Need ideas on how to bring coolant temps down on track
 

I've read the thread on cooling, but still have some questions some of you may be able to help with.

I have an 02 with a Rotrex SC. It is mainly used for track days. I have the intercooled Rotrex kit with an AEM FIC piggy and 420 RX8 injectors and a good tune. Smaller pulley..10 PSI, 207 RWHP. Stock 12" x 6" FMIC, AC condenser removed and the Rotrex oil cooler in front of an FM crossflow radiator. Stock fans with the AC fan wired to come on with the driver side fan (just did this and haven't tried on track yet). I had highish temps on track last year 220 was quite common. It makes it hard to concentrate on driving while worrying about my temps. I also have an FM oil cooler. I ran 100% distilled water with redline water wetter. My heater is still functional. I have a vented hood. I have ducted around the radiator the best I can. 180* Stant Superstat. I do NOT have a reroute. Some of my ideas to lower my temps are:

1.) Do a reroute and head gasket from 90-99 (cannot figure out how this will lower my temperatures, seems like it could only even them out)

2.) PWR fin and tube IC in lieu of the plate and frame (seems they allow more air through to the radiator) I actually picked up an MSM IC to try (it is a fin and tube) it’s only 8” X 8” …maybe enough for a Rotrex?

3.) Relocate Rotrex oil cooler to wheel well. I like this idea but I already have brake ducts in my fog light openings and IC piping in there. It will be one hell of a trick to get that all in there and get enough airflow to the Rotrex cooler.

What are your thoughts???

Out of your list I would honestly do the reroute imo.

Try to jump on Skou's next batch group buy for the rear cnc coolant spacer (its amazeballs quality)

Everything else for the reroute you'll have to acquire obviously.

1) the 94-00 gasket is to be used with re-route. without one, it will do nothing.
2) don't use the oem msm intercooler. it sucks

In addition to V's comments:

- Better ducting. Post photos of what you've got right now? Consider modifying the front crash structure to allow better airflow to the radiator (I'd outsource this to a race fabricator rather than DIY).

- Remove the AC fan, it's just in the way at track speeds. Mount the oil cooler on the back of the rad where the other fan used to be.

- TSE rad gives more cooling than FM.

--Ian

A reroute increases cooling for the following reasons:

1. The coolant picks up more heat from the engine because it has to traverse all cylinders. No shortcuts allowed.

2. With the spacer + Kia waterneck reroute, the water balance is altered so that more water flows to the radiator rather than the heater core. You'll notice after installing a reroute that your heater doesn't work as well. The increased flow to the radiator results in quite a bit more heat transfer. I don't know whether those with remote thermostats like M-tuned also see this effect.

3. Going to the earlier HG opens up flow passages through the engine. Again, more flow = more cooling. Mazda achieved the heat transfer balance in the 01+ engines by closing off holes in the HG. So, good at OEM levels, not so good at your levels.

Good luck. Looking at your mod list, I'd recommend spending less time on FM's website and more time here. FM has some good stuff, but choose carefully.

I vote remove ac fan first, then TSE rad & reroute if that doesn't do it.

Möbius 2.0 will run the TSE rad because Ijustdon'twannafuckwithcoolingnomore.

That is if Mobius 2.0 runs a miata radiator....

scirocco style crossflow ftw

#2 had a huge effect on my car.

I may try your second idea since it's free. This would allow more flow through rad and close up the hole in my undertray that allows air through existing oil cooler and into engine bay

Will do a reroute also (with 90-99 head gasket)

Have a good read ! https://www.miataturbo.net/race-prep...-thread-79930/

Any tube and fin intercooler should flow significantly more air through it.

MSM intercooler might be enough for a rotrex. Worth a try if you already own it.

But I thought is had more capacity than the non-MSM?

And from the Cooling Thread, Post#378: "To add another data point, we ran a stock plastic end tank automatic radiator fully ducted from an airdam with a reroute and blocked open thermostat on a stock horsepower racecar for 14 hours this weekend. Coolant temps never rose above 190 F on a 85 F ambient day. "

?

Intercooler not radiator.

that makes sense. and yes, after pulling the oil cooler sized intercooler off my msm they are stupid.

PWR IC didn't help. Reroute with 94-00 head gasket going in now.

Trackspeed Dual Core Race Radiator

:party:

The coolant flows through the heater core much slower since the pipes are smaller and of course the heater core blocks flow as well. This gives the water more time to pick up heat from the 2nd, 3rd, and 4th cylinder before going out. Since the sensor is at that outlet the measurement is high.

When you have a big outlet however theres more water flowing through to pick up the heat so the overall temp is lower.

You have a fixed heat output from the engine and you're changing the amount of water you throw at it. Does that make sense?

This will be next if the reroute doesn't do the trick

Yes!

