Solid Vmount set-up right there... seriously, if you kept all of the measurements for your ducting and part numbers for everything that you used, you could market this man... I'd buy it...

 

take 40 ounce's setup as an example of how to properly do a v-mount setup. i also have no clue why everyone is telling you to focus on your intercooler ducting as it is secondary on your priority list for fresh air versus the radiator and oil coolers.

the radiator should see at least 50% of the air coming through your front bumper and should have ZERO gaps on the sides for air to be pulled from anywhere aside from the opening in the front bumper cavity of the car. we have seen no pictures of how your setup is ducted so who knows what the root cause of your temperature issues is. does the car have an undertray that seals the passage to the radiator? does it have an opening after the radiator for the hot air to escape? who knows, and that will cause a massive issue with ANY setup. beyond that, the stock fans turn on at 95C so if you are thinking the whole way the car functions just because the cooling system has been upgraded, well it isn't. utilize your fan high speed circuits and use the ways to turn the fans on at lower temps in order to keep the temps lower, once they rise it is VERY difficult for the fans to pull them back down especially if they are on the usual low speed turn on settings on an upgraded setup..

what you may need is an experienced race mechanic to look at your car personally and give you their advice, as these are all just speculations without various pictures to assist you with on.

an example of poor ducting can be seen by simply pulling off your undertray and note the water temps instantly rise by about 5% and more quickly, because it is recirculating the hot air from the exit of the radiator back across the front of the radiator. the cooler the air is across the radiator the better it can do it's job. secondly, the fans lose efficiency if there is gaps around the radiator for it to pull air from the front opening of the car. thirdly if the fans have nowhere to push the hot air then they once again lose their efficiency since they cannot evacuate the hot air.

the myth that v-mounts cool the intake charge better is also false, they are further back in the air stream so they in fact cool the intake temps more poorly but the main focus is and should be put on the cooling system first and foremost anyways. sitting in traffic your v-mount will heat soak more because it's seeing no air and is being baked by the radiator heat. this is normal as they are meant to be efficient while moving, not stationary. front mounts are king of intake charge temp cooling, but they drastically sacrifice water temps to do it, which is bad business in rotary applications. if a v-mount is ducted properly even a small fan could keep it much cooler while stationary, which i see rarely utilized. intake temps can be further cooled more efficiently with a secondary injection system in the intake stream such as water injection, methanol injection, water/meth injection or any mix of alcohols and or water which allow v-mounts to be set back to the standards of a front mount, even moreso.

just like your intake and exhaust have to be optimized flow wise for power, so does your cooling system airflow and air paths the higher you go powerwise.

 

YOU MUST UPGRADE YOUR THERMOSTAT AND FAN SWITCH

its the cheapest and best thing that will help the most evar!

 

Yup. Despite its reputation, the stock cooling system on this car is very good - if the fans are set to come on significantly earlier than the stock settings.

 

I am not sure if I read this so I apologize if you mentioned it already... When you modified the radiator, did you add a plate to separate the two endtanks? This would force coolant in, down, up and out of the radiator forcing it through the cooling channels.

And on your AIT's, they will go up when sitting in traffic. There is no cool air passing through the IC to cool the charge. After a few moments of regular driving they should start to cool back down.

I went from a FMIC to my current V-Mount setup and I could not be happier. Temps are definitely improved though I would not say they were ever bad with the FMIC. As others have said, its all about the ducting as far as coolant temps are concerned.

 

Hi all,

thanks for all the responses,

I do have the baffle in the endtank to me it in to a dual pass radiator, and at the moment it doesnt have the undertray, which I will be putting in tomorrow. hopefully this helps with the temps, but cant imagine it helping temps while stationary ? at the same time Ill add some ducting and see if that helps, and probably wil be adding a turbo heat blanket as well, which should help with heat soak. hopefully a comination of these little things will help with intake temps as well as water temps (which Im more concerned about going up while stationary)
so with the thermostat do you guys mean to just replace the stock one or get a different one that opens at a lower temperature? The fans I will be getting it to turn on at say around 92C when I go for a tune


thanks

 

The fan switch from FC's works to turn the fans on earlier.
The Miata thermostat drops the opening temperature to 180*F.

