My question is geared to the turbo miata track drivers out there and their cooling systems.

Last track event i attended with my v-mounted intercooler (CX RACING/E-BAY), fully ducted, vented hood, any koyo 55mm radiator i was seeing 230*F temps. I would guess ambient temp was 70*F TOPS. Temp sensor is in the spacer in the back of the head.

This pic shows the ducting, 1/2 the air into the radiator, 1/2 the air for the radiator. Sides, top, everything is ducted to be forced through the radiator and intercooler



My setup consist of:
koyo 55mm radiator
Coolant re-route w/ heater core return (which generally goes under the exhaust mani and back to the water pump inlet) goes post T-stat.
T-stat is in the back of my 99 head between the spacer and the head which then goes back to the radiator.
2 bottles of water wetter mixed with distilled water.
No rust anywhere, no gunk caught in the radiator or anything blocking it.

My question is how are all the other turbo miata track guys keeping things cool under there? Is the 55mm koyo just not enough with the new turbo setup? 230*F is entirely too hot, right?

I am really thinking the cx racing/ebay intercooler becomes more of an obstruction than a heat exchanger at ~ 250whp. I do not have any data logs when i get to this tempature, it only happens on track after about 5-10min of driving the car hard.

Thanks in advance

 

I say its the radiator. You have everything done up like savingaids and that's the only difference. I have my heat exchangers stacked with the huge "coolradiator.com" pos and it cools fine at 90* in Tulsa on a track that has evenly spaced corners that like to overheat brakes...which usually means the same for intercoolers.

What's the altitude at Laguna? If its higher than everywhere else we run, that may be the problem. Low ambient vapor pressure probably isn't helping you.

 

What about the diversion percentage for each exchanger. I don't know how large your intercooler is, but I doubt it's as large as your radiator. I've considered taking the same ducting route as you, but was going to force 1/3 through the intercooler.

 

I adjusted Matt's air-foil thingy that splits the air between the radiator and intercooler because the FMIC was heatsoaking at 100* in the high-desert at Willowsprings. Notice that there's about 1" if not less opening up for the radiator...and this car makes over 400whp.


I blame the radiator.

 

if the koyo 55 is not any good what are you guys running in these 400hp cars

 

Have you experimented with blocking off the TSI's and/or the hood vents to some degree? Is the back of the radiator shrouded? What fans are you using?

 

The (seemingly) small OEM bumper opening can actually support enough flow for a LOT of heat exchanger. I wouldn't worry until you're greater than 3X that area.

Heat soak has a lot of variables besides flow area, but a 1" for the radiator is amazing. I'm impressed, and with you on this one.

 

oem opening is enough for 70F ambient temp. 4 suggestions:

1. on your heater core return, have you tried a small restrictor ? if you want more flow to the radiator, that's what you should do.

2. do you have an udertray. if not, pls get one.

3. block off TSI. they work against cooling.

4. with coolant reroute, it is very tricky to bleed it correctly. I had to raise the rear, to burp it out to the rear thermostat, then raise the front to bleed it through radiator cap. of use a vaccum to drip in the coolant.

 

We have even had trouble keeping it at operating temperature between dyno pulls.

edit: I may have been misunderstood, we had trouble keeping the car warm enough on the dyno because the thicker version of our radiator was too efficient. Absolutely no trouble with overheating ever.

 

I have a 55mm copper/brass radiator with spal and oem fan. For short tracks or a gp-course i switch them on, to hold an watertemp near 190°F.

You can see some pics of my radiator and cooling stuff at my cardomain page 4.

Which oiltemps have you measured than?

 

Nobody said its not any good I am having my first real issues with the radiator since turning up the boost on the new setup.

230-235*F measured from the oil feed port on the side of a 94 bottom end, the temp sensor is actual plumbed in line with the oil feed port. This was the highest oil temps I would see on track all day.

1. No restrictions what so ever, ill either try this, or have the heater core completely removed by my next track event for sure. Thanks for the info!

2. I did not have my under tray on since the front splitter went on. The bottom is ducted against the splitter, but ill for sure mock up the oem undertrey for my next track event.

3. TSIs are gone, and oem ones are back in since these readings.

4. Ill bleed the cooling system all different angles.

TSIs are now gone, so well be trying that next time out. Hood should be helping in cooling, right? The rear of the radiator was not really shrouded aside from one OEM fan working normally.

I should be looking into some new fans anyways..

 

Interested to see the results of the above..

 

I am curious what others are using with success.

spookyfish?

 

Also in for results...

 

reroute, 55mm koyo rad, awr fan shroud with twin fans, twin oil cooler setup, not much ducting (yet).
400whp, and stable temps just around 100c on warm days at the track..

 

I put a Tru cool oil thermostat in my heater core line. At 190 f it blocks 90% of the flow through the heater core. I’m pretty sure it is working because when the engine is good and warm on the track the heater on full blast doesn’t blow that hot of air. The car warms up and the heater functions normally for normal driving. Do you really need a heater at all on a California track car?

I am curious to see how my car works on Laguna. I've only driven it in a stock powered 1.6l, it seemed like a pretty big use of HP track especially up the hill and down the front straight. Im planning to install brake ducting from the lower splitter openings to blow air on my Oil cooler mounted just in front of the steering rack. Ill probably duct the brakes while Im at it. I have a 55mm Godspeed rad with a 13" and 12" shrouded spal fans.

Bob