Already mentioned, but post pics of your shrouding. I don't think a 200whp miata needs every cooling mod in the book, sounds to me like something is off. Given how bad miata ducting is, that's my guess. No matter how good your radiator, water pump, etc etc is, if you only have X amount of air going through the radiator, that limits how much heat you can shed. Also if ducting can be improved, that's cheap and lightweight too.

While I have no regrets going to the TSE radiator, I didn't really need need it. Andrew just talked me into it while I was buying several other things from him.

At 300hp my smaller aluminum radiator was doing a pretty good job holding temps below dangerous levels in 100º heat with full radiator cowling.

Do the cowling first, then, if necessary, give Andrew all your monies.

M-tuned reroute is done with 94-00 head gasket. New 949 water pump. Ducting all redone. (went a little crazy with "Great Stuff"!) Removal of AC fan. Moved my FMIC back closer to the rotrex oil cooler to allow a larger path of air around it to the radiator. I have a track day July13. There are (5) 1/2 hour sessions so I ought to know if there is any improvement. If there isn't there will be a (mostly) very nice street legal track Miata for sale!

Has anyone figured out a way to fit 2 fans with the bigass TSE radiator in an NB with a 1.125" front bar? Objective is best a/c with stop'n'go driving.

Funny I was looking at how much room I had (without AC fan) to install this if all else fails. I would have to relocate or replace my OEM fan because it won't fit with a 3" radiator. I think Andrew recommends one fan in the middle. Maybe one bigger fan would be enough. I'd check with Andrew. I'm betting someone has done this

I think it's impossible from the pics I've seen of that radiator in a NB.

I think it's a lot easier (possible) to use a smaller radiator, and bigger fans.

I've got a TSE rad and a big-ass spal in my car, but I eliminated AC and am using the AC condenser mount holes for the bottom mounts on the TSE rad.

https://www.miataturbo.net/attachmen...ine=1436219563
https://www.miataturbo.net/attachmen...ine=1436219563
https://www.miataturbo.net/attachmen...ine=1436219563

Note that the TSE rad only has one set of fan mounts welded to it, so you'd need to address that before you could even think about fore/aft clearance.

--Ian

Good to see I'm not the only fan of the aluminized tape!

Drove the car to and from work today... about 25 minute drive each way. It was pretty cool today. 60s. Temps would not go over 180*! That's a first! Normally, even with the 180*tsat it goes right up to at least 195* right away. I got a CEL PO128. I think that's thermostat is stuck open. Is the computer looking for it to heat up to 195* in a certain time? I'll live with the CEL if I get lower temps

One thing I am seeing is you do not have the plastic undertray that goes behind the radiator.

You might have the entire front ducted so whatever goes into the front bodywork gets forced though the radiator, good, but the air flows due to a pressure differential.

Right now what is likely happening is that air is going under the bumper and then when it passes the radiatior is spilling up and causing all the air in the enginebay to be turbulent. By installing the undertray (or some other ducting that goes along the bottom and sides ) it creates a low pressure zone behind the radiator and the engine bay, helping suck hot air out along the trans tunnel

The air in the engine bay is being slightly pressurized and/or backflow due to this turbulent air, so the flow from the ducted side of the rad into the engine bay is poor at speed.

If the undertray was in place the engine bay pressure would be lower and then the air would move itself though the radiator faster, thus transferring heat out of the rad system at the same time.

That is CODRUS, not me. I believe he was just showing the fan clearance not asking for help. I have my belly pan in place, although it is butchered up to fit!!

Yeah, Ian (Codrus) has his shit on lock, no worries there.

Moving the IC back to allow more air around it and over it made a big difference for me when I first installed my turbo. I originally had the IC way up in the bumper mouth and it was stifling the airflow badly. Moving it back helped a lot. Then as I turned up the power, the engine oil cooler had to be added, and the triple pass radiator with Spal fan and shroud (still has A/C). Even with the silly A/C condenser in the way it seems to be doing pretty well in reasonably hot weather on the track. I haven't run it in the middle of the summer here since the rad/Spal addition because it is miserable to try, even with a cool shirt.

Yeah, those are my photos, uploaded to illustrate clearances with big-ass fans and TSE rads.

The under tray was off in those shots because I was installing crap at the time, it gets put on for track days. Sometimes I'm lazy about putting it back on after taking it off to do something, it hasn't proven to be necessary for keeping the car cool on the street in San Jose.

Actually, the only time the car has ever overheated on the street was when I tried to run the AC in Las Vegas with ambient temps of 117F. That was a decade and many cooling system revisions ago.

