Well after a brain storming seesion with CRH and MM I think we're going to try modifying the coolant bypass sytem. As in metering he flow down for the coolant bypass.
A few people have mentioned the aspects of that in this thread.
So when I get back to Phoenix it will be on the list of things to try.
Hopefully this will allow more coolant to be sent to the radiator and not recirculated back to the engine. This should help with the "in trqaffic" overheating issue.
Seems that filling the gaps under and beside the radiator effectively helped with any freeway heat concerns.

 

that will be interesting--- and that will open doors for a lower thermostat
olddragger

 

Which will, as has been pointed out, do absolutely nothing.

 

Dont know if it will make any differents but this weekend had the time....and a few(more) beers.

I cut out the fake screens on the bottom of my rear bumper. My theory was maybe it would help suck out the air from the engine and bottom of my car. Painted my muffler and cleanned up the alumn. sheild.

 

Its very hard for me to tell from the FSM but where does the OEM ECT sensor get its reading from? Is the sensor located in the thermostat cover, is it in the keg somewhere, where is it located?

 

comes out of the front cover beside the thermostat housing and is facing the rear of the engine...

 

lower thermostat will not lower temps by itself--but it will allow a system with increased capacity to work to its new capacity. Systems have to be in balance for best performance.
olddragger

 

Argh, I think I have a Thermostat thats not opening fully when hot.

Cuz right now, if I drive and keep my car below 3000, the engine will enver get past 94 Celsius. but if I keep it more than 4K rpm. I will see stupid temp goes up to 105 Celsius and I have to "stop" pushing the car.

grrrrrr .... it wasnt like this b4 my coolant bottle broke. probably has something to do with the overheating b4 (when the bottle broke) and messed up the thermostat or whatever.

Damn still tryign to figure how to break loose the bolt behind the thermostat housing so I can replace the damn thing ......

 

Very possible. Once the operating temp for a thermostat is exceeded, it may not operate normally.

Nah. Doesn't work like that.
A thermostat is flow control. It doesn't know or care about your system's "capacity".
It just regulates the quantity of water that can pass through the radiator as a function of time and temperature.

 

you have to have proper flow to have have proper use of the cooling capacity of your system.
If you put a huge *** radiator and two 55 gph electric water pumps on your car(just for a ridiculous example) and you have a thermostat that doesnt open until 200 degrees. Then the engine will run at 200 degrees. But if you replace that thermostat with a 180 degree one then it will run at 180 degrees as long as the cooling system is not overloaded.
olddragger

 

Gonna head over to the local Sears to look at some tools

dAmn, hope I can find some stuff that works(fits) with the stupid bolt behind the thermostat housing.

 

The temperature will be regulated by the heat exchange rate of the rad, regardless of the thermo opening point.
If you put an oversized rad and pumps in, the cooling system will never stabilize.
Increasing the mass of the water system will simply change the stasis point.
If you put heat into the system faster than you can take it out (which you ALWAYS will), it will eventually overheat.
The increased mass just makes it happen later.
In the example you state above, you would actually want the thermostat to open less so that the flow through the system is slower, so that the water spends more time in the rad cooling off.

 

I'm not sure what the problem is you are having.
The t-stat housing comes right off.
Remove the alternator bracket and then the bolt.

 

So whats the optimal cruise (70mph) temp?

I have been anywhere between 195 and 205 for the last month or so. I have the BHR radiator and the RE-medy water pump.

 

Mazda believes that the optimal engine temperature is 203°F, ±4°.
They consider minimum operating temperature to be 189°F and 217° to be the maximum "normal" operating temperature.
231° is the initial warning level. 258°F is maximum warning.

 

good discussion and I think we are agreeing without realizing it.
target cooling requires the right flow within a system that has the right heat exchange capacity for the results desired. too restrictive of a thermostat is not good, not enough restriction is also not good. too much heat exchange capacity is not good, too little is also not good.
It has to be a balanced system--and system is the key word.
OD

 

Interesting.. ever since my overheating incident (265f) I always thought the car ran warmer then it did before. Although I never go past 212f in stop and go traffic. Maybe something I should look into? Since thermostats are cheap...

 

And that is where the problem lies because there is no such thing.
The engine will always be able to put more heat into the cooling system at some point.
If you go small, it takes less to overheat, but it is easier to reject the heat.
If you go big, it takes longer to overheat (but you still will eventually) and much longer to dissipate that heat.
Create a system that "balances" at cruise and it will overheat during burst loads.
Make a system that can maintain proper temps under hard stop-n-go and it will overheat at cruise.

Almost all of the energy produced by the Renesis is released as heat. Its amazing that the thing moves the car at all.

The big variable is ambient conditions.
In 90% or better of the operating conditions out there, the latent heat capacity of the ambient air is sufficient to pull heat out of the system at a rate greater than it is generated.
As the humidity drops and the temperatures go up, that balance point takes a steep dive. Unbelievably steep.
Just a 15% increase in relative humidity translates to a nearly 50% increase in cooling efficiency.

Out here, where the ambient temp is often above 110° and the RH is below 6%, our cooling system is working like it would in Georgia on a 200° day, of which (I presume) you have very few.

 

Might have something to do with the tools that I have. the 12mm socket that I have came from some "el cheapo" department stores that my father brought years ago.

I just came back from Sears with some Craftsman sockets.

I wonder should I just go get like a big tool set like this one instead of keep buying parts from here and there

http://www.sears.com/shc/s/p_10153_1...000P?adCell=A3

2 Problems with getting the set

- there're tons of 12 pt or 8 pt sockets in the set which I probably never need. All this car need is a 6 pt socket, right ?
- Plus I already have some of the sockets in the set in my garage (Duralast, Powerbuild, Husky, etc)

it will be great if I can sell my old sockets/tools on ebay. but I doubt anyone gonna buy it. Aye



Oh Hey, the manual saids to replace the O-Ring (No. 6), but I cant find the part in the service manual. how come ?

 

Very cheap, 20 something bux.

I have one thats collecting dust. Gonna try to replace it again tomorrow.

 

NEW! MM/BHR RE-Swamp Cooling system for desert climate RX-8's!!! 'Open' circuit cooling for harsh dry climates! Now, should I go with synthetic pads, or those natural ones?

-C

 

The bitch is going to be the 300 gallon water tank...

 

Out comes the sub-box.....
wait, what is the weight of water again, 8 lbs/gal? Crap, we'll have to go with a smaller tank! Just fill up water the same time as the oil.....and the gas!!!! Argg!!!

 

200F ? It would be cheap to boil water then!
pavement gets to 150F here--cant imagine what it gets there.
I think an interesting option is coming soon.
olddragger

 

I've measured the pavement at 170° or so.
Niki's Miata measured just shy of 200° last summer.