I'll share my setup for my Gridlife Touring Cup trim turbo BP NA. Power is 225whp. In ~70*F ambient temps, the coolant temps run 180*F in clean air, 185-190*F in traffic. Oil temps 220-260*F

Radiator: SuperMiata Crossflow
Intercooler: Vibrant 12800. Intercooler has its own duct to prevent air from bypassing it with about 50% open area.
Front bumper: Racing Beat Type 2 (block offs will be added for cooler events).
Radiator ducting: OEM crash bar removed, aluminum ducting, gaps sealed with bulb seals and foam blocks. Intercooler is spaced 8-10" in front of radiator. Air can flow above intercooler duct directly to radiator.
Oil cooler: 13 row Setrab mounted where the passenger headlight assembly was. Air is fed through a modified turn signal assembly into a duct for the oil cooler. Exiting air directly into engine bay. I'm likely going to redo this to duct it out the headlight lid.
Hood vents: Custom large vents.
Birch undertray from air dam to subframe.

Recommended intercooler for a stock motor 200 to 220whp?

As for the bumper support, what is that exactly? I had the bumper off to modify the original black inner lining. Due to the mounting locaiton of the IC, i couldn't reconnect it the same way as it is stock as the bumper mount points are about an inch above the lowest portion of the IC and come within about 5mm of touching it, I had to use a long bolt and spacer on each of the 3 connection points to connect it to the original locations but instead be about 2" below for the bottom portion of the inner liner's lower panel to clear the intercooler. Once that was done, I was then able to reconnect to the main undertray from it back to the stock locations on the subframe.

Is it worth it to cut a hole in it for airflow the oil cooler? I have a FM oil cooler that mounts directly below the crank pulley but now with the undertray it is completely blocked from any air movement. Lastly, how important is it to reseal the 'sides' of the main undertray? I had originally cut them off in order to have better routing for brake duct lines. Seems like there's just never enough space for everything and now those are gone b/c I haven't figured out how to fit them, there's just a big gaping sideways gap on either side of the undertray.

I have hood vents on order that have some testing data from Track Dog Racing so I'm hoping those help a ton. I'm still getting overheating temps just doing steady 60MPH in 95F heat.

That would help a ton. Right now it has 2 brackets to mount it to the stock tow hook locations and it sits 4 to 5" forward of the ac condensor.

I'm new to FI in general. What are acceptable intake air temps for my relatively low end setup? Usually when driving I'm between 90F and 110F on the IAT. I haven't been back to the track to see what it is there, but I imagine it would be near the same.

Lastly, I have a feel I know what the answer is going to be, but I'm going to ask anyways. I stuck my leaf blower up to a wind speed measurer and got about 60MPH. I stick the same setup to the front of my IC and the wind speed on the back side of the radiator and got 2mph. I know its not quite the same volume as real air so I rigged the wind speed measurer up to sit behind the radiator and took her out for a spin up to a quick 60MPH and again got a max of like 2.1MPH. Should I expect to see much higher speeds once everything is sealed up or am I missing something? I figured outside of the coolant temperatures being lower (which seems like not a very easily testable scenario) this would be a good way for me to see the improvement of each attempt at improving cooling? Anyhow, seemed like a good idea at the time.

Just as Emilio explained, you need to do all of it. All the air that goes into the grille needs to go through the radiator. That's probably the single most critical piece of the puzzle.

You have no airflow at the back of the rad because air is flowing around instead of through it.

Everything you need is here in this thread. Do it all and profit. Do some of it and overheat haha

You mean there's money at the end of this?? On a more serious note, yea I hear you. Parts are on order!

tfbmiata,

Here is an ancient thread about the bumper support delete.
https://www.miataturbo.net/race-prep...r-60104/page2/

Also search here for "vegas" and "bullet" builds.

Just as a reference. A bone stock NA or NB with air conditioning will run excessively high coolant temps on a warm day, steady state 75 mph cruising. And that is completely bone stock in perfect running condition. Double the power, remove some of the OEM ducting, block the radiator and things go from bad to kaboom. That is why this thread exists.

and a word to the wise (again) ...

For those running the stock setup, be aware of the air flowing back from the inlet area into the nosecone/bumper garnish. People concentrate on the area around the radiator, but you need to seal all-of-it.

I'm happy to report a significant improvement in my cooling situation. From before I did the following:

• Installed 2 12" spal fans set to turn on at 190F and off at 180F. This will probably be too low but I wanted to start aggressive
• Replaced my hacked up undertray with a full one and only cut it where it absolutely had to
• Used stock aluminum cut to stop open areas from in the inlet on the bumper from escaping out of the sides
• Used aluminum tape in easy to reach open sides at the top to seal them off
• Remove the black bumper support but left the cross brace. This created a HUGE opening for air to flow over the top of the intercooler to the ac/radiator.
• Added stock aluminum to either side of the intercooler to stop air from escaping out of the sides

The sealing is not perfect and there is probably still some seepage but this was good for a first attempt. I also am pending my hood vents to arrive for what I would call my final form of my first attempt at improving cooling. Already before those have gotten here, I can now hold steady state at 80mph and keep the temps in check with the ac on fully blast. The temps do start to climb with some spirited driving, but as soon as I turn off the ac, the cooling system takes over again and brings the temps down. I'm not sure it is ready for a 95+F track day, but I'm hoping with the hood vents, I'll see the spirited driving with the AC on still be under control and then I'll feel like its ready to return to track in the summer. I'm already starting to consider what I'll need to do if the temps stay too low for "cold" (40 to 60F) days.

