34 replies to this topic

[dstevens]

Here's a tip.
Point the overflow tube from your expansion tank out under the side of the hood. Then, if the car overheats to the point that the expansion tank is full, it will start spraying water on to the passenger side of your windshield. It's easy to miss a temp gauge reading but it's almost impossible to miss water spraying all over your windshield.

Keep going after that, Safety will be putting down speedy dry and/or picking up pieces from your engine.

220 isn't good.
J~

That's what we do in the stock cars. Didn't think about doing it in the Miata, good call. For the stockers we run a different temp range so when it's just spritzing, usually prior to the idiot light or danger zone on the gauge, it means keep an eye on your temps. Not uncommon to squirt a few times during a race. OTOH, if it pees out, time to park. I've seen the tube save an engine or two.

[Tom Hampton]

Dave, thanks for your advice. I am curious to know what is the optimal water temperature range for performance and at what point (high and low) should alert you to a problem?

I've seen this question asked a LOT. I've never seen it answered in the public forum.

[Keith Novak]

Dave, thanks for your advice. I am curious to know what is the optimal water temperature range for performance and at what point (high and low) should alert you to a problem?

As for a low temp warning, I would set it lower than you ever expect to see on the track. Mine is set at 140. My car must have some weird issue that causes it to perpetually run cool. I once had the warning light set higher to tell me when it was dropping out of optimum performance range but when the light goes on, now what? I’m not pulling off the track. I just have a random light that’s not a danger and I’m eventually going to ignore. Now I have a risk of not noticing when a different light pops on that is really important.

[davew]

Anything below 160 is too cold
Above 220 you will start loosing power
above 240 you will start loosing engines

Dave

[HoneyBadger - BrianW]

Anything below 160 is too cold
Above 220 you will start loosing power
above 240 you will start loosing engines

Dave

Thanks!

I didn't realize that the engine didn't loose power until 220. Is there a big difference in where you measure it (assuming it's not on the cool side of the radiator)? For instance, I use your adapter where the coolant line goes into the heater core. Is the 220 temp you mention valid at that measuring place?

[Johnny D]

Is a Coolant Reroute System NOT legal in SM ???

http://949racing.com...ute-system.aspx

J~

[James York]

Is a Coolant Reroute System NOT legal in SM ???

http://949racing.com...ute-system.aspx

J~

You are correct.

[Johnny D]

You are correct.

J~

[Keith Andrews]

Anything below 160 is too cold
Above 220 you will start loosing power
above 240 you will start loosing engines

Dave

Are you losing power at 220 because the ECU is pulling timing?

[Adax]

This question is marginally relevant but where is the best place to install the temp gauge? Upper radiator hose or heater core hose (and which one)? I assume heater core flows even when the heat is turned off (the core is not bypassed in my car). I lost and engine due to a H2O pump failure and the gauge (sensor in upper rad hose) never budged but the stocker was pegged.

[Adax]

This question is marginally relevant but where is the best place to install the temp gauge? Upper radiator hose or heater core hose (and which one)? I assume heater core flows even when the heat is turned off (the core is not bypassed in my car). I lost and engine due to a H2O pump failure and the gauge (sensor in upper rad hose) never budged but the stocker was pegged.

Any thoughts?

[Tyler Dahl]

I have my temp gauge installed in the heater line. That's where the stock gauge is as well as the temp sensor for the ecu.

[davew]

In theory the heater hose and the upper radiator hose should read the same. They are both exits from the cylinder head. In reality, the heater hose is smaller and flows less water, so cylinder #4 runs a little hot and the heater hose will be about 5* hotter than the radiator hose.

The big decision is dependant upon you gauge style. An electric gauge uses a small sending unit that can be mounted in either the heater or rad hose. If you have a mechanical type gauge, the sending unit is too large to work in the heater hose. It will restrict flow and cause the back cylinder to run hot.

There are adapters for both styles at the website below.

Dave

[Glenn]

In theory the heater hose and the upper radiator hose should read the same. They are both exits from the cylinder head. In reality, the heater hose is smaller and flows less water, so cylinder #4 runs a little hot and the heater hose will be about 5* hotter than the radiator hose.

The big decision is dependant upon you gauge style. An electric gauge uses a small sending unit that can be mounted in either the heater or rad hose. If you have a mechanical type gauge, the sending unit is too large to work in the heater hose. It will restrict flow and cause the back cylinder to run hot.

There are adapters for both styles at the website below.

Dave

SHAMELESS PLUG,

[Glenn]

Is a Coolant Reroute System NOT legal in SM ???

http://949racing.com...ute-system.aspx

J~

Would the system be legal in STL? I'll start a new thread.