cooling help
 

Okay guys, I run a spec miata, obviously not turbo charged but I think there is a great knowledge base that can be tapped here. Also, as with any racing site the guys at mazdaracers.com are not very forth coming with there knowledge.

If you are at all familiar with SM you know that we are very limited in what we can do to the car. We are allowed to run a different radiator, but it must remain within the same plane as the stock unit. We are not allowed to run a coolant reroute. I have chosen to run a radiator from Springfield Dyno, I can't duct the radiator but I can seal it so no air flows by it. After choosing a radiator the next step is to monitor cooling.

So here is the question, what location would you recommend monitoring engine temps from. I was thinking the best spot would be off the back of the head. I picked up a fitting so that I can monitor temps off the heater hose coming off the back of the head. My concern is that the sensor sticks into the flow of water pretty substantially,and may affect cooling. I was thinking that I could remove the plate on the back of the head, and weld a bung into it to take readings without impeding flow. What about taking a reading at the lower radiator hose, will that give a true reading?

Here are a few pics.

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You may not be able to run a reroute, but have you thought about changing out to the 01+ headgasket which "corrects" the earlier flow issues? Don't forget about coving those holes by the hood latch too.

Headgasket variation between 99/00 and 01+ discussion here- http://forum.miata.net/vb/showthread.php?t=350182

Has anyone welded a NPT bung to the block off plate on the back of the head? There appears to be a nice surfaces on the drivers side where the heater hose comes out. This is not the back to the plate it is on the side of the plate.

I have welded a bung in the back plate to run a mechanical temp gauge. Mine seems to read very cool, but I have reversed the flow of water to cool the head first. If water is coming from the block into the head you should get an accurate reading.


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The radiator is important for heat soak. I believe the miata motor starts pulling timing at 2xx so keeping it below that value keeps you in the power. I would def seal it off as best as you can. Have you raced this car yet? How did you place?

My very first thought when he said he couldn't do a reroute.

On '01 and up headgaskets the folks at Mazda do the reroute for you.

I have your Inline coupler as well... does not impede flow to any degree that you can notice. I pulled the ac and heater core and looped the line back to the return with Inline temp sender there. The only thing you need to worry about is grounding the coupler to body. This will give you low readings if not. I am still running a stock rad and track temps never scare me in the Texas summers.

I think the two big pieces to start with have been mentioned. 1) 01 head gasket (this is money) 2) keeping temps below 2xx otherwise stock computer pulls timing. This means you need to monitor engine temps from the location that the computer monitors the temps.

Find a way to log your CLT temps, and you'll be able to determine what changes to the radiator airflow are working.

Near temp sender to ecu... mine is right after this at the back of the head.

Lots of great information guys, thank you!!

I have not raced the car yet, my first event will be May 28 & 29th. I am hoping to test on the 24th or 25th. Then there will be an SCCA test day on Friday the 27th. Wow 2 weeks left, I need to get off my lazy a@@

Tested, on Monday this week, the car ran flawlessly! I think things will be fine cooling wise, I never saw more than 180 on the temp gauge. Will be back at the track to run a few more laps Thursday, I need to make sure the cool suit is working, a must when running the heater full blast.

Use a spotter to launch the start of the race in time.