--Ian

<p>&nbsp;</p><p></p><p>That might be my issue as well. MAT stays low, but cannot boost and run A/C at same time if ambient is 100*F. I plan to do the reroute first, and then, if more is needed try to get some air to bypass the FMIC. So you think it would work to cut back some ot the top of the bumper cover inlet, and allow air to flow over the actual bumper? (I'm not looking at the actual car).</p><p>Conversely, don't some people purposefully duct such that all air is forced through FMIC, Condensor, Radiator in that order (zero bypass)?</p><p>EDIT: I also have foam stuffed between the sides of the IC and the Air Guide. I'll pull that and see if it helps. That should bypass some of the air around the IC and guide it in the normal, stock, manner.</p><p>&nbsp;</p>

If you look at the top of the bumper mouth there is some room to trim both the bumper cover and black plastic inner bumper to give another inch or two of inlet area through the mouth most of the way across. I also sealed the huge gaps between the bumper cover and black inner bumper with cut blocks of upholstery foam. There are openings big enough to put your fist through that bleed off air towards the outsides and into the wheelwells.

Upholstery foam is cheap at any fabric store.

Did you do this bumper trimming? Do you have pics?

Yes, I opened mine up. And I sealed up inside the bumper cover as I mentioned (which is probably even more important than making the opening larger). I'm having some browser conflicts with trying to get to my photobucket pictures, though.

I tried that on my car back in 2008, but it was condenser, IC, radiator, all sealed 100% to each other. It resulted in better a/c performance, don't remember on AITs but I think they were better, I know they didn't get worse, and it overheated on the radiator big time, especially at highway speeds.

Ended up un-sealing them so the radiator could get some clean air, which helped a lot at keeping the radiator happy.

^Yes. It is more important that the radiator get air than the intercooler.

I found those pics. The rear end of the black bumper support is scalloped and has a spot in the middle for a plastic push pin that comes through the bumper cover. It isn't needed to support the bumper cover. It is redundant and blocks airflow. I started by trimming back the three scalloped areas to allow more opening but not opening up to the interior of the bumper support. Later, I trimmed it forward a bit more, exposing the chamber of the bumper support after determining it was indeed a closed chamber and would not leak air that was intended for the radiator into other areas. A larger bumper mouth opening (within reason) is a good thing to me. There is slightly less of a bottleneck there now by many square inches. Pics to follow from mobile app by phone in a minute.

Pics are worth a thousand words! By the way I've always loved your avatar.

Need ideas on how to bring coolant temps down on track
 

She has served me well.

Those pics are from the ground looking straight up. The exchanger pictured is my oil cooler which lives in the nose and is mounted to the crossbeam behind the bumper support. Air goes up in between the black inner bumper and the crossbeam, so my car is set up to have it go through the oil cooler there.

I have since cut the inner bumper back almost even with the natural line of the trailing edge of the bumper cover in the pictures.

reroute and moving IC back fixed my issues!! 180* around town, about 195* on track when it's 90* ambient. I'm a happy guy! Now I can work on my car wants instead of my car needs!! Thanks for the help

Nice, glad you got it sorted!

Before and after pics?

The IC was mounted where Kraftwerks designed it to be mounted. I had room for the AC condenser and Rotrex oil cooler behind it. I removed the AC condenser (and AC and power steering components) and found I could move the Rotrex oil cooler closer to the radiator, so I did, and this allowed me to cut some of the IC piping off so the IC ended up about 2" further back from the mouth. This allows more air to get around the IC and hit the radiator. I have before pics but it looks like any other Rotrex Miata with Kraftwerks IC. I'm an old man who is not too good at loading up the pics. It's a good day when I can get Harry's Lap Timer to work in my car!! Better day when I can load the video on to my lap top. It's a miracle if I can get it to Youtube! HAHA The reroute was good for at least a 10* degree temp reduction. Moving the IC back got about another 15*!! I was always at 220* or slightly more on track when the ambient was in the 80s. 195* at 90* is awesome. The other thing is with the lower water temps I have lower oil temps too. Win/win

<p>&nbsp;</p><p>&nbsp;</p><p></p><p>EDIT<s>: It's really funny how I tried to keep as much of the Air Guide (I think what you are calling the Inner Bumper) as intact as possible, and yes, my FMIC is right inside it. I cannot move it back due to the evaporator can, so I will have to cut the top out like you did</s></p><p>EDIT: Went out and looked more closely at the car from above and below. Now I see where Six cut the actual bumper (hence called it the Inner Bumper), which is in front of, and above&nbsp;the Air Guide. Now I understand the pictures. So, I can leave the air guide alone and direct some of the flow above it and the IC (the top section of the Air Guide just faces the top of the IC.</p><p>If&nbsp;tomiboy got 15* CLT&nbsp;improvement, that was great. As I think I mentioned, my AIT's are no issue, so bypassing some IC air would be no problem. We will see how much cutting the inner bumper does, vs his moving the IC back.</p><p>EDIT <s>Six, what year car are those pictures from?</s>&nbsp;&nbsp; NVM, now I know what I'm looking at.</p><p>&nbsp;</p><p>&nbsp;</p>

It's amazing what you see when you lay on your back and look upward into the bumper mouth, isn't it?

LOL. We've all been there . . . "I just don't have the energy to get up off this creeper right now . . ." Especially after a big fight with a bolt somewhere.