Overheating

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Craig

Overheating

Post by Craig »

I've taken my 2001 Miata to three track events -- 2 in moderate weather at Thunderhill Park, and one in 105+ degrees at the Streets of Willow. (For those who haven't been there, it's one of those tracks where you're at redline in second gear much of the time, so the car doesn't get great air flow from long, high-speed straightaways.) My car generally keeps its temperature smack dab in the middle, but at the Streets event, it overheated and caused the car to stall.

There seems to be lots of advice on the net -- including:
1. Buy the larger radiator made for Miata's with Automatic
2. Buy the significantly more expensive aluminum radiators made for racing
3. Run Redline Water Wetter with water only (no antifreeze) on track days
4. Wire the radiator fans so that both fans run whenever the car gets warm (usually the driver's-side fan only runs when the AC is on).

Has anyone tried any of these things in the kind of conditions I described?
Brian
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Post by Brian »

I have tried them all.

1. The waterwetter helps a little.
2. wiring the fans together helps a little
3. going larger radiator solves the problem forever. Note the KOYO makes a race size for your car (R2277) and a high performance "street" size (V2277) and we carry both. The smaller is 37mm and plenty for your car.

Even more simple than all the things above is to simply use your Miata's SECOND radiator. Did you know you have a second radiator? It is built in and all you need to prevent overheating is to turn it on. It's the heater core...turn your defroster on and throw the heat up to the window. You may not even need the fan on to accomplish enough additional cooling to keep temps under control. Perhaps throw the fan to the "1" position just to be sure and you will see your temps start to fall. With the top down and doing 50-100 Mph on the "streets" you won't really notice the extra heat in the cockpit much unless you really crank the fan speed up to 3 or 4 but really the 1 position is likely to give enough additional cooling to prevent overheat.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Craig

Heater

Post by Craig »

Hey Brian,

Thanks for the advice. I actually did run the heater, but it didn't help enough (it kept temps down longer, but after three or four laps, I had to pit.)

I talked to another friend who had some further advice for me: get rid of my aftermarket grille. It's a very loose weave grille (similar material to the stuff you see in a classic Bentley grille), so I didn't think it would restrict flow, but my friend said it might be causing some odd turbulence. Who knows. I guess I'll start out with water water and no grille ... then step up to the fan wiring ... and if that doesn't work, I'll be talking to you about radiators.

Do your Miata customers have lots of overheating issues on tracks?
Brian
Site Admin
Posts: 11308
Joined: Tue Feb 15, 2005 11:44 am
Location: San Diego CA
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Post by Brian »

Ah...didn't know about the grill. Yes, that is the problem and should be removed before track days. I have done "streets" in August with the track temps at 120 degrees and the defroster on with stock rad and gotten through the day without problem.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
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