Last summer, I wrote a little article about the Greddy Coolant Breather Tank, which helps keep bubbles out of the cooling system. This time around, I want to go over a few ways to keep your car chilly on the cheap.
Last weekend, I found myself at another super toasty track event at Streets of Willow. It was so toasty that every other lap was a cool-down lap. I’d run hard and try to break time, and then the car’s temp would start rising, so the following lap would be a tad weaker to let the car chill out a bit. Rinse and repeat.
FYI, at this point, my car (S14 w/ SR20DET) has a big PWR radiator, intercooler, higher-pressure radiator cap, a new oem water pump, stock clutch fan with shrouds, and that Greddy Coolant Swirl Pot I mentioned earlier. Still, things got a bit hot in the bay. I’ll have to try these things before I can post my own results, but the following is some advice I got from Miata/Evo Johnny:
Apparently, having the under-engine tray helps a lot with cooling. This is the (typically black plastic) panel that connects underneath the engine and bolts to the front bumper and stretches as far back as the rack & pinion, typically. Most cars come with this, but many people either remove it so they can… lower the car more, or it gets destroyed because they… lowered the car more. Chit happens. So, what do you do? Make one using sheet metal from the hardware store OR buy one from a company like Powered By Max. (I can’t find it on their site anymore, but there may be info archived on their forum) or GT Spec (picture seen above). Cost: – A couple hundred bucks, or about $50 or less if you make one on your own. Doubles as a skid guard.
To complement the under-car panel, you can get the upper radiator panel. ~$80 from brands like NRG or DME or a bit more from companies like Signal Auto. Or probably ~$20 if you make it yourself. Paint it black to stay under the radar if you daily your track car like I do. (hehe :3)
So, how does it all work? I probably should have written this section first, but whatever…
You’ve got high pressure and low pressure zones (air). You want the engine bay to be a low pressure zone so air from outside will rush into the engine bay when your car is moving. But, you want the air to rush through your radiator and not in through other places like above the radiator or below it, under the engine bay — that does no good for cooling. So you make or buy cooling panels to cap off those areas.
And then, if you want to get real ghetto (I admit, it works — but good luck making this look proper) you can get hood raisers to raise the rear of the hood a bit so air can exit there.
So, this stuff works. Johnny says it works. Who wants to test it out? lol
It also aids in aero. My top speeds at Fontana were higher with an undertray than w/o.