someone who is guessing that is is an issue (as you are). We have a perfect record of it not being an issue for anybody.
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07-25-2016, 02:30 PM
#608
This is really what I was grappling with. The fact of the matter is that longer tubes are not more efficient per se. As the coolant cools more, the delta T reduces and less heat transfer happens. So, that, by-itself, wasn't making sense to me.
The velocity thing makes perfect sense though -- and even single-pass cross-flow in a Miata configuration will have more velocity for a given flow rate than down-flow.
It also seems like you can improve the heat exchanger frontal area vs. tank frontal area ratio with crossflow?
The velocity thing makes perfect sense though -- and even single-pass cross-flow in a Miata configuration will have more velocity for a given flow rate than down-flow.
It also seems like you can improve the heat exchanger frontal area vs. tank frontal area ratio with crossflow?
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07-25-2016, 04:19 PM
#609
Says the hundreds of kits sold and exactly zero issues reported Across this country, Canada, Europe, etc.... plenty of places with a lot more rainfall than where we are.
There are a couple spots in the engine bay you actually wouldn't want a vent directly over during a storm, so naturally we avoided those areas, and the template we provide means nobody will accidentally put the vents in the wrong place. We get the question about water probably once per week from someone who is guessing that is is an issue (as you are). We have a perfect record of it not being an issue for anybody.
Across this country, Canada, Europe, etc.... plenty of places with a lot more rainfall than where we are.There are a couple spots in the engine bay you actually wouldn't want a vent directly over during a storm, so naturally we avoided those areas, and the template we provide means nobody will accidentally put the vents in the wrong place. We get the question about water probably once per week from someone who is guessing that is is an issue (as you are). We have a perfect record of it not being an issue for anybody.
I'm not putting hood vents (if i even need them, we will see) without a car cover. (which i need to get anyways lol)
Plus, I am a little girl. I'm all emotional. I feel better about it.
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07-25-2016, 04:35 PM
#610
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I hope not. Like i said, it only seems to happen when traveling at a high rate of speed. I've got a couple ideas i'm going to try, first being wiring the fans in parallel.
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07-25-2016, 04:37 PM
#611
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Theoretically fans will just impede air. At high speeds its all about forcing air in with ducting, and letting it out of the engine bay somehow. Fans would actually be a restriction.
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07-25-2016, 04:37 PM
#612
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It fit so bad i didn't even try to install it on the NB, which made me kinda sad. I may sell if someone wants it.
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07-25-2016, 05:18 PM
#616
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Last time i lifted the front and started it until warmup, let it cool and repeated a few times was almost 2 years ago now when i installed the reroute.
But i have been checking it periodically throughout the season.
But i have been checking it periodically throughout the season.
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07-25-2016, 07:40 PM
#617
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My WRX vents are placed so water falls between engine and radiator. I don't want water in my spark plug holes and the location is good for pressure differential.
I'm using a crossflow triple pass stock-car racing radiator because I wanted to try it. I'm happy with it but it is all custom.
I'm using a crossflow triple pass stock-car racing radiator because I wanted to try it. I'm happy with it but it is all custom.
Now I wonder how the Evo 8/9 deals with it, as the vent is more just a flat opening right over the turbo.
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07-25-2016, 08:59 PM
#618
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I was wondering about this as I drove by a WRX today. After reading a post earlier in this thread saying how as air rushed outwards with the singular vents, it prevented water from going into the bay once at speed. Looking at the WRX, using the vent as an air intake rather than exhaust I thought that lots of water would enter at speed. I knew Subaru would come up with a clever way around it.
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07-26-2016, 03:44 PM
#620
I replaced the o-ring and it helped a little, but didn't fully solve the issue. The small amount of water just makes the fluid look a bit milky. I'm sure over the years it would cause corrosion in the system, but I will yank the system out before then.
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