Any thoughts on opening the underside of the tray for my oil cooler? I have the low mount Flyin Miata one. I'm considering just leaving it as is right now (which is covered by the undertray) and then only opening it or maybe even adding a small fan to it instead of opening the undertray if I see oil temps get beyond 240F during a track session. Thoughts would be greatly appreciated. Also thanks a ton @Blkbrd69 for moral and text based support! Actually thanks everyone. I would have never solved this without this thread!

I found massive success with a similar ducting technique.

I just want to note this here, since others are using aluminum tape to seal gaps in ducting as well.

The standard very thin aluminum tape, that is super heat resistant (and you would use on a wood stove, etc), is super thin and brittle. It usually breaks down within a few thousand miles (or a few track events) on my car. I've found that I can get a full season out of "waterproofing tape", found at walmart, it's MUCH thicker with a thicker adhesive that sticks forever and doesn't break down like the thinner stuff. Just wanted to get that out there. If someone knows of a better tape or material, I'm all ears, because I've tried quite a few.

For your oil cooler I'd probably leave the bottom sealed, it's bad aerodynamically to let air in there, I can't get behind the idea of that unless you just really need the cooling. I'd like to hear other's thoughts on that.

Ducting air into the undertray behind the radiator will reduce flow through the radiator. I wouldn't do it. Mount a fan or put the oil cooler somewhere else.

Appreciate. It, yea I'm thinking a small fan if/when I see temps getting to a certain point dictating the need for it.

EDIT: Quick question, any one running E85 for cooler engine temperatures? The web searches seem ripe with people saying it makes their setup run cooler on track days, but a tuner I reached out to about the same said it was BS.

E85 lowers coolant temps for any given power level. In most cases, it will lower temps even at higher power output. Lower combustion temps and richer mixture contribute to draw heat out of the head. Lower EGT's too.

I know its not exactly a quick fix, but I assume based on what you are saying you would recommend it to continue to reduce temperatures?

Wasn't specifically making a recommendation. Just adding some data. That's up to you.

Alright alright, keep your secrets. :P

As for anyone else in the future watching this thread, second report back, after getting the car nice and hot idling (201F) about 30 seconds into driving between a few stop lights and I was already back into the 180s. Clearly the ducting and undertray are uber critical! Thanks again everyone. Still pending my hood vents for my final form.

Switching to E85 to assist with a marginal cooling system certainly sounds like a Band-Aid I don't want to rely on. I won't speak for Emilio, but I know he is smart enough not to compromise a race he's competing in by cutting it that close on cooling system tolerances.

Make your own decision and not rely solely on my info. I don't actually have an hard answer for you so there is no "secret" being kept. If you are trying to avoid making a decision and hoping for a spoon fed answer, you're on the wrong forum ;)

So far you're asking great questions, listening, making changes based on well researched data. Keep doing that!

Wanted to further update for future people, after doing all the shrouding etc, I was able to keep my temps 'under control' on the highway at 95F + ac on, but they would still creep up into the 205 to 210 range. I added 2 of the 7 vents from the DCN hood vent kit and now have a hard time getting the temps up passed the 180s much less 200+. I have my first track day with them on the 23rd and it will be a hot Florida day so I'll report back. I'm guessing that my not-so on the limit driving, plus not actually having the AC running during the event will keep temps super low. The decision for 2 out of 7 was for aesthetics, its still a street car as well and I didn't want to look like a flaming ricer mobile and haven't yet decided if more vents is more flaming ricer or not.

I've gotta ask, and only because I very much respect and trust what you have to say - do you think there are any downsides to this? Cutting out that very beefy support and bolting in a much smaller one seems like a good idea for weight savings, packaging, and airflow - but do you think any chassis integrity is lost? Seems like that might make the chassis more flexy to me, I've always been skeptical about this mod unless you are welding in something beefy in its place. Some of the bolt on thin-wall round or square tubing solutions seem weak.

Obviously, cutting away part of the chassis makes it weaker. Not hidden secrets there. We added a brace to ours to regain some stiffness. YRMV.
The brace kit never went into production.

https://cimg1.ibsrv.net/gimg/www.mia...35c5bf63ba.jpg
https://cimg3.ibsrv.net/gimg/www.mia...58faf052f2.jpg

https://cimg2.ibsrv.net/gimg/www.mia...86e6856d52.jpg

Thanks Emilio! That's about what I thought. That's a cool brace you guys were prototyping, love to see stuff like this from you guys even when it doesn't make production it gives the community some good ideas.