 

I have my Power FC set for low fans to come on at 87C, high fans at 92C. Granted this is pretty low, but it really helps control temps here in Arizona Summertime driving. BTW, the things you mentioned above are not "little things." They will make a significant difference IF your engine is healthy and the rest of your cooling system is working properly. Again, best of luck!!

 

How did this turn out for you??

Ducted with a splitter as well as the splitter having a reflective barrier on the bottom goes a long way to keeping rad heat from rising up on the IC face, even reflective barrier on the end tanks will help. They certainly do not heat soak near as bad as a SMIC in this application when done properly, and while they are more prone to heat soak than a FMIC they do not kill airflow to the Rad core, which is the main reason for a VMIC. A rotary needs good airflow to the radiator a boosted one needs a good IC setup as well that doesn't compromise that issue. For that alone, you really can't do too much better than a V-mount.

OP, seal off airflow around the core, put a splitter in there as well and I think you will notice a difference for sure. From the pic itself the IC core is big enough for moderate power. It shouldn't be too much of a issue, but I have no idea on fin density or core quality so...

~S~

 

After closing the gaps, you can always get a vented hood.

 

how did you set your PFC to do that?? Is there step by step instructions for this? And when does the fans come on at stock settings?

 

Do you still have the stock intake temp sensor?
that could be giving you false readings due to heat soaking and make you think the intercooler isnt working great.

 

Your undertray is the main problem right now. Put that on and you will see for sure a 5*C drop in temp while cruising. Right now your air is being pushed under the car, and not directed through the radiator/intercooler.

 

You need a datalogit to set the fan temps on the PFC.

 

Here's another pic of the height the radiator is mounted at, as you can see the car is quite low hence Im reluctant to give me more angle, I might consider raising the car abround 10mm and lowering the bottom of the radiator around 10mm as well, will this help with cooling in your opinion?



thanks

 

What asi radiator did you get.

 

ful aluminium for the fd, I modified it with the baffle so its a double pass now,

 

ok I found out that having the idle set to 1100 really affects your idle water temps.

after dropping it to only 850~900 the idle water temp is rock solid at 88C.

I have now just finished replacing the thermostat, the old one had a broken seal (and broken rubber bits no where to be found lol) at the same time drained half the 50/50 coolant I had in there and put in 4L of demineralised water to make it around 66:33. After starting the temps wont go above 83C rock solid, I will report on how it goes in traffic

 

If you can squeeze more angle out of your radiator that will help, too.

 

I had the same size intercooler as yours, but it was mounted more upright and had a induction electric 12 inch fan that also blew circulating air where the vaccum hoses are on top of the rotors where it is hotest.

It was manually activated from the panel inside and kept my FD engine cool during stop and go traffic or idling, never reached 90 F. I turned it off during WOT or freeway driving. Maybe in your case you could duct it to suck cool air from the front and to the top side of the engine?

 

ok just been out driving abit, now the temperature is sitting at 82C when on the highway,
idling its still creeping up above 95C, I was sure before it was staying the same, Ill lower the idle a bit more and see if that helps. but yea I was gonna give the radiator bit more angle today but decided to keep it at the current height cause I dont wanna rip or scrape the radiator off

 

cars I think running very rich during idle, showing around 5% injector duty and if idle for long enough it will start to smoke which looks like fuel to me, typically what injector duty should you be doing around 800rpms ?

 

Has anyone had success dealing with heat soaking of the i/c by mounting the radiator in the upper v-mount position?

 

Damnit temps are still climbing in traffic, defiantely dropped the overall temperature but If I sit for around 10 minutes if will keep rising and rising.

Is this actually normal ? could a bad radiator cap do this ??(cheapest next maintenance lol)